Internet-Draft tcp-ao-algs August 2026
Bonica, et al. Expires 1 March 2027 [Page]
Workgroup:
TCPM Working Group
Internet-Draft:
draft-ietf-tcpm-tcp-ao-algs-07
Published:
Intended Status:
Standards Track
Expires:
Authors:
R. Bonica
HPE
T. Li
HPE
P. Chen
HPE
P. Kumar
HPE
R. Thomas
Arista Networks
A. Sujeet Nayak
Cisco Systems
A. Banerjee
Cisco Systems

Cryptographic Algorithms That Produce 128-bit MACs For Use With TCP-AO

Abstract

RFC5926 creates a list of cryptographic algorithms that can be used with TCP-AO. This document expands that list, adding two Message Authentication Code (MAC) algorithms, HMAC-SHA256-128 and KMAC256-128. For each MAC algorithm, a corresponding Key Derivation Function (KDF) is also added.

The MAC algorithms described by this document produce 128-bit (i.e., 16-byte) MACs. When 16-byte MACs are encoded in TCP-AO, the TCP-AO consumes 20 of the 40 bytes available for TCP options.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 1 March 2027.

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Table of Contents

1. Introduction

[RFC5926] creates a list of cryptographic algorithms that can be used with TCP-AO [RFC5925]. This document expands that list, adding two Message Authentication Code (MAC) algorithms, HMAC-SHA256-128 and KMAC256-128. For each MAC algorithm, a corresponding Key Derivation Function (KDF) is also added.

The MAC algorithms described by this document produce 128-bit (i.e., 16-byte) MACs. When 16-byte MACs are encoded in TCP-AO, the TCP-AO consumes 20 of the 40 bytes available for TCP options.

2. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

3. Algorithm Classes

[RFC5925] requires the following cryptographic algorithm classes:

Section 3.1 of this document addresses KDFs while Section 3.2 addresses MAC algorithms.

3.1. Key Derivation Functions (KDFs)

A KDF converts Input Keying Material (IKM) into cryptographically secure Output Keying Material (OKM). In the case of TCP-AO, a KDF converts an administratively assigned Master_Key into a Traffic_Key.

KDFs have the following interface:

  • Traffic_Key = KDF_alg(Master_Key, Context, Output_Length)

where:

  • KDF_alg is the KDF algorithm being used.

  • Master_Key is a variable length pre-shared key (PSK). It MUST be at least 256 bits in length.

  • Context is binary string containing information related to the TCP connection, as defined in Section 5.2 of [RFC5925].

  • Output_Length is the desired length of the Traffic_Key. In this document, the Output_Length is always equal to 256 bits (i.e., 32 bytes).

This document defines two KDFs:

  • HKDF-SHA256

  • KMAC256-KDF

Section 3.1.1 of this document describes HKDF-SHA256 while Section 3.1.2 describes KMAC256-KDF.

3.1.1. HKDF-SHA256

HKDF-SHA256 is specified in [RFC5869]. It executes in the following stages:

  • Extract

  • Expand

The interface to the Extract stage is:

  • PRK = HKDF-Extract(salt, IKM)

where:

  • PRK is a Pseudo-random key, to be used in the Expand stage.

  • salt is an all-zero byte string whose length equals 32 bytes.

  • IKM is the Master_Key argument provided to the KDF interface.

According to [RFC5869], the goal of the extract stage is to concentrate the possibly dispersed entropy of the input keying material into a short, but cryptographically strong pseudorandom key. Implementations MUST execute the extract stage.

The interface to the Expand stage is:

  • OKM = HKDF-Expand(PRK, info, L)

where:

  • OKM is the Traffic_Key.

  • PRK is the value produced by the Extract stage.

  • info is the Context argument provided to the KDF interface.

  • L is equal to 32 bytes (i.e., 256 bits).

The expand stage expands the pseudorandom key to the desired length. The output key length depends on the specific cryptographic algorithms for which the keys are needed. Implementations MUST execute the expand stage.

3.1.2. KMAC256-KDF

KMAC256-KDF uses the one-step key-derivation function specified in Section 4.1 of [DOI.10.6028_NIST.SP.800-56Cr2], with KMAC256 as the auxiliary function, as described by Option 3.

The interface to KMAC256-KDF is:

  • OKM = KMAC256(salt, counter || Z || FixedInfo, H_outputBits, S)

where:

  • OKM is the Traffic_Key.

  • salt is an all-zero byte string whose length equals 132 bytes.

  • counter is the 32-bit integer 1, encoded in network byte order.

