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+Network Working Group C. Adams
+Request for Comments: 4210 University of Ottawa
+Obsoletes: 2510 S. Farrell
+Category: Standards Track Trinity College Dublin
+ T. Kause
+ SSH
+ T. Mononen
+ SafeNet
+ September 2005
+
+
+ Internet X.509 Public Key Infrastructure
+ Certificate Management Protocol (CMP)
+
+Status of This Memo
+
+ This document specifies an Internet standards track protocol for the
+ Internet community, and requests discussion and suggestions for
+ improvements. Please refer to the current edition of the "Internet
+ Official Protocol Standards" (STD 1) for the standardization state
+ and status of this protocol. Distribution of this memo is unlimited.
+
+Copyright Notice
+
+ Copyright (C) The Internet Society (2005).
+
+Abstract
+
+ This document describes the Internet X.509 Public Key Infrastructure
+ (PKI) Certificate Management Protocol (CMP). Protocol messages are
+ defined for X.509v3 certificate creation and management. CMP
+ provides on-line interactions between PKI components, including an
+ exchange between a Certification Authority (CA) and a client system.
+
+Table of Contents
+
+ 1. Introduction ....................................................5
+ 2. Requirements ....................................................5
+ 3. PKI Management Overview .........................................5
+ 3.1. PKI Management Model .......................................6
+ 3.1.1. Definitions of PKI Entities .........................6
+ 3.1.1.1. Subjects and End Entities ..................6
+ 3.1.1.2. Certification Authority ....................7
+ 3.1.1.3. Registration Authority .....................7
+ 3.1.2. PKI Management Requirements .........................8
+ 3.1.3. PKI Management Operations ..........................10
+ 4. Assumptions and Restrictions ...................................14
+ 4.1. End Entity Initialization .................................14
+
+
+
+Adams, et al. Standards Track [Page 1]
+
+RFC 4210 CMP September 2005
+
+
+ 4.2. Initial Registration/Certification ........................14
+ 4.2.1. Criteria Used ......................................15
+ 4.2.1.1. Initiation of Registration/Certification ..15
+ 4.2.1.2. End Entity Message Origin Authentication ..15
+ 4.2.1.3. Location of Key Generation ................15
+ 4.2.1.4. Confirmation of Successful Certification ..16
+ 4.2.2. Mandatory Schemes ..................................16
+ 4.2.2.1. Centralized Scheme ........................16
+ 4.2.2.2. Basic Authenticated Scheme ................17
+ 4.3. Proof-of-Possession (POP) of Private Key ..................17
+ 4.3.1. Signature Keys .....................................18
+ 4.3.2. Encryption Keys ....................................18
+ 4.3.3. Key Agreement Keys .................................19
+ 4.4. Root CA Key Update ........................................19
+ 4.4.1. CA Operator Actions ................................20
+ 4.4.2. Verifying Certificates .............................21
+ 4.4.2.1. Verification in Cases 1, 4, 5, and 8 ......22
+ 4.4.2.2. Verification in Case 2 ....................22
+ 4.4.2.3. Verification in Case 3 ....................23
+ 4.4.2.4. Failure of Verification in Case 6 .........23
+ 4.4.2.5. Failure of Verification in Case 7 .........23
+ 4.4.3. Revocation - Change of CA Key ......................23
+ 5. Data Structures ................................................24
+ 5.1. Overall PKI Message .......................................24
+ 5.1.1. PKI Message Header .................................24
+ 5.1.1.1. ImplicitConfirm ...........................27
+ 5.1.1.2. ConfirmWaitTime ...........................27
+ 5.1.2. PKI Message Body ...................................27
+ 5.1.3. PKI Message Protection .............................28
+ 5.1.3.1. Shared Secret Information .................29
+ 5.1.3.2. DH Key Pairs ..............................30
+ 5.1.3.3. Signature .................................30
+ 5.1.3.4. Multiple Protection .......................30
+ 5.2. Common Data Structures ....................................31
+ 5.2.1. Requested Certificate Contents .....................31
+ 5.2.2. Encrypted Values ...................................31
+ 5.2.3. Status codes and Failure Information for
+ PKI Messages .......................................32
+ 5.2.4. Certificate Identification .........................33
+ 5.2.5. Out-of-band root CA Public Key .....................33
+ 5.2.6. Archive Options ....................................34
+ 5.2.7. Publication Information ............................34
+ 5.2.8. Proof-of-Possession Structures .....................34
+ 5.2.8.1. Inclusion of the Private Key ..............35
+ 5.2.8.2. Indirect Method ...........................35
+ 5.2.8.3. Challenge-Response Protocol ...............35
+ 5.2.8.4. Summary of PoP Options ....................37
+
+
+
+
+Adams, et al. Standards Track [Page 2]
+
+RFC 4210 CMP September 2005
+
+
+ 5.3. Operation-Specific Data Structures ........................38
+ 5.3.1. Initialization Request .............................38
+ 5.3.2. Initialization Response ............................39
+ 5.3.3. Certification Request ..............................39
+ 5.3.4. Certification Response .............................39
+ 5.3.5. Key Update Request Content .........................40
+ 5.3.6. Key Update Response Content ........................41
+ 5.3.7. Key Recovery Request Content .......................41
+ 5.3.8. Key Recovery Response Content ......................41
+ 5.3.9. Revocation Request Content .........................41
+ 5.3.10. Revocation Response Content .......................42
+ 5.3.11. Cross Certification Request Content ...............42
+ 5.3.12. Cross Certification Response Content ..............42
+ 5.3.13. CA Key Update Announcement Content ................42
+ 5.3.14. Certificate Announcement ..........................43
+ 5.3.15. Revocation Announcement ...........................43
+ 5.3.16. CRL Announcement ..................................43
+ 5.3.17. PKI Confirmation Content ..........................43
+ 5.3.18. Certificate Confirmation Content ..................44
+ 5.3.19. PKI General Message Content .......................44
+ 5.3.19.1. CA Protocol Encryption Certificate .......44
+ 5.3.19.2. Signing Key Pair Types ...................45
+ 5.3.19.3. Encryption/Key Agreement Key Pair Types ..45
+ 5.3.19.4. Preferred Symmetric Algorithm ............45
+ 5.3.19.5. Updated CA Key Pair ......................45
+ 5.3.19.6. CRL ......................................46
+ 5.3.19.7. Unsupported Object Identifiers ...........46
+ 5.3.19.8. Key Pair Parameters ......................46
+ 5.3.19.9. Revocation Passphrase ....................46
+ 5.3.19.10. ImplicitConfirm .........................46
+ 5.3.19.11. ConfirmWaitTime .........................47
+ 5.3.19.12. Original PKIMessage .....................47
+ 5.3.19.13. Supported Language Tags .................47
+ 5.3.20. PKI General Response Content ......................47
+ 5.3.21. Error Message Content .............................47
+ 5.3.22. Polling Request and Response ......................48
+ 6. Mandatory PKI Management Functions .............................51
+ 6.1. Root CA Initialization ....................................51
+ 6.2. Root CA Key Update ........................................51
+ 6.3. Subordinate CA Initialization .............................51
+ 6.4. CRL production ............................................52
+ 6.5. PKI Information Request ...................................52
+ 6.6. Cross Certification .......................................52
+ 6.6.1. One-Way Request-Response Scheme: ...................52
+ 6.7. End Entity Initialization .................................54
+ 6.7.1. Acquisition of PKI Information .....................54
+ 6.7.2. Out-of-Band Verification of Root-CA Key ............55
+ 6.8. Certificate Request .......................................55
+
+
+
+Adams, et al. Standards Track [Page 3]
+
+RFC 4210 CMP September 2005
+
+
+ 6.9. Key Update ................................................55
+ 7. Version Negotiation ............................................56
+ 7.1. Supporting RFC 2510 Implementations .......................56
+ 7.1.1. Clients Talking to RFC 2510 Servers ................56
+ 7.1.2. Servers Receiving Version cmp1999 PKIMessages ......57
+ 8. Security Considerations ........................................57
+ 8.1. Proof-Of-Possession with a Decryption Key .................57
+ 8.2. Proof-Of-Possession by Exposing the Private Key ...........57
+ 8.3. Attack Against Diffie-Hellman Key Exchange ................57
+ 9. IANA Considerations ............................................58
+ Normative References ..............................................58
+ Informative References ............................................59
+ A. Reasons for the Presence of RAs ................................61
+ B. The Use of Revocation Passphrase ...............................61
+ C. Request Message Behavioral Clarifications ......................63
+ D. PKI Management Message Profiles (REQUIRED) .....................65
+ D.1. General Rules for Interpretation of These Profiles ........65
+ D.2. Algorithm Use Profile .....................................66
+ D.3. Proof-of-Possession Profile ...............................68
+ D.4. Initial Registration/Certification (Basic
+ Authenticated Scheme) .....................................68
+ D.5. Certificate Request .......................................74
+ D.6. Key Update Request ........................................75
+ E. PKI Management Message Profiles (OPTIONAL) .....................75
+ E.1. General Rules for Interpretation of These Profiles ........76
+ E.2. Algorithm Use Profile .....................................76
+ E.3. Self-Signed Certificates ..................................76
+ E.4. Root CA Key Update ........................................77
+ E.5. PKI Information Request/Response ..........................77
+ E.6. Cross Certification Request/Response (1-way) ..............79
+ E.7. In-Band Initialization Using External Identity
+ Certificate ..............................................82
+ F. Compilable ASN.1 Definitions ...................................83
+ G. Acknowledgements ...............................................93
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 4]
+
+RFC 4210 CMP September 2005
+
+
+1. Introduction
+
+ This document describes the Internet X.509 Public Key Infrastructure
+ (PKI) Certificate Management Protocol (CMP). Protocol messages are
+ defined for certificate creation and management. The term
+ "certificate" in this document refers to an X.509v3 Certificate as
+ defined in [X509].
+
+ This specification obsoletes RFC 2510. This specification differs
+ from RFC 2510 in the following areas:
+
+ The PKI management message profile section is split to two
+ appendices: the required profile and the optional profile. Some
+ of the formerly mandatory functionality is moved to the optional
+ profile.
+
+ The message confirmation mechanism has changed substantially.
+
+ A new polling mechanism is introduced, deprecating the old polling
+ method at the CMP transport level.
+
+ The CMP transport protocol issues are handled in a separate
+ document [CMPtrans], thus the Transports section is removed.
+
+ A new implicit confirmation method is introduced to reduce the
+ number of protocol messages exchanged in a transaction.
+
+ The new specification contains some less prominent protocol
+ enhancements and improved explanatory text on several issues.
+
+2. Requirements
+
+ The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
+ "RECOMMENDED", "MAY", and "OPTIONAL" in this document (in uppercase,
+ as shown) are to be interpreted as described in [RFC2119].
+
+3. PKI Management Overview
+
+ The PKI must be structured to be consistent with the types of
+ individuals who must administer it. Providing such administrators
+ with unbounded choices not only complicates the software required,
+ but also increases the chances that a subtle mistake by an
+ administrator or software developer will result in broader
+ compromise. Similarly, restricting administrators with cumbersome
+ mechanisms will cause them not to use the PKI.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 5]
+
+RFC 4210 CMP September 2005
+
+
+ Management protocols are REQUIRED to support on-line interactions
+ between Public Key Infrastructure (PKI) components. For example, a
+ management protocol might be used between a Certification Authority
+ (CA) and a client system with which a key pair is associated, or
+ between two CAs that issue cross-certificates for each other.
+
+3.1. PKI Management Model
+
+ Before specifying particular message formats and procedures, we first
+ define the entities involved in PKI management and their interactions
+ (in terms of the PKI management functions required). We then group
+ these functions in order to accommodate different identifiable types
+ of end entities.
+
+3.1.1. Definitions of PKI Entities
+
+ The entities involved in PKI management include the end entity (i.e.,
+ the entity to whom the certificate is issued) and the certification
+ authority (i.e., the entity that issues the certificate). A
+ registration authority MAY also be involved in PKI management.
+
+3.1.1.1. Subjects and End Entities
+
+ The term "subject" is used here to refer to the entity to whom the
+ certificate is issued, typically named in the subject or
+ subjectAltName field of a certificate. When we wish to distinguish
+ the tools and/or software used by the subject (e.g., a local
+ certificate management module), we will use the term "subject
+ equipment". In general, the term "end entity" (EE), rather than
+ "subject", is preferred in order to avoid confusion with the field
+ name. It is important to note that the end entities here will
+ include not only human users of applications, but also applications
+ themselves (e.g., for IP security). This factor influences the
+ protocols that the PKI management operations use; for example,
+ application software is far more likely to know exactly which
+ certificate extensions are required than are human users. PKI
+ management entities are also end entities in the sense that they are
+ sometimes named in the subject or subjectAltName field of a
+ certificate or cross-certificate. Where appropriate, the term "end-
+ entity" will be used to refer to end entities who are not PKI
+ management entities.
+
+ All end entities require secure local access to some information --
+ at a minimum, their own name and private key, the name of a CA that
+ is directly trusted by this entity, and that CA's public key (or a
+ fingerprint of the public key where a self-certified version is
+ available elsewhere). Implementations MAY use secure local storage
+ for more than this minimum (e.g., the end entity's own certificate or
+
+
+
+Adams, et al. Standards Track [Page 6]
+
+RFC 4210 CMP September 2005
+
+
+ application-specific information). The form of storage will also
+ vary -- from files to tamper-resistant cryptographic tokens. The
+ information stored in such local, trusted storage is referred to here
+ as the end entity's Personal Security Environment (PSE).
+
+ Though PSE formats are beyond the scope of this document (they are
+ very dependent on equipment, et cetera), a generic interchange format
+ for PSEs is defined here: a certification response message MAY be
+ used.
+
+3.1.1.2. Certification Authority
+
+ The certification authority (CA) may or may not actually be a real
+ "third party" from the end entity's point of view. Quite often, the
+ CA will actually belong to the same organization as the end entities
+ it supports.
+
+ Again, we use the term "CA" to refer to the entity named in the
+ issuer field of a certificate. When it is necessary to distinguish
+ the software or hardware tools used by the CA, we use the term "CA
+ equipment".
+
+ The CA equipment will often include both an "off-line" component and
+ an "on-line" component, with the CA private key only available to the
+ "off-line" component. This is, however, a matter for implementers
+ (though it is also relevant as a policy issue).
+
+ We use the term "root CA" to indicate a CA that is directly trusted
+ by an end entity; that is, securely acquiring the value of a root CA
+ public key requires some out-of-band step(s). This term is not meant
+ to imply that a root CA is necessarily at the top of any hierarchy,
+ simply that the CA in question is trusted directly.
+
+ A "subordinate CA" is one that is not a root CA for the end entity in
+ question. Often, a subordinate CA will not be a root CA for any
+ entity, but this is not mandatory.
+
+3.1.1.3. Registration Authority
+
+ In addition to end-entities and CAs, many environments call for the
+ existence of a Registration Authority (RA) separate from the
+ Certification Authority. The functions that the registration
+ authority may carry out will vary from case to case but MAY include
+ personal authentication, token distribution, revocation reporting,
+ name assignment, key generation, archival of key pairs, et cetera.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 7]
+
+RFC 4210 CMP September 2005
+
+
+ This document views the RA as an OPTIONAL component: when it is not
+ present, the CA is assumed to be able to carry out the RA's functions
+ so that the PKI management protocols are the same from the end-
+ entity's point of view.
+
+ Again, we distinguish, where necessary, between the RA and the tools
+ used (the "RA equipment").
+
+ Note that an RA is itself an end entity. We further assume that all
+ RAs are in fact certified end entities and that RAs have private keys
+ that are usable for signing. How a particular CA equipment
+ identifies some end entities as RAs is an implementation issue (i.e.,
+ this document specifies no special RA certification operation). We
+ do not mandate that the RA is certified by the CA with which it is
+ interacting at the moment (so one RA may work with more than one CA
+ whilst only being certified once).
+
+ In some circumstances, end entities will communicate directly with a
+ CA even where an RA is present. For example, for initial
+ registration and/or certification, the subject may use its RA, but
+ communicate directly with the CA in order to refresh its certificate.
+
+3.1.2. PKI Management Requirements
+
+ The protocols given here meet the following requirements on PKI
+ management
+
+ 1. PKI management must conform to the ISO/IEC 9594-8/ITU-T X.509
+ standards.
+
+ 2. It must be possible to regularly update any key pair without
+ affecting any other key pair.
+
+ 3. The use of confidentiality in PKI management protocols must be
+ kept to a minimum in order to ease acceptance in environments
+ where strong confidentiality might cause regulatory problems.
+
+ 4. PKI management protocols must allow the use of different
+ industry-standard cryptographic algorithms (specifically
+ including RSA, DSA, MD5, and SHA-1). This means that any given
+ CA, RA, or end entity may, in principle, use whichever
+ algorithms suit it for its own key pair(s).
+
+ 5. PKI management protocols must not preclude the generation of key
+ pairs by the end-entity concerned, by an RA, or by a CA. Key
+ generation may also occur elsewhere, but for the purposes of PKI
+ management we can regard key generation as occurring wherever
+ the key is first present at an end entity, RA, or CA.
+
+
+
+Adams, et al. Standards Track [Page 8]
+
+RFC 4210 CMP September 2005
+
+
+ 6. PKI management protocols must support the publication of
+ certificates by the end-entity concerned, by an RA, or by a CA.
+ Different implementations and different environments may choose
+ any of the above approaches.
+
+ 7. PKI management protocols must support the production of
+ Certificate Revocation Lists (CRLs) by allowing certified end
+ entities to make requests for the revocation of certificates.
+ This must be done in such a way that the denial-of-service
+ attacks, which are possible, are not made simpler.
+
+ 8. PKI management protocols must be usable over a variety of
+ "transport" mechanisms, specifically including mail, http,
+ TCP/IP and ftp.
+
+ 9. Final authority for certification creation rests with the CA.
+ No RA or end-entity equipment can assume that any certificate
+ issued by a CA will contain what was requested; a CA may alter
+ certificate field values or may add, delete, or alter extensions
+ according to its operating policy. In other words, all PKI
+ entities (end-entities, RAs, and CAs) must be capable of
+ handling responses to requests for certificates in which the
+ actual certificate issued is different from that requested (for
+ example, a CA may shorten the validity period requested). Note
+ that policy may dictate that the CA must not publish or
+ otherwise distribute the certificate until the requesting entity
+ has reviewed and accepted the newly-created certificate
+ (typically through use of the certConf message).
+
+ 10. A graceful, scheduled change-over from one non-compromised CA
+ key pair to the next (CA key update) must be supported (note
+ that if the CA key is compromised, re-initialization must be
+ performed for all entities in the domain of that CA). An end
+ entity whose PSE contains the new CA public key (following a CA
+ key update) must also be able to verify certificates verifiable
+ using the old public key. End entities who directly trust the
+ old CA key pair must also be able to verify certificates signed
+ using the new CA private key (required for situations where the
+ old CA public key is "hardwired" into the end entity's
+ cryptographic equipment).
+
+ 11. The functions of an RA may, in some implementations or
+ environments, be carried out by the CA itself. The protocols
+ must be designed so that end entities will use the same protocol
+ regardless of whether the communication is with an RA or CA.
+ Naturally, the end entity must use the correct RA of CA public
+ key to protect the communication.
+
+
+
+
+Adams, et al. Standards Track [Page 9]
+
+RFC 4210 CMP September 2005
+
+
+ 12. Where an end entity requests a certificate containing a given
+ public key value, the end entity must be ready to demonstrate
+ possession of the corresponding private key value. This may be
+ accomplished in various ways, depending on the type of
+ certification request. See Section 4.3 for details of the in-
+ band methods defined for the PKIX-CMP (i.e., Certificate
+ Management Protocol) messages.
+
+3.1.3. PKI Management Operations
+
+ The following diagram shows the relationship between the entities
+ defined above in terms of the PKI management operations. The letters
+ in the diagram indicate "protocols" in the sense that a defined set
+ of PKI management messages can be sent along each of the lettered
+ lines.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 10]
+
+RFC 4210 CMP September 2005
+
+
+ +---+ cert. publish +------------+ j
+ | | <--------------------- | End Entity | <-------
+ | C | g +------------+ "out-of-band"
+ | e | | ^ loading
+ | r | | | initial
+ | t | a | | b registration/
+ | | | | certification
+ | / | | | key pair recovery
+ | | | | key pair update
+ | C | | | certificate update
+ | R | PKI "USERS" V | revocation request
+ | L | -------------------+-+-----+-+------+-+-------------------
+ | | PKI MANAGEMENT | ^ | ^
+ | | ENTITIES a | | b a | | b
+ | R | V | | |
+ | e | g +------+ d | |
+ | p | <------------ | RA | <-----+ | |
+ | o | cert. | | ----+ | | |
+ | s | publish +------+ c | | | |
+ | i | | | | |
+ | t | V | V |
+ | o | g +------------+ i
+ | r | <------------------------| CA |------->
+ | y | h +------------+ "out-of-band"
+ | | cert. publish | ^ publication
+ | | CRL publish | |
+ +---+ | | cross-certification
+ e | | f cross-certificate
+ | | update
+ | |
+ V |
+ +------+
+ | CA-2 |
+ +------+
+
+ Figure 1 - PKI Entities
+
+ At a high level, the set of operations for which management
+ messages are defined can be grouped as follows.
+
+ 1. CA establishment: When establishing a new CA, certain steps are
+ required (e.g., production of initial CRLs, export of CA public
+ key).
+
+ 2. End entity initialization: this includes importing a root CA
+ public key and requesting information about the options supported
+ by a PKI management entity.
+
+
+
+
+Adams, et al. Standards Track [Page 11]
+
+RFC 4210 CMP September 2005
+
+
+ 3. Certification: various operations result in the creation of new
+ certificates:
+
+ 1. initial registration/certification: This is the process
+ whereby an end entity first makes itself known to a CA or RA,
+ prior to the CA issuing a certificate or certificates for
+ that end entity. The end result of this process (when it is
+ successful) is that a CA issues a certificate for an end
+ entity's public key, and returns that certificate to the end
+ entity and/or posts that certificate in a public repository.
+ This process may, and typically will, involve multiple
+ "steps", possibly including an initialization of the end
+ entity's equipment. For example, the end entity's equipment
+ must be securely initialized with the public key of a CA, to
+ be used in validating certificate paths. Furthermore, an end
+ entity typically needs to be initialized with its own key
+ pair(s).
