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author | Thomas Voss <mail@thomasvoss.com> | 2024-11-27 20:54:24 +0100 |
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committer | Thomas Voss <mail@thomasvoss.com> | 2024-11-27 20:54:24 +0100 |
commit | 4bfd864f10b68b71482b35c818559068ef8d5797 (patch) | |
tree | e3989f47a7994642eb325063d46e8f08ffa681dc /doc/rfc/rfc6109.txt | |
parent | ea76e11061bda059ae9f9ad130a9895cc85607db (diff) |
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diff --git a/doc/rfc/rfc6109.txt b/doc/rfc/rfc6109.txt new file mode 100644 index 0000000..6439122 --- /dev/null +++ b/doc/rfc/rfc6109.txt @@ -0,0 +1,3643 @@ + + + + + + +Internet Engineering Task Force (IETF) C. Petrucci +Request for Comments: 6109 DigitPA +Category: Informational F. Gennai +ISSN: 2070-1721 A. Shahin + ISTI-CNR + A. Vinciarelli + April 2011 + + + La Posta Elettronica Certificata - Italian Certified Electronic Mail + +Abstract + + Since 1997, the Italian laws have recognized electronic delivery + systems as legally usable. In 2005, after two years of technical + tests, the characteristics of an official electronic delivery + service, named certified electronic mail (in Italian "Posta + Elettronica Certificata") were defined, giving the system legal + standing. + + The design of the entire system was carried out by the National + Center for Informatics in the Public Administration of Italy + (DigitPA), followed by efforts for the implementation and testing of + the service. The DigitPA has given the Italian National Research + Council (CNR), and in particular the Institute of Information Science + and Technologies at the CNR (ISTI), the task of running tests on + providers of the service to guarantee the correct implementation and + interoperability. This document describes the certified email system + adopted in Italy. It represents the system as it is at the moment of + writing, following the technical regulations that were written based + upon the Italian Law DPR. November 2, 2005. + +Status of This Memo + + This document is not an Internet Standards Track specification; it is + published for informational purposes. + + This document is a product of the Internet Engineering Task Force + (IETF). It has been approved for publication by the Internet + Engineering Steering Group (IESG). Not all documents approved by the + IESG are a candidate for any level of Internet Standard; see Section + 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc6109. + + + + + +Petrucci, et al. Informational [Page 1] + +RFC 6109 Certified Electronic Mail April 2011 + + +Copyright Notice + + Copyright (c) 2010 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Petrucci, et al. Informational [Page 2] + +RFC 6109 Certified Electronic Mail April 2011 + + +Table of Contents + + 1. Introduction ....................................................5 + 1.1. Scope ......................................................5 + 1.2. Notational Conventions .....................................6 + 1.2.1. Requirement Conventions .............................6 + 1.2.2. Acronyms ............................................6 + 1.2.3. Terminology and Definitions .........................7 + 2. PEC Model .......................................................8 + 2.1. System-Generated Messages ..................................8 + 2.1.1. Message Types ......................................10 + 2.2. Basic Structure ...........................................12 + 2.2.1. Access Point .......................................12 + 2.2.2. Incoming Point .....................................14 + 2.2.3. Delivery Point .....................................16 + 2.2.4. Storage ............................................17 + 2.2.5. Provider Service Mailbox ...........................17 + 2.2.6. Provider Service Email Address .....................17 + 2.3. Log .......................................................17 + 3. Message Processing .............................................18 + 3.1. Access Point ..............................................18 + 3.1.1. Formal Checks on Messages ..........................18 + 3.1.2. Non-Acceptance PEC Notification Due to + Formal Exceptions ..................................19 + 3.1.3. Non-Acceptance PEC Notification Due to + Virus Detection ....................................20 + 3.1.4. Server-User Acceptance PEC Notification ............20 + 3.1.5. PEC Transport Envelope .............................21 + 3.1.6. Timeout Delivery Error PEC Notification ............23 + 3.2. Incoming Point ............................................24 + 3.2.1. Server-Server Acceptance PEC Notification ..........24 + 3.2.2. PEC Anomaly Envelope ...............................25 + 3.2.3. Virus Detection PEC Notification ...................27 + 3.2.4. Virus-Induced Delivery Error PEC notification ......28 + 3.3. Delivery Point ............................................29 + 3.3.1. Checks on Incoming Messages ........................29 + 3.3.2. Delivery PEC Notification ..........................29 + 3.3.3. Non-Delivery PEC Notification ......................34 + 3.4. Sender and Receiver Belonging to the Same Domain ..........34 + 3.5. Example: Complete Transaction between Two PEC Domains .....34 + 4. Formats ........................................................35 + 4.1. Temporal Reference ........................................35 + 4.2. User Date/Time ............................................36 + 4.3. Format of a PEC Message Body ..............................36 + 4.3.1. User Readable Text .................................37 + 4.3.2. Original Message ...................................37 + 4.3.3. Certification Data .................................37 + 4.4. Certification Data Scheme .................................37 + + + +Petrucci, et al. Informational [Page 3] + +RFC 6109 Certified Electronic Mail April 2011 + + + 4.5. PEC Providers Directory Scheme ............................39 + 4.5.1. providerCertificateHash Attribute ..................41 + 4.5.2. providerCertificate Attribute ......................41 + 4.5.3. providerName Attribute .............................41 + 4.5.4. mailReceipt Attribute ..............................42 + 4.5.5. managedDomains Attribute ...........................42 + 4.5.6. LDIFLocationURL Attribute ..........................43 + 4.5.7. providerUnit Attribute .............................43 + 4.5.8. LDIFLocationURLObject Object Class .................44 + 4.5.9. Provider Object Class ..............................44 + 4.5.10. LDIF File Example .................................44 + 5. Security-Related Aspects .......................................48 + 5.1. Digital Signature .........................................48 + 5.2. Authentication ............................................48 + 5.3. Secure Interaction ........................................49 + 5.4. Virus .....................................................49 + 5.5. S/MIME Certificate ........................................49 + 5.5.1. Provider-Related Information (Subject) .............50 + 5.5.2. Certificate Extensions .............................50 + 5.5.3. Example ............................................51 + 5.6. PEC Providers Directory ...................................55 + 6. PEC System Client Technical and Functional Prerequisites .......55 + 7. Security Considerations ........................................55 + 8. IANA Considerations ............................................56 + 8.1. Registration of PEC Message Header Fields .................56 + 8.1.1. Header Field: X-Riferimento-Message-ID: ............56 + 8.1.2. Header Field: X-Ricevuta: ..........................56 + 8.1.3. Header Field: X-VerificaSicurezza: .................57 + 8.1.4. Header Field: X-Trasporto: .........................57 + 8.1.5. Header Field: X-TipoRicevuta: ......................57 + 8.1.6. Header Field: X-Mittente: ..........................58 + 8.2. Registration of LDAP Object Identifier Descriptors ........58 + 8.2.1. Registration of Object Classes and + Attribute Types ....................................58 + 9. References .....................................................59 + 9.1. Normative References ......................................59 + 9.2. Informative References ....................................61 + 10. Acknowledgments ...............................................62 + Appendix A. Italian Fields and Values in English ..................63 + + + + + + + + + + + + +Petrucci, et al. Informational [Page 4] + +RFC 6109 Certified Electronic Mail April 2011 + + +1. Introduction + + Since 1997, the Italian laws have recognized electronic delivery + systems as legally usable. In 2005, after two years of technical + tests, the characteristics of an official electronic delivery + service, named certified electronic mail (in Italian Posta + Elettronica Certificata, from now on "PEC") were defined, giving the + system legal standing. + + This document represents the English version of the Italian + specifications + (http://www.digitpa.gov.it/sites/default/files/normativa/ + Pec_regole_tecniche_DM_2-nov-2005.pdf); the Italian version is the + normative PEC reference. + + IETF review did not result in community consensus. Since this + specification describes existing deployment and implementation, the + issues identified by the IETF community have not been addressed in + this document. However, these issues would need to be addressed + before a successor to this document could be published. At a + minimum, the successor document would need to include: + + * A clear statement of the requirements/goals that need to be + satisfied by the protocol; + + * A comprehensive diagram and description of the overall message flow + and delivery sequence required to achieve the requirements; + + * Alignment with traditional terminology for IETF email and security + + * A review of prior art; and + + * A replacement of the unregistered LDAP DN name space used in this + specification, which may lead to conflict with other registered or + unregistered names, with a registered name space. + +1.1. Scope + + To ensure secure transactions over the Internet, cryptography can be + associated with electronic messages in order to provide some + guarantee on sender identity, message integrity, confidentiality, and + non-repudiation of origin. Many end-to-end techniques exist to + accomplish such goals, and some offer a high level of security. The + downside of end-to-end cryptography is the need for an extensive + penetration of technology in society, because it is essential for + every user to have asymmetric keys and certificates signed by a + Certification Authority. Along with that, users would need to have + an adequate amount of knowledge regarding the use of such technology. + + + +Petrucci, et al. Informational [Page 5] + +RFC 6109 Certified Electronic Mail April 2011 + + + PEC, on the other hand, uses applications running on servers to + digitally sign messages, thus avoiding the complexity end-to-end + systems bring about. By doing so, the user need only have an + ordinary mail client with which to interact. The downside is that + the level of security drops, since the protection does not cover the + entire transaction. Nonetheless, application is simpler and does not + require specific user skills, making it easily more widespread among + users. + + This document describes PEC's technical aspects and features. It + presents the details of the protocol and the messages that are sent + between service providers, introducing the system adopted by the + Italian government for the exchange of certified emails. + +1.2. Notational Conventions + +1.2.1. Requirement Conventions + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in [REQ]. + +1.2.2. Acronyms + + CMS: Cryptographic Message Syntax + CNIPA: Italian National Agency for Digital Administration + (Centro Nazionale per l'Informatica nella Pubblica + Amministrazione) + CNR: Italian National Research Council (Consiglio Nazionale + delle Ricerche) + CRL: Certificate Revocation List + CRL DP: Certificate Revocation List Distribution Point + DNS: Domain Name Service + DTD: Document Type Definition + FQDN: Fully Qualified Domain Name + ISTI: The Institute of Information Science and Technologies + at the CNR (Istituto di Scienza e Tecnologie + dell'Informazione "A.Faedo") + LDAP: Lightweight Directory Access Protocol + LDIF: LDAP Data Interchange Format + MIME: Multipurpose Internet Mail Extensions + PEC: Certified Electronic Mail (Posta Elettronica + Certificata) + S/MIME: Secure/MIME + SMTP: Simple Mail Transfer Protocol + TLS: Transport Layer Security + XML: eXtensible Markup Language + + + + +Petrucci, et al. Informational [Page 6] + +RFC 6109 Certified Electronic Mail April 2011 + + +1.2.3. Terminology and Definitions + + Certification data: A set of data certified by the sender's PEC + provider that describes the original message. It includes the date + and time of dispatch, sender email address, recipient(s) email + address(es), subject, and message identifier. + + Certified electronic mail: A service based on electronic mail, as + defined by the [EMAIL] and [SMTP] standards and extensions, which + permits the transmission of documents produced with informatics + tools. + + DigitPA: Ex-CNIPA. + + Holder: The person or organization to whom a PEC mailbox is assigned. + + Message sent: A PEC message is considered sent when the sender's PEC + provider, after several checks, accepts the email and returns a + server-user acceptance PEC notification to the sender. + + Message received: A PEC message is considered received when it is + stored in the receiver's mailbox, after which the receiver PEC + provider returns a delivery PEC notification to the sender. + + Msgid: Is the message identifier generated by the email client, as + defined in [EMAIL], before the message is submitted to the PEC + system. + + Ordinary mail: Non-PEC email messages. + + Original message: Is the user-generated message before its arrival to + the sender Access Point. The original message is delivered to the + recipient inside a PEC transport envelope. + + PEC domain: Corresponds to a DNS domain dedicated to the holders' + mailboxes. + + PEC mailbox: An electronic mailbox for which delivery PEC + notifications are issued upon reception of PEC messages. Such a + mailbox can be defined exclusively within a PEC domain. + + PEC msgid: Is a unique identifier generated by the PEC system, which + will substitute the msgid. + + + + + + + + +Petrucci, et al. Informational [Page 7] + +RFC 6109 Certified Electronic Mail April 2011 + + + PEC provider: The entity that handles one or more PEC domains with + their relative points of Access, Reception, and Delivery. It is the + holder of the key that is used for signing PEC notifications and + envelopes, and it interacts with other PEC providers for + interoperability with other holders. + + PEC provider's key: Is a key released by DigitPA to every PEC + provider. It is used to sign PEC notifications and envelopes and to + authorize access to the PEC providers directory. + + PEC providers directory: Is an LDAP