  • Z is the Master_Key argument provided to the KDF interface.

  • FixedInfo is the Context argument provided to the KDF interface.

  • H_outputBits is equal to 256 bits.

  • S is the byte string 01001011 || 01000100 || 01000110, which represents the sequence of characters "K", "D", and "F" in 8-bit ASCII.

Because the required output length is equal to H_outputBits, only one KMAC256 invocation is required.

3.2. MAC Algorithms

Each MAC algorithm defined for TCP-AO has the following fixed elements as part of its definition:

  • KDF_Alg is the name of the KDF algorithm used to generate the Traffic_Key.

  • Key_Length is the length of the Traffic_Key used in this MAC, measured in bits. In this document, the Key_Length is always 256 bits.

  • MAC_Length is the desired length of the MAC to be produced by the algorithm. In this document, the MAC_Length is always 128 bits.

MACs computed for TCP-AO have the following interface:

  • MAC = MAC_alg(Traffic_Key, Message)

where:

  • MAC is the value to be encoded in TCP-AO.

  • MAC_alg is MAC Algorithm used.

  • Traffic_Key is the result of KDF.

  • Message is the message to be authenticated, as specified in Section 5.1 of [RFC5925].

3.2.1. The Use of HMAC-SHA256-128

The three fixed elements for HMAC-SHA256-128 are:

  • KDF_Alg: HKDF-SHA256.

  • Key_Length: 256 bits.

  • MAC_Length: 128 bits.

For:

  • MAC = MAC_alg (Traffic_Key, Message)

HMAC-SHA256-128 for TCP-AO has the following values:

  • MAC is the value to be encoded in TCP-AO.

  • MAC_alg is HMAC-SHA256.

  • Traffic_Key is the result of the KDF.

  • Message is the message to be authenticated, as specified in Section 5.1 of [RFC5925].

The HMAC-SHA256 output is truncated to 128 bits. The first 128 bits are preserved and subsequent bits are discarded.

3.2.2. The Use of KMAC256-128

The three fixed elements for KMAC256-128 are:

  • KDF_Alg: KMAC256-KDF with the default customization string (i.e., the empty string or "").

  • Key_Length: 256 bits.

  • MAC_Length: 128 bits.

For:

  • MAC = MAC_alg (Traffic_Key, Message)

KMAC256-128 for TCP-AO has the following values:

  • MAC is the value to be encoded in TCP-AO.

  • MAC_alg is KMAC256.

  • Traffic_Key is the result of the KDF.

  • Message is the message to be authenticated, as specified in Section 5.1 of [RFC5925].

KMAC256-128 uses its specified 128-bit output length; no truncation statement is needed.

4. Security Considerations

This document inherits all of the security considerations of [RFC5869], [RFC5925], [RFC8702], and [RFC9688].

The security of cryptography-based systems depends on both the strength of the cryptographic algorithms chosen and the strength of the keys used with those algorithms. The security also depends on the engineering of the protocol used by the system to ensure that there are no non-cryptographic ways to bypass the security of the overall system.

When using the algorithms mentioned in this document, the Master_Key MUST be at least 256 bits in length. Master_Keys SHOULD have at least 256 bits of entropy, and they SHOULD be generated by a cryptographic random number generator or similar. The use of low-entropy secrets (such as passwords) is vulnerable to brute-force attacks. If an ASCII string is used, it SHOULD be the hex or base64 representation of a cryptographic key with at least 256 bits of entropy, rather than a human-readable password or passphrase.

Master_Keys MUST be kept secret. ??Each party in the Master_Key distribution path is an opportunity for compromise and disclosure. Master_Keys MUST be changed immediately if compromise is suspected.

TCP-AO Master_Key Tuples MUST be rotated at a rate commensurate with the strength of the cryptographic algorithms.

5. IANA Considerations

IANA is requested to add the following entries to the "Cryptographic Algorithms for TCP-AO Registration" (https://www.iana.org/assignments/tcp-parameters/tcp-parameters.xhtml#tcp-parameters-3).

Table 1: IANA Actions
Algorithm Reference
HMAC-SHA256-128 This Document
KMAC256-128 This Document

6. Acknowledgements

Thanks to Eric Biggers, Lars Eggert, Gorry Fairhurst, C.M. Heard, Russ Housley, John Mattsson, Yoshifumi Nishida, Joe Touch, Michael Tuxen, and Magnus Westerlund for their review and comments.

