diff options
Diffstat (limited to 'doc/rfc/rfc4705.txt')
-rw-r--r-- | doc/rfc/rfc4705.txt | 843 |
1 files changed, 843 insertions, 0 deletions
diff --git a/doc/rfc/rfc4705.txt b/doc/rfc/rfc4705.txt new file mode 100644 index 0000000..5a71bdb --- /dev/null +++ b/doc/rfc/rfc4705.txt @@ -0,0 +1,843 @@ + + + + + + +Network Working Group R. Housley +Request for Comments: 4705 Vigil Security +Category: Informational A. Corry + GigaBeam + October 2006 + + + GigaBeam High-Speed Radio Link Encryption + +Status of This Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (2006). + +Abstract + + This document describes the encryption and key management used by + GigaBeam as part of the WiFiber(tm) family of radio link products. + The security solution is documented in the hope that other wireless + product development efforts will include comparable capabilities. + + + + + + + + + + + + + + + + + + + + + + + + + + +Housley & Corry Informational [Page 1] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + +1. Introduction + + The GigaBeam WiFiber(tm) product family provides a high-speed point- + to-point radio link. Data rates exceed 1 gigabit/second at a + distance of about a mile. The transmission beam width is less than + one degree, which means that attempts to intercept the signal are + most successful when the attacker is either between the transmitter + and receiver or the attacker is directly behind the receiver. Since + interception is possible, some customers require confidentiality and + integrity protection for the data on the radio link. This document + describes the security solution designed and deployed by GigaBeam to + provide these security services. + + The GigaBeam security solution employs: + + o AES-GCM [GCM] with a custom security protocol specified in this + document to provide confidentiality and integrity protection of + subscriber traffic on the radio link; + + o AES-CBC [CBC] and HMAC-SHA-1 [HMAC] with IPsec ESP [ESP] to + provide confidentiality and integrity protection of management + traffic between the radio control modules; + + o AES-CBC [CBC] and HMAC-SHA-1 [HMAC] with the IKE protocol [IKE] + to provide confidentiality and integrity protection of key + management traffic between the radio control modules; and + + o OAKLEY key agreement [OAKLEY] and RSA digital signatures + [PKCS1] are used with IKE to establish keying material and to + provide authentication. + + AES-GCM is used with the custom security protocol in a manner that is + very similar to its use in ESP [ESP-GCM]. + + + + + + + + + + + + + + + + + + +Housley & Corry Informational [Page 2] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + +2. GigaBeam High-Speed Radio Link Overview + + The GigaBeam high-speed radio link appears to be a fiber interface + between two network devices. Figure 1 illustrates the connection of + two devices that normally communicate using Gigabit Ethernet over a + fiber optic cable. + + +---------+ +----------+ +----------+ +---------+ + | | | +----/ | | | | + | Network | | GigaBeam | / | GigaBeam | | Network | + | Device +=====+ Radio | /---- + Radio +=====+ Device | + | | | | | | | | + +---------+ ^ +----------+ ^ +----------+ ^ +---------+ + | | | + | | | + Gigabit Ethernet | Gigabit Ethernet + GigaBeam Radio Link + + Figure 1. GigaBeam Radio Link Example. + + Gigabit Ethernet traffic is encoded in 8B/10B format. The GigaBeam + Radio Control Module (RCM) removes this coding to recover the 8-bit + characters plus an indication of whether the character is a control + code. The radio link frame is constructed from 224 10-bit input + words, and a 4-way interleaved (56,50,10) Reed-Solomon Forward Error + Correction (FEC) block is employed. Conversion of the Gigabit + Ethernet data from 8B/10B format creates 224 bits of additional + capacity in each frame, and another 196 bits is gained by recoding + the 9-bit data using 64B/65B block codes. This additional 420 bits + of capacity is used for the framing overhead required for FEC and + link control. + + + + + + + + + + + + + + + + + + + + +Housley & Corry Informational [Page 3] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + +2.1. GigaBeam Radio Link Frame Format + + The GigaBeam radio link frame fields are summarized in Figure 2, + which also provides the length of each field in bits. + + Field Length Description + ----- ------ ----------- + SYNC 11 