server positioned in an area + reachable by all PEC service providers. It constitutes the technical + structure related to the public list of PEC service providers and + contains the list of PEC domains and service providers with relevant + certificates. + + Service mailbox: A mailbox for the sole use of the provider, + dedicated for the reception of server-server acceptance and virus + detection PEC notifications. + + Time stamp: Digital evidence with which a temporal reference, that + can't be repudiated, is attributed to one or more documents. + +2. PEC Model + +2.1. System-Generated Messages + + The PEC system generates messages in MIME format composed of a + descriptive textual part and other [MIME1] parts, the number and + content of which varies according to the type of message generated. + + A system-generated message falls into one of the following + categories: + + o Notifications; + + o Envelopes. + + The message is inserted in an S/MIME v3 structure in CMS format and + signed with the PEC provider's private key. The X.509v3 certificate + associated with the key MUST be included in the aforementioned + structure. The S/MIME format used to sign system-generated messages + is the "multipart/signed" format (.p7s), as described in section + 3.4.3 of [SMIMEV3]. + + To guarantee the verifiability of signatures on as many mail clients + as possible, X.509v3 certificates used by certified email systems + MUST abide by the profile found in section 6.5. + + + +Petrucci, et al. Informational [Page 8] + +RFC 6109 Certified Electronic Mail April 2011 + + + In order for the receiving mail client to verify the signature, the + sender address MUST coincide with the one indicated within the + X.509v3 certificate. For this mechanism, PEC transport envelopes + MUST indicate in the "From:" field a single author's address which is + different from the one contained in the original message. To allow + for better message usability by the receiving user, the author's mail + address in the original message is inserted as a "display name". For + example, a "From:" field such as: + + From: "John Smith" <john.smith@domain.example.com> + + would result in the following "From:" value in the respective PEC + transport envelope: + + From: "On behalf of: john.smith@domain.example.com" + <certified-mail@provider.example.com> + + Both "From:" and "Sender:" fields MUST contain the same value. In + order for replies to be correctly sent back to the proper + destination, the "Reply-To:" field in the PEC transport envelope MUST + contain the same unaltered value of the original message's + "Reply-To:" field. When it is not explicitly specified in the + original message, the system that generates the PEC transport + envelope creates it by extracting the information from the "From:" + field in the original message. + + When PEC notifications are sent, the system MUST use the original + message sender's address as the destination address, as is specified + in the reverse path data of the SMTP protocol. PEC notifications + MUST be sent to the sender's PEC mailbox without taking into account + the "Reply-To:" field, which might be present in the original + message's header. + + All system-generated PEC messages are identifiable for having a + specific header defined in PEC according to the type of message + generated. + + To determine the certification data, the elements used for the actual + routing of the message are employed. In SMTP dialog phases, the + reverse path and forward path data ("MAIL FROM" and "RCPT TO" + commands) are thus considered certification data of both the sender + and the recipients, respectively. Addressing data present in the + message body ("To:" and "Cc:" fields) are used solely in order to + discriminate between primary and carbon copy recipients when + necessary; addressing data present in the "Bcc:" field MUST be + considered invalid by the system. + + + + + +Petrucci, et al. Informational [Page 9] + +RFC 6109 Certified Electronic Mail April 2011 + + +2.1.1. Message Types + + All system-generated messages inherit their header fields and values + from the original message, with extra fields added according to the + type of message generated. + +2.1.1.1. PEC Notifications + + They have the purpose of informing the sending user and interacting + providers of the progress the message is making within the PEC + network. + +2.1.1.1.1. Success PEC Notifications + + These notifications indicate an acknowledgment on the provider's side + for the reception or handling of a PEC message. More specifically, + it can indicate one of three situations: server-user acceptance, + server-server acceptance, or delivery. + + Added header fields are: + + o X-Ricevuta: + + o X-Riferimento-Message-ID: + + The field "X-Ricevuta:" indicates the type of PEC notification + contained in the message, whereas "X-Riferimento-Message-ID:" + contains the message identifier generated by the mail client (msgid). + + Body contents differ according to notification type. This is + described more thoroughly in section 3. + + o A server-user acceptance PEC notification informs the user that + his provider has accepted the message and will be taking care of + passing it on to the provider(s) of the addressee(s). + + o A server-server acceptance PEC notification is an inter-provider + communication only, it MUST NOT be sent to the users. With this + notification, the receiving provider simply informs the sending + one that it has received a PEC message, and will take the + responsibility of forwarding it to the addressee(s). From then + on, the sender provider is no longer held responsible as to the + whereabouts of the message, but is limited to notifying its user + of the success or failure of delivery. + + o Delivery PEC notifications take place as the final communication + of a transaction, indicating overall success in handing the + message over to the addressee(s). + + + +Petrucci, et al. Informational [Page 10] + +RFC 6109 Certified Electronic Mail April 2011 + + +2.1.1.1.2. Delay PEC Notifications + + Delay PEC notifications are sent out 12 hours after a message has + been dispatched from the sending provider, and no server-server + acceptance or delivery PEC notification has been received. These + have the sole purpose of notifying the user of the delay. + + If another 12 hours go by without any sign of a server-server + acceptance or delivery PEC notification (amounting to a 24-hour + delay), another delay PEC notification is dispatched to the user + informing him of the possible delivery failure. The provider will + not keep track of the delay any further. + +2.1.1.1.3. Failure PEC Notifications + + They are sent when there is some error in transmission or reception. + More specifically, a failure PEC notification can indicate either a + formal-exception error or a virus detection. + + Added header fields are: + + o X-Ricevuta: + + o X-Riferimento-Message-ID: + + o X-VerificaSicurezza: [optional] + + "X-Ricevuta:" and "X-Riferimento-Message-ID:" have the same role as + indicated in section 2.1.1.1.1 (Success Notifications). + "X-VerificaSicurezza:" (security verification) is an optional header + field, used for virus-related PEC notifications. + + Body contents differ according to notification type. This is + described more thoroughly in section 3. + +2.1.1.2. PEC Envelopes + + Messages entering the PEC network are inserted within specific PEC + messages, called envelopes, before they are allowed to circulate + further within the network. These envelopes MUST inherit the + following header fields, along with their unmodified values, from the + message itself: + + o Received: + + o To: + + o Cc: + + + +Petrucci, et al. Informational [Page 11] + +RFC 6109 Certified Electronic Mail April 2011 + + + o Return-Path: + + o Reply-To: (if present) + + Depending on the type of message requesting admission into the PEC + network, it will be inserted in either a PEC transport envelope or a + PEC anomaly envelope. Distinction will be possible through the + addition of the "X-Trasporto:" header field. + +2.2. Basic Structure + + +-------------+ +------------+ + | +--+ | | | + | |AP| | PEC | | + +----+ | +--+ | messages & | +---+ +--+ | +----+ + |user|<-->| |<------------->| |InP| |DP| |<-->|user| + +----+ | +--+ +---+ | notifications | +---+ +--+ | +----+ + | |DP| |InP| | | | + | +--+ +---+ | | | + +-------------+ +------------+ + PEC PEC + sender receiver + provider provider + + where: + + AP = Access Point + DP = Delivery Point + InP = Incoming Point + +2.2.1. Access Point + + This is what the user client at the sender side interacts with, + giving the user access to PEC services set up by the provider. + + Such access MUST be preceded by user authentication on the system + (see section 5.2). The Access Point receives the original messages + its user wishes to send, runs some formal checks, and acts according + to the outcome: + + o if the message passes all checks, the Access Point generates a + server-user acceptance PEC notification and inserts the original + message inside a PEC transport envelope; + + o if a formal exception is detected, the Access Point refuses the + message and emits the relevant non-acceptance PEC notification + (see section 3.1.1); + + + + +Petrucci, et al. Informational [Page 12] + +RFC 6109 Certified Electronic Mail April 2011 + + + o if a virus is detected, the Access Point generates a non- + acceptance PEC notification and inserts the original message as is + in the provider's special store. + + Generation of the server-user acceptance notification indicates to + the user that the message was accepted by the system, certifying also + the date and time of the event. The notification MUST contain user- + readable text, and an XML part containing the certification data. + The notification MAY also contain other attachments for extra + features offered by the provider. + + Using the data available in the PEC providers directory (see section + 4.5), the Access Point runs checks on every recipient in the "To:" + and "Cc:" fields present in the original message to verify whether + they belong to the PEC infrastructure or to non-PEC domains. Such + checks are done by verifying the existence, through a case- + insensitive search, of the recipients' domains in the + "managedDomains" attribute found within the PEC providers directory. + Therefore, the server-user acceptance PEC notification (and relevant + certification data) relates to, for each address, the typology of its + domain; PEC or non-PEC. + + The message identifier (PEC msgid) of accepted original messages + within the PEC infrastructure MUST be unambiguous in order to consent + correct tracking of messages and relative PEC notifications. The + format of such an identifier is: + + [alphanumeric string]@[provider mail domain] + + or: + + [alphanumeric string]@[FQDN mail server] + + Therefore, both the original message and the corresponding PEC + transport envelope MUST contain the following header field: + + Message-ID: <[unique identifier]> + + When an email client that is interacting with the Access Point has + already inserted a message identifier (msgid) in the original + message, that msgid SHALL be substituted by a PEC msgid. In order to + allow the sender to link the message sent with the relative PEC + notifications, the msgid MUST be inserted in the original message as + well as the relative PEC notifications and transport envelope. If + present, the msgid is REQUIRED in the original message's header by + adding the following header field: + + X-Riferimento-Message-ID: <[msgid]> + + + +Petrucci, et al. Informational [Page 13] + +RFC 6109 Certified Electronic Mail April 2011 + + + which will also be inserted in the PEC transport envelope and + notifications, and related in the certification data (see section + 4.4). + +2.2.2. Incoming Point + + This point permits the exchange of PEC messages and notifications + between PEC providers. It is also the point through which ordinary + mail messages can be inserted within the system of certified mail. + + The exchange of messages between providers takes place through SMTP- + based transactions, as defined in [SMTP]. If SMTP communication + errors occur, they MAY be handled using the standard error + notification mechanisms, as provided by SMTP in [SMTP] and + [SMTP-DSN]. The same mechanism is also adopted for handling + transitory errors, that result in long idling periods, during an SMTP + transmission phase. In order to guarantee that an error is returned + to the user, as defined in section 3.3.3, the system that handles PEC + traffic MUST adopt a time limit for message idleness equal to 24 + hours. + + Once a message arrives, the Incoming Point runs the following list of + checks and operations: + + o verifies correctness and type of the incoming message; + + o if the incoming message is a correct and undamaged PEC transport + envelope: + + - emits a server-server acceptance PEC notification towards the + sender provider (section 3.2.1); + + - forwards the PEC transport envelope to the Delivery Point + (section 3.3). + + o if the incoming message is a correct and undamaged PEC + notification, forwards the notification to the Delivery Point. + + o if the incoming message does not conform to the prerequisites of a + correct and undamaged PEC transport envelope or notification, but + comes from a PEC provider, i.e., passes the verifications + regarding existence, origin, and validity of the signature, then + the message MUST be propagated towards the recipient. + + Therefore, the Incoming Point: + + - inserts the incoming message in a PEC anomaly envelope (section + 3.2.2); + + + +Petrucci, et al. Informational [Page 14] + +RFC 6109 Certified Electronic Mail April 2011 + + + - forwards the PEC anomaly envelope to the Delivery Point. + + o if the incoming message does not originate from a PEC system, + i.e., fails verifications regarding existence, origin, and + validity of the signature, then the message will be treated as + ordinary email, and, if propagated to the recipient: + + - is inserted in a PEC anomaly envelope (section 3.2.2); + + - the PEC anomaly envelope is forwarded to the Delivery Point. + + The server-server acceptance PEC notification is generated by the + receiving provider and sent to the sending provider. Its purpose + is to keep track of the message in its transition from one + provider to another, and is therefore strictly intra-provider + communication; the end user knows nothing about it. + + To check the correctness and integrity of a PEC transport envelope + or notification, the Incoming Point runs the following tests: + + o Signature existence - the system verifies the presence of an + S/MIME signature structure within the incoming message; + + o Signature origin - the system verifies whether or not the + signature belongs to a PEC provider by extracting the certificate + used for signing and verifying its presence in the PEC providers + directory. To ease the check, it is possible to calculate the + certificate's [SHA1] hash value and perform a case-insensitive + search of its hexadecimal representation within