+
+ 2. key pair update: Every key pair needs to be updated regularly
+ (i.e., replaced with a new key pair), and a new certificate
+ needs to be issued.
+
+ 3. certificate update: As certificates expire, they may be
+ "refreshed" if nothing relevant in the environment has
+ changed.
+
+ 4. CA key pair update: As with end entities, CA key pairs need
+ to be updated regularly; however, different mechanisms are
+ required.
+
+ 5. cross-certification request: One CA requests issuance of a
+ cross-certificate from another CA. For the purposes of this
+ standard, the following terms are defined. A "cross-
+ certificate" is a certificate in which the subject CA and the
+ issuer CA are distinct and SubjectPublicKeyInfo contains a
+ verification key (i.e., the certificate has been issued for
+ the subject CA's signing key pair). When it is necessary to
+ distinguish more finely, the following terms may be used: a
+ cross-certificate is called an "inter-domain cross-
+ certificate" if the subject and issuer CAs belong to
+ different administrative domains; it is called an "intra-
+ domain cross-certificate" otherwise.
+
+ 1. Note 1. The above definition of "cross-certificate"
+ aligns with the defined term "CA-certificate" in X.509.
+ Note that this term is not to be confused with the X.500
+ "cACertificate" attribute type, which is unrelated.
+
+
+
+
+Adams, et al. Standards Track [Page 12]
+
+RFC 4210 CMP September 2005
+
+
+ 2. Note 2. In many environments, the term "cross-
+ certificate", unless further qualified, will be
+ understood to be synonymous with "inter-domain cross-
+ certificate" as defined above.
+
+ 3. Note 3. Issuance of cross-certificates may be, but is
+ not necessarily, mutual; that is, two CAs may issue
+ cross-certificates for each other.
+
+ 6. cross-certificate update: Similar to a normal certificate
+ update, but involving a cross-certificate.
+
+ 4. Certificate/CRL discovery operations: some PKI management
+ operations result in the publication of certificates or CRLs:
+
+ 1. certificate publication: Having gone to the trouble of
+ producing a certificate, some means for publishing it is
+ needed. The "means" defined in PKIX MAY involve the messages
+ specified in Sections 5.3.13 to 5.3.16, or MAY involve other
+ methods (LDAP, for example) as described in [RFC2559],
+ [RFC2585] (the "Operational Protocols" documents of the PKIX
+ series of specifications).
+
+ 2. CRL publication: As for certificate publication.
+
+ 5. Recovery operations: some PKI management operations are used when
+ an end entity has "lost" its PSE:
+
+ 1. key pair recovery: As an option, user client key materials
+ (e.g., a user's private key used for decryption purposes) MAY
+ be backed up by a CA, an RA, or a key backup system
+ associated with a CA or RA. If an entity needs to recover
+ these backed up key materials (e.g., as a result of a
+ forgotten password or a lost key chain file), a protocol
+ exchange may be needed to support such recovery.
+
+ 6. Revocation operations: some PKI operations result in the creation
+ of new CRL entries and/or new CRLs:
+
+ 1. revocation request: An authorized person advises a CA of an
+ abnormal situation requiring certificate revocation.
+
+ 7. PSE operations: whilst the definition of PSE operations (e.g.,
+ moving a PSE, changing a PIN, etc.) are beyond the scope of this
+ specification, we do define a PKIMessage (CertRepMessage) that
+ can form the basis of such operations.
+
+
+
+
+
+Adams, et al. Standards Track [Page 13]
+
+RFC 4210 CMP September 2005
+
+
+ Note that on-line protocols are not the only way of implementing the
+ above operations. For all operations, there are off-line methods of
+ achieving the same result, and this specification does not mandate
+ use of on-line protocols. For example, when hardware tokens are
+ used, many of the operations MAY be achieved as part of the physical
+ token delivery.
+
+ Later sections define a set of standard messages supporting the above
+ operations. Transport protocols for conveying these exchanges in
+ different environments (file-based, on-line, E-mail, and WWW) are
+ beyond the scope of this document and are specified separately.
+
+4. Assumptions and Restrictions
+
+4.1. End Entity Initialization
+
+ The first step for an end entity in dealing with PKI management
+ entities is to request information about the PKI functions supported
+ and to securely acquire a copy of the relevant root CA public key(s).
+
+4.2. Initial Registration/Certification
+
+ There are many schemes that can be used to achieve initial
+ registration and certification of end entities. No one method is
+ suitable for all situations due to the range of policies that a CA
+ may implement and the variation in the types of end entity which can
+ occur.
+
+ However, we can classify the initial registration/certification
+ schemes that are supported by this specification. Note that the word
+ "initial", above, is crucial: we are dealing with the situation where
+ the end entity in question has had no previous contact with the PKI.
+ Where the end entity already possesses certified keys, then some
+ simplifications/alternatives are possible.
+
+ Having classified the schemes that are supported by this
+ specification we can then specify some as mandatory and some as
+ optional. The goal is that the mandatory schemes cover a sufficient
+ number of the cases that will arise in real use, whilst the optional
+ schemes are available for special cases that arise less frequently.
+ In this way, we achieve a balance between flexibility and ease of
+ implementation.
+
+ We will now describe the classification of initial
+ registration/certification schemes.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 14]
+
+RFC 4210 CMP September 2005
+
+
+4.2.1. Criteria Used
+
+4.2.1.1. Initiation of Registration/Certification
+
+ In terms of the PKI messages that are produced, we can regard the
+ initiation of the initial registration/certification exchanges as
+ occurring wherever the first PKI message relating to the end entity
+ is produced. Note that the real-world initiation of the
+ registration/certification procedure may occur elsewhere (e.g., a
+ personnel department may telephone an RA operator).
+
+ The possible locations are at the end entity, an RA, or a CA.
+
+4.2.1.2. End Entity Message Origin Authentication
+
+ The on-line messages produced by the end entity that requires a
+ certificate may be authenticated or not. The requirement here is to
+ authenticate the origin of any messages from the end entity to the
+ PKI (CA/RA).
+
+ In this specification, such authentication is achieved by the PKI
+ (CA/RA) issuing the end entity with a secret value (initial
+ authentication key) and reference value (used to identify the secret
+ value) via some out-of-band means. The initial authentication key
+ can then be used to protect relevant PKI messages.
+
+ Thus, we can classify the initial registration/certification scheme
+ according to whether or not the on-line end entity -> PKI messages
+ are authenticated or not.
+
+ Note 1: We do not discuss the authentication of the PKI -> end entity
+ messages here, as this is always REQUIRED. In any case, it can be
+ achieved simply once the root-CA public key has been installed at the
+ end entity's equipment or it can be based on the initial
+ authentication key.
+
+ Note 2: An initial registration/certification procedure can be secure
+ where the messages from the end entity are authenticated via some
+ out-of-band means (e.g., a subsequent visit).
+
+4.2.1.3. Location of Key Generation
+
+ In this specification, "key generation" is regarded as occurring
+ wherever either the public or private component of a key pair first
+ occurs in a PKIMessage. Note that this does not preclude a
+ centralized key generation service; the actual key pair MAY have been
+
+
+
+
+
+Adams, et al. Standards Track [Page 15]
+
+RFC 4210 CMP September 2005
+
+
+ generated elsewhere and transported to the end entity, RA, or CA
+ using a (proprietary or standardized) key generation request/response
+ protocol (outside the scope of this specification).
+
+ Thus, there are three possibilities for the location of "key
+ generation": the end entity, an RA, or a CA.
+
+4.2.1.4. Confirmation of Successful Certification
+
+ Following the creation of an initial certificate for an end entity,
+ additional assurance can be gained by having the end entity
+ explicitly confirm successful receipt of the message containing (or
+ indicating the creation of) the certificate. Naturally, this
+ confirmation message must be protected (based on the initial
+ authentication key or other means).
+
+ This gives two further possibilities: confirmed or not.
+
+4.2.2. Mandatory Schemes
+
+ The criteria above allow for a large number of initial
+ registration/certification schemes. This specification mandates that
+ conforming CA equipment, RA equipment, and EE equipment MUST support
+ the second scheme listed below (Section 4.2.2.2). Any entity MAY
+ additionally support other schemes, if desired.
+
+4.2.2.1. Centralized Scheme
+
+ In terms of the classification above, this scheme is, in some ways,
+ the simplest possible, where:
+
+ o initiation occurs at the certifying CA;
+
+ o no on-line message authentication is required;
+
+ o "key generation" occurs at the certifying CA (see Section
+ 4.2.1.3);
+
+ o no confirmation message is required.
+
+ In terms of message flow, this scheme means that the only message
+ required is sent from the CA to the end entity. The message must
+ contain the entire PSE for the end entity. Some out-of-band means
+ must be provided to allow the end entity to authenticate the message
+ received and to decrypt any encrypted values.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 16]
+
+RFC 4210 CMP September 2005
+
+
+4.2.2.2. Basic Authenticated Scheme
+
+ In terms of the classification above, this scheme is where:
+
+ o initiation occurs at the end entity;
+
+ o message authentication is REQUIRED;
+
+ o "key generation" occurs at the end entity (see Section 4.2.1.3);
+
+ o a confirmation message is REQUIRED.
+
+ In terms of message flow, the basic authenticated scheme is as
+ follows:
+
+ End entity RA/CA
+ ========== =============
+ out-of-band distribution of Initial Authentication
+ Key (IAK) and reference value (RA/CA -> EE)
+ Key generation
+ Creation of certification request
+ Protect request with IAK
+ -->>-- certification request -->>--
+ verify request
+ process request
+ create response
+ --<<-- certification response --<<--
+ handle response
+ create confirmation
+ -->>-- cert conf message -->>--
+ verify confirmation
+ create response
+ --<<-- conf ack (optional) --<<--
+ handle response
+
+ (Where verification of the cert confirmation message fails, the RA/CA
+ MUST revoke the newly issued certificate if it has been published or
+ otherwise made available.)
+
+4.3. Proof-of-Possession (POP) of Private Key
+
+ In order to prevent certain attacks and to allow a CA/RA to properly
+ check the validity of the binding between an end entity and a key
+ pair, the PKI management operations specified here make it possible
+ for an end entity to prove that it has possession of (i.e., is able
+ to use) the private key corresponding to the public key for which a
+ certificate is requested. A given CA/RA is free to choose how to
+ enforce POP (e.g., out-of-band procedural means versus PKIX-CMP
+
+
+
+Adams, et al. Standards Track [Page 17]
+
+RFC 4210 CMP September 2005
+
+
+ in-band messages) in its certification exchanges (i.e., this may be a
+ policy issue). However, it is REQUIRED that CAs/RAs MUST enforce POP
+ by some means because there are currently many non-PKIX operational
+ protocols in use (various electronic mail protocols are one example)
+ that do not explicitly check the binding between the end entity and
+ the private key. Until operational protocols that do verify the
+ binding (for signature, encryption, and key agreement key pairs)
+ exist, and are ubiquitous, this binding can only be assumed to have
+ been verified by the CA/RA. Therefore, if the binding is not
+ verified by the CA/RA, certificates in the Internet Public-Key
+ Infrastructure end up being somewhat less meaningful.
+
+ POP is accomplished in different ways depending upon the type of key
+ for which a certificate is requested. If a key can be used for
+ multiple purposes (e.g., an RSA key) then any appropriate method MAY
+
+ be used (e.g., a key that may be used for signing, as well as other
+ purposes, SHOULD NOT be sent to the CA/RA in order to prove
+ possession).
+
+ This specification explicitly allows for cases where an end entity
+ supplies the relevant proof to an RA and the RA subsequently attests
+ to the CA that the required proof has been received (and validated!).
+ For example, an end entity wishing to have a signing key certified
+ could send the appropriate signature to the RA, which then simply
+ notifies the relevant CA that the end entity has supplied the
+ required proof. Of course, such a situation may be disallowed by
+ some policies (e.g., CAs may be the only entities permitted to verify
+ POP during certification).
+
+4.3.1. Signature Keys
+
+ For signature keys, the end entity can sign a value to prove
+ possession of the private key.
+
+4.3.2. Encryption Keys
+
+ For encryption keys, the end entity can provide the private key to
+ the CA/RA, or can be required to decrypt a value in order to prove
+ possession of the private key (see Section 5.2.8). Decrypting a
+ value can be achieved either directly or indirectly.
+
+ The direct method is for the RA/CA to issue a random challenge to
+ which an immediate response by the EE is required.
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 18]
+
+RFC 4210 CMP September 2005
+
+
+ The indirect method is to issue a certificate that is encrypted for
+ the end entity (and have the end entity demonstrate its ability to
+ decrypt this certificate in the confirmation message). This allows a
+ CA to issue a certificate in a form that can only be used by the
+ intended end entity.
+
+ This specification encourages use of the indirect method because it
+ requires no extra messages to be sent (i.e., the proof can be
+ demonstrated using the {request, response, confirmation} triple of
+ messages).
+
+4.3.3. Key Agreement Keys
+
+ For key agreement keys, the end entity and the PKI management entity
+ (i.e., CA or RA) must establish a shared secret key in order to prove
+ that the end entity has possession of the private key.
+
+ Note that this need not impose any restrictions on the keys that can
+ be certified by a given CA. In particular, for Diffie-Hellman keys
+ the end entity may freely choose its algorithm parameters provided
+ that the CA can generate a short-term (or one-time) key pair with the
+ appropriate parameters when necessary.
+
+4.4. Root CA Key Update
+
+ This discussion only applies to CAs that are directly trusted by some
+ end entities. Self-signed CAs SHALL be considered as directly
+ trusted CAs. Recognizing whether a non-self-signed CA is supposed to
+ be directly trusted for some end entities is a matter of CA policy
+ and is thus beyond the scope of this document.
+
+ The basis of the procedure described here is that the CA protects its
+ new public key using its previous private key and vice versa. Thus,
+ when a CA updates its key pair it must generate two extra
+ cACertificate attribute values if certificates are made available
+ using an X.500 directory (for a total of four: OldWithOld,
+ OldWithNew, NewWithOld, and NewWithNew).
+
+ When a CA changes its key pair, those entities who have acquired the
+ old CA public key via "out-of-band" means are most affected. It is
+ these end entities who will need access to the new CA public key
+ protected with the old CA private key. However, they will only
+ require this for a limited period (until they have acquired the new
+ CA public key via the "out-of-band" mechanism). This will typically
+ be easily achieved when these end entities' certificates expire.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 19]
+
+RFC 4210 CMP September 2005
+
+
+ The data structure used to protect the new and old CA public keys is
+ a standard certificate (which may also contain extensions). There
+ are no new data structures required.
+
+ Note 1. This scheme does not make use of any of the X.509 v3
+ extensions as it must be able to work even for version 1
+ certificates. The presence of the KeyIdentifier extension would make
+ for efficiency improvements.
+
+ Note 2. While the scheme could be generalized to cover cases where
+ the CA updates its key pair more than once during the validity period
+ of one of its end entities' certificates, this generalization seems
+ of dubious value. Not having this generalization simply means that
+ the validity periods of certificates issued with the old CA key pair
+ cannot exceed the end of the OldWithNew validity period.
+
+ Note 3. This scheme ensures that end entities will acquire the new
+ CA public key, at the latest by the expiry of the last certificate
+ they owned that was signed with the old CA private key (via the
+ "out-of-band" means). Certificate and/or key update operations
+ occurring at other times do not necessarily require this (depending
+ on the end entity's equipment).
+
+4.4.1. CA Operator Actions
+
+ To change the key of the CA, the CA operator does the following:
+
+ 1. Generate a new key pair;
+
+ 2. Create a certificate containing the old CA public key signed with
+ the new private key (the "old with new" certificate);
+
+ 3. Create a certificate containing the new CA public key signed with
+ the old private key (the "new with old" certificate);
+
+ 4. Create a certificate containing the new CA public key signed with
+ the new private key (the "new with new" certificate);
+
+ 5. Publish these new certificates via the repository and/or other
+ means (perhaps using a CAKeyUpdAnn message);
+
+ 6. Export the new CA public key so that end entities may acquire it
+ using the "out-of-band" mechanism (if required).
+
+ The old CA private key is then no longer required. However, the old
+ CA public key will remain in use for some time. The old CA public
+ key is no longer required (other than for non-repudiation) when all
+ end entities of this CA have securely acquired the new CA public key.
+
+
+
+Adams, et al. Standards Track [Page 20]
+
+RFC 4210 CMP September 2005
+
+
+ The "old with new" certificate must have a validity period starting
+ at the generation time of the old key pair and ending at the expiry
+ date of the old public key.
+
+ The "new with old" certificate must have a validity period starting
+ at the generation time of the new key pair and ending at the time by
+ which all end entities of this CA will securely possess the new CA
+ public key (at the latest, the expiry date of the old public key).
+
+ The "new with new" certificate must have a validity period starting
+ at the generation time of the new key pair and ending at or before
+ the time by which the CA will next update its key pair.
+
+4.4.2. Verifying Certificates
+
+ Normally when verifying a signature, the verifier verifies (among
+ other things) the certificate containing the public key of the
+ signer. However, once a CA is allowed to update its key there are a
+ range of new possibilities. These are shown in the table below.
+
+ Repository contains NEW Repository contains only OLD
+ and OLD public keys public key (due to, e.g.,
+ delay in publication)
+
+ PSE PSE Contains PSE Contains PSE Contains
+ Contains OLD public NEW public OLD public
+ NEW public key key key
+ key
+
+ Signer's Case 1: Case 3: Case 5: Case 7:
+ certifi- This is In this case Although the In this case
+ cate is the the verifier CA operator the CA
+ protected standard must access has not operator has
+ using NEW case where the updated the not updated
+ public the repository in repository the the repository
+ key verifier order to get verifier can and so the
+ can the value of verify the verification
+ directly the NEW certificate will FAIL
+ verify the public key directly -
+ certificate this is thus
+ without the same as
+ using the case 1.
+ repository
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 21]
+
+RFC 4210 CMP September 2005
+
+
+ Signer's Case 2: Case 4: Case 6: Case 8:
+ certifi- In this In this case The verifier Although the
+ cate is case the the verifier thinks this CA operator
+ protected verifier can directly is the has not
+ using OLD must verify the situation of updated the
+ public access the certificate case 2 and repository the
+ key repository without will access verifier can
+ in order using the the verify the
+ to get the repository repository; certificate
+ value of however, the directly -
+ the OLD verification this is thus
+ public key will FAIL the same as
+ case 4.
+
+4.4.2.1. Verification in Cases 1, 4, 5, and 8
+
+ In these cases, the verifier has a local copy of the CA public key
+ that can be used to verify the certificate directly. This is the
+ same as the situation where no key change has occurred.
+
+ Note that case 8 may arise between the time when the CA operator has
+ generated the new key pair and the time when the CA operator stores
+ the updated attributes in the repository. Case 5 can only arise if
+
+ the CA operator has issued both the signer's and verifier's
+ certificates during this "gap" (the CA operator SHOULD avoid this as
+ it leads to the failure cases described below)
+
+4.4.2.2. Verification in Case 2
+
+ In case 2, the verifier must get access to the old public key of the
+ CA. The verifier does the following:
+
+ 1. Look up the caCertificate attribute in the repository and pick
+ the OldWithNew certificate (determined based on validity periods;
+ note that the subject and issuer fields must match);
+
+ 2. Verify that this is correct using the new CA key (which the
+ verifier has locally);
+
+ 3. If correct, check the signer's certificate using the old CA key.
+
+ Case 2 will arise when the CA operator has issued the signer's
+ certificate, then changed the key, and then issued the verifier's
+ certificate; so it is quite a typical case.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 22]
+
+RFC 4210 CMP September 2005
+
+
+4.4.2.3. Verification in Case 3
+
+ In case 3, the verifier must get access to the new public key of the
+ CA. The verifier does the following:
+
+ 1. Look up the CACertificate attribute in the repository and pick
+ the NewWithOld certificate (determined based on validity periods;
+ note that the subject and issuer fields must match);
+
+ 2. Verify that this is correct using the old CA key (which the
+ verifier has stored locally);
+
+ 3. If correct, check the signer's certificate using the new CA key.
+
+ Case 3 will arise when the CA operator has issued the verifier's
+ certificate, then changed the key, and then issued the signer's
+ certificate; so it is also quite a typical case.
+
+4.4.2.4. Failure of Verification in Case 6
+
+ In this case, the CA has issued the verifier's PSE, which contains
+ the new key, without updating the repository attributes. This means
+ that the verifier has no means to get a trustworthy version of the
+ CA's old key and so verification fails.
+
+ Note that the failure is the CA operator's fault.
+
+4.4.2.5. Failure of Verification in Case 7
+
+ In this case, the CA has issued the signer's certificate protected
+ with the new key without updating the repository attributes. This
+ means that the verifier has no means to get a trustworthy version of
+ the CA's new key and so verification fails.
+
+ Note that the failure is again the CA operator's fault.
+
+4.4.3. Revocation - Change of CA Key
+
+ As we saw above, the verification of a certificate becomes more
+ complex once the CA is allowed to change its key. This is also true
+ for revocation checks as the CA may have signed the CRL using a newer
+ private key than the one within the user's PSE.
+
+ The analysis of the alternatives is the same as for certificate
+ verification.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 23]
+
+RFC 4210 CMP September 2005
+
+
+5. Data Structures
+
+ This section contains descriptions of the data structures required
+ for PKI management messages. Section 6 describes constraints on
+ their values and the sequence of events for each of the various PKI
+ management operations.
+
+5.1. Overall PKI Message
+
+ All of the messages used in this specification for the purposes of
+ PKI management use the following structure:
+
+ PKIMessage ::= SEQUENCE {
+ header PKIHeader,
+ body PKIBody,
+ protection [0] PKIProtection OPTIONAL,
+ extraCerts [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
+ OPTIONAL
+ }
+ PKIMessages ::= SEQUENCE SIZE (1..MAX) OF PKIMessage
+
+ The PKIHeader contains information that is common to many PKI
+ messages.
+
+ The PKIBody contains message-specific information.
+
+ The PKIProtection, when used, contains bits that protect the PKI
+ message.
+
+ The extraCerts field can contain certificates that may be useful to
+ the recipient. For example, this can be used by a CA or RA to
+ present an end entity with certificates that it needs to verify its
+ own new certificate (if, for example, the CA that issued the end
+ entity's certificate is not a root CA for the end entity). Note that
+ this field does not necessarily contain a certification path; the
+ recipient may have to sort, select from, or otherwise process the
+ extra certificates in order to use them.