7. Normative References

[DOI.10.6028_NIST.SP.800-56Cr2]
Barker, E., Chen, L., and R. Davis, "Recommendation for Key-Derivation Methods in Key-Establishment Schemes", National Institute of Standards and Technology, DOI 10.6028/nist.sp.800-56cr2, , <https://doi.org/10.6028/nist.sp.800-56cr2>.
[DOI.10.6028_NIST.SP.800-185]
Kelsey, J., Change, S., and R. Perlner, "SHA-3 derived functions: cSHAKE, KMAC, TupleHash and ParallelHash", National Institute of Standards and Technology, DOI 10.6028/nist.sp.800-185, , <https://doi.org/10.6028/nist.sp.800-185>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC5869]
Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)", RFC 5869, DOI 10.17487/RFC5869, , <https://www.rfc-editor.org/rfc/rfc5869>.
[RFC5925]
Touch, J., Mankin, A., and R. Bonica, "The TCP Authentication Option", RFC 5925, DOI 10.17487/RFC5925, , <https://www.rfc-editor.org/rfc/rfc5925>.
[RFC5926]
Lebovitz, G. and E. Rescorla, "Cryptographic Algorithms for the TCP Authentication Option (TCP-AO)", RFC 5926, DOI 10.17487/RFC5926, , <https://www.rfc-editor.org/rfc/rfc5926>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8702]
Kampanakis, P. and Q. Dang, "Use of the SHAKE One-Way Hash Functions in the Cryptographic Message Syntax (CMS)", RFC 8702, DOI 10.17487/RFC8702, , <https://www.rfc-editor.org/rfc/rfc8702>.
[RFC9235]
Touch, J. and J. Kuusisaari, "TCP Authentication Option (TCP-AO) Test Vectors", RFC 9235, DOI 10.17487/RFC9235, , <https://www.rfc-editor.org/rfc/rfc9235>.
[RFC9688]
Housley, R., "Use of the SHA3 One-Way Hash Functions in the Cryptographic Message Syntax (CMS)", RFC 9688, DOI 10.17487/RFC9688, , <https://www.rfc-editor.org/rfc/rfc9688>.

Appendix A. Test Vectors

This appendix provides test vectors to validate the correct implementation of TCP-AO and the cryptographic algorithms defined in this document.

In the following sections, all values are indicated as 2-digit hexadecimal values with spacing per line representing the contents of 16 consecutive bytes, as is typical for data dumps. The IP/TCP data indicates the entire IP packet, including the TCP segment and its options (whether covered by TCP-AO or not, as indicated), including TCP-AO.

In these test vectors, the Master_Key is equal to 0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef.

A.1. IPv4 HMAC-SHA256-128 Output Test Vectors

A.1.1. HMAC-SHA256-128 (Default - Covers TCP Options)

A.1.1.1. Send (Client) SYN (Covers Options) 
   Client ISN = 0xfbfbab5a

   Send_SYN_traffic_key:

     eb 5a 40 32 e9 3e 6c 78 02 a7 41 ac 89 9a 63 12
     d3 46 a9 dc 1d 2b ed 62 e2 b6 de 94 7f 6c 5c 7d

   IPv4/TCP:
     45 e0 00 50 dd 0f 40 00 ff 06 bf 67 0a 0b 0c 0d
     ac 1b 1c 1d e9 d7 00 b3 fb fb ab 5a 00 00 00 00
     f0 02 ff ff 80 15 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a 00 15 5a b7 00 00 00 00 1d 14 3d 54

   MAC:

     fc 6b 9f 5e 69 2f 0a 69 a7 92 35 67 ec 55 79 bc
A.1.1.2. Receive (Server) SYN-ACK (Covers Options) 
   Server ISN = 0x11c14261

   Receive_SYN_traffic_key:

      d9 9f d0 ae be 69 c9 aa 6c 3d 60 d6 37 c5 6a a9
      b7 28 10 93 2a a9 c1 69 f6 a9 80 0f 6a 8c f0 b5

   IPv4/TCP:
     45 e0 00 50 65 06 40 00 ff 06 37 71 ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 e9 d7 11 c1 42 61 fb fb ab 5b
     f0 12 ff ff d6 d9 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a 84 a5 0b eb 00 15 5a b7 1d 14 54 3d

   MAC:

     ac 1e c2 63 e1 45 25 78 88 77 69 1d b4 d7 e4 50
A.1.1.3. Send (Client) Non-SYN (Covers Options) 
   Send_other_traffic_key:

     3d a8 19 31 9b 16 cb 05 2b 21 ce 1b 64 d2 5d 8a
     62 c4 7e fa 15 8c 7b f2 42 9f 28 8d 6d 58 f6 fb