Frame Synchronization Pattern ('10110111000'b) + KEYSEL 1 Indicates which AES key was used for this frame + PN 40 AES-GCM Packet Number + FLAGS 28 Control bits, one bit for each 64B/65B data block + DCC 8 Data Communications Channel + DATA 1792 Data (28 encrypted 64B/65B code blocks) + TAG 96 Authentication Tag + SPARE 24 Reserved for alternative FEC algorithms + CHECK 240 Reed-Solomon Check Words for 4 10-bit + symbol (56,50) code + + Figure 2. GigaBeam Radio Link Frame Structure. + + Each of the fields in the GigaBeam 2240-bit radio link frame is + described below. + + SYNC Synchronization field, an 11-bit Barker code. Always set + to '10110111000'b. + + KEYSEL Key Selector -- select the appropriate key register for + this frame. Two key registers are maintained to allow + seamless rollover between encryption keys. + + PN Packet Number -- needed by AES-GCM; it carries the unique + counter value for this frame. The value is incremented + for each frame. + + FLAGS Control bits, one for each 64B/65B data block carried in + the DATA field. If the bit is set, then the + corresponding 64B/65B block in the DATA field contains a + control code. This field is integrity protected by AES- + GCM. + + DCC Data Communications Channel -- each frame carries one + octet of the point-to-point data communications channel + between the two radio control modules. See Section 2.2 + for more information on the DCC. + + DATA Subscriber data carried as 28 64B/65B code blocks. This + field is encrypted and integrity protected by AES-GCM. + + + + +Housley & Corry Informational [Page 4] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + TAG The authentication tag generated by AES-GCM, truncated to + 96 bits. + + SPARE 24 bits, set to zero. + + CHECK Forward error correction check value -- 24 check symbols + are generated by a 4-way interleaved Reed-Solomon + (56,50,10) algorithm. FEC is always active, but + correction can be selectively enabled. For each frame, + FEC processing also returns the number of bit errors, the + number of symbols in error, and whether the FEC + processing failed for the frame. This information allows + an estimation of the bit error rate for the link. + +2.2. Data Communications Channel + + The Data Communications Channel (DCC) field reserves eight bits in + each 2240-bit radio link frame for use in constructing a dedicated + point-to-point link between the two RCMs. The DCC content is + connected to a Universal Asynchronous Receiver/Transmitter (UART) + controller that processes the DCC bit stream to provide an + asynchronous serial channel that is visible to the RCM operating + system. The Point-to-Point Protocol (PPP) [PPP] is used on the + serial channel to create a simple two-node Internet Protocol (IP) + network. Each IP datagram is spread over a large number of radio + link frames. This two-node IP network carries management protocols + between the GigaBeam RCMs. + + IKE [IKE] runs on this two-node IP network to manage all + cryptographic keying material. IPsec ESP [ESP] is used in the usual + fashion to protect all non-IKE traffic on the data control channel. + IPsec ESP employs AES-CBC as described in [ESP-CBC] and HMAC-SHA-1 as + described in [ESP-HMAC]. + +3. Radio Link Processing + + The fiber interface constantly provides a stream of data encoded in + 8B/10B format. A radio link frame is constructed from 224 10-bit + input words. Conversion of the data from 8B/10B format creates 224 + bits of additional capacity in each frame, and then recoding using + 64B/65B block codes creates another 196 bits of additional capacity. + After encryption, the 64B/65B blocks are carried in the DATA field, + and the control code indicator bits are carried in the FLAGS field. + The additional capacity is used for the framing overhead. + + + + + + + +Housley & Corry Informational [Page 5] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + Processing proceeds as follows: + + o encryption and integrity protection as described in Section 3.1; + + o forward error correction (FEC) processing as described in Section + 3.2; + + o scrambling as described in Section 3.3; and + + o differential encoding as described in Section 3.4. + +3.1. Encryption and Integrity Protection + + The GigaBeam RCM contains two key registers. The single-bit KEYSEL + field indicates which of the two registers was used for the frame. + + AES-GCM [GCM] employs counter mode for encryption. Therefore, a + unique value for each frame is needed to construct the counter. The + counter includes a 32-bit salt value provided by IKE and a 40-bit + packet number from the PN field in the radio link frame. The same + counter value must not be used for more than one frame encrypted with + the same key. The 128-bit counter block is constructed as shown in + Figure 3. The first 96 bits of the AES counter block are called the + Nonce in the AES-GCM algorithm description. Note that AES-GCM uses + BLOCK values of zero and one for its own use. The values beginning + with two are used for encrypting the radio link frame payload. + + Field Length Description + ----- ------ ----------- + SALT 32 Salt value generated during the IKE exchange + MBZ1 24 These bits must be zero + PN 40 AES-GCM Packet Number carried in PN field + MBZ2 28 These bits must be zero + BLOCK 4 Block counter used in AES-GCM + + Figure 3. AES Counter Block Construction. + + AES-GCM is used to protect the FLAGS and DATA fields. The FLAGS + field is treated as authenticated header data, and it is integrity + protected, but it is not encrypted. The DATA field is encrypted and + authenticated. The TAG field contains the authentication tag + generated by AES-GCM, truncated to 96 bits. + + Reception processing performs decryption and integrity checking. If + the integrity checks fail, to maintain a continuous stream of + traffic, the frame is replaced with K30.7 control characters. These + + + + + +Housley & Corry Informational [Page 6] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + control characters are normally used to mark errors in the data + stream. Without encryption and integrity checking, these control + characters usually indicate 8B/10B running disparity or code errors. + +3.2. Forward Error Correction (FEC) + + The 224 10-bit data symbols that make up each radio link frame are + grouped into 4 subframes each consisting of 56 symbols. The + subframes are formed by symbol interleaving. A Reed-Solomon Code, + RS(56,50), designed for 10-bit symbols is applied to each subframe. + + This Reed Solomon Code detects 6 errors and corrects 3 errors within + each subframe. The FEC function is always active; however, it is + possible to disable correction of the received data to support + debugging. + +3.3. Scrambler + + The scrambler ensures that long series of one bits and long series of + zero bits do not occur. When encryption is enabled, long series of + common bit values is very unlikely; however, during the initial IKE + exchange, the radio link frame payload is all zero bits. + + The scrambling polynomial is (1 + x^14 + x^15). All words of a frame + except the SYNC pattern are scrambled prior to transmission using + this linear feedback shift register (LFSR). The LFSR is initialized + to all ones at the start of each frame, prior to the first processed + bit. Each processed input bit is added modulo 2 (i.e., an XOR) to + the output of the x15 tap to form the output bit. + + On reception, an identical process is performed after frame + synchronization and prior to subsequent processing to recover the + original bit pattern. + +3.4. Differential Encoding + + The data stream is differentially encoded to avoid symbol ambiguity + at the receiver. Since the demodulator could produce true or + inverted data depending on the details of the radio frequency (RF) + and intermediate frequency (IF) processing chains, differential + encoding is used to ensure proper reception of the intended bit + value. A zero bit is encoded as no change from the previous output + bit, and a one bit is encoded as a change from the previous output + bit. Thus, an output bit is the result of XORing the unencoded bit + with the previously transmitted encoded bit. + + + + + + +Housley & Corry Informational [Page 7] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + On reception, a complementary operation will be performed to produce + the decoded datastream. The bitstream is formed by XORing the + received encoded bit and the previously received encoded bit. + +4. Key Management + + The Internet Key Exchange (IKE) is used for key management [IKE]. + IKE has two phases. In Phase 1, two Internet Security Association + and Key Management Protocol (ISAKMP) peers establish a secure, + authenticated channel with which to communicate. This is called