the + "providerCertificateHash" attribute found in the PEC providers + directory. This operation allows one to easily identify the + sender provider for subsequent and necessary matching checks + between the extracted certificate and the one present in the + provider's record; + + o Signature validity - S/MIME signature correctness is verified by + recalculating the signature value, checking the entire + certification path, and verifying the [CRL] and temporal validity + of the certificate. In case some caching mechanism is used for + CRL contents, an update interval MUST be adopted so that the most + up-to-date data is guaranteed, thus minimizing the possible delay + between a publication revocation by the Certification Authority + and the variation acknowledgment by the provider; + + o Formal correctness - the provider performs sufficient and + necessary checks to guarantee that the incoming message is + compliant with the formats specified in this document (PEC + transport envelope and notifications). + + + +Petrucci, et al. Informational [Page 15] + +RFC 6109 Certified Electronic Mail April 2011 + + + If a virus-infected PEC transport envelope passes the checks just + mentioned, it is still considered correct and undamaged. The + presence of the virus will be detected in a second phase, during + which the contents of the PEC transport envelope are verified. + Thus, the Incoming Point will refrain from forwarding the message + to the recipient, instead sending the appropriate PEC notification + of non-delivery and storing the virus-infected message in the + provider's special storage. + + In case ordinary mail messages are received, the PEC provider + SHALL perform virus checks in order to prevent the infiltration of + potentially dangerous mail messages within the PEC system. If a + virus is detected in an ordinary mail message, the latter can be + discarded at the Incoming Point before it enters the PEC system. + In other words, no special treatment is reserved for the error; it + is handled in a manner that is conformant to the procedures + usually followed for messages going through the Internet. + + When the receiving provider detects a virus inside a PEC transport + envelope during the reception phase, it emits a virus detection + PEC notification to the sending provider, which then realizes its + checks failed to detect that virus. When this happens, the + sending provider MUST: + + o check what virus typologies were not detected by its own antivirus + to verify the possibility of interventions + + o send a virus-induced non-delivery PEC notification to the sender's + mailbox. + +2.2.3. Delivery Point + + This point is the point that receives messages from the Incoming + Point and forwards them to the final recipient. + + It MUST run a series of tests on received messages before forwarding + them to the user (see section 3.3.1). It first verifies the typology + of the message and decides whether or not a PEC notification should + be issued to the sender. The delivery PEC notification (section + 3.3.2) is emitted after the message was delivered to the recipient's + PEC mailbox and only at reception of a valid PEC transport envelope + (sections 2.2.2 and 3.1.5). + + In all other cases, such as PEC anomaly envelopes and PEC + notifications, the delivery PEC notification is not emitted. + Regardless, the message received from the Delivery Point MUST be + delivered unmodified to the recipient's mailbox. + + + + +Petrucci, et al. Informational [Page 16] + +RFC 6109 Certified Electronic Mail April 2011 + + + The delivery PEC notification indicates to the sender that the + message sent was in fact conveyed to the specified recipient's + mailbox and certifies the date and time of delivery through use of + user-readable text and an XML part containing certification data, + along with other possible attachments added for extra features + offered by the provider. + + If a PEC transport envelope received at the Delivery Point can't be + delivered to the destination mailbox, the Delivery Point emits a non- + delivery PEC notification (section 3.3.3). If, on the other hand, + the delivery error concerns a message that arrives from Internet + (i.e., a non-PEC message), no such notification is emitted. + +2.2.4. Storage + + Each provider MUST dedicate a special storage for the deposition of + any virus-infected messages encountered. Whether the virus be + detected by the sender's Access Point or the receiver's Incoming + Point, the provider that detects it MUST store the mail message in + its own storage, and keep it for 30 months. + +2.2.5. Provider Service Mailbox + + For exclusive use of the provider, dedicated to the reception of PEC + notifications in two cases only: + + o server-server acceptance notification; and + + o virus detection notification. + +2.2.6. Provider Service Email Address + + Each provider MUST register a special purpose email address for use + when sending PEC transport envelopes and notifications, as delineated + in section 3. This address MAY coincide with that of the service + mailbox described in section 2.2.5. + +2.3. Log + + The server administrator MUST keep track of any and all operations + carried out in a specific message log file. The information kept in + the log for each operation is the following: + + o message identifier (msgid) + + o date and time of event + + o sender of original message + + + +Petrucci, et al. Informational [Page 17] + +RFC 6109 Certified Electronic Mail April 2011 + + + o recipient(s) of original message + + o subject of original message + + o event type (reception, delivery, PEC notification emission, etc.) + + o message identifiers of related generated messages + + o sending provider + + The service provider MUST store this data and preserve it unmodified. + Italian laws have specified that the service provider retain the data + for 30 months. + +3. Message Processing + +3.1. Access Point + + The Access Point acts as a submission service as defined in + [SUBMISSION]. + +3.1.1. Formal Checks on Messages + + When the Access Point receives a message the user wishes to send, it + MUST guarantee said message's formal conformity as defined in + [EMAIL], and verify that the: + + o [EMAIL] header section contains a "From:" header field holding an + [EMAIL] compliant email address; + + o [EMAIL] header section contains a "To:" header field holding one + or more [EMAIL] compliant email addresses; + + o sender's address, specified in the SMTP reverse path, coincides + with the one in the message's "From:" header field; + + o recipients' addresses specified in the SMTP forward path coincide + with the ones present in the "To:" or "Cc:" header fields of the + message; + + o "Bcc:" header field does not contain any value; + + o total message size falls within the limits accepted by the + provider. Such limits apply depending on the number of recipients + as well; by multiplying it to the message size, the outcome MUST + fall within the limits accepted by the provider. Italian laws + have specified this limit as being 30 MB. + + + + +Petrucci, et al. Informational [Page 18] + +RFC 6109 Certified Electronic Mail April 2011 + + + If the message does not pass the tests, the Access Point MUST NOT + accept the message within the PEC system, thus emitting the relative + PEC notification of non-acceptance. + +3.1.2. Non-Acceptance PEC Notification Due to Formal Exceptions + + When the Access Point cannot forward the message received due to + failure in passing formal checks, the sender is notified of such an + outcome. If the error is caused by the message failing size checks, + a non-acceptance PEC notification is sent as long as the size remains + bound by a certain limit. If the size exceeds said limit, error + handling is left to SMTP. + + The notification header will contain the following fields: + + X-Ricevuta: non-accettazione + Date: [date of notification emission] + Subject: AVVISO DI NON ACCETTAZIONE: [original subject] + From: posta-certificata@[mail domain] + To: [original sender] + X-Riferimento-Message-ID: [msgid] + + The notification body will contain a text part that constitutes the + actual notification in readable format according to a model that + relates the following information: + + Error in message acceptance + On [date] at [time] ([time zone]), in the message "[subject]" + originating from "[original sender]" and addressed to: + [recipient_1] + [recipient_2] + [recipient_n] + a problem was detected that prevents its acceptance due to + [error description]. + The message was not accepted. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification information is inserted in an XML file to be + added to the notification body, thus allowing automatic checks on the + message (section 4.4). Parsing MUST be done on the XML part only. + Additional parts MAY be included by the provider for provider- + specific services. Regardless, the original message MUST NOT be + included. The message MUST follow the format described in section + 4.3. + + + + + + +Petrucci, et al. Informational [Page 19] + +RFC 6109 Certified Electronic Mail April 2011 + + +3.1.3. Non-Acceptance PEC Notification Due to Virus Detection + + The Access Point MUST run some tests on the content of messages it + receives from its users and reject them if a virus is detected. In + which case, a virus-detection-induced non-acceptance PEC notification + MUST be emitted to clearly inform the user of the reason the message + was refused. + + The notification header contains the following fields: + + X-Ricevuta: non-accettazione + X-VerificaSicurezza: errore + Date: [notification emission date] + Subject: AVVISO DI NON ACCETTAZIONE PER VIRUS: [original + subject] + From: posta-certificata@[mail domain] + To: [original sender] + X-Riferimento-Message-ID: [msgid] + + The body contains a readable text part according to the following + model: + + Error in message acceptance due to virus presence + On [date] at [time] ([time zone]), in the message "[subject]" + originating from "[original sender]" and addressed to: + [recipient_1] + [recipient_2] + [recipient_n] + a security problem was detected [ID of detected content type]. + The message was not accepted. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted in an XML file added to the + notification to allow for automatic checks (section 4.4). Parsing + MUST be done on the XML part only. Additional parts MAY be included + by the provider for provider-specific services. Regardless, the + original message MUST NOT be included. The message MUST follow the + format described in section 4.3. + +3.1.4. Server-User Acceptance PEC Notification + + The server-user acceptance PEC notification is a message sent to the + sender by his server, containing date and time of message acceptance + into the system, sender and recipient data, and subject. + + + + + + +Petrucci, et al. Informational [Page 20] + +RFC 6109 Certified Electronic Mail April 2011 + + + The header contains the following fields: + + X-Ricevuta: accettazione + Date: [actual date of server-user acceptance] + Subject: ACCETTAZIONE: [original subject] + From: posta-certificata@[mail domain] + To: [original sender] + X-Riferimento-Message-ID: [msgid] + + The message body contains a text part that constitutes the + notification in readable format, according to a model that relates + the following information: + + Server-User Acceptance PEC notification + On [date] at [time] ([time zone]), the message "[subject]" + originating from "[original sender]" and addressed to: + [recipient_1] (["certified mail" | "ordinary mail"]) + [recipient_2] (["certified mail" | "ordinary mail"]) + [recipient_n] (["certified mail" | "ordinary mail"]) + was accepted by the system and forwarded to the recipient(s). + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted in an XML file added to the + notification message, allowing automatic checks on it (section 4.4). + Parsing MUST be done on the XML part only. Additional parts MAY be + included by the provider for provider-specific services. The message + MUST follow the format described in section 4.3. + +3.1.5. PEC Transport Envelope + + A PEC transport envelope is a message generated by the Access Point + that contains the original message as well as certification data. + + As mentioned in section 2.1.1.2, the PEC transport envelope inherits + from the original message the values of the following header fields, + which MUST be related unmodified: + + o Received: + + o To: + + o Cc: + + o Return-Path: + + o Reply-To: (if present) + + + + +Petrucci, et al. Informational [Page 21] + +RFC 6109 Certified Electronic Mail April 2011 + + + On the other hand, the following fields MUST be modified, or inserted + if necessary: + + X-Trasporto: posta-certificata + Date: [actual date of server-user acceptance] + Subject: POSTA CERTIFICATA: [original subject] + From: "On behalf of: [original sender]" + <certified-mail@[mail_domain]> + Reply-To: [original sender] (inserted only if not present) + Message-ID: [PEC msgid generated as in section 2.2.1] + X-Riferimento-Message-ID: [msgid] + X-TipoRicevuta: [completa/breve/sintetica] + + The "X-TipoRicevuta:" field indicates the type of delivery PEC + notification the sender wishes to receive -- complete, brief, or + concise. + + The body of the PEC transport envelope contains a text part that + constitutes the readable format of the message according to a model + that relates the following certification data: + + Certified mail message + On [date] at [time] ([time zone]), the message "[subject]" was + sent by "[original sender]" and addressed to: + [recipient_1] + [recipient_2] + [recipient_n] + The original message is included in attachment. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + Within the PEC transport envelope, the entire, non-modified original + message is inserted in a format compliant with [EMAIL] (except for + what has been said regarding the message identifier), as well as an + XML part, which contains the certification data that was already + related in text format, and information on the type of message and + PEC notification requested (section 4.4). Parsing MUST be done on + the XML part only. Additional parts MAY be included by the provider + for provider-specific services. The message MUST follow the format + described in section 4.3. + + Note that the routing data of the PEC transport envelope (forward and + reverse paths) remain unaltered. + + + + + + + + +Petrucci, et al. Informational [Page 22] + +RFC 6109 Certified Electronic Mail April 2011 + + +3.1.6. Timeout Delivery Error PEC Notification + + If the sending provider doesn't receive a server-server acceptance or + delivery PEC notification from the receiving provider within 12 hours + of the message dispatch, it informs the user that the recipient's + provider might not be able to deliver the message. In case the + sending provider doesn't receive a delivery PEC notification within + 24 hours after message dispatch, it emits another non-delivery PEC + notification to the user by the 24-hour timeout, but not before 22 + hours have passed. + + Such a communication takes place through a PEC notification of non- + delivery due to timeout, the header of which contains the following + fields: + + X-Ricevuta: preavviso-errore-consegna + Date: [date of notification emission] + Subject: AVVISO DI MANCATA CONSEGNA PER SUP. TEMPO MASSIMO: + [original subject] + From: posta-certificata@[mail domain] + To: [original recipient] + X-Riferimento-Message-ID: [msgid] + + The body of the first non-delivery PEC notification (12-hour timeout) + contains a text part that represents the readable format of the + notification which will relate the following data: + + Non-delivery PEC notification + On [date] at [time] ([time zone]), the message + "[subject]" originating from "[original sender]" + and addressed to "[recipient]" + has not been delivered within the first 12 hours following + its dispatch. Not excluding that the message might eventually + be delivered, it is deemed useful to consider that dispatch + might not have a positive outcome. The system will see to + sending another non-delivery PEC notification if in the + following twelve hours no confirmation is received from the + recipient. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + On the other hand, 24-hour-timeout induced PEC notifications, which + have the same header as described above, will have the following text + in their body: + + + + + + + +Petrucci, et al. Informational [Page 23] + +RFC 6109 Certified Electronic Mail April 2011 + + + Non-delivery PEC notification + On [date] at [time] ([time zone]), the message + "[subject]" originating from "[original sender]" + and addressed to "[recipient]" + has not been delivered within 24 hours of its dispatch. + + The transaction is deemed to be considered terminated with a + negative outcome. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted in an XML file added to both + PEC notification types to allow automatic checks (section 4.4). + + Parsing MUST be done on the XML part only. Additional parts MAY be + added for services supplied by the PEC provider. Regardless, the + original message MUST NOT be included. The message MUST follow the + format described in section 4.3. + + A timeout PEC notification is generated if one of the following + scenarios occurs: + + o the sending provider receives a server-server acceptance PEC + notification during the first 12 hours following message dispatch, + but does not receive a delivery PEC notification at all. In this + case, it would be a 24-hour timeout PEC notification. + + o the sending provider does not receive a server-server acceptance + PEC notification, but receives a delivery PEC notification after + 12 hours and before the 24-hour timeout. In this case it would be + a 12-hour timeout PEC notification. + + o the sending provider doesn't receive either a server-server + acceptance or a delivery PEC notification. In this case, two + timeout PEC notifications are generated; a 12-hour and a 24-hour + timeout PEC notification. + +3.2. Incoming Point + +3.2.1. Server-Server Acceptance PEC Notification + + When correct PEC transport envelopes (as defined in section 2.2.2.) + are exchanged between PEC providers, the receiver MUST send a server- + server acceptance PEC notification to the sender. The single + dispatched notification concerns all recipients who belong to the + same provider, and to whom the incoming message was addressed, as + stated in the routing data (forward and reverse paths) of the SMTP + transaction. Within the certification data of a single server-server + + + +Petrucci, et al. Informational [Page 24] + +RFC 6109 Certified Electronic Mail April 2011 + + + acceptance PEC notification, all recipients of the message to which + it refers are listed. In general, when receiving a PEC transport + envelope, each provider MUST emit one or more server-server + acceptance PEC notifications to cover, in absence of SMTP transport + errors, all the recipients in its jurisdiction. + + The header of a server-server acceptance PEC notification contains + the following fields: + + X-Ricevuta: presa-in-carico + Date: [date of server-server acceptance] + Subject: PRESA IN CARICO: [original subject] + From: posta-certificata@[mail domain] + To: [sender provider service mailbox] + X-Riferimento-Message-ID: [msgid] + + The provider's service email address is obtained from the PEC + providers directory during the necessary queries made in the + signature verification stage. + + The body contains a text part that follows the underlying model: + + Server-server acceptance PEC notification + On [date] at [time] ([time zone]), the message "[subject]" + originating from "[original sender]" and addressed to: + [recipient_1] + [recipient_2] + [recipient_n] + was accepted by the system. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted in an XML file which is added + to the notification message to allow for automatic checks (section + 4.4). Parsing MUST be done on the XML part only. Additional parts + MAY be added by the provider for provider-specific services. The + message MUST follow the format described in section 4.3. + +3.2.2. PEC Anomaly Envelope + + If the tests on an incoming message detect an error, or the message + is identified as being ordinary mail and the provider is set to + forward it to the recipient, the system MUST insert such a message in + a PEC anomaly envelope. Before delivery, the entire message received + + + + + + + +Petrucci, et al. Informational [Page 25] + +RFC 6109 Certified Electronic Mail April 2011 + + + at the Incoming Point is inserted in a format compliant with [EMAIL] + as a [MIME1] part inside a new message that MUST inherit the + unmodified values for the following header fields from the received + message: + + o Received: + + o To: + + o Cc: + + o Return-Path: + + o Message-ID: + + Whereas, the following header fields MUST be modified or inserted: + + X-Trasplorto: errore + Date: [mlessage arrival date] + Subject: ANOMALIA MESSAGGIO: [original subject] + From: "On behalf of: [original sender]" + <posta-certificata@[mail_domain]> + Reply-To: [original sender (inserted only if not already + present)] + + The body contains a user-readable text part according to a model that + relates the following data: + + Message anomaly + On [date] at [time] ([time zone]), the message "[subject]" + originating from "[original sender]" and addressed to: + [recipient_1] + [recipient_2] + [recipient_n] + was received. + The data has not been certified due to the following error: + [concise description of error] + The original message is attached. + + Due to uncertainty regarding origin and/or conformity of the message + received, the PEC anomaly envelope MUST NOT contain [MIME1] parts + other than the entire message that arrived at the Incoming Point. + + Note that the routing data of such an envelope (forward and reverse + paths) remain unaltered. Doing so guarantees both message forwarding + to the recipients, and reception of SMTP error notifications, if any + occur, by the sender (as specified in [SMTP] and [SMTP-DSN]). + + + + +Petrucci, et al. Informational [Page 26] + +RFC 6109 Certified Electronic Mail April 2011 + + +3.2.3. Virus Detection PEC Notification + + If the Incoming Point receives virus-infected PEC messages, it MUST + NOT forward them. Rather it MUST inform the sending provider, which + will in turn inform the sending user, of the failed transmission. A + separate PEC notification of virus detection MUST be sent on behalf + of every recipient within the provider's domain. + + In case a virus is detected during the reception phase of a message + whose origin was asserted through sender signature verification, the + system generates a virus-detected PEC notification indicating the + error found, and sends it to the sending provider's service mailbox. + + The header of this PEC notification contains the following fields: + + X-Ricevuta: rilevazione-virus + X-Mittente: [original sender] + Date: [date of notification emission] + Subject: PROBLEMA DI SICUREZZA: [original subject] + From: posta-certificata@[mail domain] + To: [sender provider notifications] + X-Riferimento-Message-ID: [msgid] + + The body contains a readable text part according to a model that + relates the following data: + + Virus detection PEC notification + On [date] at [time] ([time zone]), in the message "[subject]" + originating from "[original sender]" and addressed to + "[recipient]" + a security problem was detected [ID of content type detected]. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted in an XML file and added to + the notification to allow for automatic checks (section 4.4). + Parsing MUST be done on the XML part only. Additional parts MAY be + included by the provider for provider-specific services. Regardless, + the original message MUST NOT be included. The message MUST follow + the format described in section 4.3. + + The message body MUST contain the reason for which the transmission + could not be completed. + + + + + + + + +Petrucci, et al. Informational [Page 27] + +RFC 6109 Certified Electronic Mail April 2011 + + +3.2.4. Virus-Induced Delivery Error PEC notification + + At the reception of a virus detection PEC notification from the + receiving provider, the sender provider emits a non-delivery PEC + notification to the sending user. + + The header for this notification contains the following fields: + + X-Ricevuta: errore-consegna + X-VerificaSicurezza: errore + Date: [date of notification emission] + Subject: AVVISO DI MANCATA CONSEGNA PER VIRUS: [original + subject] + From: posta-certificata@[mail domain] + To: [original sender] + X-Riferimento-Message-ID: [msgid] + + The body contains a readable text part according to a model that + relates the following data: + + Delivery error PEC notification due to virus + On [date] at [time] ([time zone]), in the message "[subject]" + addressed to "[recipient]" + a security problem was detected [ID of content type detected + by the anti-virus]. + The message was not delivered. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + All the information necessary for the construction of such a PEC + notification can be obtained from the correlated virus-detected PEC + notification. + + The same certification data is inserted in an XML file and added to + the notification message to allow for automatic checks (section 4.4). + Parsing MUST be done on the XML part only. Additional parts MAY be + included by the provider for provider-specific services. The reason + the transaction was not completed MUST be specified in the message, + which MUST follow the format described in section 4.3. + + + + + + + + + + + + +Petrucci, et al. Informational [Page 28] + +RFC 6109 Certified Electronic Mail April 2011 + + +3.3. Delivery Point + +3.3.1. Checks on Incoming Messages + + When a message arrives at the Delivery Point, the system verifies: + + o message type + + o whether or not a PEC notification has to be returned. + +3.3.2. Delivery PEC Notification + + A delivery PEC notification is issued only after a correct PEC + transport envelope (sections 2.2.2 and 3.1.5) has been delivered to + the recipient's mailbox. + + In all other cases (e.g., PEC anomaly envelopes, PEC notifications), + the delivery PEC notification is not issued. Regardless, the message + received at the Delivery Point MUST be delivered to the recipient's + mailbox unchanged. + + This notification tells the user that his/her message has been + successfully delivered to the specified recipient. It includes + readable text that certifies the date and time of delivery, sender + and receiver data, and the subject. It also contains an XML + certification data file and other optional parts for functionalities + offered by the provider. + + The following fields are inserted in the header: + + X-Ricevuta: avvenuta-consegna + Date: [delivery date] + Subject: CONSEGNA: [original subject] + From: posta-certificata@[mail domain] + To: [original sender] + X-Riferimento-Message-ID: [msgid] + + The value of the "X-TipoRicevuta:" header field in the PEC transport + envelope is derived from the original message, thus allowing the + sender to determine the type of delivery PEC notification requested + from the primary recipients of the original message. The + notification MUST follow the format described in section 4.3. + +3.3.2.1. Delivery PEC Notification: Complete + + This is the default value for delivery PEC notifications. When no + value for "X-TipoRicevuta:" is specified, or when it contains the + value "completa" (complete), the system will require a complete + + + +Petrucci, et al. Informational [Page 29] + +RFC 6109 Certified Electronic Mail April 2011 + + + delivery PEC notification from addressees in the "To:" field, while a + concise PEC notification (section 3.3.2.3) will be required from + those in the "Cc:" field. The distinction between primary recipients + and those in carbon copy is done through an analysis of the "To:" and + "Cc:" fields. For PEC notifications sent on behalf of primary + recipients, a complete copy of the original message along with any + attachments is inserted in the notification. In case the system in + charge of delivery is not able to determine the recipient type due to + ambiguity problems in the "To:" and "Cc:" fields, delivery MUST be + considered as if addressed to a primary recipient and include the + complete copy of the original message. + + The notification body contains a readable text part that relates + certification data according to the following model: + + Delivery PEC notification + On [date] at [time] ([time zone]), the message "[subject]" + originating from "[original sender]" and addressed to + "[recipient]" + was placed in the destination's mailbox. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted in an XML file and added to + the notification (section 4.4), along with any other parts that MAY + be inserted by the provider for provider-specific services. Parsing + MUST be done on the XML part only. The delivery PEC notification + MUST be issued on behalf of every recipient of the message, and MUST + follow the format described in section 4.3. + +3.3.2.2. Delivery PEC Notification: Brief + + In order to decrease the amount of data flowing, it is possible for + the sender to ask for a delivery PEC notification in "brief" format. + The brief delivery PEC notification contains the original message and + a ciphered hash value for each of its parts. The hash value SHOULD + be calculated on base64 encoded parts. As specified in section 5.3, + PEC messages MUST transit only on machines that belong to the PEC + network and that MUST NOT alter the encoding of the message during + its transition/processing. + + NOTE: Even though PEC uses these relaxed specifications, PEC + interoperability tests between over 20 service providers have never + revealed any problems. This is probably due to mail servers leaning + more towards leaving the messages they receive intact without + + + + + + +Petrucci, et al. Informational [Page 30] + +RFC 6109 Certified Electronic Mail April 2011 + + + applying any changes. But issues might arise if a server decides to + modify encoded parts; for example, change the base64 line length, + whose hash value calculated at the receiver's end would then differ + from that at the sender's side. + + To be able to verify the transmitted contents it is necessary for the + sender to keep the unaltered original copy of the part(s) to which + the hash values refer. + + If the PEC transport envelope contains the header: + + X-TipoRicevuta: breve + + the Delivery Point emits a brief delivery PEC notification on behalf + of the primary recipients, and a concise one (section 3.3.2.3) on + behalf of carbon copy recipients. The value of the header field in + the PEC transport envelope is derived from the original message. + + The notification body contains a readable text part according to a + model that relates the following certification data: + + Brief delivery PEC notification + On [date] at [time] ([time zone]), the message "[subject]" + originating from "[original sender]" and addressed to + "[recipient]" + was placed in the destination's mailbox. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted in an XML file and added to + the notification (section 4.4), along with other parts that MAY be + included for specific provider-supplied services. Parsing MUST be + done on the XML part only. The delivery PEC notification is issued + on behalf of every recipient of the message, and MUST follow the + format described in section 4.3. + + The MIME structure of the original message is unaltered as it is + added to the notification, but each MIME part with a "name" parameter + in the header field "Content-Type:" or a "filename" parameter in the + header field "Content-Disposition:" MUST be substituted by a text + file containing that MIME part's hash value. + + When the original message has an S/MIME format, it is necessary not + to alter the integrity of the message structure. Verification of the + S/MIME part in the original message takes place when the MIME type of + the top-level entity (which coincides with the message itself) is + checked. An S/MIME message MAY have the following MIME types (as per + [SMIMEV3]): + + + +Petrucci, et al. Informational [Page 31] + +RFC 6109 Certified Electronic Mail April 2011 + + + o multipart/signed + + Represents an original message signed by the sender using the + structure described in [MIME-SECURE]. The message is made up of + two MIME parts: the first is the message itself before the + application of the sender's signature, whereas the second contains + signature data. The second part (generally of type + "application/pkcs7-signature" or "application/x-pkcs-signature") + contains data added during the signing phase and MUST be left + unchanged to avoid compromising the overall message structure; + + o "application/pkcs7-mime" or "application/x-pkcs7-mime" + + The message is composed of a sole CMS object within the MIME part. + Given that attachments cannot be separated from the CMS object, + the MIME part is left intact (i.e., it is not replaced by the hash + value); therefore, the brief PEC notification is the same as the + complete PEC notification. + + If the original message contains parts whose "Content-Type:" is + "message/rfc822", i.e., contains an email message as attachment, the + entire attached message is substituted with its corresponding hash + value. + + Therefore, when emitting a brief delivery PEC notification, the + provider MUST: + + 1. identify and extract all the parts from the first MIME part of the + multipart/signed S/MIME message; + + 2. calculate the hash values of all the files attached by the sender + to the original message; + + 3. substitute originals with their hash values. + + In general, in the case of original messages in S/MIME format, the + copy of the message inserted within the brief delivery PEC + notification will have the following characteristics: + + o if the original message is signed, the S/MIME structure and + signature-relative data will remain unchanged. The message will + generate an error in a future signature integrity verification + phase following the substitution of attachments with the + corresponding hash values. + + o if the original message contains the "application/pkcs7-mime" or + "application/x-pkcs7-mime" MIME type, attachments present in the + message will not be substituted by their hash values, due to + + + +Petrucci, et al. Informational [Page 32] + +RFC 6109 Certified Electronic Mail April 2011 + + + impossibility of identification within a CMS structure. The + content of the brief delivery PEC notification will coincide with + that of a normal delivery PEC notification. + + The algorithm used for hash calculation is the [SHA1], calculated on + the entire content of the part. To allow distinction between hash + files and the files to which they refer, the suffix ".hash" is added + to the original filename. The hash value is written in the file + using a hexadecimal representation as a single sequence of 40 + characters. The MIME type of these attachments is set to + "text/plain" to highlight their textual nature. + +3.3.2.3. Delivery PEC Notification: Concise + + If the PEC transport envelope contains the header: + + X-TipoRicevuta: sintetica + + the Delivery Point emits, both to primary and carbon copy recipients, + a concise delivery PEC notification that does not contain the + original message. + + The message body of the notification contains a readable text part + according to a model that relates the following certification data: + + Concise delivery PEC notification + On [date] at [time] ([time zone]), the message "[subject]" + originating from "[original sender]" and addressed to + "[recipient]" + was placed in the destination's mailbox. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted within an XML file and added + to the notification (section 4.4), along with additional parts that + MAY be included for provider-specific services. Parsing MUST be done + on the XML part only. The notification is sent to each one of the + recipients to whom the message is delivered, and MUST follow the + format described in section 4.3. + + The concise delivery PEC notification follows the same emission rules + as the delivery PEC notification; added to it is only the XML file + containing the certification data, not the original message. + + + + + + + + +Petrucci, et al. Informational [Page 33] + +RFC 6109 Certified Electronic Mail April 2011 + + +3.3.3. Non-Delivery PEC Notification + + If an error occurs during the delivery of a correct PEC transport + message, the system returns to the sender a non-delivery PEC + notification that indicates the error condition. + + The header will contain the following fields: + + X-Ricevuta: errore-consegna + Date: [date of notification emission] + Subject: AVVISO DI MANCATA CONSEGNA: [original subject] + From: posta-certificata@[mail domain] + To: [original sender] + X-Riferimento-Message-ID: [msgid] + + The notification body contains a readable text part according to a + model that relates the following data: + + Non-delivery PEC notification + On [date] at [time] ([time zone]), in the message "[subject]" + originating from "[original sender]" and addressed to + "[recipient]" + an error was detected [brief error description]. + The message was refused by the system. + Message identifier: [PEC msgid of corresponding + PEC transport envelope] + + The same certification data is inserted within an XML file and added + to the notification in order to allow for automatic checks (section + 4.4). Parsing MUST be done on the XML part only. Additional parts + MAY be included by the PEC provider for provider-specific services. + The notification MUST follow the format described in section 4.3. + +3.4. Sender and Receiver Belonging to the Same Domain + + PEC messages MUST be processed even if both sender and receiver(s) + belong to the same PEC domain. + +3.5. Example: Complete Transaction between Two PEC Domains + + A correct transaction between two PEC domains goes through the + following steps: + + o The sending user sends an email to his provider's Access Point; + + o The Access Point runs all checks and emits a server-user + acceptance PEC notification to the user; + + + + +Petrucci, et al. Informational [Page 34] + +RFC 6109 Certified Electronic Mail April 2011 + + + o The Access Point creates a PEC transport envelope and forwards it + to the Incoming Point of the receiving provider; + + o The receiver's Incoming Point verifies the PEC transport envelope + and creates a server-server acceptance PEC notification to be sent + to the sending provider; + + o The sender's Incoming Point verifies the validity of the server- + server acceptance PEC notification and forwards it to the Delivery + Point; + + o The sender's Delivery Point saves the server-server acceptance PEC + notification in the provider's service mailbox; + + o The receiver's Incoming Point forwards the PEC transport envelope + to the receiver's Delivery Point; + + o The receiver's Delivery Point verifies the contents of the PEC + transport envelope and saves it in the recipient's mailbox; + + o The receiver's Delivery Point creates a delivery PEC notification + and sends it to the sender's Incoming Point; + + o The sender's Incoming Point verifies the validity of the delivery + PEC notification and forwards it to the sender's Delivery Point; + + o The sender's Delivery Point saves the delivery PEC notification in + the sending user's mailbox; + + o The receiving user has the message at his disposition. + + NOTE: Some of these steps might occur in parallel, thus the + interaction might complete in a different order. + +4. Formats + +4.1. Temporal Reference + + For all operations carried out during message, notification, and log + elaboration processes by the Access, Incoming, and Delivery Points, + it is necessary to have an accurate temporal reference available. + All events (generation of PEC notifications, transport envelopes, + logs, etc.) that constitute the transaction of message elaboration at + the Access, Incoming, and Delivery Points MUST employ a sole temporal + value obtained from within the transaction itself. + + + + + + +Petrucci, et al. Informational [Page 35] + +RFC 6109 Certified Electronic Mail April 2011 + + + Doing this renders the instant of message elaboration unambiguous + within PEC logs, notifications, messages, etc., generated by the + server. + +4.2. User Date/Time + + Temporal indications supplied by the service in readable format (text + in PEC notifications, transport envelopes, etc.) are provided with + reference to the legal time at the moment of the operation. + Following is the specification using the syntax description notation + defined in [ABNF]. + + date-fullyear = 4DIGIT + date-month = 2DIGIT ; 01-12 + date-mday = 2DIGIT ; 01-28, 01-29, 01-30, 01-31 based on + ; month/year + time-hour = 2DIGIT ; 00-23 + time-minute = 2DIGIT ; 00-59 + time-second = 2DIGIT ; 00-58, 00-59, 00-60 based on leap second + ; rules + + time-offset = "(" ("+" / "-") time-hour ":" time-minute ")" + + partial-time = time-hour ":" time-minute ":" time-second + + full-date = date-mday "/" date-month "/" date-fullyear + full-time = partial-time time-offset + + NOTE: For number of days in a month, leap year, and leap second + restrictions see section 5.7 of [TIMESTAMP]. + +4.3. Format of a PEC Message Body + + This section describes the characteristics of the various components + of PEC messages and notifications generated by a PEC system. If one + of the message parts contains characters with values outside of the + range 0-127 (7-bit ASCII), that part will have to be adequately + encoded so that 7-bit transportation compatibility is guaranteed + (e.g., quoted-printable, base64 as per [MIME1]). + + Before applying the signature, the message body has Content-Type: + multipart/mixed. Each part is described in the sections below. The + first part is the user readable text generated by the PEC system, + while the second and third parts are interchangeable in order and + contain the original message and the XML file for the certification + data. + + + + + +Petrucci, et al. Informational [Page 36] + +RFC 6109 Certified Electronic Mail April 2011 + + +4.3.1. User Readable Text + + Character set: ISO-8859-1 (Latin-1) + MIME type: text/plain or multipart/alternative + + The multipart/alternative MIME type MAY be used to add an HTML + version of the body of system-generated messages. In this case, two + sub-parts MUST be present: one of type text/plain, the other + text/html. For the HTML part: + + o it MUST contain the same information as related in the text part; + + o it MUST NOT contain references to elements (e.g., images, sounds, + font, style sheets), neither internal to the message (added MIME + parts) nor external (e.g., hosted on the provider's server); + + o it MUST NOT have active content (e.g., JavaScript, VBscript, Plug- + in, ActiveX). + +4.3.2. Original Message + + MIME type: message/rfc822 + Attachment name: postacert.eml + +4.3.3. Certification Data + + Character set: UTF-8 + MIME type: application/xml + Attachment name: certdata.xml + +4.4. Certification Data Scheme + + Following is the DTD relative to the [XML] file that contains + certification data attached to PEC notifications. + + <!--Use the element "postacert" as root--> + <!--"tipo" indicates the typology of the PEC message--> + <!--The attribute "errore" can have the following values--> + <!--"nessuno" = no error--> + <!--"no-dest" (with type="errore-consegna") = --> + <!-- wrong recipient--> + <!--"no-dominio" (with type="errore-consegna") = --> + <!-- wrong domain--> + <!--"virus" (with type="errore-consegna") = virus--> + <!--"virus" (with type="non-accettazione") = virus--> + <!--"altro" = generic error--> + <!ELEMENT postacert (intestazione, dati)> + <!ATTLIST postacert + + + +Petrucci, et al. Informational [Page 37] + +RFC 6109 Certified Electronic Mail April 2011 + + + tipo (accettazione | + non-accettazione | + presa-in-carico | + avvenuta-consegna | + posta-certificata | + errore-consegna | + preavviso-errore-consegna | + rilevazione-virus) #REQUIRED + errore (nessuno | + no-dest | + no-dominio | + virus | + altro) "nessuno"> + + <!--Header of the original message--> + <!ELEMENT intestazione (mittente, + destinatari+, + risposte, + oggetto?)> + + <!--Sender ("From:" field) of the original message--> + <!ELEMENT mittente (#PCDATA)> + + <!--Complete list of recipients ("To:" and "Cc:" fields)--> + <!--of the original message--> + <!--"tipo" indicates the typology of the recipient--> + <!ELEMENT destinatari (#PCDATA)> + <!ATTLIST destinatari + tipo (certificato | esterno) "certificato"> + + <!--Value of the "Reply-To:" field of the original message--> + <!ELEMENT risposte (#PCDATA)> + <!--Value of the "Subject:" field of the original message--> + <!ELEMENT oggetto (#PCDATA)> + + <!--PEC message data--> + <!ELEMENT dati (gestore-emittente, + data, + identificativo, + msgid?, + ricevuta?, + consegna?, + ricezione*, + errore-esteso?)> + + <!--Descriptive string of the provider that certifies --> + <!--the data--> + <!ELEMENT gestore-emittente (#PCDATA)> + + + +Petrucci, et al. Informational [Page 38] + +RFC 6109 Certified Electronic Mail April 2011 + + + <!