   IPv4/TCP:
     45 e0 00 8b 36 a1 40 00 ff 06 65 9b 0a 0b 0c 0d
     ac 1b 1c 1d e9 d7 00 b3 fb fb ab 5b 11 c1 42 62
     d0 18 01 04 c4 51 00 00 01 01 08 0a 00 15 5a c1
     84 a5 0b eb 1d 14 3d 54 7a 8d b5 2a 22 51 4c 93
     de 2f 94 8a 69 80 73 0a ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4
     0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

     7a 8d b5 2a 22 51 4c 93 de 2f 94 8a 69 80 73 0a
A.1.1.4. Receive (Server) Non-SYN (Covers Options) 
   Receive_other_traffic_key:

     d9 9f d0 ae be 69 c9 aa 6c 3d 60 d6 37 c5 6a a9
     b7 28 10 93 2a a9 c1 69 f6 a9 80 0f 6a 8c f0 b5

   IPv4/TCP:
     45 e0 00 8b 1f a9 40 00 ff 06 7c 93 ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 e9 d7 11 c1 42 62 fb fb ab 9e
     d0 18 01 00 e6 9e 00 00 01 01 08 0a 84 a5 0b f5
     00 15 5a c1 1d 14 54 3d 99 fc 54 28 2d 84 34 8f
     be 3f f5 7c 20 99 dc b2 ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4
     ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

     99 fc 54 28 2d 84 34 8f be 3f f5 7c 20 99 dc b2

A.1.2. HMAC-SHA256-128 (Omits TCP Options)

A.1.2.1. Send (Client) SYN (Omits Options) 
   Client ISN = 0xcb0efbee

   Send_SYN_traffic_key:

      af ea c8 22 53 08 be e3 a0 01 a2 69 6c d2 d3 c6
      9b 47 e7 71 e7 f4 4c cd c5 6d 8b bd 74 93 d4 7a

   IPv4/TCP:
     45 e0 00 50 53 99 40 00 ff 06 48 de 0a 0b 0c 0d
     ac 1b 1c 1d ff 12 00 b3 cb 0e fb ee 00 00 00 00
     f0 02 ff ff fe f3 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a 00 02 4c ce 00 00 00 00 1d 14 3d 54

   MAC:

      06 19 b9 b5 16 73 1c 24 66 8c 40 04 1e 65 f5 4e
A.1.2.2. Receive (Server) SYN-ACK (Omits Options) 
   Server ISN = 0xacd5b5e1

   Receive_SYN_traffic_key:

      7b 4f d3 74 25 3a 5a 87 5e 86 86 f9 5a 60 69 1c
      3b 5a 3f 4e a1 46 8e d6 fc 9c d2 9a 5a 41 56 9f

   IPv4/TCP:
     45 e0 00 50 32 84 40 00 ff 06 69 f3 ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 ff 12 ac d5 b5 e1 cb 0e fb ef
     f0 12 ff ff e6 fa 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a 57 67 72 f3 00 02 4c ce 1d 14 54 3d

   MAC:

      12 a4 eb 6d 6c e7 07 e1 d5 cd 4b 5b 74 24 78 6f
A.1.2.3. Send (Client) Non-SYN (Omits Options) 
   Send_other_traffic_key:

      2e d5 79 59 d5 45 37 cf 3c a1 73 7d a4 24 0e a6
      38 8a d4 c2 b8 e4 c0 eb ca 06 a2 6b 00 93 8b 55

   IPv4/TCP:
     45 e0 00 8b a8 f5 40 00 ff 06 f3 46 0a 0b 0c 0d
     ac 1b 1c 1d ff 12 00 b3 cb 0e fb ef ac d5 b5 e2
     d0 18 01 04 ef 52 00 00 01 01 08 0a 00 02 4c ce
     57 67 72 f3 1d 14 3d 54 57 0f 47 ca b1 31 03 bd
     ea 02 53 a5 c3 5f fe d4 ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4
     0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

      57 0f 47 ca b1 31 03 bd ea 02 53 a5 c3 5f fe d4
A.1.2.4. Receive (Server) Non-SYN (Omits Options) 
   Receive_other_traffic_key:

      7b 4f d3 74 25 3a 5a 87 5e 86 86 f9 5a 60 69 1c
      3b 5a 3f 4e a1 46 8e d6 fc 9c d2 9a 5a 41 56 9f