the + ISAKMP Security Association (SA). In the GigaBeam environment, the + Phase 1 exchange is IKE Aggressive Mode with signatures and + certificates. The RSA signature algorithm is used. + + Phase 2 negotiates the Security Associations for the GigaBeam custom + security protocol that protects subscriber traffic and IPsec ESP that + protects management traffic between the GigaBeam RCMs. In the + GigaBeam environment, the Phase 2 exchange is IKE Quick Mode, without + perfect forward secrecy (PFS). The information exchanged along with + Quick Mode is protected by the ISAKMP SA. That is, all payloads + except the ISAKMP header are encrypted. A detailed description of + Quick Mode can be found in Section 5.5 of [IKE]. + + When the Security Association is no longer needed, the ISAKMP Delete + Payload is used to tell the peer GigaBeam device that it is being + discarded. + +4.1. Certificates + + Each GigaBeam device generates its own public/private key pair. This + generation is performed at the factory, and the public key is + certified by a Certification Authority (CA) in the factory. The + certificate includes a name of the following format: + + C=US O=GigaBeam Corporation OU=GigaBeam WiFiber(tm) + SerialNumber=<device-model-identifier>/<device-serial-number> + + The ISAKMP Certificate Payload is used to transport certificates, and + in the GigaBeam environment, the "X.509 Certificate - Signature" + certificate encoding type (indicated by a value of 4) is always used. + + GigaBeam devices are always installed in pairs. At installation + time, each one is configured with the device model identifier and + device serial number of its peer. The device model identifier and + device serial number of a backup device can also be provided. An + access control check is performed when certificates are exchanged. + The certificate subject name must match one of these configured + + + + +Housley & Corry Informational [Page 8] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + values, and the certification path must validate to a configured + trust anchor, such as the GigaBeam Root CA, using the validation + rules in [PKIX1]. + +4.2. Oakley Groups + + With IKE, several possible Diffie-Hellman groups are supported. + These groups originated with the Oakley protocol and are therefore + called "Oakley Groups". + + GigaBeam devices use group 14, which is described in Section 3 of + [MODP]. + +4.3. Security Protocol Identifier + + The ISAKMP proposal syntax was specifically designed to allow for the + simultaneous negotiation of multiple Phase 2 security protocol + suites. The identifiers for the IPsec Domain of Interpretation (DOI) + are given in [IPDOI]. + + The GigaBeam custom security protocol has been assigned the + PROTO_GIGABEAM_RADIO protocol identifier, with a value of 5. + + The PROTO_GIGABEAM_RADIO specifies the use of the GigaBeam radio link + frame structure, which uses a single algorithm for both + confidentiality and authentication. The following table indicates + the algorithm values that are currently defined. + + Transform ID Value + ------------ ----- + RESERVED 0 + GIGABEAM_AES128_GCM 1 + +4.4. Keying Material + + GIGABEAM_AES128_GCM requires 20 octets of keying material (called + KEYMAT in [IKE]). The first 16 octets are the 128-bit AES key, and + the remaining four octets are used as the salt value in the AES + counter block. + + Presently, AES with a 128-bit key is the only encryption algorithm + that is supported. Other encryption algorithms could be registered + in the future. + + + + + + + + +Housley & Corry Informational [Page 9] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + +4.5. Identification Type Values + + The following table lists the assigned values for the Identification + Type field found in the ISAKMP Identification Payload. + + ID Type Value + ------- ----- + RESERVED 0 + ID_IPV4_ADDR 1 + ID_FQDN 2 + ID_USER_FQDN 3 + ID_IPV4_ADDR_SUBNET 4 + ID_IPV6_ADDR 5 + ID_IPV6_ADDR_SUBNET 6 + ID_IPV4_ADDR_RANGE 7 + ID_IPV6_ADDR_RANGE 8 + ID_DER_ASN1_DN 9 + ID_DER_ASN1_GN 10 + ID_KEY_ID 11 + + The ID_DER_ASN1_DN will be used when negotiating security + associations for use with the GigaBeam custom security protocol. The + provided distinguished name must match the peer's subject name + provided in the X.509 certificate. + +4.6. Security Parameter Index + + The least significant bit of the Security Parameter