+
+5.1.1. PKI Message Header
+
+ All PKI messages require some header information for addressing and
+ transaction identification. Some of this information will also be
+ present in a transport-specific envelope. However, if the PKI
+ message is protected, then this information is also protected (i.e.,
+ we make no assumption about secure transport).
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 24]
+
+RFC 4210 CMP September 2005
+
+
+ The following data structure is used to contain this information:
+
+ PKIHeader ::= SEQUENCE {
+ pvno INTEGER { cmp1999(1), cmp2000(2) },
+ sender GeneralName,
+ recipient GeneralName,
+ messageTime [0] GeneralizedTime OPTIONAL,
+ protectionAlg [1] AlgorithmIdentifier OPTIONAL,
+ senderKID [2] KeyIdentifier OPTIONAL,
+ recipKID [3] KeyIdentifier OPTIONAL,
+ transactionID [4] OCTET STRING OPTIONAL,
+ senderNonce [5] OCTET STRING OPTIONAL,
+ recipNonce [6] OCTET STRING OPTIONAL,
+ freeText [7] PKIFreeText OPTIONAL,
+ generalInfo [8] SEQUENCE SIZE (1..MAX) OF
+ InfoTypeAndValue OPTIONAL
+ }
+ PKIFreeText ::= SEQUENCE SIZE (1..MAX) OF UTF8String
+
+ The pvno field is fixed (at 2) for this version of this
+ specification.
+
+ The sender field contains the name of the sender of the PKIMessage.
+ This name (in conjunction with senderKID, if supplied) should be
+ sufficient to indicate the key to use to verify the protection on the
+ message. If nothing about the sender is known to the sending entity
+ (e.g., in the init. req. message, where the end entity may not know
+ its own Distinguished Name (DN), e-mail name, IP address, etc.), then
+ the "sender" field MUST contain a "NULL" value; that is, the SEQUENCE
+ OF relative distinguished names is of zero length. In such a case,
+ the senderKID field MUST hold an identifier (i.e., a reference
+ number) that indicates to the receiver the appropriate shared secret
+ information to use to verify the message.
+
+ The recipient field contains the name of the recipient of the
+ PKIMessage. This name (in conjunction with recipKID, if supplied)
+ should be usable to verify the protection on the message.
+
+ The protectionAlg field specifies the algorithm used to protect the
+ message. If no protection bits are supplied (note that PKIProtection
+ is OPTIONAL) then this field MUST be omitted; if protection bits are
+ supplied, then this field MUST be supplied.
+
+ senderKID and recipKID are usable to indicate which keys have been
+ used to protect the message (recipKID will normally only be required
+ where protection of the message uses Diffie-Hellman (DH) keys).
+
+
+
+
+
+Adams, et al. Standards Track [Page 25]
+
+RFC 4210 CMP September 2005
+
+
+ These fields MUST be used if required to uniquely identify a key
+ (e.g., if more than one key is associated with a given sender name)
+ and SHOULD be omitted otherwise.
+
+ The transactionID field within the message header is to be used to
+ allow the recipient of a message to correlate this with an ongoing
+ transaction. This is needed for all transactions that consist of
+ more than just a single request/response pair. For transactions that
+ consist of a single request/response pair, the rules are as follows.
+ A client MAY populate the transactionID field of the request. If a
+ server receives such a request that has the transactionID field set,
+ then it MUST set the transactionID field of the response to the same
+ value. If a server receives such request with a missing
+ transactionID field, then it MAY set transactionID field of the
+ response.
+
+ For transactions that consist of more than just a single
+ request/response pair, the rules are as follows. Clients SHOULD
+ generate a transactionID for the first request. If a server receives
+ such a request that has the transactionID field set, then it MUST set
+ the transactionID field of the response to the same value. If a
+ server receives such request with a missing transactionID field, then
+ it MUST populate the transactionID field of the response with a
+ server-generated ID. Subsequent requests and responses MUST all set
+ the transactionID field to the thus established value. In all cases
+ where a transactionID is being used, a given client MUST NOT have
+ more than one transaction with the same transactionID in progress at
+ any time (to a given server). Servers are free to require uniqueness
+ of the transactionID or not, as long as they are able to correctly
+ associate messages with the corresponding transaction. Typically,
+ this means that a server will require the {client, transactionID}
+ tuple to be unique, or even the transactionID alone to be unique, if
+ it cannot distinguish clients based on transport-level information.
+ A server receiving the first message of a transaction (which requires
+ more than a single request/response pair) that contains a
+ transactionID that does not allow it to meet the above constraints
+ (typically because the transactionID is already in use) MUST send
+ back an ErrorMsgContent with a PKIFailureInfo of transactionIdInUse.
+ It is RECOMMENDED that the clients fill the transactionID field with
+ 128 bits of (pseudo-) random data for the start of a transaction to
+ reduce the probability of having the transactionID in use at the
+ server.
+
+ The senderNonce and recipNonce fields protect the PKIMessage against
+ replay attacks. The senderNonce will typically be 128 bits of
+ (pseudo-) random data generated by the sender, whereas the recipNonce
+ is copied from the senderNonce of the previous message in the
+ transaction.
+
+
+
+Adams, et al. Standards Track [Page 26]
+
+RFC 4210 CMP September 2005
+
+
+ The messageTime field contains the time at which the sender created
+ the message. This may be useful to allow end entities to
+ correct/check their local time for consistency with the time on a
+ central system.
+
+ The freeText field may be used to send a human-readable message to
+ the recipient (in any number of languages). The first language used
+ in this sequence indicates the desired language for replies.
+
+ The generalInfo field may be used to send machine-processable
+ additional data to the recipient. The following generalInfo
+ extensions are defined and MAY be supported.
+
+5.1.1.1. ImplicitConfirm
+
+ This is used by the EE to inform the CA that it does not wish to send
+ a certificate confirmation for issued certificates.
+
+ implicitConfirm OBJECT IDENTIFIER ::= {id-it 13}
+ ImplicitConfirmValue ::= NULL
+
+ If the CA grants the request to the EE, it MUST put the same
+ extension in the PKIHeader of the response. If the EE does not find
+ the extension in the response, it MUST send the certificate
+ confirmation.
+
+5.1.1.2. ConfirmWaitTime
+
+ This is used by the CA to inform the EE how long it intends to wait
+ for the certificate confirmation before revoking the certificate and
+ deleting the transaction.
+
+ confirmWaitTime OBJECT IDENTIFIER ::= {id-it 14}
+ ConfirmWaitTimeValue ::= GeneralizedTime
+
+5.1.2. PKI Message Body
+
+ PKIBody ::= CHOICE {
+ ir [0] CertReqMessages, --Initialization Req
+ ip [1] CertRepMessage, --Initialization Resp
+ cr [2] CertReqMessages, --Certification Req
+ cp [3] CertRepMessage, --Certification Resp
+ p10cr [4] CertificationRequest, --PKCS #10 Cert. Req.
+ popdecc [5] POPODecKeyChallContent --pop Challenge
+ popdecr [6] POPODecKeyRespContent, --pop Response
+ kur [7] CertReqMessages, --Key Update Request
+ kup [8] CertRepMessage, --Key Update Response
+ krr [9] CertReqMessages, --Key Recovery Req
+
+
+
+Adams, et al. Standards Track [Page 27]
+
+RFC 4210 CMP September 2005
+
+
+ krp [10] KeyRecRepContent, --Key Recovery Resp
+ rr [11] RevReqContent, --Revocation Request
+ rp [12] RevRepContent, --Revocation Response
+ ccr [13] CertReqMessages, --Cross-Cert. Request
+ ccp [14] CertRepMessage, --Cross-Cert. Resp
+ ckuann [15] CAKeyUpdAnnContent, --CA Key Update Ann.
+ cann [16] CertAnnContent, --Certificate Ann.
+ rann [17] RevAnnContent, --Revocation Ann.
+ crlann [18] CRLAnnContent, --CRL Announcement
+ pkiconf [19] PKIConfirmContent, --Confirmation
+ nested [20] NestedMessageContent, --Nested Message
+ genm [21] GenMsgContent, --General Message
+ genp [22] GenRepContent, --General Response
+ error [23] ErrorMsgContent, --Error Message
+ certConf [24] CertConfirmContent, --Certificate confirm
+ pollReq [25] PollReqContent, --Polling request
+ pollRep [26] PollRepContent --Polling response
+ }
+
+ The specific types are described in Section 5.3 below.
+
+5.1.3. PKI Message Protection
+
+ Some PKI messages will be protected for integrity. (Note that if an
+ asymmetric algorithm is used to protect a message and the relevant
+ public component has been certified already, then the origin of the
+ message can also be authenticated. On the other hand, if the public
+ component is uncertified, then the message origin cannot be
+ automatically authenticated, but may be authenticated via out-of-band
+ means.)
+
+ When protection is applied, the following structure is used:
+
+ PKIProtection ::= BIT STRING
+
+ The input to the calculation of PKIProtection is the DER encoding of
+ the following data structure:
+
+ ProtectedPart ::= SEQUENCE {
+ header PKIHeader,
+ body PKIBody
+ }
+
+ There MAY be cases in which the PKIProtection BIT STRING is
+ deliberately not used to protect a message (i.e., this OPTIONAL field
+ is omitted) because other protection, external to PKIX, will be
+ applied instead. Such a choice is explicitly allowed in this
+ specification. Examples of such external protection include PKCS #7
+
+
+
+Adams, et al. Standards Track [Page 28]
+
+RFC 4210 CMP September 2005
+
+
+ [PKCS7] and Security Multiparts [RFC1847] encapsulation of the
+ PKIMessage (or simply the PKIBody (omitting the CHOICE tag), if the
+ relevant PKIHeader information is securely carried in the external
+ mechanism). It is noted, however, that many such external mechanisms
+ require that the end entity already possesses a public-key
+ certificate, and/or a unique Distinguished Name, and/or other such
+ infrastructure-related information. Thus, they may not be
+ appropriate for initial registration, key-recovery, or any other
+ process with "boot-strapping" characteristics. For those cases it
+ may be necessary that the PKIProtection parameter be used. In the
+ future, if/when external mechanisms are modified to accommodate
+ boot-strapping scenarios, the use of PKIProtection may become rare or
+ non-existent.
+
+ Depending on the circumstances, the PKIProtection bits may contain a
+ Message Authentication Code (MAC) or signature. Only the following
+ cases can occur:
+
+5.1.3.1. Shared Secret Information
+
+ In this case, the sender and recipient share secret information
+ (established via out-of-band means or from a previous PKI management
+ operation). PKIProtection will contain a MAC value and the
+ protectionAlg will be the following (see also Appendix D.2):
+
+ id-PasswordBasedMac OBJECT IDENTIFIER ::= {1 2 840 113533 7 66 13}
+ PBMParameter ::= SEQUENCE {
+ salt OCTET STRING,
+ owf AlgorithmIdentifier,
+ iterationCount INTEGER,
+ mac AlgorithmIdentifier
+ }
+
+ In the above protectionAlg, the salt value is appended to the shared
+ secret input. The OWF is then applied iterationCount times, where
+ the salted secret is the input to the first iteration and, for each
+ successive iteration, the input is set to be the output of the
+ previous iteration. The output of the final iteration (called
+ "BASEKEY" for ease of reference, with a size of "H") is what is used
+ to form the symmetric key. If the MAC algorithm requires a K-bit key
+ and K <= H, then the most significant K bits of BASEKEY are used. If
+ K > H, then all of BASEKEY is used for the most significant H bits of
+ the key, OWF("1" || BASEKEY) is used for the next most significant H
+ bits of the key, OWF("2" || BASEKEY) is used for the next most
+ significant H bits of the key, and so on, until all K bits have been
+ derived. [Here "N" is the ASCII byte encoding the number N and "||"
+ represents concatenation.]
+
+
+
+
+Adams, et al. Standards Track [Page 29]
+
+RFC 4210 CMP September 2005
+
+
+ Note: it is RECOMMENDED that the fields of PBMParameter remain
+ constant throughout the messages of a single transaction (e.g.,
+ ir/ip/certConf/pkiConf) in order to reduce the overhead associated
+ with PasswordBasedMac computation).
+
+5.1.3.2. DH Key Pairs
+
+ Where the sender and receiver possess Diffie-Hellman certificates
+ with compatible DH parameters, in order to protect the message the
+ end entity must generate a symmetric key based on its private DH key
+ value and the DH public key of the recipient of the PKI message.
+ PKIProtection will contain a MAC value keyed with this derived
+ symmetric key and the protectionAlg will be the following:
+
+ id-DHBasedMac OBJECT IDENTIFIER ::= {1 2 840 113533 7 66 30}
+
+ DHBMParameter ::= SEQUENCE {
+ owf AlgorithmIdentifier,
+ -- AlgId for a One-Way Function (SHA-1 recommended)
+ mac AlgorithmIdentifier
+ -- the MAC AlgId (e.g., DES-MAC, Triple-DES-MAC [PKCS11],
+ } -- or HMAC [RFC2104, RFC2202])
+
+ In the above protectionAlg, OWF is applied to the result of the
+ Diffie-Hellman computation. The OWF output (called "BASEKEY" for
+ ease of reference, with a size of "H") is what is used to form the
+ symmetric key. If the MAC algorithm requires a K-bit key and K <= H,
+ then the most significant K bits of BASEKEY are used. If K > H, then
+ all of BASEKEY is used for the most significant H bits of the key,
+ OWF("1" || BASEKEY) is used for the next most significant H bits of
+ the key, OWF("2" || BASEKEY) is used for the next most significant H
+ bits of the key, and so on, until all K bits have been derived.
+ [Here "N" is the ASCII byte encoding the number N and "||" represents
+ concatenation.]
+
+5.1.3.3. Signature
+
+ In this case, the sender possesses a signature key pair and simply
+ signs the PKI message. PKIProtection will contain the signature
+ value and the protectionAlg will be an AlgorithmIdentifier for a
+ digital signature (e.g., md5WithRSAEncryption or dsaWithSha-1).
+
+5.1.3.4. Multiple Protection
+
+ In cases where an end entity sends a protected PKI message to an RA,
+ the RA MAY forward that message to a CA, attaching its own protection
+ (which MAY be a MAC or a signature, depending on the information and
+ certificates shared between the RA and the CA). This is accomplished
+
+
+
+Adams, et al. Standards Track [Page 30]
+
+RFC 4210 CMP September 2005
+
+
+ by nesting the entire message sent by the end entity within a new PKI
+ message. The structure used is as follows.
+
+ NestedMessageContent ::= PKIMessages
+
+ (The use of PKIMessages, a SEQUENCE OF PKIMessage, lets the RA batch
+ the requests of several EEs in a single new message. For simplicity,
+ all messages in the batch MUST be of the same type (e.g., ir).) If
+ the RA wishes to modify the message(s) in some way (e.g., add
+ particular field values or new extensions), then it MAY create its
+ own desired PKIBody. The original PKIMessage from the EE MAY be
+ included in the generalInfo field of PKIHeader (to accommodate, for
+ example, cases in which the CA wishes to check POP or other
+ information on the original EE message). The infoType to be used in
+ this situation is {id-it 15} (see Section 5.3.19 for the value of
+ id-it) and the infoValue is PKIMessages (contents MUST be in the same
+ order as the requests in PKIBody).
+
+5.2. Common Data Structures
+
+ Before specifying the specific types that may be placed in a PKIBody,
+ we define some data structures that are used in more than one case.
+
+5.2.1. Requested Certificate Contents
+
+ Various PKI management messages require that the originator of the
+ message indicate some of the fields that are required to be present
+ in a certificate. The CertTemplate structure allows an end entity or
+ RA to specify as much as it wishes about the certificate it requires.
+ CertTemplate is identical to a Certificate, but with all fields
+ optional.
+
+ Note that even if the originator completely specifies the contents of
+ a certificate it requires, a CA is free to modify fields within the
+ certificate actually issued. If the modified certificate is
+ unacceptable to the requester, the requester MUST send back a
+ certConf message that either does not include this certificate (via a
+ CertHash), or does include this certificate (via a CertHash) along
+ with a status of "rejected". See Section 5.3.18 for the definition
+ and use of CertHash and the certConf message.
+
+ See Appendix C and [CRMF] for CertTemplate syntax.
+
+5.2.2. Encrypted Values
+
+ Where encrypted values (restricted, in this specification, to be
+ either private keys or certificates) are sent in PKI messages, the
+ EncryptedValue data structure is used.
+
+
+
+Adams, et al. Standards Track [Page 31]
+
+RFC 4210 CMP September 2005
+
+
+ See [CRMF] for EncryptedValue syntax.
+
+ Use of this data structure requires that the creator and intended
+ recipient be able to encrypt and decrypt, respectively. Typically,
+ this will mean that the sender and recipient have, or are able to
+ generate, a shared secret key.
+
+ If the recipient of the PKIMessage already possesses a private key
+ usable for decryption, then the encSymmKey field MAY contain a
+ session key encrypted using the recipient's public key.
+
+5.2.3. Status codes and Failure Information for PKI Messages
+
+ All response messages will include some status information. The
+ following values are defined.
+
+ PKIStatus ::= INTEGER {
+ accepted (0),
+ grantedWithMods (1),
+ rejection (2),
+ waiting (3),
+ revocationWarning (4),
+ revocationNotification (5),
+ keyUpdateWarning (6)
+ }
+
+ Responders may use the following syntax to provide more information
+ about failure cases.
+
+ PKIFailureInfo ::= BIT STRING {
+ badAlg (0),
+ badMessageCheck (1),
+ badRequest (2),
+ badTime (3),
+ badCertId (4),
+ badDataFormat (5),
+ wrongAuthority (6),
+ incorrectData (7),
+ missingTimeStamp (8),
+ badPOP (9),
+ certRevoked (10),
+ certConfirmed (11),
+ wrongIntegrity (12),
+ badRecipientNonce (13),
+ timeNotAvailable (14),
+ unacceptedPolicy (15),
+ unacceptedExtension (16),
+ addInfoNotAvailable (17),
+
+
+
+Adams, et al. Standards Track [Page 32]
+
+RFC 4210 CMP September 2005
+
+
+ badSenderNonce (18),
+ badCertTemplate (19),
+ signerNotTrusted (20),
+ transactionIdInUse (21),
+ unsupportedVersion (22),
+ notAuthorized (23),
+ systemUnavail (24),
+ systemFailure (25),
+ duplicateCertReq (26)
+ }
+
+ PKIStatusInfo ::= SEQUENCE {
+ status PKIStatus,
+ statusString PKIFreeText OPTIONAL,
+ failInfo PKIFailureInfo OPTIONAL
+ }
+
+5.2.4. Certificate Identification
+
+ In order to identify particular certificates, the CertId data
+ structure is used.
+
+ See [CRMF] for CertId syntax.
+
+5.2.5. Out-of-band root CA Public Key
+
+ Each root CA must be able to publish its current public key via some
+ "out-of-band" means. While such mechanisms are beyond the scope of
+ this document, we define data structures that can support such
+ mechanisms.
+
+ There are generally two methods available: either the CA directly
+ publishes its self-signed certificate, or this information is
+ available via the Directory (or equivalent) and the CA publishes a
+ hash of this value to allow verification of its integrity before use.
+
+ OOBCert ::= Certificate
+
+ The fields within this certificate are restricted as follows:
+
+ o The certificate MUST be self-signed (i.e., the signature must be
+ verifiable using the SubjectPublicKeyInfo field);
+
+ o The subject and issuer fields MUST be identical;
+
+ o If the subject field is NULL, then both subjectAltNames and
+ issuerAltNames extensions MUST be present and have exactly the
+ same value;
+
+
+
+Adams, et al. Standards Track [Page 33]
+
+RFC 4210 CMP September 2005
+
+
+ o The values of all other extensions must be suitable for a self-
+ signed certificate (e.g., key identifiers for subject and issuer
+ must be the same).
+
+ OOBCertHash ::= SEQUENCE {
+ hashAlg [0] AlgorithmIdentifier OPTIONAL,
+ certId [1] CertId OPTIONAL,
+ hashVal BIT STRING
+ }
+
+ The intention of the hash value is that anyone who has securely
+ received the hash value (via the out-of-band means) can verify a
+ self-signed certificate for that CA.
+
+5.2.6. Archive Options
+
+ Requesters may indicate that they wish the PKI to archive a private
+ key value using the PKIArchiveOptions structure.
+
+ See [CRMF] for PKIArchiveOptions syntax.
+
+5.2.7. Publication Information
+
+ Requesters may indicate that they wish the PKI to publish a
+ certificate using the PKIPublicationInfo structure.
+
+ See [CRMF] for PKIPublicationInfo syntax.
+
+5.2.8. Proof-of-Possession Structures
+
+ If the certification request is for a signing key pair (i.e., a
+ request for a verification certificate), then the proof-of-possession
+ of the private signing key is demonstrated through use of the
+ POPOSigningKey structure.
+
+ See Appendix C and [CRMF] for POPOSigningKey syntax, but note that
+ POPOSigningKeyInput has the following semantic stipulations in this
+ specification.
+
+ POPOSigningKeyInput ::= SEQUENCE {
+ authInfo CHOICE {
+ sender [0] GeneralName,
+ publicKeyMAC PKMACValue
+ },
+ publicKey SubjectPublicKeyInfo
+ }
+
+
+
+
+
+Adams, et al. Standards Track [Page 34]
+
+RFC 4210 CMP September 2005
+
+
+ On the other hand, if the certification request is for an encryption
+ key pair (i.e., a request for an encryption certificate), then the
+ proof-of-possession of the private decryption key may be demonstrated
+ in one of three ways.
+
+5.2.8.1. Inclusion of the Private Key
+
+ By the inclusion of the private key (encrypted) in the CertRequest
+ (in the thisMessage field of POPOPrivKey (see Appendix C) or in the
+ PKIArchiveOptions control structure, depending upon whether or not
+ archival of the private key is also desired).
+
+5.2.8.2. Indirect Method
+
+ By having the CA return not the certificate, but an encrypted
+ certificate (i.e., the certificate encrypted under a randomly-
+ generated symmetric key, and the symmetric key encrypted under the
+ public key for which the certification request is being made) -- this
+ is the "indirect" method mentioned previously in Section 4.3.2. The
+ end entity proves knowledge of the private decryption key to the CA
+ by providing the correct CertHash for this certificate in the
+ certConf message. This demonstrates POP because the EE can only
+ compute the correct CertHash if it is able to recover the
+ certificate, and it can only recover the certificate if it is able to
+ decrypt the symmetric key using the required private key. Clearly,
+ for this to work, the CA MUST NOT publish the certificate until the
+ certConf message arrives (when certHash is to be used to demonstrate
+ POP). See Section 5.3.18 for further details.