   IPv4/TCP:
     45 e0 00 8b 54 37 40 00 ff 06 48 05 ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 ff 12 ac d5 b5 e2 cb 0e fc 32
     d0 18 01 00 ff ef 00 00 01 01 08 0a 57 67 72 f3
     00 02 4c ce 1d 14 54 3d a1 88 d1 8f ec 70 47 2b
     f5 99 a9 3a 37 cd fb 67 ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4
     ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

      a1 88 d1 8f ec 70 47 2b f5 99 a9 3a 37 cd fb 67

A.2. IPv4 KMAC256-128 Output Test Vectors

A.2.1. KMAC256-128 (Default - Covers TCP Options)

A.2.1.1. Send (Client) SYN (Covers Options) 
   Client ISN = 0x787a1ddf

   Send_SYN_traffic_key:

      57 8e 81 ab c6 6b b1 02 1d 2c 97 c1 39 85 bf a4
      2b 3d e7 91 01 7f 1f 15 8e 17 a9 1d 0d cd 7f 09

  IPv4/TCP:
     45 e0 00 50 7b 9f 40 00 ff 06 20 d8 0a 0b 0c 0d
     ac 1b 1c 1d c4 fa 00 b3 78 7a 1d df 00 00 00 00
     f0 02 ff ff 26 c9 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a 00 01 7e d0 00 00 00 00 1d 14 3d 54

   MAC:

      90 13 67 b3 82 47 5f 0f 3e aa ce af 06 a7 d0 71
A.2.1.2. Receive (Server) SYN-ACK (Covers Options) 
   Server ISN = 0xfadd6de9

   Receive_SYN_traffic_key:

      16 8d 69 c0 a9 14 fe be f9 24 1b 1c d1 de e3 19
      86 cc a6 58 68 46 ba e0 f0 9d 9a 7f aa 33 d4 c1

   IPv4/TCP:
     45 e0 00 50 4b ad 40 00 ff 06 50 ca ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 c4 fa fa dd 6d e9 78 7a 1d e0
     f0 12 ff ff f7 0a 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a 93 f4 e9 e8 00 01 7e d0 1d 14 54 3d

   MAC:

      b8 ef 2e 1f 29 f0 f5 8a 8b ce 3b 08 e8 14 3a 3a
A.2.1.3. Send (Client) Non-SYN (Covers Options) 
   Send_other_traffic_key:

      fa a5 10 73 c7 fc 24 0a 39 58 a3 6b d0 75 f9 85
      1b e7 7a 0d 53 90 6a e7 82 60 c0 f8 19 cc 84 2b

   IPv4/TCP:
     45 e0 00 8b fb 4f 40 00 ff 06 a0 ec 0a 0b 0c 0d
     ac 1b 1c 1d c4 fa 00 b3 78 7a 1d e0 fa dd 6d ea
     d0 18 01 04 8b f7 00 00 01 01 08 0a 00 01 7e d0
     93 f4 e9 e8 1d 14 3d 54 59 c1 be 8f 96 ee 2d ad
     49 c9 0d 4f 60 be a1 65 ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4
     0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

      59 c1 be 8f 96 ee 2d ad 49 c9 0d 4f 60 be a1 65
A.2.1.4. Receive (Server) Non-SYN (Covers Options) 
   Receive_other_traffic_key:

      16 8d 69 c0 a9 14 fe be f9 24 1b 1c d1 de e3 19
      86 cc a6 58 68 46 ba e0 f0 9d 9a 7f aa 33 d4 c1

   IPv4/TCP:
     45 e0 00 8b b9 14 40 00 ff 06 e3 27 ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 c4 fa fa dd 6d ea 78 7a 1e 23
     d0 18 01 00 e8 f2 00 00 01 01 08 0a 93 f4 e9 e8
     00 01 7e d0 1d 14 54 3d fa f4 17 d2 32 c2 b0 8c
     31 65 6a c8 8f 4f ed 50 ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4
     ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

      fa f4 17 d2 32 c2 b0 8c 31 65 6a c8 8f 4f ed 50

A.2.2. KMAC256-128 (Omits TCP Options)

A.2.2.1. Send (Client) SYN (Omits Options) 
   Client ISN = 0x389bed71

   Send_SYN_traffic_key:

      0a 14 73 b7 6e 34 d8 0a c5 dc 7e 31 07 8a 8d a3
      f9 7f 8a 25 79 95 d9 69 ce ea 2a 7f 1f 26 ae 68

   IPv4/TCP:
     45 e0 00 50 f2 2e 40 00 ff 06 aa 48 0a 0b 0c 0d
     ac 1b 1c 1d da 1c 00 b3 38 9b ed 71 00 00 00 00
     f0 02 ff ff 4a a4 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a 00 01 85 e1 00 00 00 00 1d 14 3d 54