--Date/time of message elaboration--> + <!--"zona" is the difference between local time and UTC in --> + <!--"[+|-]hhmm" format--> + <!ELEMENT data (giorno, ora)> + <!ATTLIST data + zona CDATA #REQUIRED> + + <!--Day in "dd/mm/yyyy" format--> + <!ELEMENT giorno (#PCDATA)> + <!--Local hour in "hh:mm:ss" format--> + <!ELEMENT ora (#PCDATA)> + + <!--PEC msgid--> + <!ELEMENT identificativo (#PCDATA)> + + <!--msgid of the original message before modifications--> + <!ELEMENT msgid (#PCDATA)> + + <!--For PEC transport envelopes and delivery notifications--> + <!--indicate the type of PEC notification requested by the--> + <!--sender--> + <!ELEMENT ricevuta EMPTY> + <!ATTLIST ricevuta + tipo (completa | + breve | + sintetica ) #REQUIRED> + + <!--For delivery, non-delivery, virus-induced non-delivery, --> + <!-- virus detection, and timeout PEC notifications--> + <!--Recipient address to which delivery has been carried --> + <!--out/tried--> + <!ELEMENT consegna (#PCDATA)> + <!--For server-server acceptance PEC notifications--> + <!--recipients for whom it is the relative PEC notification--> + <!ELEMENT ricezione (#PCDATA)> + + <!--In case of error--> + <!--brief description of the error--> + <!ELEMENT errore-esteso (#PCDATA)> + +4.5. PEC Providers Directory Scheme + + The PEC providers directory is created through a centralized LDAP + server that contains the providers' data and their corresponding PEC + mail domains. + + + + + + +Petrucci, et al. Informational [Page 39] + +RFC 6109 Certified Electronic Mail April 2011 + + + The following are the directory scheme's attributes: + + - providerCertificateHash: hash of provider's certificate + + - providerCertificate: provider certificate + + - providerName: provider name + + - mailReceipt: provider reception email address + + - managedDomains: managed domains + + - LDIFLocationURL: provider LDIF record URL + + - providerUnit: secondary operating environment name + + The directory's base root is "o=postacert" and the + "DistinguishedName" of single records is of the type + "<providerName=<name>,o=postacert>". Search within the directory is + carried out mainly in case-sensitive mode using the + "providerCertificateHash" attribute (during envelope signature + verification phase) or the "managedDomains" attribute (during message + acceptance phase). It is possible for the record of a single + provider to contain multiple "providerCertificate" attributes with + the related "providerCertificateHash" attributes in order to allow + the handling of the renewal of expiring certificates. The provider + MUST make sure to update its record with sufficient advance before + the certificate expiration date, by adding a new certificate whose + validity overlaps that of the previous one. + + The data of all PEC providers is encompassed in a [LDIF] file, which + is available as an [HTTPS] object and can be found at the URL to + which the 'LDIFLocationURL' attribute in the "dn: o=postacert" record + points (see section 4.5.6). To guarantee authenticity, that file + MUST be signed by the provider for the operations regarding its PEC + services using the method described for single providers. The file, + the signature, and the X.509v3 certificate MUST be inserted in a + PKCS#7 structure in binary ASN.1 DER format as a file with ".p7m" + extension. The centralized [LDAP] system downloads that file on a + daily basis and, after suitable verifications of the signature, + applies it to the provider's record. + + Through the [LDIF] file, single providers MUST keep a copy of the + directory locally, updated on a daily basis, in order to improve + system performance by avoiding continuous request dispatches to the + central system for every message elaboration phase. + + + + + +Petrucci, et al. Informational [Page 40] + +RFC 6109 Certified Electronic Mail April 2011 + + + If secondary environments are present, the [LDIF] file indicated in + the main environment's record MUST relate the contents of all the + provider-relevant records. + + NOTE: This specification uses an unregistered LDAP DN name space + that may lead to conflict with other registered or + unregistered names. + +4.5.1. providerCertificateHash Attribute + + The 'providerCertificateHash' attribute is a hexadecimal + representation of the hash in SHA1 format of the X.509v3 certificate + used by the provider for PEC notifications and envelope signatures. + + ( 1.3.6.1.4.1.16572.2.2.1 NAME 'providerCertificateHash' + DESC 'Hash SHA1 of X.509 certificate in hexadecimal format' + EQUALITY caseIgnoreIA5Match + SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 ) + + The IA5String ( 1.3.6.1.4.1.1466.115.121.1.26 ) syntax is defined in + [LDAP-SYNTAXES]. + +4.5.2. providerCertificate Attribute + + The 'providerCertificate' attribute holds a set of certificate(s) + used by the provider to sign PEC notifications and transport + envelopes. + + ( 1.3.6.1.4.1.16572.2.2.2 NAME 'providerCertificate' + DESC 'X.509 certificate in ASN.1 DER binary format' + SYNTAX 1.3.6.1.4.1.1466.115.121.1.8 ) + + The Certificate syntax ( 1.3.6.1.4.1.1466.115.121.1.8 ) is defined in + [RFC4523]. + + As required by this attribute type's syntax, values of this attribute + are requested and transferred using the attribute description + "providerCertificate;binary" [RFC4522]. + +4.5.3. providerName Attribute + + The 'providerName' attribute contains the name of the PEC provider. + All records MUST contain their provider's name in this attribute. + + + + + + + + +Petrucci, et al. Informational [Page 41] + +RFC 6109 Certified Electronic Mail April 2011 + + + ( 1.3.6.1.4.1.16572.2.2.3 NAME 'providerName' + DESC 'PEC provider name' + EQUALITY caseIgnoreMatch + SUBSTR caseIgnoreSubstringsMatch + SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 + SINGLE-VALUE ) + + The Directory String ( 1.3.6.1.4.1.1466.115.121.1.15 ) syntax is + defined in [LDAP-SYNTAXES]. + +4.5.4. mailReceipt Attribute + + The 'mailReceipt' attribute contains the provider's email address + within the provider to which server-server acceptance and virus + detection PEC notifications are sent. This address is a limited + version of the addr-spec construct described in [EMAIL] (without + angle brackets); it only permits the dot-atom-text form on both the + left- and right-hand sides of the "@", and does not have internal + CFWS. + + ( 1.3.6.1.4.1.16572.2.2.4 NAME 'mailReceipt' + DESC 'E-mail address of the service mailbox' + EQUALITY caseIgnoreIA5Match + SUBSTR caseIgnoreIA5SubstringsMatch + SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 + SINGLE-VALUE ) + + The IA5String ( 1.3.6.1.4.1.1466.115.121.1.26 ) syntax is defined in + [LDAP-SYNTAXES]. + +4.5.5. managedDomains Attribute + + The 'managedDomains' attribute holds a set of domains [SMTP] that are + handled by a PEC provider. Domains are limited to dot-atom form + ([RFC1034], [EMAIL]). + + ( 1.3.6.1.4.1.16572.2.2.5 NAME 'managedDomains' + DESC 'Domains handled by the PEC provider' + EQUALITY caseIgnoreIA5Match + SUBSTR caseIgnoreIA5SubstringsMatch + SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 ) + + The IA5String ( 1.3.6.1.4.1.1466.115.121.26 ) syntax is defined in + [LDAP-SYNTAXES]. + + The 'managedDomains' attribute holds a set of domains [SMTP] that are + handled by a PEC provider. Domains are limited to dot-atom form + ([RFC1034], [EMAIL]). + + + +Petrucci, et al. Informational [Page 42] + +RFC 6109 Certified Electronic Mail April 2011 + + +4.5.6. LDIFLocationURL Attribute + + The 'LDIFLocationURL' attribute contains an [HTTPS] URL that points + to the location of the [LDIF] file defining the provider's record. + When the attribute is present in the record "dn: o=postacert", then + it contains the definition of the entire directory in [LDIF] format. + The LDIF file will have a MIME type of application/pkcs7-mime, with + the parameter smime-type/signed-data. [SMIMEV3] The LDIF file is + encoded using the UTF-8 character set. + + Secondary environment records MUST NOT contain the 'LDIFLocationURL' + attribute which is obtained from the main environment's attributes + for all records connected to the provider. + + ( 1.3.6.1.4.1.16572.2.2.6 NAME 'LDIFLocationURL' + DESC 'URL of the LDIF file that defines the entry' + EQUALITY caseExactMatch + SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 + SINGLE-VALUE ) + + The Directory String ( 1.3.6.1.4.1.1466.115.121.1.15 ) syntax is + defined in [LDAP-SYNTAXES]. + +4.5.7. providerUnit Attribute + + The 'providerUnit' attribute contains the name of secondary operating + environments -- an attribute not present for the main environment. + It is possible for the provider to define several distinct records, + each indicating a single, different, secondary operating environment, + for which it is possible to declare specific attributes that are, if + need be, distinct from those relative to the main and other + environments. + + The "DistinguishedName" of the records relative to the secondary + operating environments are of the type + "<providerUnits=<environment>,providerName=<name>,o=postacert>". + Every provider MUST have a record associated to its own main + environment, distinguishable for the absence of the "providerUnit" + attribute within the record and the DistinguishedName. + + ( 1.3.6.1.4.1.16572.2.2.7 NAME 'providerUnit' + DESC 'Name of the secondary operative environment' + EQUALITY caseIgnoreMatch + SUBSTR caseIgnoreSubstringsMatch + SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 + SINGLE-VALUE ) + + + + + +Petrucci, et al. Informational [Page 43] + +RFC 6109 Certified Electronic Mail April 2011 + + + The Directory String ( 1.3.6.1.4.1.1466.115.121.1.15 ) syntax is + defined in [LDAP-SYNTAXES]. + +4.5.8. LDIFLocationURLObject Object Class + + The schema definition of the 'LDIFLocationURLObject' object class: + + ( 1.3.6.1.4.1.16572.2.1.1 NAME 'LDIFLocationURLObject' + SUP top AUXILIARY + MAY ( LDIFLocationURL ) ) + +4.5.9. Provider Object Class + + The schema definition of the 'provider' object class: + + ( 1.3.6.1.4.1.16572.2.1.2 NAME 'provider' + SUP top STRUCTURAL + MUST ( providerCertificateHash + providerCertificate + providerName + mailReceipt + managedDomains ) + + MAY ( description + LDIFLocationURL + providerUnit ) + +4.5.10. LDIF File Example + + The following LDIF file represents an example of a providers' + directory, containing a base root and two fictitious providers. The + inserted certificates are two self-signed certificates used for + example purposes only: + + dn: o=postacert + objectclass: top + objectclass: organization + objectClass: LDIFLocationURLObject + o: postacert + LDIFLocationURL: https://igpec.rupa.example.com/igpec.ldif.p7m + description: Base root for the PEC providers directory + dn: providerName=Anonymous Certified Mail S.p.A.,o=postacert + objectclass: top + objectclass: provider + providerName: Anonymous Certified Mail S.p.A. + providerCertificateHash: + 7E7AEF1059AE0F454F2643A95F69EC3556009239 + providerCertificate;binary:: + + + +Petrucci, et al. Informational [Page 44] + +RFC 6109 Certified Electronic Mail April 2011 + + + MIIDBjCCAm+gAwIBAgIBADANBgkqhkiG9w0BAQQFADBmMQswCQYDVQQGEw + JJVDEpMCcGA1UEChMgQW5vbmltYSBQb3N0YSBDZXJ0aWZpY2F0YSBTLnAu + QS4xLDAqBgkqhkiG9w0BCQEWHXBvc3RhLWNlcnRpZmljYXRhQGFucG9jZX + J0Lml0MB4XDTAyMTIwOTE3MjQxNVoXDTAzMTIwOTE3MjQxNVowZjELMAkG + A1UEBhMCSVQxKTAnBgNVBAoTIEFub25pbWEgUG9zdGEgQ2VydGlmaWNhdG + EgUy5wLkEuMSwwKgYJKoZIhvcNAQkBFh1wb3N0YS1jZXJ0aWZpY2F0YUBh + bnBvY2VydC5pdDCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAr8J+qK + KdxV9LzDMPqwnEy0P8H/KwbI0Szs8p6UZajZdpeUK0Ncbrv1QyXZNNtSMC + 2uL09HDyx8agjgZWdhypnehguiSK3busha15RSpMGhiqxmz2b0HhOG73Gf + alZelqrwqmElna4MNUaLhbOvTd/sqPUS378w5IaIhWxzy34XcCAwEAAaOB + wzCBwDAdBgNVHQ4EFgQUN8lC0znQWEs0xspZ/aBzsaGvRZMwgZAGA1UdIw + SBiDCBhYAUN8lC0znQWEs0xspZ/aBzsaGvRZOhaqRoMGYxCzAJBgNVBAYT + AklUMSkwJwYDVQQKEyBBbm9uaW1hIFBvc3RhIENlcnRpZmljYXRhIFMucC + 5BLjEsMCoGCSqGSIb3DQEJARYdcG9zdGEtY2VydGlmaWNhdGFAYW5wb2Nl + cnQuaXSCAQAwDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0BAQQFAAOBgQA58B + Z+q1qSKpuffzTBpMtbeFkDIxMqMa+ycnxdMNvcWgCm1A9ZiFJsvqYhDDqA + XxfHjkrzXuSZkYq6WiQCsLp0aYVy40QCIwbOunhrvsxh3vsG5CgN76JzZ9 + 5Z/1OCFNhLfqf1VH2NSS8TaYCCi/VO7W1Q1KkcA2VlxlQP7McSUw== + mailReceipt: ssacceptance@postalser.example.com + LDIFLocationURL: https://anpocert.example.com/anpocert.ldif.p7m + managedDomains: mail.anpocert.example.com + managedDomains: cert.company.example.com + managedDomains: costmec.example.com + description: Certified mail services for companies + + dn: providerName=Postal Services S.p.A,o=postacert + objectclass: top + objectclass: provider + providerName: Postal Services S.p.A + providerCertificateHash: + e00fdd9d88be0e2cc766b893315caf93d5701a6a + providerCertificate;binary:: + MIIDHjCCAoegAwIBAgIBADANBgkqhkiG9w0BAQQFADBuMQswCQYDVQQGEw + JJVDEfMB0GA1UEChMWU2Vydml6aSBQb3N0YWxpIFMuci5sLjEPMA0GA1UE + CxMGRC5DLkMuMS0wKwYJKoZIhvcNAQkBFh5wb3N0YS1jZXJ0aWZpY2F0YU + BzZXJwb3N0YWwuaXQwHhcNMDIxMjA5MTczMjE2WhcNMDMxMjA5MTczMjE2 + WjBuMQswCQYDVQQGEwJJVDEfMB0GA1UEChMWU2Vydml6aSBQb3N0YWxpIF + Muci5sLjEPMA0GA1UECxMGRC5DLkMuMS0wKwYJKoZIhvcNAQkBFh5wb3N0 + YS1jZXJ0aWZpY2F0YUBzZXJwb3N0YWwuaXQwgZ8wDQYJKoZIhvcNAQEBBQ + ADgY0AMIGJAoGBAKoc7n6zA+sO8NATMcfJ+U2aoDEsrj/cObG3QAN6Sr+l + ygWxYXLBZNfSDWqL1K4edLr4gCZIDFsq0PIEaYZhYRGjhbcuJ9H/ZdtWdX + xcwEWN4mwFzlsASogsh5JeqS8db3A1JWkvhO9EUfaCYk8YMAkXYdCtLD9s + 9tCYZeTE2ut9AgMBAAGjgcswgcgwHQYDVR0OBBYEFHPw7VJIoIM3VYhuHa + eAwpPF5leMMIGYBgNVHSMEgZAwgY2AFHPw7VJIoIM3VYhuHaeAwpPF5leM + oXKkcDBuMQswCQYDVQQGEwJJVDEfMB0GA1UEChMWU2Vydml6aSBQb3N0YW + xpIFMuci5sLjEPMA0GA1UECxMGRC5DLkMuMS0wKwYJKoZIhvcNAQkBFh5w + b3N0YS1jZXJ0aWZpY2F0YUBzZXJwb3N0YWwuaXSCAQAwDAYDVR0TBAUwAw + EB/zANBgkqhkiG9w0BAQQFAAOBgQApqeXvmOyEjwhMrXezPAXELMZwv4qq + + + +Petrucci, et al. Informational [Page 45] + +RFC 6109 Certified Electronic Mail April 2011 + + + r5ri4XuxTq6sS9jRsEbZrS+NmbcJ7S7eFwNQMNxYFVJqdWoLh8qExsTLXn + sKycSnHbCfuphrKvXjQvR2da75U4zGSkroiyvJ2s9TtiCcT3lQtIjmvrFb + aSBiyzj+za7foFUCQmxCLtDaA== + mailReceipt: takecharge@postalser.example.com + LDIFLocationURL: https://postalser.example.com/ldif.txt.p7m + managedDomains: postal-services.example.com + managedDomains: receivedmail.example.com + description: Certified mail services for the public + + The following LDIF file represents an example of a PEC providers' + directory, containing a base root and two fictitious providers, the + first of which handles a secondary environment as well. The + certificates inserted are two self-signed certificates used for + example purposes only: + + dn: o=postacert + objectclass: top + objectclass: organization + objectClass: LDIFLocationURLObject + o: postacert + LDIFLocationURL: https://igpec.rupa.example.com/igpec.ldif.p7m + description: Base root for the PEC providers directory + + dn: providerName=Anonymous Certified Mail S.p.A.,o=postacert + objectclass: top + objectclass: provider + providerName: Anonymous Certified Mail S.p.A. + + providerCertificateHash: + 7E7AEF1059AE0F454F2643A95F69EC3556009239 + providerCertificate;binary:: + MIIDBjCCAm+gAwIBAgIBADANBgkqhkiG9w0BAQQFADBmMQswCQYDVQQGEw + JJVDEpMCcGA1UEChMgQW5vbmltYSBQb3N0YSBDZXJ0aWZpY2F0YSBTLnAu + QS4xLDAqBgkqhkiG9w0BCQEWHXBvc3RhLWNlcnRpZmljYXRhQGFucG9jZX + J0Lml0MB4XDTAyMTIwOTE3MjQxNVoXDTAzMTIwOTE3MjQxNVowZjELMAkG + A1UEBhMCSVQxKTAnBgNVBAoTIEFub25pbWEgUG9zdGEgQ2VydGlmaWNhdG + EgUy5wLkEuMSwwKgYJKoZIhvcNAQkBFh1wb3N0YS1jZXJ0aWZpY2F0YUBh + bnBvY2VydC5pdDCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAr8J+qK + KdxV9LzDMPqwnEy0P8H/KwbI0Szs8p6UZajZdpeUK0Ncbrv1QyXZNNtSMC + 2uL09HDyx8agjgZWdhypnehguiSK3busha15RSpMGhiqxmz2b0HhOG73Gf + alZelqrwqmElna4MNUaLhbOvTd/sqPUS378w5IaIhWxzy34XcCAwEAAaOB + wzCBwDAdBgNVHQ4EFgQUN8lC0znQWEs0xspZ/aBzsaGvRZMwgZAGA1UdIw + SBiDCBhYAUN8lC0znQWEs0xspZ/aBzsaGvRZOhaqRoMGYxCzAJBgNVBAYT + AklUMSkwJwYDVQQKEyBBbm9uaW1hIFBvc3RhIENlcnRpZmljYXRhIFMucC + 5BLjEsMCoGCSqGSIb3DQEJARYdcG9zdGEtY2VydGlmaWNhdGFAYW5wb2Nl + cnQuaXSCAQAwDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0BAQQFAAOBgQA58B + Z+q1qSKpuffzTBpMtbeFkDIxMqMa+ycnxdMNvcWgCm1A9ZiFJsvqYhDDqA + XxfHjkrzXuSZkYq6WiQCsLp0aYVy40QCIwbOunhrvsxh3vsG5CgN76JzZ9 + + + +Petrucci, et al. Informational [Page 46] + +RFC 6109 Certified Electronic Mail April 2011 + + + 5Z/1OCFNhLfqf1VH2NSS8TaYCCi/VO7W1Q1KkcA2VlxlQP7McSUw== + mailReceipt: notifications@anpocert.it.example + LDIFLocationURL: http://anpocert.example.com/anpocert.ldif.p7m + managedDomains: mail.anpocert.example.com + managedDomains: cert.company.example.com + managedDomains: costmec.example.com + description: Certified mail services for companies + dn: providerUnit=Secondary Environment, providerName=Anonymous + Certified Mail S.p.A.,o=postacert + objectclass: top + objectclass: provider + providerName: Certified Mail S.p.A. + providerUnit: Secondary Environment + providerCertificateHash: + 7E7AEF1059AE0F454F2643A95F69EC3556009239 + providerCertificate;binary:: + MIIDBjCCAm+gAwIBAgIBADANBgkqhkiG9w0BAQQFADBmMQswCQYDVQQGEw + JJVDEpMCcGA1UEChMgQW5vbmltYSBQb3N0YSBDZXJ0aWZpY2F0YSBTLnAu + QS4xLDAqBgkqhkiG9w0BCQEWHXBvc3RhLWNlcnRpZmljYXRhQGFucG9jZX + J0Lml0MB4XDTAyMTIwOTE3MjQxNVoXDTAzMTIwOTE3MjQxNVowZjELMAkG + A1UEBhMCSVQxKTAnBgNVBAoTIEFub25pbWEgUG9zdGEgQ2VydGlmaWNhdG + EgUy5wLkEuMSwwKgYJKoZIhvcNAQkBFh1wb3N0YS1jZXJ0aWZpY2F0YUBh + bnBvY2VydC5pdDCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAr8J+qK + KdxV9LzDMPqwnEy0P8H/KwbI0Szs8p6UZajZdpeUK0Ncbrv1QyXZNNtSMC + 2uL09HDyx8agjgZWdhypnehguiSK3busha15RSpMGhiqxmz2b0HhOG73Gf + alZelqrwqmElna4MNUaLhbOvTd/sqPUS378w5IaIhWxzy34XcCAwEAAaOB + wzCBwDAdBgNVHQ4EFgQUN8lC0znQWEs0xspZ/aBzsaGvRZMwgZAGA1UdIw + SBiDCBhYAUN8lC0znQWEs0xspZ/aBzsaGvRZOhaqRoMGYxCzAJBgNVBAYT + AklUMSkwJwYDVQQKEyBBbm9uaW1hIFBvc3RhIENlcnRpZmljYXRhIFMucC + 5BLjEsMCoGCSqGSIb3DQEJARYdcG9zdGEtY2VydGlmaWNhdGFAYW5wb2Nl + cnQuaXSCAQAwDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0BAQQFAAOBgQA58B + Z+q1qSKpuffzTBpMtbeFkDIxMqMa+ycnxdMNvcWgCm1A9ZiFJsvqYhDDqA + XxfHjkrzXuSZkYq6WiQCsLp0aYVy40QCIwbOunhrvsxh3vsG5CgN76JzZ9 + 5Z/1OCFNhLfqf1VH2NSS8TaYCCi/VO7W1Q1KkcA2VlxlQP7McSUw== + mailReceipt: notifications@secondary.anpocert.example.com + managedDomains: management.anpocert.example.com + managedDomains: personnel.anpocert.example.com + description: Corporate internal services + dn: providerName=Postal Services S.r.l.,o=postacert + objectclass: top + objectclass: provider + providerName: Postal Services S.r.l. + providerCertificateHash: + e00fdd9d88be0e2cc766b893315caf93d5701a6a + providerCertificate;binary:: + MIIDHjCCAoegAwIBAgIBADANBgkqhkiG9w0BAQQFADBuMQswCQYDVQQGEw + JJVDEfMB0GA1UEChMWU2Vydml6aSBQb3N0YWxpIFMuci5sLjEPMA0GA1UE + CxMGRC5DLkMuMS0wKwYJKoZIhvcNAQkBFh5wb3N0YS1jZXJ0aWZpY2F0YU + + + +Petrucci, et al. Informational [Page 47] + +RFC 6109 Certified Electronic Mail April 2011 + + + BzZXJwb3N0YWwuaXQwHhcNMDIxMjA5MTczMjE2WhcNMDMxMjA5MTczMjE2 + WjBuMQswCQYDVQQGEwJJVDEfMB0GA1UEChMWU2Vydml6aSBQb3N0YWxpIF + Muci5sLjEPMA0GA1UECxMGRC5DLkMuMS0wKwYJKoZIhvcNAQkBFh5wb3N0 + YS1jZXJ0aWZpY2F0YUBzZXJwb3N0YWwuaXQwgZ8wDQYJKoZIhvcNAQEBBQ + ADgY0AMIGJAoGBAKoc7n6zA+sO8NATMcfJ+U2aoDEsrj/cObG3QAN6Sr+l + ygWxYXLBZNfSDWqL1K4edLr4gCZIDFsq0PIEaYZhYRGjhbcuJ9H/ZdtWdX + xcwEWN4mwFzlsASogsh5JeqS8db3A1JWkvhO9EUfaCYk8YMAkXYdCtLD9s + 9tCYZeTE2ut9AgMBAAGjgcswgcgwHQYDVR0OBBYEFHPw7VJIoIM3VYhuHa + eAwpPF5leMMIGYBgNVHSMEgZAwgY2AFHPw7VJIoIM3VYhuHaeAwpPF5leM + oXKkcDBuMQswCQYDVQQGEwJJVDEfMB0GA1UEChMWU2Vydml6aSBQb3N0YW + xpIFMuci5sLjEPMA0GA1UECxMGRC5DLkMuMS0wKwYJKoZIhvcNAQkBFh5w + b3N0YS1jZXJ0aWZpY2F0YUBzZXJwb3N0YWwuaXSCAQAwDAYDVR0TBAUwAw + EB/zANBgkqhkiG9w0BAQQFAAOBgQApqeXvmOyEjwhMrXezPAXELMZwv4qq + r5ri4XuxTq6sS9jRsEbZrS+NmbcJ7S7eFwNQMNxYFVJqdWoLh8qExsTLXn + sKycPSnHbCfuphrKvXjQvR2da75U4zGSkroiyvJ2s9TtiCcT3lQtIjmvrF + baSBiyzj+za7foFUCQmxCLtDaA== + mailReceipt: ssacceptance@postalser.example.com + LDIFLocationURL: http://postalser.example.com/ldif.txt.p7m + managedDomains: postal-services.example.com + managedDomains: receivedmail.example.com + description: Certified mail services for the public + +5. Security-Related Aspects + +5.1. Digital Signature + + It is recommended that a dedicated hardware module be used to handle + private key and signature operations, the specifications of which are + outside the scope of this document. It's up to the PEC providers to + conform to security requisites expected for the service. + +5.2. Authentication + + User access to PEC services through the Access Point MUST be allowed + only upon successful user authentication on the system. + + For example, authentication might use user-ID and password, or, if + available and considered necessary for the type of service provided, + an electronic ID card or the national services card. Choice of + authentication method is left to the better judgment of the service + provider. Authentication is necessary to guarantee as much as + possible that the message is sent by a PEC user whose identification + data is congruent with the specified sender, so as to avoid + falsification of the latter. + + + + + + + +Petrucci, et al. Informational [Page 48] + +RFC 6109 Certified Electronic Mail April 2011 + + +5.3. Secure Interaction + + To guarantee that the original message remains unaltered during + transaction, envelopment and signature are applied on outgoing + messages at the Access Point, and subsequent verification of incoming + messages is done at the Incoming Point. + + All communications within the PEC network MUST use secure channels. + Integrity and confidentiality of connections between PEC provider and + user MUST be guaranteed through the use of secure protocols, such as + those based on [TLS] and those that create a secure transport channel + on which non-secure protocols can transmit (e.g., IPsec). + + The interaction between providers MUST take place using SMTP on + [TLS], as per [SMTP-TLS]. The Incoming Point MUST provide and + announce its support for the STARTTLS extension, as well as accept + both unencrypted connections (for ordinary mail) and protected ones. + To guarantee complete traceability in the flow of PEC messages, these + MUST NOT transit on systems external to the PEC network. When + exchanging messages between different providers, all transactions + MUST take place between machines that belong to the PEC network or + are directly managed by the provider. An "MX" type record MAY be + associated to each PEC domain defined within the system for name + resolution, in which case secondary reception systems specified in + that record MUST be under direct control of the provider. All in + conformance with [SMTP]. + +5.4. Virus + + Another important security aspect that concerns the PEC system, is + related to the technical and functional architecture that MUST block + the presence of viruses from endangering the security of all handled + messages. It is therefore REQUIRED to have installations and + continuous updates of anti-virus systems that hinder infections as + much as possible without intervening on the content of the certified + mail, in compliance with what has been discussed thus far. + +5.5. S/MIME Certificate + + In this document the S/MIME certificate profile is defined for use in + the certification of PEC messages done by the providers. The + proposed profile of the S/MIME certificate is based on the IETF + standards [SMIMECERT] and [CRL], which in turn are based on the + standard ISO/IEC 9594-8:2001. + + + + + + + +Petrucci, et al. Informational [Page 49] + +RFC 6109 Certified Electronic Mail April 2011 + + +5.5.1. Provider-Related Information (Subject) + + The information related to the PEC provider holder of the certificate + MUST be inserted in the Subject field (Subject DN). More precisely, + the Subject DN MUST contain the PEC provider's name as it is in the + "providerName" attribute published in the PEC providers directory + (section 4.5), but the Subject DN does not have to match the Provider + entry DN in the LDIF. The providerName MUST be present in the + CommonName or OrganizationName attributes of the "Subject:" field in + the certificate. + + Certificates MUST contain an Internet mail address, which MUST have a + value in the subjectAltName extension, and SHOULD NOT be present in + the Subject Distinguished Name. + + Valid subjectDN are: + + C=IT, O=AcmePEC S.p.A, CN=Posta Certificata + + C=IT, O=ServiziPEC S.p.A, CN=Posta Certificata + + Valorization of other attributes in the Subject DN, if present, MUST + be done in compliance with [CRL]. + +5.5.2. Certificate Extensions + + Extensions that MUST be present in the S/MIME certificate are: + + o Key Usage + + o Authority Key Identifier + + o Subject Key Identifier + + o Subject Alternative Name + + The Basic Constraints extension (Object ID:2.5.29.19) MUST NOT be + present. + + The valorization of the above listed extensions for the described + profile follows. + + The Key Usage extension (Object ID: 2.5.29.15) MUST have the + digitalSignature bit (bit 0) activated and MUST be marked as + critical. The extension MAY contain other active bits corresponding + to different Key Usage, as long as that doesn't contrast with the + indications in [CRL]. + + + + +Petrucci, et al. Informational [Page 50] + +RFC 6109 Certified Electronic Mail April 2011 + + + The Authority Key Identifier (Object ID: 2.5.29.35) MUST contain at + least the keyIdentifier field and MUST NOT be marked as critical. + + The Subject Key Identifier extension (Object ID: 2.5.29.14) MUST + contain at least the keyIdentifier field and MUST NOT be marked as + critical. + + The Subject Alternative Name (Object ID: 2.5.29.17) MUST contain at + least the rfc822Name field and MUST NOT be marked as critical. + + Adding other extensions that have not been described in this document + is to be considered OPTIONAL, as long as it remains compliant with + [CRL]; such added extensions MUST NOT be marked as critical. + +5.5.3. Example + + Following is an example of an S/MIME certificate compliant with the + minimal requisites described in this profile. Values used are of + fictitious providers generated for example purposes only. + +5.5.3.1. General-Use Certificate in Annotated Version + + An asterisk near the label of an extension means that such an + extension has been marked as critical. + + VERSION: 3 + SERIAL: 11226 (0x2bda) + INNER SIGNATURE: + ALG. ID: id-sha1-with-rsa-encryption + PARAMETER: 0 + ISSUER: + Country Name: IT + Organization Name: Certifier 1 + Organizational Unit Name: Certification Service Provider + Common Name: Certifier S.p.A. + VALIDITY: + Not Before: Oct 5, 04 09:04:23 GMT + Not After: Oct 5, 05 09:04:23 GMT + SUBJECT: + Country Name: IT + Organization Name: AcmePEC S.p.A. + Common Name: Certified Mail + PUBLIC KEY: (key size is 1024 bits) + ALGORITHM: + ALG. ID: id-rsa-encryption + PARAMETER: 0 + MODULUS: 0x00afbeb4 5563198a aa9bac3f 1b29b5be + 7f691945 89d01569 ca0d555b 5c33d7e9 + + + +Petrucci, et al. Informational [Page 51] + +RFC 6109 Certified Electronic Mail April 2011 + + + ... + d15ff128 6792def5 b3f884e6 54b326db + cf + EXPONENT: 0x010001 + EXTENSIONS: + Subject Alt Name: + RFC Name: posta-certificata@acmepec.it + Key Usage*: Digital Signature + Authority Key Identifier: 0x12345678 aaaaaaaa bbbbbbbb + cccccccc dddddddd + Subject Key Identifier: 0x3afae080 6453527a 3e5709d8 49a941a8 + a3a70ae1 + SIGNATURE: + ALG. ID: id-sha1-with-rsa-encryption + PARAMETER: 0 + VALUE: 0x874b4d25 70a46180 c9770a85 fe7923ce + b22d2955 2f3af207 142b2aba 643aaa61 + ... + d8fd10b4 c9e00ebc c089f7a3 549a1907 + ff885220 ce796328 b0f8ecac 86ffb1cc + +5.5.3.2. General-Use Certificate in Dump ASN.1 + + 0 30 794: SEQUENCE { + 4 30 514: SEQUENCE { + 8 A0 3: [0] { + 10 02 1: INTEGER 2 + : } + 13 02 2: INTEGER 11226 + 17 30 13: SEQUENCE { + 19 06 9: OBJECT IDENTIFIER + : sha1withRSAEncryption (1 2 840 113549 1 1 5) + 30 05 0: NULL + : } + 32 30 101: SEQUENCE { + 34 31 11: SET { + 36 30 9: SEQUENCE { + 38 06 3: OBJECT IDENTIFIER countryName (2 5 4 6) + 43 13 2: PrintableString 'IT' + : } + : } + 47 31 28: SET { + 49 30 26: SEQUENCE { + 51 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10) + 56 13 19: PrintableString 'Certificatore 1' + : } + : } + 77 31 22: SET { + + + +Petrucci, et al. Informational [Page 52] + +RFC 6109 Certified Electronic Mail April 2011 + + + 79 30 20: SEQUENCE { + 81 06 3: OBJECT IDENTIFIER organizationalUnitName (2 5 4 11) + 86 13 13: PrintableString 'Certification Service Provider' + : } + : } + 101 31 32: SET { + 103 30 30: SEQUENCE { + 105 06 3: OBJECT IDENTIFIER commonName (2 5 4 3) + 110 13 23: PrintableString 'Certificatore S.p.A.' + : } + : } + : } + 135 30 30: SEQUENCE { + 137 17 13: UTCTime '041005090423Z' + 152 17 13: UTCTime '051005090423Z' + : } + 167 30 66: SEQUENCE { + 169 31 11: SET { + 171 30 9: SEQUENCE { + 173 06 3: OBJECT IDENTIFIER countryName (2 5 4 6) + 178 13 2: PrintableString 'IT' + : } + : } + 182 31 23: SET { + 184 30 21: SEQUENCE { + 186 06 3: OBJECT IDENTIFIER organizationName (2 5 4 10) + 191 13 14: PrintableString 'AcmePEC S.p.A.' + : } + : } + 207 31 26: SET { + 209 30 24: SEQUENCE { + 211 06 3: OBJECT IDENTIFIER commonName (2 5 4 3) + 216 13 17: PrintableString 'Posta Certificata' + : } + : } + : } + 235 30 159: SEQUENCE { + 238 30 13: SEQUENCE { + 240 06 9: OBJECT IDENTIFIER rsaEncryption (1 2 840 113549 + 1 1 1) + 251 05 0: NULL + : } + 253 03 141: BIT STRING 0 unused bits + : 30 81 89 02 81 81 00 AF BE B4 55 63 19 8A AA 9B + : AC 3F 1B 29 B5 BE 7F 69 19 45 89 D0 15 69 CA 0D + : 55 5B 5C 33 D7 E9 C8 6E FC 14 46 C3 C3 09 47 DD + : CD 10 74 1D 76 4E 71 14 E7 69 42 BE 1C 47 61 85 + : 4D 74 76 DD 0B B5 78 4F 1E 84 DD B4 86 7F 96 DF + + + +Petrucci, et al. Informational [Page 53] + +RFC 6109 Certified Electronic Mail April 2011 + + + : 5E 7B AF 0E CE EA 12 57 0B DF 9B 63 67 4D F9 37 + : B7 48 35 27 C2 89 F3 C3 54 66 F7 DA 6C BE 4F 5D + : 85 55 07 A4 97 8C D1 5F F1 28 67 92 DE F5 B3 F8 + : [ Another 12 bytes skipped ] + : } + 397 A3 123: [3] { + 399 30 121: SEQUENCE { + 401 30 39: SEQUENCE { + 403 06 3: OBJECT IDENTIFIER subjectAltName (2 5 29 17) + 408 04 32: OCTET STRING + : 30 1E 81 1C 70 6F 73 74 61 2D 63 65 72 74 69 66 + : 69 63 61 74 61 40 61 63 6D 65 70 65 63 2E 69 74 + : } + 442 30 14: SEQUENCE { + 444 06 3: OBJECT IDENTIFIER keyUsage (2 5 29 15) + 449 01 1: BOOLEAN TRUE + 452 04 4: OCTET STRING + : 03 02 07 80 + : } + 458 30 31: SEQUENCE { + 460 06 3: OBJECT IDENTIFIER authorityKeyIdentifier (2 5 29 35) + 465 04 24: OCTET