+
+5.2.8.3. Challenge-Response Protocol
+
+ By having the end entity engage in a challenge-response protocol
+ (using the messages POPODecKeyChall and POPODecKeyResp; see below)
+ between CertReqMessages and CertRepMessage -- this is the "direct"
+ method mentioned previously in Section 4.3.2. (This method would
+ typically be used in an environment in which an RA verifies POP and
+ then makes a certification request to the CA on behalf of the end
+ entity. In such a scenario, the CA trusts the RA to have done POP
+ correctly before the RA requests a certificate for the end entity.)
+ The complete protocol then looks as follows (note that req' does not
+ necessarily encapsulate req as a nested message):
+
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 35]
+
+RFC 4210 CMP September 2005
+
+
+ EE RA CA
+ ---- req ---->
+ <--- chall ---
+ ---- resp --->
+ ---- req' --->
+ <--- rep -----
+ ---- conf --->
+ <--- ack -----
+ <--- rep -----
+ ---- conf --->
+ <--- ack -----
+
+ This protocol is obviously much longer than the 3-way exchange given
+ in choice (2) above, but allows a local Registration Authority to be
+ involved and has the property that the certificate itself is not
+ actually created until the proof-of-possession is complete. In some
+ environments, a different order of the above messages may be
+ required, such as the following (this may be determined by policy):
+
+ EE RA CA
+ ---- req ---->
+ <--- chall ---
+ ---- resp --->
+ ---- req' --->
+ <--- rep -----
+ <--- rep -----
+ ---- conf --->
+ ---- conf --->
+ <--- ack -----
+ <--- ack -----
+
+ If the cert. request is for a key agreement key (KAK) pair, then the
+ POP can use any of the 3 ways described above for enc. key pairs,
+ with the following changes: (1) the parenthetical text of bullet 2)
+ is replaced with "(i.e., the certificate encrypted under the
+ symmetric key derived from the CA's private KAK and the public key
+ for which the certification request is being made)"; (2) the first
+ parenthetical text of the challenge field of "Challenge" below is
+ replaced with "(using PreferredSymmAlg (see Section 5.3.19.4 and
+ Appendix E.5) and a symmetric key derived from the CA's private KAK
+ and the public key for which the certification request is being
+ made)". Alternatively, the POP can use the POPOSigningKey structure
+ given in [CRMF] (where the alg field is DHBasedMAC and the signature
+ field is the MAC) as a fourth alternative for demonstrating POP if
+ the CA already has a D-H certificate that is known to the EE.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 36]
+
+RFC 4210 CMP September 2005
+
+
+ The challenge-response messages for proof-of-possession of a private
+ decryption key are specified as follows (see [MvOV97], p.404 for
+ details). Note that this challenge-response exchange is associated
+ with the preceding cert. request message (and subsequent cert.
+ response and confirmation messages) by the transactionID used in the
+ PKIHeader and by the protection (MACing or signing) applied to the
+ PKIMessage.
+
+ POPODecKeyChallContent ::= SEQUENCE OF Challenge
+ Challenge ::= SEQUENCE {
+ owf AlgorithmIdentifier OPTIONAL,
+ witness OCTET STRING,
+ challenge OCTET STRING
+ }
+
+ Note that the size of Rand needs to be appropriate for encryption
+ under the public key of the requester. Given that "int" will
+ typically not be longer than 64 bits, this leaves well over 100 bytes
+ of room for the "sender" field when the modulus is 1024 bits. If, in
+ some environment, names are so long that they cannot fit (e.g., very
+ long DNs), then whatever portion will fit should be used (as long as
+ it includes at least the common name, and as long as the receiver is
+ able to deal meaningfully with the abbreviation).
+
+ POPODecKeyRespContent ::= SEQUENCE OF INTEGER
+
+5.2.8.4. Summary of PoP Options
+
+ The text in this section provides several options with respect to POP
+ techniques. Using "SK" for "signing key", "EK" for "encryption key",
+ and "KAK" for "key agreement key", the techniques may be summarized
+ as follows:
+
+ RAVerified;
+ SKPOP;
+ EKPOPThisMessage;
+ KAKPOPThisMessage;
+ KAKPOPThisMessageDHMAC;
+ EKPOPEncryptedCert;
+ KAKPOPEncryptedCert;
+ EKPOPChallengeResp; and
+ KAKPOPChallengeResp.
+
+ Given this array of options, it is natural to ask how an end entity
+ can know what is supported by the CA/RA (i.e., which options it may
+ use when requesting certificates). The following guidelines should
+ clarify this situation for EE implementers.
+
+
+
+
+Adams, et al. Standards Track [Page 37]
+
+RFC 4210 CMP September 2005
+
+
+ RAVerified. This is not an EE decision; the RA uses this if and only
+ if it has verified POP before forwarding the request on to the CA, so
+ it is not possible for the EE to choose this technique.
+
+ SKPOP. If the EE has a signing key pair, this is the only POP method
+ specified for use in the request for a corresponding certificate.
+
+ EKPOPThisMessage and KAKPOPThisMessage. Whether or not to give up
+ its private key to the CA/RA is an EE decision. If the EE decides to
+ reveal its key, then these are the only POP methods available in this
+ specification to achieve this (and the key pair type will determine
+ which of these two methods to use).
+
+ KAKPOPThisMessageDHMAC. The EE can only use this method if (1) the
+ CA has a DH certificate available for this purpose, and (2) the EE
+ already has a copy of this certificate. If both these conditions
+ hold, then this technique is clearly supported and may be used by the
+ EE, if desired.
+
+ EKPOPEncryptedCert, KAKPOPEncryptedCert, EKPOPChallengeResp,
+ KAKPOPChallengeResp. The EE picks one of these (in the
+ subsequentMessage field) in the request message, depending upon
+ preference and key pair type. The EE is not doing POP at this point;
+ it is simply indicating which method it wants to use. Therefore, if
+ the CA/RA replies with a "badPOP" error, the EE can re-request using
+ the other POP method chosen in subsequentMessage. Note, however,
+ that this specification encourages the use of the EncryptedCert
+ choice and, furthermore, says that the challenge-response would
+ typically be used when an RA is involved and doing POP verification.
+ Thus, the EE should be able to make an intelligent decision regarding
+ which of these POP methods to choose in the request message.
+
+5.3. Operation-Specific Data Structures
+
+5.3.1. Initialization Request
+
+ An Initialization request message contains as the PKIBody a
+ CertReqMessages data structure, which specifies the requested
+ certificate(s). Typically, SubjectPublicKeyInfo, KeyId, and Validity
+ are the template fields which may be supplied for each certificate
+ requested (see Appendix D profiles for further information). This
+ message is intended to be used for entities when first initializing
+ into the PKI.
+
+ See Appendix C and [CRMF] for CertReqMessages syntax.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 38]
+
+RFC 4210 CMP September 2005
+
+
+5.3.2. Initialization Response
+
+ An Initialization response message contains as the PKIBody an
+ CertRepMessage data structure, which has for each certificate
+ requested a PKIStatusInfo field, a subject certificate, and possibly
+ a private key (normally encrypted with a session key, which is itself
+ encrypted with the protocolEncrKey).
+
+ See Section 5.3.4 for CertRepMessage syntax. Note that if the PKI
+ Message Protection is "shared secret information" (see Section
+ 5.1.3), then any certificate transported in the caPubs field may be
+ directly trusted as a root CA certificate by the initiator.
+
+5.3.3. Certification Request
+
+ A Certification request message contains as the PKIBody a
+ CertReqMessages data structure, which specifies the requested
+ certificates. This message is intended to be used for existing PKI
+ entities who wish to obtain additional certificates.
+
+ See Appendix C and [CRMF] for CertReqMessages syntax.
+
+ Alternatively, the PKIBody MAY be a CertificationRequest (this
+ structure is fully specified by the ASN.1 structure
+ CertificationRequest given in [PKCS10]). This structure may be
+ required for certificate requests for signing key pairs when
+ interoperation with legacy systems is desired, but its use is
+ strongly discouraged whenever not absolutely necessary.
+
+5.3.4. Certification Response
+
+ A Certification response message contains as the PKIBody a
+ CertRepMessage data structure, which has a status value for each
+ certificate requested, and optionally has a CA public key, failure
+ information, a subject certificate, and an encrypted private key.
+
+ CertRepMessage ::= SEQUENCE {
+ caPubs [1] SEQUENCE SIZE (1..MAX) OF Certificate
+ OPTIONAL,
+ response SEQUENCE OF CertResponse
+ }
+
+ CertResponse ::= SEQUENCE {
+ certReqId INTEGER,
+ status PKIStatusInfo,
+ certifiedKeyPair CertifiedKeyPair OPTIONAL,
+ rspInfo OCTET STRING OPTIONAL
+ -- analogous to the id-regInfo-utf8Pairs string defined
+
+
+
+Adams, et al. Standards Track [Page 39]
+
+RFC 4210 CMP September 2005
+
+
+ -- for regInfo in CertReqMsg [CRMF]
+ }
+
+ CertifiedKeyPair ::= SEQUENCE {
+ certOrEncCert CertOrEncCert,
+ privateKey [0] EncryptedValue OPTIONAL,
+ -- see [CRMF] for comment on encoding
+ publicationInfo [1] PKIPublicationInfo OPTIONAL
+ }
+
+ CertOrEncCert ::= CHOICE {
+ certificate [0] Certificate,
+ encryptedCert [1] EncryptedValue
+ }
+
+ Only one of the failInfo (in PKIStatusInfo) and certificate (in
+ CertifiedKeyPair) fields can be present in each CertResponse
+ (depending on the status). For some status values (e.g., waiting),
+ neither of the optional fields will be present.
+
+ Given an EncryptedCert and the relevant decryption key, the
+ certificate may be obtained. The purpose of this is to allow a CA to
+ return the value of a certificate, but with the constraint that only
+ the intended recipient can obtain the actual certificate. The
+ benefit of this approach is that a CA may reply with a certificate
+ even in the absence of a proof that the requester is the end entity
+ that can use the relevant private key (note that the proof is not
+ obtained until the certConf message is received by the CA). Thus,
+ the CA will not have to revoke that certificate in the event that
+ something goes wrong with the proof-of-possession (but MAY do so
+ anyway, depending upon policy).
+
+5.3.5. Key Update Request Content
+
+ For key update requests the CertReqMessages syntax is used.
+ Typically, SubjectPublicKeyInfo, KeyId, and Validity are the template
+ fields that may be supplied for each key to be updated. This message
+ is intended to be used to request updates to existing (non-revoked
+ and non-expired) certificates (therefore, it is sometimes referred to
+ as a "Certificate Update" operation). An update is a replacement
+ certificate containing either a new subject public key or the current
+ subject public key (although the latter practice may not be
+ appropriate for some environments).
+
+ See Appendix C and [CRMF] for CertReqMessages syntax.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 40]
+
+RFC 4210 CMP September 2005
+
+
+5.3.6. Key Update Response Content
+
+ For key update responses, the CertRepMessage syntax is used. The
+ response is identical to the initialization response.
+
+ See Section 5.3.4 for CertRepMessage syntax.
+
+5.3.7. Key Recovery Request Content
+
+ For key recovery requests the syntax used is identical to the
+ initialization request CertReqMessages. Typically,
+ SubjectPublicKeyInfo and KeyId are the template fields that may be
+ used to supply a signature public key for which a certificate is
+ required (see Appendix D profiles for further information).
+
+ See Appendix C and [CRMF] for CertReqMessages syntax. Note that if a
+ key history is required, the requester must supply a Protocol
+ Encryption Key control in the request message.
+
+5.3.8. Key Recovery Response Content
+
+ For key recovery responses, the following syntax is used. For some
+ status values (e.g., waiting) none of the optional fields will be
+ present.
+
+ KeyRecRepContent ::= SEQUENCE {
+ status PKIStatusInfo,
+ newSigCert [0] Certificate OPTIONAL,
+ caCerts [1] SEQUENCE SIZE (1..MAX) OF
+ Certificate OPTIONAL,
+ keyPairHist [2] SEQUENCE SIZE (1..MAX) OF
+ CertifiedKeyPair OPTIONAL
+ }
+
+5.3.9. Revocation Request Content
+
+ When requesting revocation of a certificate (or several
+ certificates), the following data structure is used. The name of the
+ requester is present in the PKIHeader structure.
+
+ RevReqContent ::= SEQUENCE OF RevDetails
+
+ RevDetails ::= SEQUENCE {
+ certDetails CertTemplate,
+ crlEntryDetails Extensions OPTIONAL
+ }
+
+
+
+
+
+Adams, et al. Standards Track [Page 41]
+
+RFC 4210 CMP September 2005
+
+
+5.3.10. Revocation Response Content
+
+ The revocation response is the response to the above message. If
+ produced, this is sent to the requester of the revocation. (A
+ separate revocation announcement message MAY be sent to the subject
+ of the certificate for which revocation was requested.)
+
+ RevRepContent ::= SEQUENCE {
+ status SEQUENCE SIZE (1..MAX) OF PKIStatusInfo,
+ revCerts [0] SEQUENCE SIZE (1..MAX) OF CertId OPTIONAL,
+ crls [1] SEQUENCE SIZE (1..MAX) OF CertificateList
+ OPTIONAL
+ }
+
+5.3.11. Cross Certification Request Content
+
+ Cross certification requests use the same syntax (CertReqMessages) as
+ normal certification requests, with the restriction that the key pair
+ MUST have been generated by the requesting CA and the private key
+ MUST NOT be sent to the responding CA. This request MAY also be used
+ by subordinate CAs to get their certificates signed by the parent CA.
+
+ See Appendix C and [CRMF] for CertReqMessages syntax.
+
+5.3.12. Cross Certification Response Content
+
+ Cross certification responses use the same syntax (CertRepMessage) as
+ normal certification responses, with the restriction that no
+ encrypted private key can be sent.
+
+ See Section 5.3.4 for CertRepMessage syntax.
+
+5.3.13. CA Key Update Announcement Content
+
+ When a CA updates its own key pair, the following data structure MAY
+ be used to announce this event.
+
+ CAKeyUpdAnnContent ::= SEQUENCE {
+ oldWithNew Certificate,
+ newWithOld Certificate,
+ newWithNew Certificate
+ }
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 42]
+
+RFC 4210 CMP September 2005
+
+
+5.3.14. Certificate Announcement
+
+ This structure MAY be used to announce the existence of certificates.
+
+ Note that this message is intended to be used for those cases (if
+ any) where there is no pre-existing method for publication of
+ certificates; it is not intended to be used where, for example, X.500
+ is the method for publication of certificates.
+
+ CertAnnContent ::= Certificate
+
+5.3.15. Revocation Announcement
+
+ When a CA has revoked, or is about to revoke, a particular
+ certificate, it MAY issue an announcement of this (possibly upcoming)
+ event.
+
+ RevAnnContent ::= SEQUENCE {
+ status PKIStatus,
+ certId CertId,
+ willBeRevokedAt GeneralizedTime,
+ badSinceDate GeneralizedTime,
+ crlDetails Extensions OPTIONAL
+ }
+
+ A CA MAY use such an announcement to warn (or notify) a subject that
+ its certificate is about to be (or has been) revoked. This would
+ typically be used where the request for revocation did not come from
+ the subject concerned.
+
+ The willBeRevokedAt field contains the time at which a new entry will
+ be added to the relevant CRLs.
+
+5.3.16. CRL Announcement
+
+ When a CA issues a new CRL (or set of CRLs) the following data
+ structure MAY be used to announce this event.
+
+ CRLAnnContent ::= SEQUENCE OF CertificateList
+
+5.3.17. PKI Confirmation Content
+
+ This data structure is used in the protocol exchange as the final
+ PKIMessage. Its content is the same in all cases -- actually there
+ is no content since the PKIHeader carries all the required
+ information.
+
+ PKIConfirmContent ::= NULL
+
+
+
+Adams, et al. Standards Track [Page 43]
+
+RFC 4210 CMP September 2005
+
+
+ Use of this message for certificate confirmation is NOT RECOMMENDED;
+ certConf SHOULD be used instead. Upon receiving a PKIConfirm for a
+ certificate response, the recipient MAY treat it as a certConf with
+ all certificates being accepted.
+
+5.3.18. Certificate Confirmation Content
+
+ This data structure is used by the client to send a confirmation to
+ the CA/RA to accept or reject certificates.
+
+ CertConfirmContent ::= SEQUENCE OF CertStatus
+
+ CertStatus ::= SEQUENCE {
+ certHash OCTET STRING,
+ certReqId INTEGER,
+ statusInfo PKIStatusInfo OPTIONAL
+ }
+
+ For any particular CertStatus, omission of the statusInfo field
+ indicates ACCEPTANCE of the specified certificate. Alternatively,
+ explicit status details (with respect to acceptance or rejection) MAY
+ be provided in the statusInfo field, perhaps for auditing purposes at
+ the CA/RA.
+
+ Within CertConfirmContent, omission of a CertStatus structure
+ corresponding to a certificate supplied in the previous response
+ message indicates REJECTION of the certificate. Thus, an empty
+ CertConfirmContent (a zero-length SEQUENCE) MAY be used to indicate
+ rejection of all supplied certificates. See Section 5.2.8, item (2),
+ for a discussion of the certHash field with respect to proof-of-
+ possession.
+
+5.3.19. PKI General Message Content
+
+ InfoTypeAndValue ::= SEQUENCE {
+ infoType OBJECT IDENTIFIER,
+ infoValue ANY DEFINED BY infoType OPTIONAL
+ }
+ -- where {id-it} = {id-pkix 4} = {1 3 6 1 5 5 7 4}
+ GenMsgContent ::= SEQUENCE OF InfoTypeAndValue
+
+5.3.19.1. CA Protocol Encryption Certificate
+
+ This MAY be used by the EE to get a certificate from the CA to use to
+ protect sensitive information during the protocol.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 44]
+
+RFC 4210 CMP September 2005
+
+
+ GenMsg: {id-it 1}, < absent >
+ GenRep: {id-it 1}, Certificate | < absent >
+
+ EEs MUST ensure that the correct certificate is used for this
+ purpose.
+
+5.3.19.2. Signing Key Pair Types
+
+ This MAY be used by the EE to get the list of signature algorithms
+ (e.g., RSA, DSA) whose subject public key values the CA is willing to
+ certify. Note that for the purposes of this exchange, rsaEncryption
+ and rsaWithSHA1, for example, are considered to be equivalent; the
+ question being asked is, "Is the CA willing to certify an RSA public
+ key?"
+
+ GenMsg: {id-it 2}, < absent >
+ GenRep: {id-it 2}, SEQUENCE SIZE (1..MAX) OF
+ AlgorithmIdentifier
+
+5.3.19.3. Encryption/Key Agreement Key Pair Types
+
+ This MAY be used by the client to get the list of encryption/key
+ agreement algorithms whose subject public key values the CA is
+ willing to certify.
+
+ GenMsg: {id-it 3}, < absent >
+ GenRep: {id-it 3}, SEQUENCE SIZE (1..MAX) OF
+ AlgorithmIdentifier
+
+5.3.19.4. Preferred Symmetric Algorithm
+
+ This MAY be used by the client to get the CA-preferred symmetric
+ encryption algorithm for any confidential information that needs to
+ be exchanged between the EE and the CA (for example, if the EE wants
+ to send its private decryption key to the CA for archival purposes).
+
+ GenMsg: {id-it 4}, < absent >
+ GenRep: {id-it 4}, AlgorithmIdentifier
+
+5.3.19.5. Updated CA Key Pair
+
+ This MAY be used by the CA to announce a CA key update event.
+
+ GenMsg: {id-it 5}, CAKeyUpdAnnContent
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 45]
+
+RFC 4210 CMP September 2005
+
+
+5.3.19.6. CRL
+
+ This MAY be used by the client to get a copy of the latest CRL.
+
+ GenMsg: {id-it 6}, < absent >
+ GenRep: {id-it 6}, CertificateList
+
+5.3.19.7. Unsupported Object Identifiers
+
+ This is used by the server to return a list of object identifiers
+ that it does not recognize or support from the list submitted by the
+ client.
+
+ GenRep: {id-it 7}, SEQUENCE SIZE (1..MAX) OF OBJECT IDENTIFIER
+
+5.3.19.8. Key Pair Parameters
+
+ This MAY be used by the EE to request the domain parameters to use
+ for generating the key pair for certain public-key algorithms. It
+ can be used, for example, to request the appropriate P, Q, and G to
+ generate the DH/DSA key, or to request a set of well-known elliptic
+ curves.
+
+ GenMsg: {id-it 10}, OBJECT IDENTIFIER -- (Algorithm object-id)
+ GenRep: {id-it 11}, AlgorithmIdentifier | < absent >
+
+ An absent infoValue in the GenRep indicates that the algorithm
+ specified in GenMsg is not supported.
+
+ EEs MUST ensure that the parameters are acceptable to it and that the
+ GenRep message is authenticated (to avoid substitution attacks).
+
+5.3.19.9. Revocation Passphrase
+
+ This MAY be used by the EE to send a passphrase to a CA/RA for the
+ purpose of authenticating a later revocation request (in the case
+ that the appropriate signing private key is no longer available to
+ authenticate the request). See Appendix B for further details on the
+ use of this mechanism.
+
+ GenMsg: {id-it 12}, EncryptedValue
+ GenRep: {id-it 12}, < absent >
+
+5.3.19.10. ImplicitConfirm
+
+ See Section 5.1.1.1 for the definition and use of {id-it 13}.
+
+
+
+
+
+Adams, et al. Standards Track [Page 46]
+
+RFC 4210 CMP September 2005
+
+
+5.3.19.11. ConfirmWaitTime
+
+ See Section 5.1.1.2 for the definition and use of {id-it 14}.
+
+5.3.19.12 Original PKIMessage
+
+ See Section 5.1.3 for the definition and use of {id-it 15}.
+
+5.3.19.13. Supported Language Tags
+
+ This MAY be used to determine the appropriate language tag to use in
+ subsequent messages. The sender sends its list of supported
+ languages (in order, most preferred to least); the receiver returns
+ the one it wishes to use. (Note: each UTF8String MUST include a
+ language tag.) If none of the offered tags are supported, an error
+ MUST be returned.