   MAC:

      8c 05 05 09 3f 3e 69 a9 81 62 4e c7 1b de c7 d0
A.2.2.2. Receive (Server) SYN-ACK (Omits Options) 
   Server ISN = 0xd3844a6f

   Receive_SYN_traffic_key:

      78 55 de 82 11 7e fc 48 48 fd c6 c9 a7 de 50 fd
      87 74 3a 95 38 c1 a7 24 a5 f1 37 96 6c 08 ce e3

   IPv4/TCP:
     45 e0 00 50 6c c0 40 00 ff 06 2f b7 ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 da 1c d3 84 4a 6f 38 9b ed 72
     f0 12 ff ff 84 20 00 00 02 04 05 b4 01 03 03 08
     04 02 08 0a ce 45 98 38 00 01 85 e1 1d 14 54 3d

   MAC:

      e5 dc fd 62 c5 67 9d 29 17 31 9c 89 19 f0 05 6a
A.2.2.3. Send (Client) Non-SYN (Omits Options) 
   Send_other_traffic_key:

      64 50 fb e2 99 2d 8a 7e f4 63 7f dd 2c b4 60 69
      34 fc c4 25 3b 12 ed 5e e6 cf 61 e4 d6 ca 8c c4

   IPv4/TCP:
     45 e0 00 8b ee 91 40 00 ff 06 ad aa 0a 0b 0c 0d
     ac 1b 1c 1d da 1c 00 b3 38 9b ed 72 d3 84 4a 70
     d0 18 01 04 02 2c 00 00 01 01 08 0a 00 01 85 e1
     ce 45 98 38 1d 14 3d 54 0e 34 9c c1 8d 69 41 d4
     3f b1 60 c5 a6 da b4 bb ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4
     0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

      0e 34 9c c1 8d 69 41 d4 3f b1 60 c5 a6 da b4 bb
A.2.2.4. Receive (Server) Non-SYN (Omits Options) 
   Receive_other_traffic_key:

      78 55 de 82 11 7e fc 48 48 fd c6 c9 a7 de 50 fd
      87 74 3a 95 38 c1 a7 24 a5 f1 37 96 6c 08 ce e3

   IPv4/TCP:
     45 e0 00 8b 6a 21 40 00 ff 06 32 1b ac 1b 1c 1d
     0a 0b 0c 0d 00 b3 da 1c d3 84 4a 70 38 9b ed 72
     d0 18 01 00 97 10 00 00 01 01 08 0a ce 45 98 38
     00 01 85 e1 1d 14 54 3d c1 ee 1d 27 a9 33 67 fc
     35 35 b1 f6 da 68 65 7a ff ff ff ff ff ff ff ff
     ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4
     ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80
     00 02 02 02 00 02 02 42 00 02 06

   MAC:

      c1 ee 1d 27 a9 33 67 fc 35 35 b1 f6 da 68 65 7a

A.3. IPv6 HMAC-SHA256-128 Output Test Vectors

A.3.1. HMAC-SHA256-128 (Default - Covers TCP Options)

A.3.1.1. Send (Client) SYN (Covers Options) 
   Client ISN = 0x176a833f

   Send_SYN_traffic_key:

      c1 da af dc 82 db 45 22 3d 30 08 ec 48 17 7f 09
      11 a5 91 3a 43 d0 c9 3a 6d eb a5 21 7c d5 10 37

   IPv6/TCP:
     6e 08 91 dc 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 f7 e4 00 b3 17 6a 83 3f
     00 00 00 00 f0 02 ff ff 0a c5 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a 00 41 d0 87 00 00 00 00
     1d 14 3d 54

   MAC:

      74 90 45 01 59 9b 53 71 8a d3 43 94 05 c9 f9 f3
A.3.1.2. Receive (Server) SYN-ACK (Covers Options) 
   Server ISN = 0x3f51994b

   Receive_SYN_traffic_key:

      e0 20 78 20 1b b6 29 3a 09 cb 3d 6a 1f 89 fa 28
      77 92 f1 70 be 5f f8 a6 c5 d3 d5 ab a9 96 bc c2

   IPv6/TCP:
     6e 01 00 9e 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 f7 e4 3f 51 99 4b
     17 6a 83 40 f0 12 ff ff 67 90 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a bd 33 12 9b 00 41 d0 87
     1d 14 54 3d

   MAC:

      57 50 d1 27 db cc d2 97 ce 22 80 97 e5 aa 0d 50
A.3.1.3. Send (Client) Non-SYN (Covers Options) 
   Send_other_traffic_key:

      00 15 82 70 f0 1b 12 11 d9 7a eb 0f 2d a1 6a 22
      84 20 86 62 5c 84 02 bb 0b 63 ae 6e 0d b0 e5 14

   IPv6/TCP:
     6e 08 91 dc 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 f7 e4 00 b3 17 6a 83 40
     3f 51 99 4c d0 18 01 00 8e 1a 00 00 01 01 08 0a
     00 41 d0 91 bd 33 12 9b 1d 14 3d 54 7c 30 78 7a
     7b 15 41 02 ef 9f f6 e4 3e 3f bf 1e ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      7c 30 78 7a 7b 15 41 02 ef 9f f6 e4 3e 3f bf 1e
A.3.1.4. Receive (Server) Non-SYN (Covers Options) 
   Receive_other_traffic_key:

      e0 20 78 20 1b b6 29 3a 09 cb 3d 6a 1f 89 fa 28
      77 92 f1 70 be 5f f8 a6 c5 d3 d5 ab a9 96 bc c2

   IPv6/TCP:
     6e 01 00 9e 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 f7 e4 3f 51 99 4c
     17 6a 83 83 d0 18 01 00 1c 40 00 00 01 01 08 0a
     bd 33 12 a5 00 41 d0 91 1d 14 54 3d e2 1e dd a2
     7a 40 5d d0 4a 60 a9 ac 5f 84 03 e5 ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      e2 1e dd a2 7a 40 5d d0 4a 60 a9 ac 5f 84 03 e5

A.3.2. HMAC-SHA256-128 (Omits TCP Options)

A.3.2.1. Send (Client) SYN (Omits Options) 
   Client ISN = 0x020c1e69

   Send_SYN_traffic_key:

      cc de 26 1c 40 80 79 8c b3 e6 de c2 fd 10 04 e2
      15 67 ed 9b 96 12 aa ce f8 6b 52 ed 0d 9f 9c af

   IPv6/TCP:
     6e 07 8f cd 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 c6 cd 00 b3 02 0c 1e 69
     00 00 00 00 f0 02 ff ff 65 cc 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a 00 9d b9 5b 00 00 00 00
     1d 14 3d 54

   MAC:

      1b 21 f1 0d d8 c8 60 84 f0 14 a9 45 8f de 2d 22
A.3.2.2. Receive (Server) SYN-ACK (Omits Options) 
   Server ISN = 0xeba3734d

   Receive_SYN_traffic_key:

      05 37 33 e3 ef 40 1b d7 e9 92 f3 cb 03 8b ac 18
      a2 bf 90 91 b1 ad dd 5e f9 39 3f 3c ab 60 d4 5e

   IPv6/TCP:
     6e 0a 7e 1f 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 c6 cd eb a3 73 4d
     02 0c 1e 6a f0 12 ff ff af bf 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a 5e c9 9b 70 00 9d b9 5b
     1d 14 54 3d

   MAC:

      d8 51 95 7a c6 27 ce 69 62 8f a2 24 69 d7 70 d5
A.3.2.3. Send (Client) Non-SYN (Omits Options) 
   Send_other_traffic_key:

      80 67 5f 71 25 52 35 f8 68 d9 7b b4 a9 76 d7 ad
      c7 d5 66 d2 25 73 24 dc 2b ea 79 c2 5f d6 41 ee

   IPv6/TCP:
     6e 07 8f cd 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 c6 cd 00 b3 02 0c 1e 6a
     eb a3 73 4e d0 18 01 00 df 66 00 00 01 01 08 0a
     00 9d b9 65 5e c9 9b 70 1d 14 3d 54 a3 56 7d 0a
     8e 8f 04 66 cc 06 26 b9 1e c7 8f d7 ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      a3 56 7d 0a 8e 8f 04 66 cc 06 26 b9 1e c7 8f d7
A.3.2.4. Receive (Server) Non-SYN (Omits Options) 
   Receive_other_traffic_key:

      05 37 33 e3 ef 40 1b d7 e9 92 f3 cb 03 8b ac 18
      a2 bf 90 91 b1 ad dd 5e f9 39 3f 3c ab 60 d4 5e

   IPv6/TCP:
     6e 0a 7e 1f 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 c6 cd eb a3 73 4e
     02 0c 1e ad d0 18 01 00 5e 0c 00 00 01 01 08 0a
     5e c9 9b 7a 00 9d b9 65 1d 14 54 3d 8a 58 25 6c
     40 0e f1 a5 5f 32 b3 9d 26 ff a3 90 ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      8a 58 25 6c 40 0e f1 a5 5f 32 b3 9d 26 ff a3 90