Index (SPI) is + used in the GigaBeam custom security protocol. When two GigaBeam + custom security protocol security associations are active at the same + time for communications in the same direction, the least significant + bit of the SPI must be different to ensure that these active security + associations can be distinguished by the single bit in the GigaBeam + custom security protocol. + +4.7. Key Management Latency + + The IKE exchange over the DCC must complete before subscriber data + can be exchanged in the GigaBeam radio link frame payload. Since + each radio link frame carries a small portion of an IP datagram, many + radio link frames carrying all zero bits must be sent and received to + complete the IKE exchange. + + Once the initial keying material is in place, the IKE exchanges to + establish subsequent keying material can be performed concurrent with + the transfer of subscriber data in the radio link frame payload. The + KEYSEL field in the radio link frame is used to indicate which keying + material is being used. + + + +Housley & Corry Informational [Page 10] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + The PN field in radio link frame provides a continuous indication of + the number of frames that have been encrypted with a particular key. + Once a threshold is exceeded, the IKE exchanges begin to establish + the replacement keying material. Currently, the exchanges begin when + half of the packet numbers have been used, but any threshold can be + employed, as long as the replacement keying material is available + before the packet counters are exhausted. + +5. Security Considerations + + The security considerations in [IKE], [OAKLEY], [PKCS1], and [ESP] + apply to the security system defined in this document. + + Confidentiality and integrity are provided by the use of negotiated + algorithms. AES-GCM [GCM] is used with the GigaBeam custom security + protocol to provide confidentiality and integrity protection of + subscriber traffic on the radio link. AES-CBC [CBC] and HMAC-SHA-1 + [HMAC] are used with IPsec ESP [ESP] to provide confidentiality and + integrity protection of management traffic between the radio control + modules. + + AES-GCM makes use of AES Counter mode to provide confidentiality. + Unfortunately, it is very easy to misuse counter mode. If counter + block values are ever used for more than one frame with the same key, + then the same key stream will be used to encrypt both frames, and the + confidentiality guarantees are voided. Using AES Counter mode with + the same counter values to encrypt two plaintexts under the same key + leaks the plaintext. The automated key management described here is + intended to prevent this from ever happening. + + Since AES has a 128-bit block size, regardless of the mode employed, + the ciphertext generated by AES encryption becomes distinguishable + from random values after 2^64 blocks are encrypted with a single key. + Since the GigaBeam radio link frame allows for up to 2^40 fixed- + length frames in a single security association, there is no + possibility for more than 2^64 blocks to be encrypted with one key. + + The lifetime of a particular AES key can be shorter than 2^40 frames. + A smaller threshold can be used as a trigger to transition to the + next key. This capability allows straightforward implementation of + policies that require the key to be changed after a particular volume + of traffic or a particular amount of time. + + There are fairly generic precomputation attacks against all block + cipher modes that allow a meet-in-the-middle attack against the key. + These attacks require the creation and searching of huge tables of + ciphertext associated with known plaintext and known keys. Assuming + that the memory and processor resources are available for a + + + +Housley & Corry Informational [Page 11] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + precomputation attack, then the theoretical strength of AES Counter + mode (and any other block cipher mode) is limited to 2^(n/2) bits, + where n is the number of bits in the key. The use of long keys is + the best countermeasure to precomputation attacks. The unpredictable + nonce value in the counter block significantly increases the size of + the table that the attacker must compute to mount a successful + precomputation attack. + + Rekeying with Quick Mode results