+
+ GenMsg: {id-it 16}, SEQUENCE SIZE (1..MAX) OF UTF8String
+ GenRep: {id-it 16}, SEQUENCE SIZE (1) OF UTF8String
+
+5.3.20. PKI General Response Content
+
+ GenRepContent ::= SEQUENCE OF InfoTypeAndValue
+
+ Examples of GenReps that MAY be supported include those listed in the
+ subsections of Section 5.3.19.
+
+5.3.21. Error Message Content
+
+ This data structure MAY be used by EE, CA, or RA to convey error
+ info.
+
+ ErrorMsgContent ::= SEQUENCE {
+ pKIStatusInfo PKIStatusInfo,
+ errorCode INTEGER OPTIONAL,
+ errorDetails PKIFreeText OPTIONAL
+ }
+
+ This message MAY be generated at any time during a PKI transaction.
+ If the client sends this request, the server MUST respond with a
+ PKIConfirm response, or another ErrorMsg if any part of the header is
+ not valid. Both sides MUST treat this message as the end of the
+ transaction (if a transaction is in progress).
+
+ If protection is desired on the message, the client MUST protect it
+ using the same technique (i.e., signature or MAC) as the starting
+ message of the transaction. The CA MUST always sign it with a
+ signature key.
+
+
+
+Adams, et al. Standards Track [Page 47]
+
+RFC 4210 CMP September 2005
+
+
+5.3.22. Polling Request and Response
+
+ This pair of messages is intended to handle scenarios in which the
+ client needs to poll the server in order to determine the status of
+ an outstanding ir, cr, or kur transaction (i.e., when the "waiting"
+ PKIStatus has been received).
+
+ PollReqContent ::= SEQUENCE OF SEQUENCE {
+ certReqId INTEGER }
+
+ PollRepContent ::= SEQUENCE OF SEQUENCE {
+ certReqId INTEGER,
+ checkAfter INTEGER, -- time in seconds
+ reason PKIFreeText OPTIONAL }
+
+ The following clauses describe when polling messages are used, and
+ how they are used. It is assumed that multiple certConf messages can
+ be sent during transactions. There will be one sent in response to
+ each ip, cp, or kup that contains a CertStatus for an issued
+ certificate.
+
+ 1. In response to an ip, cp, or kup message, an EE will send a
+ certConf for all issued certificates and, following the ack, a
+ pollReq for all pending certificates.
+
+ 2. In response to a pollReq, a CA/RA will return an ip, cp, or kup
+ if one or more of the pending certificates is ready; otherwise,
+ it will return a pollRep.
+
+ 3. If the EE receives a pollRep, it will wait for at least as long
+ as the checkAfter value before sending another pollReq.
+
+ 4. If an ip, cp, or kup is received in response to a pollReq, then
+ it will be treated in the same way as the initial response.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 48]
+
+RFC 4210 CMP September 2005
+
+
+ START
+ |
+ v
+ Send ir
+ | ip
+ v
+ Check status
+ of returned <------------------------+
+ certs |
+ | |
+ +------------------------>|<------------------+ |
+ | | | |
+ | (issued) v (waiting) | |
+ Add to <----------- Check CertResponse ------> Add to |
+ conf list for each certificate pending list |
+ / |
+ / |
+ (conf list) / (empty conf list) |
+ / ip |
+ / +----------------+
+ (empty pending list) / | pRep
+ END <---- Send certConf Send pReq------------>Wait
+ | ^ ^ |
+ | | | |
+ +-----------------+ +---------------+
+ (pending list)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 49]
+
+RFC 4210 CMP September 2005
+
+
+ In the following exchange, the end entity is enrolling for two
+ certificates in one request.
+
+ Step End Entity PKI
+ --------------------------------------------------------------------
+ 1 Format ir
+ 2 -> ir ->
+ 3 Handle ir
+ 4 Manual intervention is
+ required for both certs.
+ 5 <- ip <-
+ 6 Process ip
+ 7 Format pReq
+ 8 -> pReq ->
+ 9 Check status of cert requests
+ 10 Certificates not ready
+ 11 Format pRep
+ 12 <- pRep <-
+ 13 Wait
+ 14 Format pReq
+ 15 -> pReq ->
+ 16 Check status of cert requests
+ 17 One certificate is ready
+ 18 Format ip
+ 19 <- ip <-
+ 20 Handle ip
+ 21 Format certConf
+ 22 -> certConf ->
+ 23 Handle certConf
+ 24 Format ack
+ 25 <- pkiConf <-
+ 26 Format pReq
+ 27 -> pReq ->
+ 28 Check status of certificate
+ 29 Certificate is ready
+ 30 Format ip
+ 31 <- ip <-
+ 31 Handle ip
+ 32 Format certConf
+ 33 -> certConf ->
+ 34 Handle certConf
+ 35 Format ack
+ 36 <- pkiConf <-
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 50]
+
+RFC 4210 CMP September 2005
+
+
+6. Mandatory PKI Management Functions
+
+ Some of the PKI management functions outlined in Section 3.1 above
+ are described in this section.
+
+ This section deals with functions that are "mandatory" in the sense
+ that all end entity and CA/RA implementations MUST be able to provide
+ the functionality described. This part is effectively the profile of
+ the PKI management functionality that MUST be supported. Note,
+ however, that the management functions described in this section do
+ not need to be accomplished using the PKI messages defined in Section
+ 5 if alternate means are suitable for a given environment (see
+ Appendix D for profiles of the PKIMessages that MUST be supported).
+
+6.1. Root CA Initialization
+
+ [See Section 3.1.1.2 for this document's definition of "root CA".]
+
+ A newly created root CA must produce a "self-certificate", which is a
+ Certificate structure with the profile defined for the "newWithNew"
+ certificate issued following a root CA key update.
+
+ In order to make the CA's self certificate useful to end entities
+ that do not acquire the self certificate via "out-of-band" means, the
+ CA must also produce a fingerprint for its certificate. End entities
+ that acquire this fingerprint securely via some "out-of-band" means
+ can then verify the CA's self-certificate and, hence, the other
+ attributes contained therein.
+
+ The data structure used to carry the fingerprint is the OOBCertHash.
+
+6.2. Root CA Key Update
+
+ CA keys (as all other keys) have a finite lifetime and will have to
+ be updated on a periodic basis. The certificates NewWithNew,
+ NewWithOld, and OldWithNew (see Section 4.4.1) MAY be issued by the
+ CA to aid existing end entities who hold the current self-signed CA
+ certificate (OldWithOld) to transition securely to the new self-
+ signed CA certificate (NewWithNew), and to aid new end entities who
+ will hold NewWithNew to acquire OldWithOld securely for verification
+ of existing data.
+
+6.3. Subordinate CA Initialization
+
+ [See Section 3.1.1.2 for this document's definition of "subordinate
+ CA".]
+
+
+
+
+
+Adams, et al. Standards Track [Page 51]
+
+RFC 4210 CMP September 2005
+
+
+ From the perspective of PKI management protocols, the initialization
+ of a subordinate CA is the same as the initialization of an end
+ entity. The only difference is that the subordinate CA must also
+ produce an initial revocation list.
+
+6.4. CRL production
+
+ Before issuing any certificates, a newly established CA (which issues
+ CRLs) must produce "empty" versions of each CRL which are to be
+ periodically produced.
+
+6.5. PKI Information Request
+
+ When a PKI entity (CA, RA, or EE) wishes to acquire information about
+ the current status of a CA, it MAY send that CA a request for such
+ information.
+
+ The CA MUST respond to the request by providing (at least) all of the
+ information requested by the requester. If some of the information
+ cannot be provided, then an error must be conveyed to the requester.
+
+ If PKIMessages are used to request and supply this PKI information,
+ then the request MUST be the GenMsg message, the response MUST be the
+ GenRep message, and the error MUST be the Error message. These
+ messages are protected using a MAC based on shared secret information
+ (i.e., PasswordBasedMAC) or using any other authenticated means (if
+ the end entity has an existing certificate).
+
+6.6. Cross Certification
+
+ The requester CA is the CA that will become the subject of the
+ cross-certificate; the responder CA will become the issuer of the
+ cross-certificate.
+
+ The requester CA must be "up and running" before initiating the
+ cross-certification operation.
+
+6.6.1. One-Way Request-Response Scheme:
+
+ The cross-certification scheme is essentially a one way operation;
+ that is, when successful, this operation results in the creation of
+ one new cross-certificate. If the requirement is that cross-
+ certificates be created in "both directions", then each CA, in turn,
+ must initiate a cross-certification operation (or use another
+ scheme).
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 52]
+
+RFC 4210 CMP September 2005
+
+
+ This scheme is suitable where the two CAs in question can already
+ verify each other's signatures (they have some common points of
+ trust) or where there is an out-of-band verification of the origin of
+ the certification request.
+
+ Detailed Description:
+
+ Cross certification is initiated at one CA known as the responder.
+ The CA administrator for the responder identifies the CA it wants to
+ cross certify and the responder CA equipment generates an
+ authorization code. The responder CA administrator passes this
+ authorization code by out-of-band means to the requester CA
+ administrator. The requester CA administrator enters the
+ authorization code at the requester CA in order to initiate the on-
+ line exchange.
+
+ The authorization code is used for authentication and integrity
+ purposes. This is done by generating a symmetric key based on the
+ authorization code and using the symmetric key for generating Message
+ Authentication Codes (MACs) on all messages exchanged.
+ (Authentication may alternatively be done using signatures instead of
+ MACs, if the CAs are able to retrieve and validate the required
+ public keys by some means, such as an out-of-band hash comparison.)
+
+ The requester CA initiates the exchange by generating a cross-
+ certification request (ccr) with a fresh random number (requester
+ random number). The requester CA then sends the ccr message to the
+ responder CA. The fields in this message are protected from
+ modification with a MAC based on the authorization code.
+
+ Upon receipt of the ccr message, the responder CA validates the
+ message and the MAC, saves the requester random number, and generates
+ its own random number (responder random number). It then generates
+ (and archives, if desired) a new requester certificate that contains
+ the requester CA public key and is signed with the responder CA
+ signature private key. The responder CA responds with the cross
+ certification response (ccp) message. The fields in this message are
+ protected from modification with a MAC based on the authorization
+ code.
+
+ Upon receipt of the ccp message, the requester CA validates the
+ message (including the received random numbers) and the MAC. The
+ requester CA responds with the certConf message. The fields in this
+ message are protected from modification with a MAC based on the
+ authorization code. The requester CA MAY write the requester
+ certificate to the Repository as an aid to later certificate path
+ construction.
+
+
+
+
+Adams, et al. Standards Track [Page 53]
+
+RFC 4210 CMP September 2005
+
+
+ Upon receipt of the certConf message, the responder CA validates the
+ message and the MAC, and sends back an acknowledgement using the
+ PKIConfirm message. It MAY also publish the requester certificate as
+ an aid to later path construction.
+
+ Notes:
+
+ 1. The ccr message must contain a "complete" certification request;
+ that is, all fields except the serial number (including, e.g., a
+ BasicConstraints extension) must be specified by the requester
+ CA.
+
+ 2. The ccp message SHOULD contain the verification certificate of
+ the responder CA; if present, the requester CA must then verify
+ this certificate (for example, via the "out-of-band" mechanism).
+
+ (A simpler, non-interactive model of cross-certification may also be
+ envisioned, in which the issuing CA acquires the subject CA's public
+ key from some repository, verifies it via some out-of-band mechanism,
+ and creates and publishes the cross-certificate without the subject
+ CA's explicit involvement. This model may be perfectly legitimate
+ for many environments, but since it does not require any protocol
+ message exchanges, its detailed description is outside the scope of
+ this specification.)
+
+6.7. End Entity Initialization
+
+ As with CAs, end entities must be initialized. Initialization of end
+ entities requires at least two steps:
+
+ o acquisition of PKI information
+
+ o out-of-band verification of one root-CA public key
+
+ (other possible steps include the retrieval of trust condition
+ information and/or out-of-band verification of other CA public keys).
+
+6.7.1. Acquisition of PKI Information
+
+ The information REQUIRED is:
+
+ o the current root-CA public key
+
+ o (if the certifying CA is not a root-CA) the certification path
+ from the root CA to the certifying CA together with appropriate
+ revocation lists
+
+
+
+
+
+Adams, et al. Standards Track [Page 54]
+
+RFC 4210 CMP September 2005
+
+
+ o the algorithms and algorithm parameters that the certifying CA
+ supports for each relevant usage
+
+ Additional information could be required (e.g., supported extensions
+ or CA policy information) in order to produce a certification request
+ that will be successful. However, for simplicity we do not mandate
+ that the end entity acquires this information via the PKI messages.
+ The end result is simply that some certification requests may fail
+ (e.g., if the end entity wants to generate its own encryption key,
+ but the CA doesn't allow that).
+
+ The required information MAY be acquired as described in Section 6.5.
+
+6.7.2. Out-of-Band Verification of Root-CA Key
+
+ An end entity must securely possess the public key of its root CA.
+ One method to achieve this is to provide the end entity with the CA's
+ self-certificate fingerprint via some secure "out-of-band" means.
+ The end entity can then securely use the CA's self-certificate.
+
+ See Section 6.1 for further details.
+
+6.8. Certificate Request
+
+ An initialized end entity MAY request an additional certificate at
+ any time (for any purpose). This request will be made using the
+ certification request (cr) message. If the end entity already
+ possesses a signing key pair (with a corresponding verification
+ certificate), then this cr message will typically be protected by the
+ entity's digital signature. The CA returns the new certificate (if
+ the request is successful) in a CertRepMessage.
+
+6.9. Key Update
+
+ When a key pair is due to expire, the relevant end entity MAY request
+ a key update; that is, it MAY request that the CA issue a new
+ certificate for a new key pair (or, in certain circumstances, a new
+ certificate for the same key pair). The request is made using a key
+ update request (kur) message (referred to, in some environments, as a
+ "Certificate Update" operation). If the end entity already possesses
+ a signing key pair (with a corresponding verification certificate),
+ then this message will typically be protected by the entity's digital
+ signature. The CA returns the new certificate (if the request is
+ successful) in a key update response (kup) message, which is
+ syntactically identical to a CertRepMessage.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 55]
+
+RFC 4210 CMP September 2005
+
+
+7. Version Negotiation
+
+ This section defines the version negotiation used to support older
+ protocols between client and servers.
+
+ If a client knows the protocol version(s) supported by the server
+ (e.g., from a previous PKIMessage exchange or via some out-of-band
+ means), then it MUST send a PKIMessage with the highest version
+ supported by both it and the server. If a client does not know what
+ version(s) the server supports, then it MUST send a PKIMessage using
+ the highest version it supports.
+
+ If a server receives a message with a version that it supports, then
+ the version of the response message MUST be the same as the received
+ version. If a server receives a message with a version higher or
+ lower than it supports, then it MUST send back an ErrorMsg with the
+ unsupportedVersion bit set (in the failureInfo field of the
+ pKIStatusInfo). If the received version is higher than the highest
+ supported version, then the version in the error message MUST be the
+ highest version the server supports; if the received version is lower
+ than the lowest supported version then the version in the error
+ message MUST be the lowest version the server supports.
+
+ If a client gets back an ErrorMsgContent with the unsupportedVersion
+ bit set and a version it supports, then it MAY retry the request with
+ that version.
+
+7.1. Supporting RFC 2510 Implementations
+
+ RFC 2510 did not specify the behaviour of implementations receiving
+ versions they did not understand since there was only one version in
+ existence. With the introduction of the present revision of the
+ specification, the following versioning behaviour is recommended.
+
+7.1.1. Clients Talking to RFC 2510 Servers
+
+ If, after sending a cmp2000 message, a client receives an
+ ErrorMsgContent with a version of cmp1999, then it MUST abort the
+ current transaction. It MAY subsequently retry the transaction using
+ version cmp1999 messages.
+
+ If a client receives a non-error PKIMessage with a version of
+ cmp1999, then it MAY decide to continue the transaction (if the
+ transaction hasn't finished) using RFC 2510 semantics. If it does
+ not choose to do so and the transaction is not finished, then it MUST
+ abort the transaction and send an ErrorMsgContent with a version of
+ cmp1999.
+
+
+
+
+Adams, et al. Standards Track [Page 56]
+
+RFC 4210 CMP September 2005
+
+
+7.1.2. Servers Receiving Version cmp1999 PKIMessages
+
+ If a server receives a version cmp1999 message it MAY revert to RFC
+ 2510 behaviour and respond with version cmp1999 messages. If it does
+ not choose to do so, then it MUST send back an ErrorMsgContent as
+ described above in Section 7.
+
+8. Security Considerations
+
+8.1. Proof-Of-Possession with a Decryption Key
+
+ Some cryptographic considerations are worth explicitly spelling out.
+ In the protocols specified above, when an end entity is required to
+ prove possession of a decryption key, it is effectively challenged to
+ decrypt something (its own certificate). This scheme (and many
+ others!) could be vulnerable to an attack if the possessor of the
+ decryption key in question could be fooled into decrypting an
+ arbitrary challenge and returning the cleartext to an attacker.
+ Although in this specification a number of other failures in security
+ are required in order for this attack to succeed, it is conceivable
+ that some future services (e.g., notary, trusted time) could
+ potentially be vulnerable to such attacks. For this reason, we re-
+ iterate the general rule that implementations should be very careful
+ about decrypting arbitrary "ciphertext" and revealing recovered
+ "plaintext" since such a practice can lead to serious security
+ vulnerabilities.
+
+8.2. Proof-Of-Possession by Exposing the Private Key
+
+ Note also that exposing a private key to the CA/RA as a proof-of-
+ possession technique can carry some security risks (depending upon
+ whether or not the CA/RA can be trusted to handle such material
+ appropriately). Implementers are advised to:
+
+ Exercise caution in selecting and using this particular POP
+ mechanism
+
+ When appropriate, have the user of the application explicitly
+ state that they are willing to trust the CA/RA to have a copy of
+ their private key before proceeding to reveal the private key.
+
+8.3. Attack Against Diffie-Hellman Key Exchange
+
+ A small subgroup attack during a Diffie-Hellman key exchange may be
+ carried out as follows. A malicious end entity may deliberately
+ choose D-H parameters that enable him/her to derive (a significant
+ number of bits of) the D-H private key of the CA during a key
+ archival or key recovery operation. Armed with this knowledge, the
+
+
+
+Adams, et al. Standards Track [Page 57]
+
+RFC 4210 CMP September 2005
+
+
+ EE would then be able to retrieve the decryption private key of
+ another unsuspecting end entity, EE2, during EE2's legitimate key
+ archival or key recovery operation with that CA. In order to avoid
+ the possibility of such an attack, two courses of action are
+ available. (1) The CA may generate a fresh D-H key pair to be used
+ as a protocol encryption key pair for each EE with which it
+
+ interacts. (2) The CA may enter into a key validation protocol (not
+ specified in this document) with each requesting end entity to ensure
+ that the EE's protocol encryption key pair will not facilitate this
+ attack. Option (1) is clearly simpler (requiring no extra protocol
+ exchanges from either party) and is therefore RECOMMENDED.
+
+9. IANA Considerations
+
+ The PKI General Message types are identified by object identifiers
+ (OIDs). The OIDs for the PKI General Message types defined in this
+ document were assigned from an arc delegated by the IANA to the PKIX
+ Working Group.
+
+ The cryptographic algorithms referred to in this document are
+ identified by object identifiers (OIDs). The OIDs for cryptographic
+ algorithms were assigned from several arcs owned by various
+ organizations, including RSA Security, Entrust Technologies, IANA and
+ IETF.
+
+ Should additional encryption algorithms be introduced, the advocates
+ for such algorithms are expected to assign the necessary OIDs from
+ their own arcs.
+
+ No further action by the IANA is necessary for this document or any
+ anticipated updates.
+
+Normative References
+
+ [X509] International Organization for Standardization and
+ International Telecommunications Union, "Information
+ technology - Open Systems Interconnection - The
+ Directory: Public-key and attribute certificate
+ frameworks", ISO Standard 9594-8:2001, ITU-T
+ Recommendation X.509, March 2000.
+
+ [MvOV97] Menezes, A., van Oorschot, P. and S. Vanstone, "Handbook
+ of Applied Cryptography", CRC Press ISBN 0-8493-8523-7,
+ 1996.
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 58]
+
+RFC 4210 CMP September 2005
+
+
+ [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC:
+ Keyed-Hashing for Message Authentication", RFC 2104,
+ February 1997.
+
+ [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
+ Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+ [RFC2202] Cheng, P. and R. Glenn, "Test Cases for HMAC-MD5 and
+ HMAC-SHA-1", RFC 2202, September 1997.
+
+ [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
+ 10646", STD 63, RFC 3629, November 2003.
+
+ [RFC2482] Whistler, K. and G. Adams, "Language Tagging in Unicode
+ Plain Text", RFC 2482, January 1999.
+
+ [CRMF] Schaad, J., "Internet X.509 Public Key Infrastructure
+ Certificate Request Message Format (CRMF)", RFC 4211,
+ September 2005.
+
+ [RFC3066] Alvestrand, H., "Tags for the Identification of
+ Languages", BCP 47, RFC 3066, January 2001.
+
+Informative References
+
+ [CMPtrans] Kapoor, A., Tschalar, R. and T. Kause, "Internet X.509
+ Public Key Infrastructure -- Transport Protocols for
+ CMP", Work in Progress. 2004.
+
+ [PKCS7] RSA Laboratories, "The Public-Key Cryptography Standards
+ - Cryptographic Message Syntax Standard. Version 1.5",
+ PKCS 7, November 1993.
+
+ [PKCS10] Nystrom, M., and B. Kaliski, "The Public-Key
+ Cryptography Standards - Certification Request Syntax
+ Standard, Version 1.7", RFC 2986, May 2000.
+
+ [PKCS11] RSA Laboratories, "The Public-Key Cryptography Standards
+ - Cryptographic Token Interface Standard. Version
+ 2.10", PKCS 11, December 1999.
+
+ [RFC1847] Galvin, J., Murphy, S., Crocker, S., and N. Freed,
+ "Security Multiparts for MIME: Multipart/Signed and
+ Multipart/Encrypted", RFC 1847, October 1995.
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 59]
+
+RFC 4210 CMP September 2005
+
+
+ [RFC2559] Boeyen, S., Howes, T. and P. Richard, "Internet X.509
+ Public Key Infrastructure Operational Protocols -
+ LDAPv2", RFC 2559, April 1999.