STRING + : 30 16 11 11 11 11 AA AA AA AA AA BB BB BB BB CC CC + : CC CC DD DD DD DD + : } + 491 30 29: SEQUENCE { + 493 06 3: OBJECT IDENTIFIER subjectKeyIdentifier (2 5 29 14) + 498 04 22: OCTET STRING + : 04 14 3A FA E0 80 64 53 52 7A 3E 57 09 D8 49 A9 + : 41 A8 A3 A7 0A E1 + : } + : } + : } + : } + 522 30 13: SEQUENCE { + 524 06 9: OBJECT IDENTIFIER + : sha1withRSAEncryption (1 2 840 113549 1 1 5) + 535 05 0: NULL + : } + 537 03 257: BIT STRING 0 unused bits + : 87 4B 4D 25 70 A4 61 80 C9 77 0A 85 FE 79 23 CE + : B2 2D 29 55 2F 3A F2 07 14 2B 2A BA 64 3A AA 61 + : 1F F0 E7 3F C4 E6 13 E2 09 3D F0 E1 83 A0 C0 F2 + : C6 71 7F 3A 1C 80 7F 15 B3 D6 1E 22 79 B8 AC 91 + : 51 83 F2 3A 84 86 B6 07 2B 22 E8 01 52 2D A4 50 + : 9F C6 42 D4 7C 38 B1 DD 88 CD FC E8 C3 12 C3 62 + : 64 0F 16 BF 70 15 BC 01 16 78 30 2A DA FA F3 70 + : E2 D3 0F 00 B0 FD 92 11 6C 55 45 48 F5 64 ED 98 + + + +Petrucci, et al. Informational [Page 54] + +RFC 6109 Certified Electronic Mail April 2011 + + + : [ Another 128 bytes skipped ] + : } + +5.6. PEC Providers Directory + + The contents of the PEC providers directory MUST be queried via + [HTTP] on a Secure Socket Layer (SSL), as described in [TLS], + exclusively by licensed providers that have the necessary user + certificates; this access modality guarantees authenticity, + integrity, and confidentiality of data. Each provider downloads the + LDIF file through an [HTTPS] session, which is authenticated by + checking the X.509 certificate issued by a certification authority. + +6. PEC System Client Technical and Functional Prerequisites + + This section lists the prerequisites that must be respected by a + client in order to guarantee the minimal operative functionalities to + the user of a general PEC system: + + o handling of Access and Delivery Points through secure channels; + + o handling of user authentication in message dispatch and reception + which make use of standard protocols, such as [IMAP], [POP3], and + [HTTP]; + + o support for MIME format according to [MIME1] and [MIME5]; + + o support for "ISO-8859-1 (Latin-1)" character set; + + o support for S/MIME v3 standard, as in [SMIMEV3], for verification + of signatures applied to PEC envelopes and notifications. + +7. Security Considerations + + All security considerations from [CMS] and [SMIMEV3] apply to + applications that use procedures described in this document. + + The centralized LDAP server is a critical point for the security of + the whole PEC system. An attack could compromise the whole PEC + system. PEC providers that periodically download the LDIF file + SHOULD use the best security technology to protect it from local + attacks. A PEC provider could be compromised if an attacker changed + a certificate or modified the list of domains associated to it in the + LDIF file that was copied to the PEC provider system. + + + + + + + +Petrucci, et al. Informational [Page 55] + +RFC 6109 Certified Electronic Mail April 2011 + + + When verifying the validity of the signature of a message, the + recipient system SHOULD verify that the certificate included in the + [CMS] message is present in the LDIF file (section 4.5) and that the + domain extracted by the [EMAIL] "From:" header is listed in the + managedDomains attribute associated to said certificate. + +8. IANA Considerations + +8.1. Registration of PEC Message Header Fields + + This document defines new header fields used in the messages that + transit in the PEC network. As specified and required by + [HEADERS-IANA], this document registers new header fields as + Provisional Message Header Fields as follows. + +8.1.1. Header Field: X-Riferimento-Message-ID: + + Applicable protocol: mail [EMAIL] + + Status: provisional + + Author/Change controller: + + Claudio Petrucci + DigitPA + Viale Carlo Marx 31/49 + 00137 Roma + Italy + EMail: PETRUCCI@digitpa.gov.it + + Specification document: this document, section 2.2.1, Appendix A. + +8.1.2. Header Field: X-Ricevuta: + + Applicable protocol: mail [EMAIL] + + Status: provisional + + Author/Change controller: + + Claudio Petrucci + DigitPA + Viale Carlo Marx 31/49 + 00137 Roma + Italy + EMail: PETRUCCI@digitpa.gov.it + + + + + +Petrucci, et al. Informational [Page 56] + +RFC 6109 Certified Electronic Mail April 2011 + + + Specification document: this document, sections 2.1.1.1.1, 3.1.2, + 3.1.3, 3.1.4, 3.1.6, 3.2.1, 3.2.3, 3.2.4, + 3.3.2, 3.3.3, Appendix A. + +8.1.3. Header Field: X-VerificaSicurezza: + + Applicable protocol: mail [EMAIL] + + Status: provisional + + Author/Change controller: + + Claudio Petrucci + DigitPA + Viale Carlo Marx 31/49 + 00137 Roma + Italy + EMail: PETRUCCI@digitpa.gov.it + + Specification document: this document, sections 2.1.1.1.3, 3.1.3, + 3.2.4, Appendix A. + +8.1.4. Header Field: X-Trasporto: + + Applicable protocol: mail [EMAIL] + + Status: provisional + + Author/Change controller: + + Claudio Petrucci + DigitPA + Viale Carlo Marx 31/49 + 00137 Roma + Italy + EMail: PETRUCCI@digitpa.gov.it + + Specification document: this document, sections 3.1.5, 3.2.2, + Appendix A. + +8.1.5. Header Field: X-TipoRicevuta: + + Applicable protocol: mail [EMAIL] + + Status: provisional + + + + + + +Petrucci, et al. Informational [Page 57] + +RFC 6109 Certified Electronic Mail April 2011 + + + Author/Change controller: + + Claudio Petrucci + DigitPA + Viale Carlo Marx 31/49 + 00137 Roma + Italy + EMail: PETRUCCI@digitpa.gov.it + + Specification document: this document, sections 3.1.5, 3.3.2, + 3.3.2.1, 3.3.2.2, 3.3.2.3, Appendix A. + +8.1.6. Header Field: X-Mittente: + + Applicable protocol: mail [EMAIL] + + Status: provisional + + Author/Change controller: + + Claudio Petrucci + DigitPA + Viale Carlo Marx 31/49 + 00137 Roma + Italy + EMail: PETRUCCI@digitpa.gov.it + + Specification document: this document, sections 3.2.3, Appendix A. + +8.2. Registration of LDAP Object Identifier Descriptors + + This document defines new LDAP attributes and object classes for + object identifier descriptors. As specified and required by + [LDAP-IANA], this document registers new descriptors as follows per + the Expert Review. + +8.2.1. Registration of Object Classes and Attribute Types + + Subject: Request for LDAP Descriptor Registration + + Descriptor (short name): See comments + + Object Identifier: See comments + + Person & email address to contact for further information: + See "Author/Change Controller" + + Usage: See comments + + + +Petrucci, et al. Informational [Page 58] + +RFC 6109 Certified Electronic Mail April 2011 + + + Specification: (I-D) + + Author/Change Controller: + + Claudio Petrucci + DigitPA + Viale Carlo Marx 31/49 + 00137 Roma + Italy + EMail: PETRUCCI@digitpa.gov.it + + Comments: + + The following object identifiers and associated object classes/ + attribute types are requested to be registered. + + OID Descriptor Usage + ------------------------ --------------------- ------ + 1.3.6.1.4.1.16572.2.1.1 LDIFLocationURLObject O + 1.3.6.1.4.1.16572.2.1.2 provider O + 1.3.6.1.4.1.16572.2.2.1 providerCertificateHash A + 1.3.6.1.4.1.16572.2.2.2 providerCertificate A + 1.3.6.1.4.1.16572.2.2.3 providerName A + 1.3.6.1.4.1.16572.2.2.4 mailReceipt A + 1.3.6.1.4.1.16572.2.2.5 managedDomains A + 1.3.6.1.4.1.16572.2.2.6 LDIFLocationURL A + 1.3.6.1.4.1.16572.2.2.7 providerUnit A + + Legend + ------------------- + O => Object Class + A => Attribute Type + +9. References + +9.1. Normative References + + [ABNF] Crocker, D., Ed., and P. Overell, "Augmented BNF for + Syntax Specifications: ABNF", STD 68, RFC 5234, + January 2008. + + [CMS] Housley, R., "Cryptographic Message Syntax (CMS)", + STD 70, RFC 5652, September 2009. + + [CRL] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., + Housley, R., and W. Polk, "Internet X.509 Public Key + Infrastructure Certificate and Certificate Revocation + List (CRL) Profile", RFC 5280, May 2008. + + + +Petrucci, et al. Informational [Page 59] + +RFC 6109 Certified Electronic Mail April 2011 + + + [EMAIL] Resnick, P., Ed., "Internet Message Format", RFC + 5322, October 2008. + + [HEADERS-IANA] Klyne, G., Nottingham, M., and J. Mogul, + "Registration Procedures for Message Header Fields", + BCP 90, RFC 3864, September 2004. + + [HTTP] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., + Masinter, L., Leach, P., and T. Berners-Lee, + "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, + June 1999. + + [HTTPS] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. + + [IMAP] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - + VERSION 4rev1", RFC 3501, March 2003. + + [LDAP] Zeilenga, K., Ed., "Lightweight Directory Access + Protocol (LDAP): Technical Specification Road Map", + RFC 4510, June 2006. + + [LDAP-IANA] Zeilenga, K., "Internet Assigned Numbers Authority + (IANA) Considerations for the Lightweight Directory + Access Protocol (LDAP)", BCP 64, RFC 4520, June 2006. + + [LDAP-SYNTAXES] Legg, S., Ed., "Lightweight Directory Access Protocol + (LDAP): Syntaxes and Matching Rules", RFC 4517, June + 2006. + + [LDIF] Good, G., "The LDAP Data Interchange Format (LDIF) - + Technical Specification", RFC 2849, June 2000. + + [MIME1] Freed, N. and N. Borenstein, "Multipurpose Internet + Mail Extensions (MIME) Part One: Format of Internet + Message Bodies", RFC 2045, November 1996. + + [MIME5] Freed, N. and N. Borenstein, "Multipurpose Internet + Mail Extensions (MIME) Part Five: Conformance + Criteria and Examples", RFC 2049, November 1996. + + [SUBMISSION] Gellens, R. and J. Klensin, "Message Submission for + Mail", RFC 4409, April 2006. + + [POP3] Myers, J. and M. Rose, "Post Office Protocol - + Version 3", STD 53, RFC 1939, May 1996. + + + + + + +Petrucci, et al. Informational [Page 60] + +RFC 6109 Certified Electronic Mail April 2011 + + + [REQ] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [SHA1] Eastlake 3rd, D. and P. Jones, "US Secure Hash + Algorithm 1 (SHA1)", RFC 3174, September 2001. + + [MIME-SECURE] Galvin, J., Murphy, S., Crocker, S., and N. Freed, + "Security Multiparts for MIME: Multipart/Signed and + Multipart/Encrypted", RFC 1847, October 1995. + + [SMIMEV3] Ramsdell, B. and S. Turner, "Secure/Multipurpose + Internet Mail Extensions (S/MIME) Version 3.2 Message + Specification", RFC 5751, January 2010. + + [SMIMECERT] Ramsdell, B. and S. Turner, "Secure/Multipurpose + Internet Mail Extensions (S/MIME) Version 3.2 + Certificate Handling", RFC 5750, January 2010. + + [SMTP] Klensin, J., "Simple Mail Transfer Protocol", RFC + 5321, October 2008. + + [SMTP-DSN] Moore, K., "Simple Mail Transfer Protocol (SMTP) + Service Extension for Delivery Status Notifications + (DSNs)", RFC 3461, January 2003. + + [SMTP-TLS] Hoffman, P., "SMTP Service Extension for Secure SMTP + over Transport Layer Security", RFC 3207, February + 2002. + + [TIMESTAMP] Klyne, G. and C. Newman, "Date and Time on the + Internet: Timestamps", RFC 3339, July 2002. + + [TLS] Dierks, T. and E. Rescorla, "The Transport Layer + Security (TLS) Protocol Version 1.2", RFC 5246, + August 2008. + + [XML] W3C, "Extensible Markup Language (XML) 1.0 (Fifth + Edition)", W3C Recommendation, November 2008, + <http://www.w3.org/TR/2006/REC-xml-20060816/>. + +9.2. Informative References + + [RFC1034] Mockapetris, P., "Domain names - concepts and + facilities", STD 13, RFC 1034, November 1987. + + + + + + + +Petrucci, et al. Informational [Page 61] + +RFC 6109 Certified Electronic Mail April 2011 + + + [RFC4522] Legg, S., "Lightweight Directory Access Protocol + (LDAP): The Binary Encoding Option", RFC 4522, June + 2006. + + [RFC4523] Zeilenga, K., "Lightweight Directory Access Protocol + (LDAP) Schema Definitions for X.509 Certificates", + RFC 4523, June 2006. + +10. Acknowledgments + + The Italian document on which this document is based, is a product of + the collaboration of many with the supervision of the National Center + for Informatics in the Public Administration of Italy (DigitPA). + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Petrucci, et al. Informational [Page 62] + +RFC 6109 Certified Electronic Mail April 2011 + + +Appendix A. Italian Fields and Values in English + + NOTE: The right column represents a translation of the Italian fields + for readability's sake only. Header fields that MUST be used + are the ones in the left column. + + X-Riferimento-Message-ID Reference Message Identifier + X-Ricevuta Notification + non-accettazione non acceptance + accettazione server-user acceptance + preavviso-errore-consegna delivery error advance notice + presa-in-carico server-server acceptance + rilevazione-virus virus detection + errore-consegna delivery error + avvenuta-consegna message delivered + X-Mittente Sender + X-VerificaSicurezza Security Verification + errore error + X-Trasporto Transport + posta-certificata certified mail + errore error + X-TipoRicevuta Notification Type + completa complete + breve brief + sintetica concise + + certificatore certificator + + Subject values: + + Accettazione SERVER-USER ACCEPTANCE + Posta certificata CERTIFIED MAIL + Presa in carico SERVER-SERVER ACCEPTANCE + Consegna DELIVERY + Anomalia messaggio MESSAGE ANOMALY + Problema di sicurezza SECURITY PROBLEM + Avviso di non accettazione NON ACCEPTANCE PEC NOTIFICATION + Avviso di non accettazione VIRUS DETECTION INDUCED NON + per virus ACCEPTANCE PEC NOTIFICATION + Avviso di mancata consegna NON DELIVERY PEC NOTIFICATION + Avviso di mancata consegna NON DELIVERY DUE TO VIRUS PEC + per virus NOTIFICATION + Avviso di mancata consegna NON DELIVERY DUE TO TIMEOUT PEC + per sup. tempo massimo NOTIFICATION + + + + + + + +Petrucci, et al. Informational [Page 63] + +RFC 6109 Certified Electronic Mail April 2011 + + + Italian terms in the DTD relative to the certification XML file: + + accettazione server-user acceptance + altro other + avvenuta-consegna delivered + certificato certificate + consegna delivery + data date + dati data + destinatari recipients + esterno external + errore error + errore-consegna delivery error + errore-esteso extensive error + gestore-emittente transmitting provider + giorno day + identificativo identifier + intestazione header + mittente sender + no-dest(inatario) no recipient + no-dominio no domain + non-accettazione non acceptance + nessuno none + oggetto subject + ora hour + posta-certificata certified mail + preavviso-errore-consegna delivery error advance notice + presa-in-carico server-server acceptance + ricevuta notification + ricezione receipt (the act of receiving) + rilevazione-virus virus detection + risposte replies + tipo type + + + + + + + + + + + + + + + + + + +Petrucci, et al. Informational [Page 64] + +RFC 6109 Certified Electronic Mail April 2011 + + +Authors' Addresses + + Claudio Petrucci + DigitPA + Viale Marx 31/49 + 00137 Roma + Italy + + EMail: petrucci@digitpa.gov.it + + Francesco Gennai + ISTI-CNR + Via Moruzzi, 1 + 56126 Pisa + Italy + + EMail: francesco.gennai@isti.cnr.it + + + Alba Shahin + ISTI-CNR + Via Moruzzi, 1 + 56126 Pisa + Italy + + EMail: alba.shahin@isti.cnr.it + + + Alessandro Vinciarelli + Via delle Vigne di Morena 113 + 00118 Roma + Italy + + EMail: alessandro.vinciarelli@gmail.com + + + + + + + + + + + + + + + + + +Petrucci, et al. Informational [Page 65] + |