in new keys to protect GigaBeam + radio link frames; however, these keys are generated from the same + Diffie-Hellman shared secret. In order to limit the amount of data + that would be exposed by the disclosure of this Diffie-Hellman shared + secret or the associated Diffie-Hellman private key, implementations + should periodically rekey using a new Phase 1 exchange. + + Diffie-Hellman exponents used in IKE Phase 1 should be erased from + memory immediately after use. Likewise, AES and HMAC-SHA-1 keying + material should be erased from memory when it is no longer needed. + + This security solution makes use of IKEv1 [IKE]. IKEv1 was selected + over IKEv2 [IKEv2] primarily due to the availability of an + implementation for the processing environment. The use of IKEv2 + would provide some useful capabilities, such as Diffie-Hellman group + negotiation. These additional capabilities would not significantly + improve the security of the overall key management solution that runs + on the two-node IP network. + +6. IANA Considerations + + IANA has assigned one IPsec Security Protocol Identifier in + http://www.iana.org/assignments/isakmp-registry for + PROTO_GIGABEAM_RADIO. It was assigned the value 5. + +7. Informative References + + [CBC] Dworkin, M., "Recommendation for Block Cipher Modes of + Operation: Methods and Techniques," NIST Special + Publication 800-38A, December 2001. + + [ESP] Kent, S., "IP Encapsulating Security Payload (ESP)", RFC + 4303, December 2005. + + [ESP-CBC] Frankel, S., Glenn, R., and S. Kelly, "The AES-CBC Cipher + Algorithm and Its Use with IPsec", RFC 3602, September + 2003. + + + + + + +Housley & Corry Informational [Page 12] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + + [ESP-GCM] Viega, J. and D. McGrew, "The Use of Galois/Counter Mode + (GCM) in IPsec Encapsulating Security Payload (ESP)", RFC + 4106, June 2005. + + [ESP-HMAC] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within + ESP and AH", RFC 2404, November 1998. + + [GCM] McGrew, D. and J. Viega, "The Galois/Counter Mode of + Operation (GCM)", Submission to NIST. + http://csrc.nist.gov/CryptoToolkit/modes/proposedmodes/ + gcm/gcm-spec.pdf, January 2004. [Soon: NIST SP 800-38D.] + + [HMAC] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- + Hashing for Message Authentication", RFC 2104, February + 1997. + + [IKE] Harkins, D. and D. Carrel, "The Internet Key Exchange + (IKE)", RFC 2409, November 1998. + + [IKEv2] Kaufman, C., "The Internet Key Exchange (IKEv2) Protocol", + RFC 2306, December 2005. + + [IPDOI] Piper, D., "The Internet IP Security Domain of + Interpretation for ISAKMP", RFC 2407, November 1998. + + [MODP] Kivinen, T. and M. Kojo. "More Modular Exponential (MODP) + Diffie-Hellman groups for Internet Key Exchange (IKE)", + RFC 3526, May 2003. + + [OAKLEY] Orman, H., "The Oakley Key Determination Protocol", RFC + 2412, November 1998. + + [PKCS1] Kaliski, B., "PKCS #1: RSA Encryption Version 1.5", RFC + 2313, March 1998. + + [PKIX1] Housley, R., Polk, W., Ford, W., and D. Solo, "Internet + X.509 Public Key Infrastructure Certificate and + Certificate Revocation List (CRL) Profile", RFC 3280, + April 2002. + + [PPP] Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51, + RFC 1661, July 1994. + +8. Acknowledgements + + The authors thank Bob Sutherland and Dave Marcellas for their + contributions and review. + + + + +Housley & Corry Informational [Page 13] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + +Authors' Addresses + + Russell Housley + Vigil Security, LLC + 918 Spring Knoll Drive + Herndon, VA 20170 + USA + + EMail: housley@vigilsec.com + + + Alan Corry + GigaBeam Corporation + 470 Springpark Place, Suite 900 + Herndon, VA 20170 + USA + + EMail: publications@gigabeam.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Housley & Corry Informational [Page 14] + +RFC 4705 GigaBeam Radio Link Encryption October 2006 + + +Full Copyright Statement + + Copyright (C) The Internet Society (2006). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET + ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, + INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE + INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + +Acknowledgement + + Funding for the RFC Editor function is provided by the IETF + Administrative Support Activity (IASA). + + + + + + + +Housley & Corry Informational [Page 15] + |