+
+ [RFC2585] Housley, R. and P. Hoffman, "Internet X.509 Public Key
+ Infrastructure Operational Protocols: FTP and HTTP", RFC
+ 2585, May 1999.
+
+ [FIPS-180] National Institute of Standards and Technology, "Secure
+ Hash Standard", FIPS PUB 180-1, May 1994.
+
+ [FIPS-186] National Institute of Standards and Technology, "Digital
+ Signature Standard", FIPS PUB 186, May 1994.
+
+ [ANSI-X9.42] American National Standards Institute, "Public Key
+ Cryptography for The Financial Services Industry:
+ Agreement of Symmetric Keys Using Discrete Logarithm
+ Cryptography", ANSI X9.42, February 2000.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 60]
+
+RFC 4210 CMP September 2005
+
+
+Appendix A. Reasons for the Presence of RAs
+
+ The reasons that justify the presence of an RA can be split into
+ those that are due to technical factors and those which are
+ organizational in nature. Technical reasons include the following.
+
+ o If hardware tokens are in use, then not all end entities will have
+ the equipment needed to initialize these; the RA equipment can
+ include the necessary functionality (this may also be a matter of
+ policy).
+
+ o Some end entities may not have the capability to publish
+ certificates; again, the RA may be suitably placed for this.
+
+ o The RA will be able to issue signed revocation requests on behalf
+ of end entities associated with it, whereas the end entity may not
+ be able to do this (if the key pair is completely lost).
+
+ Some of the organizational reasons that argue for the presence of an
+ RA are the following.
+
+ o It may be more cost effective to concentrate functionality in the
+ RA equipment than to supply functionality to all end entities
+ (especially if special token initialization equipment is to be
+ used).
+
+ o Establishing RAs within an organization can reduce the number of
+ CAs required, which is sometimes desirable.
+
+ o RAs may be better placed to identify people with their
+ "electronic" names, especially if the CA is physically remote from
+ the end entity.
+
+ o For many applications, there will already be in place some
+ administrative structure so that candidates for the role of RA are
+ easy to find (which may not be true of the CA).
+
+Appendix B. The Use of Revocation Passphrase
+
+ A revocation request must incorporate suitable security mechanisms,
+ including proper authentication, in order to reduce the probability
+ of successful denial-of-service attacks. A digital signature on the
+ request -- MANDATORY to support within this specification if
+ revocation requests are supported -- can provide the authentication
+ required, but there are circumstances under which an alternative
+ mechanism may be desirable (e.g., when the private key is no longer
+ accessible and the entity wishes to request a revocation prior to
+ re-certification of another key pair). In order to accommodate such
+
+
+
+Adams, et al. Standards Track [Page 61]
+
+RFC 4210 CMP September 2005
+
+
+ circumstances, a PasswordBasedMAC on the request is also MANDATORY to
+ support within this specification (subject to local security policy
+ for a given environment) if revocation requests are supported and if
+ shared secret information can be established between the requester
+ and the responder prior to the need for revocation.
+
+ A mechanism that has seen use in some environments is "revocation
+ passphrase", in which a value of sufficient entropy (i.e., a
+ relatively long passphrase rather than a short password) is shared
+ between (only) the entity and the CA/RA at some point prior to
+ revocation; this value is later used to authenticate the revocation
+ request.
+
+ In this specification, the following technique to establish shared
+ secret information (i.e., a revocation passphrase) is OPTIONAL to
+ support. Its precise use in CMP messages is as follows.
+
+ o The OID and value specified in Section 5.3.19.9 MAY be sent in a
+ GenMsg message at any time, or MAY be sent in the generalInfo
+ field of the PKIHeader of any PKIMessage at any time. (In
+ particular, the EncryptedValue may be sent in the header of the
+ certConf message that confirms acceptance of certificates
+ requested in an initialization request or certificate request
+ message.) This conveys a revocation passphrase chosen by the
+ entity (i.e., the decrypted bytes of the encValue field) to the
+ relevant CA/RA; furthermore, the transfer is accomplished with
+ appropriate confidentiality characteristics (because the
+ passphrase is encrypted under the CA/RA's protocolEncryptionKey).
+
+ o If a CA/RA receives the revocation passphrase (OID and value
+ specified in Section 5.3.19.9) in a GenMsg, it MUST construct and
+ send a GenRep message that includes the OID (with absent value)
+ specified in Section 5.3.19.9. If the CA/RA receives the
+ revocation passphrase in the generalInfo field of a PKIHeader of
+ any PKIMessage, it MUST include the OID (with absent value) in the
+ generalInfo field of the PKIHeader of the corresponding response
+ PKIMessage. If the CA/RA is unable to return the appropriate
+ response message for any reason, it MUST send an error message
+ with a status of "rejection" and, optionally, a failInfo reason
+ set.
+
+ o The valueHint field of EncryptedValue MAY contain a key identifier
+ (chosen by the entity, along with the passphrase itself) to assist
+ in later retrieval of the correct passphrase (e.g., when the
+ revocation request is constructed by the entity and received by
+ the CA/RA).
+
+
+
+
+
+Adams, et al. Standards Track [Page 62]
+
+RFC 4210 CMP September 2005
+
+
+ o The revocation request message is protected by a PasswordBasedMAC,
+ with the revocation passphrase as the key. If appropriate, the
+ senderKID field in the PKIHeader MAY contain the value previously
+ transmitted in valueHint.
+
+ Using the technique specified above, the revocation passphrase may be
+ initially established and updated at any time without requiring extra
+ messages or out-of-band exchanges. For example, the revocation
+ request message itself (protected and authenticated through a MAC
+ that uses the revocation passphrase as a key) may contain, in the
+ PKIHeader, a new revocation passphrase to be used for authenticating
+ future revocation requests for any of the entity's other
+ certificates. In some environments this may be preferable to
+ mechanisms that reveal the passphrase in the revocation request
+ message, since this can allow a denial-of-service attack in which the
+ revealed passphrase is used by an unauthorized third party to
+ authenticate revocation requests on the entity's other certificates.
+ However, because the passphrase is not revealed in the request
+ message, there is no requirement that the passphrase must always be
+ updated when a revocation request is made (that is, the same
+ passphrase MAY be used by an entity to authenticate revocation
+ requests for different certificates at different times).
+
+ Furthermore, the above technique can provide strong cryptographic
+ protection over the entire revocation request message even when a
+ digital signature is not used. Techniques that do authentication of
+ the revocation request by simply revealing the revocation passphrase
+ typically do not provide cryptographic protection over the fields of
+ the request message (so that a request for revocation of one
+ certificate may be modified by an unauthorized third party to a
+ request for revocation of another certificate for that entity).
+
+Appendix C. Request Message Behavioral Clarifications
+
+ In the case of updates to [CRMF], which cause interpretation or
+ interoperability issues, [CRMF] SHALL be the normative document.
+
+ The following definitions are from [CRMF]. They are included here in
+ order to codify behavioral clarifications to that request message;
+ otherwise, all syntax and semantics are identical to [CRMF].
+
+ CertRequest ::= SEQUENCE {
+ certReqId INTEGER,
+ certTemplate CertTemplate,
+ controls Controls OPTIONAL }
+
+ -- If certTemplate is an empty SEQUENCE (i.e., all fields
+ -- omitted), then controls MAY contain the
+
+
+
+Adams, et al. Standards Track [Page 63]
+
+RFC 4210 CMP September 2005
+
+
+ -- id-regCtrl-altCertTemplate control, specifying a template
+ -- for a certificate other than an X.509v3 public-key
+ -- certificate. Conversely, if certTemplate is not empty
+ -- (i.e., at least one field is present), then controls MUST
+ -- NOT contain id-regCtrl- altCertTemplate. The new control is
+ -- defined as follows:
+
+ id-regCtrl-altCertTemplate OBJECT IDENTIFIER ::= {id-regCtrl 7}
+ AltCertTemplate ::= AttributeTypeAndValue
+
+ POPOSigningKey ::= SEQUENCE {
+ poposkInput [0] POPOSigningKeyInput OPTIONAL,
+ algorithmIdentifier AlgorithmIdentifier,
+ signature BIT STRING }
+
+ -- **********
+ -- * For the purposes of this specification, the ASN.1 comment
+ -- * given in [CRMF] pertains not only to certTemplate, but
+ -- * also to the altCertTemplate control. That is,
+ -- **********
+ -- * The signature (using "algorithmIdentifier") is on the
+ -- * DER-encoded value of poposkInput (i.e., the "value" OCTETs
+ -- * of the POPOSigningKeyInput DER). NOTE: If CertReqMsg
+ -- * certReq certTemplate (or the altCertTemplate control)
+ -- * contains the subject and publicKey values, then poposkInput
+ -- * MUST be omitted and the signature MUST be computed on the
+ -- * DER-encoded value of CertReqMsg certReq (or the DER-
+ -- * encoded value of AltCertTemplate). If
+ -- * certTemplate/altCertTemplate does not contain both the
+ -- * subject and public key values (i.e., if it contains only
+ -- * one of these, or neither), then poposkInput MUST be present
+ -- * and MUST be signed.
+ -- **********
+
+ POPOPrivKey ::= CHOICE {
+ thisMessage [0] BIT STRING,
+
+ -- **********
+ -- * the type of "thisMessage" is given as BIT STRING in
+ -- * [CRMF]; it should be "EncryptedValue" (in accordance
+ -- * with Section 5.2.2, "Encrypted Values", of this specification).
+ -- * Therefore, this document makes the behavioral clarification
+ -- * of specifying that the contents of "thisMessage" MUST be encoded
+ -- * as an EncryptedValue and then wrapped in a BIT STRING. This
+ -- * allows the necessary conveyance and protection of the
+ -- * private key while maintaining bits-on-the-wire compatibility
+ -- * with [CRMF].
+ -- **********
+
+
+
+Adams, et al. Standards Track [Page 64]
+
+RFC 4210 CMP September 2005
+
+
+ subsequentMessage [1] SubsequentMessage,
+ dhMAC [2] BIT STRING }
+
+Appendix D. PKI Management Message Profiles (REQUIRED).
+
+ This appendix contains detailed profiles for those PKIMessages that
+ MUST be supported by conforming implementations (see Section 6).
+
+ Profiles for the PKIMessages used in the following PKI management
+ operations are provided:
+
+ o initial registration/certification
+
+ o basic authenticated scheme
+
+ o certificate request
+
+ o key update
+
+D.1. General Rules for Interpretation of These Profiles.
+
+ 1. Where OPTIONAL or DEFAULT fields are not mentioned in individual
+ profiles, they SHOULD be absent from the relevant message (i.e.,
+ a receiver can validly reject a message containing such fields as
+ being syntactically incorrect). Mandatory fields are not
+ mentioned if they have an obvious value (e.g., in this version of
+ the specification, pvno is always 2).
+
+ 2. Where structures occur in more than one message, they are
+ separately profiled as appropriate.
+
+ 3. The algorithmIdentifiers from PKIMessage structures are profiled
+ separately.
+
+ 4. A "special" X.500 DN is called the "NULL-DN"; this means a DN
+ containing a zero-length SEQUENCE OF RelativeDistinguishedNames
+ (its DER encoding is then '3000'H).
+
+ 5. Where a GeneralName is required for a field, but no suitable
+ value is available (e.g., an end entity produces a request before
+ knowing its name), then the GeneralName is to be an X.500 NULL-DN
+ (i.e., the Name field of the CHOICE is to contain a NULL-DN).
+ This special value can be called a "NULL-GeneralName".
+
+ 6. Where a profile omits to specify the value for a GeneralName,
+ then the NULL-GeneralName value is to be present in the relevant
+ PKIMessage field. This occurs with the sender field of the
+ PKIHeader for some messages.
+
+
+
+Adams, et al. Standards Track [Page 65]
+
+RFC 4210 CMP September 2005
+
+
+ 7. Where any ambiguity arises due to naming of fields, the profile
+ names these using a "dot" notation (e.g., "certTemplate.subject"
+ means the subject field within a field called certTemplate).
+
+ 8. Where a "SEQUENCE OF types" is part of a message, a zero-based
+ array notation is used to describe fields within the SEQUENCE OF
+ (e.g., crm[0].certReq.certTemplate.subject refers to a subfield
+ of the first CertReqMsg contained in a request message).
+
+ 9. All PKI message exchanges in Appendix D.4 to D.6 require a
+ certConf message to be sent by the initiating entity and a
+ PKIConfirm to be sent by the responding entity. The PKIConfirm
+ is not included in some of the profiles given since its body is
+ NULL and its header contents are clear from the context. Any
+ authenticated means can be used for the protectionAlg (e.g.,
+ password-based MAC, if shared secret information is known, or
+ signature).
+
+D.2. Algorithm Use Profile
+
+ The following table contains definitions of algorithm uses within PKI
+ management protocols. The columns in the table are:
+
+ Name: an identifier used for message profiles
+
+ Use: description of where and for what the algorithm is used
+
+ Mandatory: an AlgorithmIdentifier which MUST be supported by
+ conforming implementations
+
+ Others: alternatives to the mandatory AlgorithmIdentifier
+
+ Name Use Mandatory Others
+
+ MSG_SIG_ALG Protection of PKI DSA/SHA-1 RSA/MD5,
+ messages using signature ECDSA, ...
+ MSG_MAC_ALG protection of PKI PasswordBasedMac HMAC,
+ messages using MACing X9.9...
+ SYM_PENC_ALG symmetric encryption of 3-DES (3-key- AES,RC5,
+ an end entity's private EDE, CBC mode) CAST-128...
+ key where symmetric
+ key is distributed
+ out-of-band
+ PROT_ENC_ALG asymmetric algorithm D-H RSA,
+ used for encryption of ECDH, ...
+ (symmetric keys for
+ encryption of) private
+ keys transported in
+
+
+
+Adams, et al. Standards Track [Page 66]
+
+RFC 4210 CMP September 2005
+
+
+ PKIMessages
+ PROT_SYM_ALG symmetric encryption 3-DES (3-key- AES,RC5,
+ algorithm used for EDE, CBC mode) CAST-128...
+ encryption of private
+ key bits (a key of this
+ type is encrypted using
+ PROT_ENC_ALG)
+
+ Mandatory AlgorithmIdentifiers and Specifications:
+
+ DSA/SHA-1:
+ AlgId: {1 2 840 10040 4 3};
+
+ Digital Signature Standard [FIPS-186]
+
+ Public Modulus size: 1024 bits.
+
+ PasswordBasedMac:
+
+ AlgId: {1 2 840 113533 7 66 13}, with SHA-1 {1 3 14 3 2 26} as the
+ owf parameter and HMAC-SHA1 {1 3 6 1 5 5 8 1 2} as the mac
+ parameter;
+
+ (this specification), along with
+
+ Secure Hash Standard [FIPS-180] and [RFC2104]
+
+ HMAC key size: 160 bits (i.e., "K" = "H" in Section 5.1.3.1,
+ "Shared secret information")
+
+ 3-DES:
+
+ AlgId: {1 2 840 113549 3 7};
+ (used in RSA's BSAFE and in S/MIME).
+
+ D-H:
+
+ AlgId: {1 2 840 10046 2 1};
+
+ [ANSI-X9.42]
+
+ Public Modulus Size: 1024 bits.
+ DomainParameters ::= SEQUENCE {
+ p INTEGER, -- odd prime, p=jq +1
+ g INTEGER, -- generator, g^q = 1 mod p
+ q INTEGER, -- prime factor of p-1
+ j INTEGER OPTIONAL, -- cofactor, j>=2
+ validationParms ValidationParms OPTIONAL
+
+
+
+Adams, et al. Standards Track [Page 67]
+
+RFC 4210 CMP September 2005
+
+
+ }
+ ValidationParms ::= SEQUENCE {
+ seed BIT STRING, -- seed for prime generation
+ pGenCounter INTEGER -- parameter verification
+ }
+
+D.3. Proof-of-Possession Profile
+
+ POP fields for use (in signature field of pop field of
+ ProofOfPossession structure) when proving possession of a private
+ signing key that corresponds to a public verification key for which a
+ certificate has been requested.
+
+ Field Value Comment
+
+ algorithmIdentifier MSG_SIG_ALG only signature protection is
+ allowed for this proof
+
+ signature present bits calculated using MSG_SIG_ALG
+
+ Proof-of-possession of a private decryption key that corresponds to a
+ public encryption key for which a certificate has been requested does
+ not use this profile; the CertHash field of the certConf message is
+ used instead.
+
+ Not every CA/RA will do Proof-of-Possession (of signing key,
+ decryption key, or key agreement key) in the PKIX-CMP in-band
+ certification request protocol (how POP is done MAY ultimately be a
+ policy issue that is made explicit for any given CA in its publicized
+ Policy OID and Certification Practice Statement). However, this
+ specification MANDATES that CA/RA entities MUST do POP (by some
+ means) as part of the certification process. All end entities MUST
+ be prepared to provide POP (i.e., these components of the PKIX-CMP
+ protocol MUST be supported).
+
+D.4. Initial Registration/Certification (Basic Authenticated Scheme)
+
+ An (uninitialized) end entity requests a (first) certificate from a
+ CA. When the CA responds with a message containing a certificate,
+ the end entity replies with a certificate confirmation. The CA sends
+ a PKIConfirm back, closing the transaction. All messages are
+ authenticated.
+
+ This scheme allows the end entity to request certification of a
+ locally-generated public key (typically a signature key). The end
+ entity MAY also choose to request the centralized generation and
+ certification of another key pair (typically an encryption key pair).
+
+
+
+
+Adams, et al. Standards Track [Page 68]
+
+RFC 4210 CMP September 2005
+
+
+ Certification may only be requested for one locally generated public
+ key (for more, use separate PKIMessages).
+
+ The end entity MUST support proof-of-possession of the private key
+ associated with the locally-generated public key.
+
+ Preconditions:
+
+ 1. The end entity can authenticate the CA's signature based on out-
+ of-band means
+
+ 2. The end entity and the CA share a symmetric MACing key
+
+ Message flow:
+
+ Step# End entity PKI
+ 1 format ir
+ 2 -> ir ->
+ 3 handle ir
+ 4 format ip
+ 5 <- ip <-
+ 6 handle ip
+ 7 format certConf
+ 8 -> certConf ->
+ 9 handle certConf
+ 10 format PKIConf
+ 11 <- PKIConf <-
+ 12 handle PKIConf
+
+ For this profile, we mandate that the end entity MUST include all
+ (i.e., one or two) CertReqMsg in a single PKIMessage, and that the
+ PKI (CA) MUST produce a single response PKIMessage that contains the
+ complete response (i.e., including the OPTIONAL second key pair, if
+ it was requested and if centralized key generation is supported).
+ For simplicity, we also mandate that this message MUST be the final
+ one (i.e., no use of "waiting" status value).
+
+ The end entity has an out-of-band interaction with the CA/RA. This
+ transaction established the shared secret, the referenceNumber and
+ OPTIONALLY the distinguished name used for both sender and subject
+ name in the certificate template. It is RECOMMENDED that the shared
+ secret be at least 12 characters long.
+
+ Initialization Request -- ir
+
+ Field Value
+
+ recipient CA name
+
+
+
+Adams, et al. Standards Track [Page 69]
+
+RFC 4210 CMP September 2005
+
+
+ -- the name of the CA who is being asked to produce a certificate
+ protectionAlg MSG_MAC_ALG
+ -- only MAC protection is allowed for this request, based
+ -- on initial authentication key
+ senderKID referenceNum
+ -- the reference number which the CA has previously issued
+ -- to the end entity (together with the MACing key)
+ transactionID present
+ -- implementation-specific value, meaningful to end
+ -- entity.
+ -- [If already in use at the CA, then a rejection message MUST
+ -- be produced by the CA]
+
+ senderNonce present
+ -- 128 (pseudo-)random bits
+ freeText any valid value
+ body ir (CertReqMessages)
+ only one or two CertReqMsg
+ are allowed
+ -- if more certificates are required, requests MUST be
+ -- packaged in separate PKIMessages
+
+ CertReqMsg one or two present
+ -- see below for details, note: crm[0] means the first
+ -- (which MUST be present), crm[1] means the second (which
+ -- is OPTIONAL, and used to ask for a centrally-generated key)
+
+ crm[0].certReq. fixed value of zero
+ certReqId
+ -- this is the index of the template within the message
+ crm[0].certReq present
+ certTemplate
+ -- MUST include subject public key value, otherwise unconstrained
+ crm[0].pop... optionally present if public key
+ POPOSigningKey from crm[0].certReq.certTemplate is
+ a signing key
+ -- proof-of-possession MAY be required in this exchange
+ -- (see Appendix D.3 for details)
+ crm[0].certReq. optionally present
+ controls.archiveOptions
+ -- the end entity MAY request that the locally-generated
+ -- private key be archived
+
+ crm[0].certReq. optionally present
+ controls.publicationInfo
+ -- the end entity MAY ask for publication of resulting cert.
+
+ crm[1].certReq fixed value of one
+
+
+
+Adams, et al. Standards Track [Page 70]
+
+RFC 4210 CMP September 2005
+
+
+ certReqId
+ -- the index of the template within the message
+ crm[1].certReq present
+ certTemplate
+ -- MUST NOT include actual public key bits, otherwise
+ -- unconstrained (e.g., the names need not be the same as in
+ -- crm[0]). Note that subjectPublicKeyInfo MAY be present
+ -- and contain an AlgorithmIdentifier followed by a
+ -- zero-length BIT STRING for the subjectPublicKey if it is
+ -- desired to inform the CA/RA of algorithm and parameter
+ -- preferences regarding the to-be-generated key pair.
+
+ crm[1].certReq. present [object identifier MUST be PROT_ENC_ALG]
+
+ controls.protocolEncrKey
+ -- if centralized key generation is supported by this CA,
+ -- this short-term asymmetric encryption key (generated by
+ -- the end entity) will be used by the CA to encrypt (a
+ -- symmetric key used to encrypt) a private key generated by
+ -- the CA on behalf of the end entity
+
+ crm[1].certReq. optionally present
+ controls.archiveOptions
+ crm[1].certReq. optionally present
+ controls.publicationInfo
+ protection present
+ -- bits calculated using MSG_MAC_ALG
+
+ Initialization Response -- ip
+
+ Field Value
+
+ sender CA name
+ -- the name of the CA who produced the message
+ messageTime present
+ -- time at which CA produced message
+ protectionAlg MS_MAC_ALG
+ -- only MAC protection is allowed for this response
+ senderKID referenceNum
+ -- the reference number that the CA has previously issued to the
+ -- end entity (together with the MACing key)
+ transactionID present
+ -- value from corresponding ir message
+ senderNonce present
+ -- 128 (pseudo-)random bits
+ recipNonce present
+ -- value from senderNonce in corresponding ir message
+ freeText any valid value
+
+
+
+Adams, et al. Standards Track [Page 71]
+
+RFC 4210 CMP September 2005
+
+
+ body ip (CertRepMessage)
+ contains exactly one response
+ for each request
+
+ -- The PKI (CA) responds to either one or two requests as
+ -- appropriate. crc[0] denotes the first (always present);
+ -- crc[1] denotes the second (only present if the ir message
+ -- contained two requests and if the CA supports centralized
+ -- key generation).
+ crc[0]. fixed value of zero
+ certReqId
+ -- MUST contain the response to the first request in the
+ -- corresponding ir message
+
+ crc[0].status. present, positive values allowed:
+ status "accepted", "grantedWithMods"
+ negative values allowed:
+ "rejection"
+ crc[0].status. present if and only if
+ failInfo crc[0].status.status is "rejection"
+ crc[0]. present if and only if
+ certifiedKeyPair crc[0].status.status is
+ "accepted" or "grantedWithMods"
+ certificate present unless end entity's public
+ key is an encryption key and POP
+ is done in this in-band exchange
+ encryptedCert present if and only if end entity's
+ public key is an encryption key and
+ POP done in this in-band exchange
+ publicationInfo optionally present
+
+ -- indicates where certificate has been published (present
+ -- at discretion of CA)
+
+ crc[1]. fixed value of one
+ certReqId
+ -- MUST contain the response to the second request in the
+ -- corresponding ir message
+ crc[1].status. present, positive values allowed:
+ status "accepted", "grantedWithMods"
+ negative values allowed:
+ "rejection"
+ crc[1].status. present if and only if
+ failInfo crc[0].status.status is "rejection"
+ crc[1]. present if and only if
+ certifiedKeyPair crc[0].status.status is "accepted"
+ or "grantedWithMods"
+ certificate present
+
+
+
+Adams, et al. Standards Track [Page 72]
+
+RFC 4210 CMP September 2005
+
+
+ privateKey present
+ -- see Appendix C, Request Message Behavioral Clarifications
+ publicationInfo optionally present
+ -- indicates where certificate has been published (present
+ -- at discretion of CA)
+
+ protection present
+ -- bits calculated using MSG_MAC_ALG
+ extraCerts optionally present
+ -- the CA MAY provide additional certificates to the end
+ -- entity
+
+ Certificate confirm; certConf
+
+ Field Value
+
+ sender present
+ -- same as in ir
+ recipient CA name
+ -- the name of the CA who was asked to produce a certificate
+ transactionID present
+ -- value from corresponding ir and ip messages
+ senderNonce present
+ -- 128 (pseudo-) random bits
+ recipNonce present
+ -- value from senderNonce in corresponding ip message
+ protectionAlg MSG_MAC_ALG
+ -- only MAC protection is allowed for this message. The
+ -- MAC is based on the initial authentication key shared
+ -- between the EE and the CA.
+
+ senderKID referenceNum
+ -- the reference number which the CA has previously issued
+ -- to the end entity (together with the MACing key)
+
+ body certConf
+ -- see Section 5.3.18, "PKI Confirmation Content", for the
+ -- contents of the certConf fields.
+ -- Note: two CertStatus structures are required if both an
+ -- encryption and a signing certificate were sent.
+
+ protection present
+ -- bits calculated using MSG_MAC_ALG
+
+ Confirmation; PKIConf
+
+ Field Value
+
+
+
+
+Adams, et al. Standards Track [Page 73]
+
+RFC 4210 CMP September 2005
+
+
+ sender present
+ -- same as in ip
+ recipient present
+ -- sender name from certConf
+ transactionID present
+ -- value from certConf message
+ senderNonce present
+ -- 128 (pseudo-) random bits
+ recipNonce present
+ -- value from senderNonce from certConf message
+ protectionAlg MSG_MAC_ALG
+ -- only MAC protection is allowed for this message.
+ senderKID referenceNum
+ body PKIConf
+ protection present
+ -- bits calculated using MSG_MAC_ALG
+
+D.5. Certificate Request
+
+ An (initialized) end entity requests a certificate from a CA (for any
+ reason). When the CA responds with a message containing a
+ certificate, the end entity replies with a certificate confirmation.
+ The CA replies with a PKIConfirm, to close the transaction. All
+ messages are authenticated.
+
+ The profile for this exchange is identical to that given in Appendix
+ D.4, with the following exceptions:
+
+ o sender name SHOULD be present
+
+ o protectionAlg of MSG_SIG_ALG MUST be supported (MSG_MAC_ALG MAY
+ also be supported) in request, response, certConfirm, and
+ PKIConfirm messages;
+
+ o senderKID and recipKID are only present if required for message
+ verification;
+
+ o body is cr or cp;
+
+ o body may contain one or two CertReqMsg structures, but either
+ CertReqMsg may be used to request certification of a locally-
+ generated public key or a centrally-generated public key (i.e.,
+ the position-dependence requirement of Appendix D.4 is removed);
+
+ o protection bits are calculated according to the protectionAlg
+ field.
+
+
+
+
+
+Adams, et al. Standards Track [Page 74]
+
+RFC 4210 CMP September 2005
+
+
+D.6. Key Update Request
+
+ An (initialized) end entity requests a certificate from a CA (to
+ update the key pair and/or corresponding certificate that it already
+ possesses). When the CA responds with a message containing a
+ certificate, the end entity replies with a certificate confirmation.
+ The CA replies with a PKIConfirm, to close the transaction. All
+ messages are authenticated.
+
+ The profile for this exchange is identical to that given in Appendix
+ D.4, with the following exceptions:
+
+ 1. sender name SHOULD be present
+
+ 2. protectionAlg of MSG_SIG_ALG MUST be supported (MSG_MAC_ALG MAY
+ also be supported) in request, response, certConfirm, and
+ PKIConfirm messages;
+
+ 3. senderKID and recipKID are only present if required for message
+ verification;
+
+ 4. body is kur or kup;
+
+ 5. body may contain one or two CertReqMsg structures, but either
+ CertReqMsg may be used to request certification of a locally-
+ generated public key or a centrally-generated public key (i.e.,
+ the position-dependence requirement of Appendix D.4 is removed);
+
+ 6. protection bits are calculated according to the protectionAlg
+ field;
+
+ 7. regCtrl OldCertId SHOULD be used (unless it is clear to both
+ sender and receiver -- by means not specified in this document --
+ that it is not needed).
+
+Appendix E. PKI Management Message Profiles (OPTIONAL).
+
+ This appendix contains detailed profiles for those PKIMessages that
+ MAY be supported by implementations (in addition to the messages
+ which MUST be supported; see Section 6 and Appendix D).
+
+ Profiles for the PKIMessages used in the following PKI management
+ operations are provided:
+
+ o root CA key update
+
+ o information request/response
+
+
+
+
+Adams, et al. Standards Track [Page 75]
+
+RFC 4210 CMP September 2005
+
+
+ o cross-certification request/response (1-way)
+
+ o in-band initialization using external identity certificate
+
+ Later versions of this document may extend the above to include
+ profiles for the operations listed below (along with other
+ operations, if desired).
+
+ o revocation request
+
+ o certificate publication
+
+ o CRL publication
+
+E.1. General Rules for Interpretation of These Profiles.
+
+ Identical to Appendix D.1.
+
+E.2. Algorithm Use Profile
+
+ Identical to Appendix D.2.
+
+E.3. Self-Signed Certificates
+
+ Profile of how a Certificate structure may be "self-signed". These
+ structures are used for distribution of CA public keys. This can
+ occur in one of three ways (see Section 4.4 above for a description
+ of the use of these structures):
+
+ Type Function
+ -----------------------------------------------------------------
+ newWithNew a true "self-signed" certificate; the contained
+ public key MUST be usable to verify the signature
+ (though this provides only integrity and no
+ authentication whatsoever)
+ oldWithNew previous root CA public key signed with new private key
+ newWithOld new root CA public key signed with previous private key
+
+ Such certificates (including relevant extensions) must contain
+ "sensible" values for all fields. For example, when present,
+ subjectAltName MUST be identical to issuerAltName, and, when present,
+ keyIdentifiers must contain appropriate values, et cetera.
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 76]
+
+RFC 4210 CMP September 2005
+
+
+E.4. Root CA Key Update
+
+ A root CA updates its key pair. It then produces a CA key update
+ announcement message that can be made available (via some transport
+ mechanism) to the relevant end entities. A confirmation message is
+ NOT REQUIRED from the end entities.
+
+ ckuann message:
+
+ Field Value Comment
+ --------------------------------------------------------------
+ sender CA name CA name
+ body ckuann(CAKeyUpdAnnContent)
+ oldWithNew present see Appendix E.3 above
+ newWithOld present see Appendix E.3 above
+ newWithNew present see Appendix E.3 above
+ extraCerts optionally present can be used to "publish"
+ certificates (e.g.,
+ certificates signed using
+ the new private key)
+
+E.5. PKI Information Request/Response
+
+ The end entity sends a general message to the PKI requesting details
+ that will be required for later PKI management operations. RA/CA
+ responds with a general response. If an RA generates the response,
+ then it will simply forward the equivalent message that it previously
+ received from the CA, with the possible addition of certificates to
+ the extraCerts fields of the PKIMessage. A confirmation message is
+ NOT REQUIRED from the end entity.
+
+ Message Flows:
+
+ Step# End entity PKI
+
+ 1 format genm
+ 2 -> genm ->
+ 3 handle genm
+ 4 produce genp
+ 5 <- genp <-
+ 6 handle genp
+
+ genM:
+
+ Field Value
+
+ recipient CA name
+ -- the name of the CA as contained in issuerAltName
+
+
+
+Adams, et al. Standards Track [Page 77]
+
+RFC 4210 CMP September 2005
+
+
+ -- extensions or issuer fields within certificates
+ protectionAlg MSG_MAC_ALG or MSG_SIG_ALG
+ -- any authenticated protection alg.
+ SenderKID present if required
+ -- must be present if required for verification of message
+ -- protection
+ freeText any valid value
+ body genr (GenReqContent)
+ GenMsgContent empty SEQUENCE
+ -- all relevant information requested
+ protection present
+ -- bits calculated using MSG_MAC_ALG or MSG_SIG_ALG
+
+ genP:
+
+ Field Value
+
+ sender CA name
+ -- name of the CA which produced the message
+ protectionAlg MSG_MAC_ALG or MSG_SIG_ALG
+ -- any authenticated protection alg.
+ senderKID present if required
+ -- must be present if required for verification of message
+ -- protection
+ body genp (GenRepContent)
+ CAProtEncCert present (object identifier one
+ of PROT_ENC_ALG), with relevant
+ value
+ -- to be used if end entity needs to encrypt information for
+ -- the CA (e.g., private key for recovery purposes)
+
+ SignKeyPairTypes present, with relevant value
+ -- the set of signature algorithm identifiers that this CA will
+ -- certify for subject public keys
+ EncKeyPairTypes present, with relevant value
+ -- the set of encryption/key agreement algorithm identifiers that
+ -- this CA will certify for subject public keys
+ PreferredSymmAlg present (object identifier one
+ of PROT_SYM_ALG) , with relevant
+ value
+ -- the symmetric algorithm that this CA expects to be used
+ -- in later PKI messages (for encryption)
+ CAKeyUpdateInfo optionally present, with
+ relevant value
+ -- the CA MAY provide information about a relevant root CA
+ -- key pair using this field (note that this does not imply
+ -- that the responding CA is the root CA in question)
+ CurrentCRL optionally present, with relevant value
+
+
+
+Adams, et al. Standards Track [Page 78]
+
+RFC 4210 CMP September 2005
+
+
+ -- the CA MAY provide a copy of a complete CRL (i.e.,
+ -- fullest possible one)
+ protection present
+ -- bits calculated using MSG_MAC_ALG or MSG_SIG_ALG
+ extraCerts optionally present
+ -- can be used to send some certificates to the end
+ -- entity. An RA MAY add its certificate here.
+
+E.6. Cross Certification Request/Response (1-way)
+
+ Creation of a single cross-certificate (i.e., not two at once). The
+ requesting CA MAY choose who is responsible for publication of the
+ cross-certificate created by the responding CA through use of the
+ PKIPublicationInfo control.
+
+ Preconditions:
+
+ 1. Responding CA can verify the origin of the request (possibly
+ requiring out-of-band means) before processing the request.
+
+ 2. Requesting CA can authenticate the authenticity of the origin of
+ the response (possibly requiring out-of-band means) before
+ processing the response
+
+ The use of certificate confirmation and the corresponding server
+ confirmation is determined by the generalInfo field in the PKIHeader
+ (see Section 5.1.1). The following profile does not mandate support
+ for either confirmation.
+
+ Message Flows:
+
+ Step# Requesting CA Responding CA
+ 1 format ccr
+ 2 -> ccr ->
+ 3 handle ccr
+ 4 produce ccp
+ 5 <- ccp <-
+ 6 handle ccp
+
+ ccr:
+
+ Field Value
+
+ sender Requesting CA name
+ -- the name of the CA who produced the message
+ recipient Responding CA name
+ -- the name of the CA who is being asked to produce a certificate
+ messageTime time of production of message
+
+
+
+Adams, et al. Standards Track [Page 79]
+
+RFC 4210 CMP September 2005
+
+
+ -- current time at requesting CA
+ protectionAlg MSG_SIG_ALG
+ -- only signature protection is allowed for this request
+ senderKID present if required
+ -- must be present if required for verification of message
+ -- protection
+ recipKID present if required
+ -- must be present if required for verification of message
+ -- protection
+ transactionID present
+ -- implementation-specific value, meaningful to requesting CA.
+ -- [If already in use at responding CA then a rejection message
+ -- MUST be produced by responding CA]
+ senderNonce present
+ -- 128 (pseudo-)random bits
+ freeText any valid value
+ body ccr (CertReqMessages)
+ only one CertReqMsg
+ allowed
+ -- if multiple cross certificates are required, they MUST be
+ -- packaged in separate PKIMessages
+ certTemplate present
+ -- details follow
+ version v1 or v3
+ -- v3 STRONGLY RECOMMENDED
+ signingAlg present
+ -- the requesting CA must know in advance with which algorithm it
+ -- wishes the certificate to be signed
+
+ subject present
+ -- may be NULL-DN only if subjectAltNames extension value proposed
+ validity present
+ -- MUST be completely specified (i.e., both fields present)
+ issuer present
+ -- may be NULL-DN only if issuerAltNames extension value proposed
+ publicKey present
+ -- the key to be certified (which must be for a signing algorithm)
+ extensions optionally present
+ -- a requesting CA must propose values for all extensions
+ -- that it requires to be in the cross-certificate
+ POPOSigningKey present
+ -- see Section D3: Proof-of-possession profile
+ protection present
+ -- bits calculated using MSG_SIG_ALG
+ extraCerts optionally present
+ -- MAY contain any additional certificates that requester wishes
+ -- to include
+
+
+
+
+Adams, et al. Standards Track [Page 80]
+
+RFC 4210 CMP September 2005
+
+
+ ccp:
+
+ Field Value
+
+ sender Responding CA name
+ -- the name of the CA who produced the message
+ recipient Requesting CA name
+ -- the name of the CA who asked for production of a certificate
+ messageTime time of production of message
+ -- current time at responding CA
+ protectionAlg MSG_SIG_ALG
+ -- only signature protection is allowed for this message
+ senderKID present if required
+ -- must be present if required for verification of message
+ -- protection
+ recipKID present if required
+ transactionID present
+ -- value from corresponding ccr message
+ senderNonce present
+ -- 128 (pseudo-)random bits
+ recipNonce present
+ -- senderNonce from corresponding ccr message
+ freeText any valid value
+ body ccp (CertRepMessage)
+ only one CertResponse allowed
+ -- if multiple cross certificates are required they MUST be
+ -- packaged in separate PKIMessages
+ response present
+ status present
+
+ PKIStatusInfo.status present
+ -- if PKIStatusInfo.status is one of:
+ -- accepted, or
+ -- grantedWithMods,
+ -- then certifiedKeyPair MUST be present and failInfo MUST
+ -- be absent
+
+ failInfo present depending on
+ PKIStatusInfo.status
+ -- if PKIStatusInfo.status is:
+ -- rejection
+ -- then certifiedKeyPair MUST be absent and failInfo MUST be
+ -- present and contain appropriate bit settings
+
+ certifiedKeyPair present depending on
+ PKIStatusInfo.status
+ certificate present depending on
+ certifiedKeyPair
+
+
+
+Adams, et al. Standards Track [Page 81]
+
+RFC 4210 CMP September 2005
+
+
+ -- content of actual certificate must be examined by requesting CA
+ -- before publication
+ protection present
+ -- bits calculated using MSG_SIG_ALG
+ extraCerts optionally present
+ -- MAY contain any additional certificates that responder wishes
+ -- to include
+
+E.7. In-Band Initialization Using External Identity Certificate
+
+ An (uninitialized) end entity wishes to initialize into the PKI with
+ a CA, CA-1. It uses, for authentication purposes, a pre-existing
+ identity certificate issued by another (external) CA, CA-X. A trust
+ relationship must already have been established between CA-1 and CA-X
+ so that CA-1 can validate the EE identity certificate signed by CA-X.
+ Furthermore, some mechanism must already have been established within
+ the Personal Security Environment (PSE) of the EE that would allow it
+ to authenticate and verify PKIMessages signed by CA-1 (as one
+ example, the PSE may contain a certificate issued for the public key
+ of CA-1, signed by another CA that the EE trusts on the basis of
+ out-of-band authentication techniques).
+
+ The EE sends an initialization request to start the transaction.
+ When CA-1 responds with a message containing the new certificate, the
+ end entity replies with a certificate confirmation. CA-1 replies
+ with a PKIConfirm to close the transaction. All messages are signed
+ (the EE messages are signed using the private key that corresponds to
+ the public key in its external identity certificate; the CA-1
+ messages are signed using the private key that corresponds to the
+ public key in a
+
+ certificate that can be chained to a trust anchor in the EE's PSE).
+
+ The profile for this exchange is identical to that given in Appendix
+ D.4, with the following exceptions:
+
+ o the EE and CA-1 do not share a symmetric MACing key (i.e., there
+ is no out-of-band shared secret information between these
+ entities);
+
+ o sender name in ir MUST be present (and identical to the subject
+ name present in the external identity certificate);
+
+ o protectionAlg of MSG_SIG_ALG MUST be used in all messages;
+
+ o external identity cert. MUST be carried in ir extraCerts field
+
+ o senderKID and recipKID are not used;
+
+
+
+Adams, et al. Standards Track [Page 82]
+
+RFC 4210 CMP September 2005
+
+
+ o body is ir or ip;
+
+ o protection bits are calculated according to the protectionAlg
+ field.
+
+Appendix F. Compilable ASN.1 Definitions
+
+ PKIXCMP {iso(1) identified-organization(3)
+ dod(6) internet(1) security(5) mechanisms(5) pkix(7)
+ id-mod(0) id-mod-cmp2000(16)}
+
+ DEFINITIONS EXPLICIT TAGS ::=
+
+ BEGIN
+
+ -- EXPORTS ALL --
+
+ IMPORTS
+
+ Certificate, CertificateList, Extensions, AlgorithmIdentifier,
+ UTF8String -- if required; otherwise, comment out
+ FROM PKIX1Explicit88 {iso(1) identified-organization(3)
+ dod(6) internet(1) security(5) mechanisms(5) pkix(7)
+ id-mod(0) id-pkix1-explicit-88(1)}
+
+ GeneralName, KeyIdentifier
+ FROM PKIX1Implicit88 {iso(1) identified-organization(3)
+ dod(6) internet(1) security(5) mechanisms(5) pkix(7)
+ id-mod(0) id-pkix1-implicit-88(2)}
+
+ CertTemplate, PKIPublicationInfo, EncryptedValue, CertId,
+ CertReqMessages
+ FROM PKIXCRMF-2005 {iso(1) identified-organization(3)
+ dod(6) internet(1) security(5) mechanisms(5) pkix(7)
+ id-mod(0) id-mod-crmf2005(36)}
+
+ -- see also the behavioral clarifications to CRMF codified in
+ -- Appendix C of this specification
+
+ CertificationRequest
+ FROM PKCS-10 {iso(1) member-body(2)
+ us(840) rsadsi(113549)
+ pkcs(1) pkcs-10(10) modules(1) pkcs-10(1)}
+
+ -- (specified in RFC 2986 with 1993 ASN.1 syntax and IMPLICIT
+ -- tags). Alternatively, implementers may directly include
+ -- the [PKCS10] syntax in this module
+
+
+
+
+Adams, et al. Standards Track [Page 83]
+
+RFC 4210 CMP September 2005
+
+
+ ;
+
+ -- the rest of the module contains locally-defined OIDs and
+ -- constructs
+
+ CMPCertificate ::= CHOICE {
+ x509v3PKCert Certificate
+ }
+ -- This syntax, while bits-on-the-wire compatible with the
+ -- standard X.509 definition of "Certificate", allows the
+ -- possibility of future certificate types (such as X.509
+ -- attribute certificates, WAP WTLS certificates, or other kinds
+ -- of certificates) within this certificate management protocol,
+ -- should a need ever arise to support such generality. Those
+ -- implementations that do not foresee a need to ever support
+ -- other certificate types MAY, if they wish, comment out the
+ -- above structure and "un-comment" the following one prior to
+ -- compiling this ASN.1 module. (Note that interoperability
+ -- with implementations that don't do this will be unaffected by
+ -- this change.)
+
+ -- CMPCertificate ::= Certificate
+
+ PKIMessage ::= SEQUENCE {
+ header PKIHeader,
+ body PKIBody,
+ protection [0] PKIProtection OPTIONAL,
+ extraCerts [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
+ OPTIONAL
+ }
+
+ PKIMessages ::= SEQUENCE SIZE (1..MAX) OF PKIMessage
+
+ PKIHeader ::= SEQUENCE {
+ pvno INTEGER { cmp1999(1), cmp2000(2) },
+ sender GeneralName,
+ -- identifies the sender
+ recipient GeneralName,
+ -- identifies the intended recipient
+ messageTime [0] GeneralizedTime OPTIONAL,
+ -- time of production of this message (used when sender
+ -- believes that the transport will be "suitable"; i.e.,
+ -- that the time will still be meaningful upon receipt)
+ protectionAlg [1] AlgorithmIdentifier OPTIONAL,
+ -- algorithm used for calculation of protection bits
+ senderKID [2] KeyIdentifier OPTIONAL,
+ recipKID [3] KeyIdentifier OPTIONAL,
+ -- to identify specific keys used for protection
+
+
+
+Adams, et al. Standards Track [Page 84]
+
+RFC 4210 CMP September 2005
+
+
+ transactionID [4] OCTET STRING OPTIONAL,
+ -- identifies the transaction; i.e., this will be the same in
+ -- corresponding request, response, certConf, and PKIConf
+ -- messages
+ senderNonce [5] OCTET STRING OPTIONAL,
+ recipNonce [6] OCTET STRING OPTIONAL,
+ -- nonces used to provide replay protection, senderNonce
+ -- is inserted by the creator of this message; recipNonce
+ -- is a nonce previously inserted in a related message by
+ -- the intended recipient of this message
+ freeText [7] PKIFreeText OPTIONAL,
+ -- this may be used to indicate context-specific instructions
+ -- (this field is intended for human consumption)
+ generalInfo [8] SEQUENCE SIZE (1..MAX) OF
+ InfoTypeAndValue OPTIONAL
+ -- this may be used to convey context-specific information
+ -- (this field not primarily intended for human consumption)
+ }
+
+ PKIFreeText ::= SEQUENCE SIZE (1..MAX) OF UTF8String
+ -- text encoded as UTF-8 String [RFC3629] (note: each
+ -- UTF8String MAY include an [RFC3066] language tag
+ -- to indicate the language of the contained text
+ -- see [RFC2482] for details)
+
+ PKIBody ::= CHOICE { -- message-specific body elements
+ ir [0] CertReqMessages, --Initialization Request
+ ip [1] CertRepMessage, --Initialization Response
+ cr [2] CertReqMessages, --Certification Request
+ cp [3] CertRepMessage, --Certification Response
+ p10cr [4] CertificationRequest, --imported from [PKCS10]
+ popdecc [5] POPODecKeyChallContent, --pop Challenge
+ popdecr [6] POPODecKeyRespContent, --pop Response
+ kur [7] CertReqMessages, --Key Update Request
+ kup [8] CertRepMessage, --Key Update Response
+ krr [9] CertReqMessages, --Key Recovery Request
+ krp [10] KeyRecRepContent, --Key Recovery Response
+ rr [11] RevReqContent, --Revocation Request
+ rp [12] RevRepContent, --Revocation Response
+ ccr [13] CertReqMessages, --Cross-Cert. Request
+ ccp [14] CertRepMessage, --Cross-Cert. Response
+ ckuann [15] CAKeyUpdAnnContent, --CA Key Update Ann.
+ cann [16] CertAnnContent, --Certificate Ann.
+ rann [17] RevAnnContent, --Revocation Ann.
+ crlann [18] CRLAnnContent, --CRL Announcement
+ pkiconf [19] PKIConfirmContent, --Confirmation
+ nested [20] NestedMessageContent, --Nested Message
+ genm [21] GenMsgContent, --General Message
+
+
+
+Adams, et al. Standards Track [Page 85]
+
+RFC 4210 CMP September 2005
+
+
+ genp [22] GenRepContent, --General Response
+ error [23] ErrorMsgContent, --Error Message
+ certConf [24] CertConfirmContent, --Certificate confirm
+ pollReq [25] PollReqContent, --Polling request
+ pollRep [26] PollRepContent --Polling response
+ }
+
+ PKIProtection ::= BIT STRING
+
+ ProtectedPart ::= SEQUENCE {
+ header PKIHeader,
+ body PKIBody
+ }
+
+ id-PasswordBasedMac OBJECT IDENTIFIER ::= {1 2 840 113533 7 66 13}
+ PBMParameter ::= SEQUENCE {
+ salt OCTET STRING,
+ -- note: implementations MAY wish to limit acceptable sizes
+ -- of this string to values appropriate for their environment
+ -- in order to reduce the risk of denial-of-service attacks
+ owf AlgorithmIdentifier,
+ -- AlgId for a One-Way Function (SHA-1 recommended)
+ iterationCount INTEGER,
+ -- number of times the OWF is applied
+ -- note: implementations MAY wish to limit acceptable sizes
+ -- of this integer to values appropriate for their environment
+ -- in order to reduce the risk of denial-of-service attacks
+ mac AlgorithmIdentifier
+ -- the MAC AlgId (e.g., DES-MAC, Triple-DES-MAC [PKCS11],
+ } -- or HMAC [RFC2104, RFC2202])
+
+ id-DHBasedMac OBJECT IDENTIFIER ::= {1 2 840 113533 7 66 30}
+ DHBMParameter ::= SEQUENCE {
+ owf AlgorithmIdentifier,
+ -- AlgId for a One-Way Function (SHA-1 recommended)
+ mac AlgorithmIdentifier
+ -- the MAC AlgId (e.g., DES-MAC, Triple-DES-MAC [PKCS11],
+ } -- or HMAC [RFC2104, RFC2202])
+
+
+ NestedMessageContent ::= PKIMessages
+
+ PKIStatus ::= INTEGER {
+ accepted (0),
+ -- you got exactly what you asked for
+ grantedWithMods (1),
+ -- you got something like what you asked for; the
+ -- requester is responsible for ascertaining the differences
+
+
+
+Adams, et al. Standards Track [Page 86]
+
+RFC 4210 CMP September 2005
+
+
+ rejection (2),
+ -- you don't get it, more information elsewhere in the message
+ waiting (3),
+ -- the request body part has not yet been processed; expect to
+ -- hear more later (note: proper handling of this status
+ -- response MAY use the polling req/rep PKIMessages specified
+ -- in Section 5.3.22; alternatively, polling in the underlying
+ -- transport layer MAY have some utility in this regard)
+ revocationWarning (4),
+ -- this message contains a warning that a revocation is
+ -- imminent
+ revocationNotification (5),
+ -- notification that a revocation has occurred
+ keyUpdateWarning (6)
+ -- update already done for the oldCertId specified in
+ -- CertReqMsg
+ }
+
+ PKIFailureInfo ::= BIT STRING {
+ -- since we can fail in more than one way!
+ -- More codes may be added in the future if/when required.
+ badAlg (0),
+ -- unrecognized or unsupported Algorithm Identifier
+ badMessageCheck (1),
+ -- integrity check failed (e.g., signature did not verify)
+ badRequest (2),
+ -- transaction not permitted or supported
+ badTime (3),
+ -- messageTime was not sufficiently close to the system time,
+ -- as defined by local policy
+ badCertId (4),
+ -- no certificate could be found matching the provided criteria
+ badDataFormat (5),
+ -- the data submitted has the wrong format
+ wrongAuthority (6),
+ -- the authority indicated in the request is different from the
+ -- one creating the response token
+ incorrectData (7),
+ -- the requester's data is incorrect (for notary services)
+ missingTimeStamp (8),
+ -- when the timestamp is missing but should be there
+ -- (by policy)
+ badPOP (9),
+ -- the proof-of-possession failed
+ certRevoked (10),
+ -- the certificate has already been revoked
+ certConfirmed (11),
+ -- the certificate has already been confirmed
+
+
+
+Adams, et al. Standards Track [Page 87]
+
+RFC 4210 CMP September 2005
+
+
+ wrongIntegrity (12),
+ -- invalid integrity, password based instead of signature or
+ -- vice versa
+ badRecipientNonce (13),
+ -- invalid recipient nonce, either missing or wrong value
+ timeNotAvailable (14),
+ -- the TSA's time source is not available
+ unacceptedPolicy (15),
+ -- the requested TSA policy is not supported by the TSA.
+ unacceptedExtension (16),
+ -- the requested extension is not supported by the TSA.
+ addInfoNotAvailable (17),
+ -- the additional information requested could not be
+ -- understood or is not available
+ badSenderNonce (18),
+ -- invalid sender nonce, either missing or wrong size
+ badCertTemplate (19),
+ -- invalid cert. template or missing mandatory information
+ signerNotTrusted (20),
+ -- signer of the message unknown or not trusted
+ transactionIdInUse (21),
+ -- the transaction identifier is already in use
+ unsupportedVersion (22),
+ -- the version of the message is not supported
+ notAuthorized (23),
+ -- the sender was not authorized to make the preceding
+ -- request or perform the preceding action
+ systemUnavail (24),
+ -- the request cannot be handled due to system unavailability
+ systemFailure (25),
+ -- the request cannot be handled due to system failure
+ duplicateCertReq (26)
+ -- certificate cannot be issued because a duplicate
+ -- certificate already exists
+ }
+
+ PKIStatusInfo ::= SEQUENCE {
+ status PKIStatus,
+ statusString PKIFreeText OPTIONAL,
+ failInfo PKIFailureInfo OPTIONAL
+ }
+
+ OOBCert ::= CMPCertificate
+
+ OOBCertHash ::= SEQUENCE {
+ hashAlg [0] AlgorithmIdentifier OPTIONAL,
+ certId [1] CertId OPTIONAL,
+ hashVal BIT STRING
+
+
+
+Adams, et al. Standards Track [Page 88]
+
+RFC 4210 CMP September 2005
+
+
+ -- hashVal is calculated over the DER encoding of the
+ -- self-signed certificate with the identifier certID.
+ }
+
+ POPODecKeyChallContent ::= SEQUENCE OF Challenge
+ -- One Challenge per encryption key certification request (in the
+ -- same order as these requests appear in CertReqMessages).
+
+ Challenge ::= SEQUENCE {
+ owf AlgorithmIdentifier OPTIONAL,
+
+ -- MUST be present in the first Challenge; MAY be omitted in
+ -- any subsequent Challenge in POPODecKeyChallContent (if
+ -- omitted, then the owf used in the immediately preceding
+ -- Challenge is to be used).
+
+ witness OCTET STRING,
+ -- the result of applying the one-way function (owf) to a
+ -- randomly-generated INTEGER, A. [Note that a different
+ -- INTEGER MUST be used for each Challenge.]
+ challenge OCTET STRING
+ -- the encryption (under the public key for which the cert.
+ -- request is being made) of Rand, where Rand is specified as
+ -- Rand ::= SEQUENCE {
+ -- int INTEGER,
+ -- - the randomly-generated INTEGER A (above)
+ -- sender GeneralName
+ -- - the sender's name (as included in PKIHeader)
+ -- }
+ }
+
+ POPODecKeyRespContent ::= SEQUENCE OF INTEGER
+ -- One INTEGER per encryption key certification request (in the
+ -- same order as these requests appear in CertReqMessages). The
+ -- retrieved INTEGER A (above) is returned to the sender of the
+ -- corresponding Challenge.
+
+ CertRepMessage ::= SEQUENCE {
+ caPubs [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
+ OPTIONAL,
+ response SEQUENCE OF CertResponse
+ }
+
+ CertResponse ::= SEQUENCE {
+ certReqId INTEGER,
+ -- to match this response with corresponding request (a value
+ -- of -1 is to be used if certReqId is not specified in the
+ -- corresponding request)
+
+
+
+Adams, et al. Standards Track [Page 89]
+
+RFC 4210 CMP September 2005
+
+
+ status PKIStatusInfo,
+ certifiedKeyPair CertifiedKeyPair OPTIONAL,
+ rspInfo OCTET STRING OPTIONAL
+ -- analogous to the id-regInfo-utf8Pairs string defined
+ -- for regInfo in CertReqMsg [CRMF]
+ }
+
+ CertifiedKeyPair ::= SEQUENCE {
+ certOrEncCert CertOrEncCert,
+ privateKey [0] EncryptedValue OPTIONAL,
+ -- see [CRMF] for comment on encoding
+ publicationInfo [1] PKIPublicationInfo OPTIONAL
+ }
+
+ CertOrEncCert ::= CHOICE {
+ certificate [0] CMPCertificate,
+ encryptedCert [1] EncryptedValue
+ }
+
+ KeyRecRepContent ::= SEQUENCE {
+ status PKIStatusInfo,
+ newSigCert [0] CMPCertificate OPTIONAL,
+ caCerts [1] SEQUENCE SIZE (1..MAX) OF
+ CMPCertificate OPTIONAL,
+ keyPairHist [2] SEQUENCE SIZE (1..MAX) OF
+ CertifiedKeyPair OPTIONAL
+ }
+
+ RevReqContent ::= SEQUENCE OF RevDetails
+
+ RevDetails ::= SEQUENCE {
+ certDetails CertTemplate,
+ -- allows requester to specify as much as they can about
+ -- the cert. for which revocation is requested
+ -- (e.g., for cases in which serialNumber is not available)
+ crlEntryDetails Extensions OPTIONAL
+ -- requested crlEntryExtensions
+ }
+
+ RevRepContent ::= SEQUENCE {
+ status SEQUENCE SIZE (1..MAX) OF PKIStatusInfo,
+ -- in same order as was sent in RevReqContent
+ revCerts [0] SEQUENCE SIZE (1..MAX) OF CertId
+ OPTIONAL,
+ -- IDs for which revocation was requested
+ -- (same order as status)
+ crls [1] SEQUENCE SIZE (1..MAX) OF CertificateList
+ OPTIONAL
+
+
+
+Adams, et al. Standards Track [Page 90]
+
+RFC 4210 CMP September 2005
+
+
+ -- the resulting CRLs (there may be more than one)
+ }
+
+ CAKeyUpdAnnContent ::= SEQUENCE {
+ oldWithNew CMPCertificate, -- old pub signed with new priv
+ newWithOld CMPCertificate, -- new pub signed with old priv
+ newWithNew CMPCertificate -- new pub signed with new priv
+ }
+
+ CertAnnContent ::= CMPCertificate
+
+ RevAnnContent ::= SEQUENCE {
+ status PKIStatus,
+ certId CertId,
+ willBeRevokedAt GeneralizedTime,
+ badSinceDate GeneralizedTime,
+ crlDetails Extensions OPTIONAL
+ -- extra CRL details (e.g., crl number, reason, location, etc.)
+ }
+
+ CRLAnnContent ::= SEQUENCE OF CertificateList
+
+ CertConfirmContent ::= SEQUENCE OF CertStatus
+
+ CertStatus ::= SEQUENCE {
+ certHash OCTET STRING,
+ -- the hash of the certificate, using the same hash algorithm
+ -- as is used to create and verify the certificate signature
+ certReqId INTEGER,
+ -- to match this confirmation with the corresponding req/rep
+ statusInfo PKIStatusInfo OPTIONAL
+ }
+
+ PKIConfirmContent ::= NULL
+
+ InfoTypeAndValue ::= SEQUENCE {
+ infoType OBJECT IDENTIFIER,
+ infoValue ANY DEFINED BY infoType OPTIONAL
+ }
+ -- Example InfoTypeAndValue contents include, but are not limited
+ -- to, the following (un-comment in this ASN.1 module and use as
+ -- appropriate for a given environment):
+ --
+ -- id-it-caProtEncCert OBJECT IDENTIFIER ::= {id-it 1}
+ -- CAProtEncCertValue ::= CMPCertificate
+ -- id-it-signKeyPairTypes OBJECT IDENTIFIER ::= {id-it 2}
+ -- SignKeyPairTypesValue ::= SEQUENCE OF AlgorithmIdentifier
+ -- id-it-encKeyPairTypes OBJECT IDENTIFIER ::= {id-it 3}
+
+
+
+Adams, et al. Standards Track [Page 91]
+
+RFC 4210 CMP September 2005
+
+
+ -- EncKeyPairTypesValue ::= SEQUENCE OF AlgorithmIdentifier
+ -- id-it-preferredSymmAlg OBJECT IDENTIFIER ::= {id-it 4}
+ -- PreferredSymmAlgValue ::= AlgorithmIdentifier
+ -- id-it-caKeyUpdateInfo OBJECT IDENTIFIER ::= {id-it 5}
+ -- CAKeyUpdateInfoValue ::= CAKeyUpdAnnContent
+ -- id-it-currentCRL OBJECT IDENTIFIER ::= {id-it 6}
+ -- CurrentCRLValue ::= CertificateList
+ -- id-it-unsupportedOIDs OBJECT IDENTIFIER ::= {id-it 7}
+ -- UnsupportedOIDsValue ::= SEQUENCE OF OBJECT IDENTIFIER
+ -- id-it-keyPairParamReq OBJECT IDENTIFIER ::= {id-it 10}
+ -- KeyPairParamReqValue ::= OBJECT IDENTIFIER
+ -- id-it-keyPairParamRep OBJECT IDENTIFIER ::= {id-it 11}
+ -- KeyPairParamRepValue ::= AlgorithmIdentifer
+ -- id-it-revPassphrase OBJECT IDENTIFIER ::= {id-it 12}
+ -- RevPassphraseValue ::= EncryptedValue
+ -- id-it-implicitConfirm OBJECT IDENTIFIER ::= {id-it 13}
+ -- ImplicitConfirmValue ::= NULL
+ -- id-it-confirmWaitTime OBJECT IDENTIFIER ::= {id-it 14}
+ -- ConfirmWaitTimeValue ::= GeneralizedTime
+ -- id-it-origPKIMessage OBJECT IDENTIFIER ::= {id-it 15}
+ -- OrigPKIMessageValue ::= PKIMessages
+ -- id-it-suppLangTags OBJECT IDENTIFIER ::= {id-it 16}
+ -- SuppLangTagsValue ::= SEQUENCE OF UTF8String
+ --
+ -- where
+ --
+ -- id-pkix OBJECT IDENTIFIER ::= {
+ -- iso(1) identified-organization(3)
+ -- dod(6) internet(1) security(5) mechanisms(5) pkix(7)}
+ -- and
+ -- id-it OBJECT IDENTIFIER ::= {id-pkix 4}
+ --
+ --
+ -- This construct MAY also be used to define new PKIX Certificate
+ -- Management Protocol request and response messages, or general-
+ -- purpose (e.g., announcement) messages for future needs or for
+ -- specific environments.
+
+ GenMsgContent ::= SEQUENCE OF InfoTypeAndValue
+
+ -- May be sent by EE, RA, or CA (depending on message content).
+ -- The OPTIONAL infoValue parameter of InfoTypeAndValue will
+ -- typically be omitted for some of the examples given above.
+ -- The receiver is free to ignore any contained OBJ. IDs that it
+ -- does not recognize. If sent from EE to CA, the empty set
+ -- indicates that the CA may send
+ -- any/all information that it wishes.
+
+
+
+
+Adams, et al. Standards Track [Page 92]
+
+RFC 4210 CMP September 2005
+
+
+ GenRepContent ::= SEQUENCE OF InfoTypeAndValue
+ -- Receiver MAY ignore any contained OIDs that it does not
+ -- recognize.
+
+ ErrorMsgContent ::= SEQUENCE {
+ pKIStatusInfo PKIStatusInfo,
+ errorCode INTEGER OPTIONAL,
+ -- implementation-specific error codes
+ errorDetails PKIFreeText OPTIONAL
+ -- implementation-specific error details
+ }
+
+ PollReqContent ::= SEQUENCE OF SEQUENCE {
+ certReqId INTEGER
+ }
+
+ PollRepContent ::= SEQUENCE OF SEQUENCE {
+ certReqId INTEGER,
+ checkAfter INTEGER, -- time in seconds
+ reason PKIFreeText OPTIONAL
+ }
+
+ END -- of CMP module
+
+Appendix G. Acknowledgements
+
+ The authors gratefully acknowledge the contributions of various
+ members of the IETF PKIX Working Group and the ICSA CA-talk mailing
+ list (a list solely devoted to discussing CMP interoperability
+ efforts). Many of these contributions significantly clarified and
+ improved the utility of this specification. Tomi Kause thanks Vesa
+ Suontama and Toni Tammisalo for review and comments.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 93]
+
+RFC 4210 CMP September 2005
+
+
+Authors' Addresses
+
+ Carlisle Adams
+ University of Ottawa
+ 800 King Edward Avenue
+ P.O.Box 450, Station A
+ Ottawa, Ontario K1N 6N5
+ CA
+
+ Phone: (613) 562-5800 ext. 2345
+ Fax: (613) 562-5664
+ EMail: cadams@site.uottawa.ca
+
+
+ Stephen Farrell
+ Trinity College Dublin
+ Distributed Systems Group
+ Computer Science Department
+ Dublin
+ IE
+
+ Phone: +353-1-608-2945
+ EMail: stephen.farrell@cs.tcd.ie
+
+
+ Tomi Kause
+ SSH Communications Security Corp
+ Valimotie 17
+ Helsinki 00380
+ FI
+
+ Phone: +358 20 500 7415
+ EMail: toka@ssh.com
+
+
+ Tero Mononen
+ SafeNet, Inc.
+ Fredrikinkatu 47
+ Helsinki 00100
+ FI
+
+ Phone: +358 20 500 7814
+ EMail: tmononen@safenet-inc.com
+
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 94]
+
+RFC 4210 CMP September 2005
+
+
+Full Copyright Statement
+
+ Copyright (C) The Internet Society (2005).
+
+ This document is subject to the rights, licenses and restrictions
+ contained in BCP 78, and except as set forth therein, the authors
+ retain all their rights.
+
+ This document and the information contained herein are provided on an
+ "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
+ OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
+ ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
+ INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
+ INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
+ WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Intellectual Property
+
+ The IETF takes no position regarding the validity or scope of any
+ Intellectual Property Rights or other rights that might be claimed to
+ pertain to the implementation or use of the technology described in
+ this document or the extent to which any license under such rights
+ might or might not be available; nor does it represent that it has
+ made any independent effort to identify any such rights. Information
+ on the procedures with respect to rights in RFC documents can be
+ found in BCP 78 and BCP 79.
+
+ Copies of IPR disclosures made to the IETF Secretariat and any
+ assurances of licenses to be made available, or the result of an
+ attempt made to obtain a general license or permission for the use of
+ such proprietary rights by implementers or users of this
+ specification can be obtained from the IETF on-line IPR repository at
+ http://www.ietf.org/ipr.
+
+ The IETF invites any interested party to bring to its attention any
+ copyrights, patents or patent applications, or other proprietary
+ rights that may cover technology that may be required to implement
+ this standard. Please address the information to the IETF at ietf-
+ ipr@ietf.org.
+
+Acknowledgement
+
+ Funding for the RFC Editor function is currently provided by the
+ Internet Society.
+
+
+
+
+
+
+
+Adams, et al. Standards Track [Page 95]
+