A.4. IPv6 KMAC256-128 Output Test Vectors

A.4.1. KMAC256-128 (Default - Covers TCP Options)

A.4.1.1. Send (Client) SYN (Covers Options) 
   Client ISN = 0x193cccec

   Send_SYN_traffic_key:

      d2 d7 cb ea 4e 15 6b 75 c8 c8 f6 42 4d 0a 71 b6
      f5 cd c9 6c 8e 0e 65 01 dc 28 98 00 2e db 51 d8

  IPv6/TCP:
     6e 04 a7 06 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 f8 5a 00 b3 19 3c cc ec
     00 00 00 00 f0 02 ff ff 38 a8 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a 13 e4 ab 99 00 00 00 00
     1d 14 3d 54

   MAC:

      30 d5 65 1a a0 ce 84 31 cb 13 bc 5e 77 9d 12 36
A.4.1.2. Receive (Server) SYN-ACK (Covers Options) 
   Server ISN = 0xa6744ecb

   Receive_SYN_traffic_key:

      c8 f9 c7 65 d4 05 85 e7 e2 34 63 65 b1 f5 7f ac
      9b 80 1e cc d3 c9 68 a0 22 39 7c a0 00 e9 cf bf

   IPv6/TCP:
     6e 06 15 20 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 f8 5a a6 74 4e cb
     19 3c cc ed f0 12 ff ff f8 14 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a 71 da ab c8 13 e4 ab 99
     1d 14 54 3d

   MAC:

      41 d6 0e 40 cd d6 fb 70 67 3a 4d 43 8c e6 88 29
A.4.1.3. Send (Client) Non-SYN (Covers Options) 
   Send_other_traffic_key:

      2a 86 ea c4 60 ac 2a 76 52 40 1d 08 d9 41 32 41
      fb 32 15 b0 8e 42 21 9d dc 93 1c 23 2f d0 35 14

   IPv6/TCP:
     6e 04 a7 06 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 f8 5a 00 b3 19 3c cc ed
     a6 74 4e cc d0 18 01 00 7e 67 00 00 01 01 08 0a
     13 e4 ab a3 71 da ab c8 1d 14 3d 54 5c fe 00 e1
     c8 4d f2 07 0b 7d 81 43 dd 70 7c d0 ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      5c fe 00 e1 c8 4d f2 07 0b 7d 81 43 dd 70 7c d0
A.4.1.4. Receive (Server) Non-SYN (Covers Options) 
   Receive_other_traffic_key:

      c8 f9 c7 65 d4 05 85 e7 e2 34 63 65 b1 f5 7f ac
      9b 80 1e cc d3 c9 68 a0 22 39 7c a0 00 e9 cf bf

   IPv6/TCP:
     6e 06 15 20 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 f8 5a a6 74 4e cc
     19 3c cd 30 d0 18 01 00 d3 2c 00 00 01 01 08 0a
     71 da ab d3 13 e4 ab a3 1d 14 54 3d 6b d0 63 2b
     84 5b eb 5b 5b 98 e6 6e 5d af b4 cf ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      6b d0 63 2b 84 5b eb 5b 5b 98 e6 6e 5d af b4 cf

A.4.2. KMAC256-128 (Omits TCP Options)

A.4.2.1. Send (Client) SYN (Omits Options) 
   Client ISN = 0xb01da74a

   Send_SYN_traffic_key:

      9e 3f 17 70 15 9b dd d9 01 51 18 13 10 e9 7e 85
      f9 84 2c dd 67 fc b6 e1 eb 66 e2 58 4a 8b aa 92

   IPv6/TCP:
     6e 09 3d 76 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 f2 88 00 b3 b0 1d a7 4a
     00 00 00 00 f0 02 ff ff 1a 84 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a 14 27 5b 3b 00 00 00 00
     1d 14 3d 54

   MAC:

      85 33 47 e6 0e bc 68 05 3f dc 02 43 5c 7d ec 8f
A.4.2.2. Receive (Server) SYN-ACK (Omits Options) 
   Server ISN = 0xa6246145

   Receive_SYN_traffic_key:

      fa b8 f8 8f 4c 4a ed 05 ff 0d 1e 8a d5 3b 25 ba
      59 2d 0e ae fb 4b a2 70 77 3b 43 9e fc 7c 0d 04

   IPv6/TCP:
     6e 0c 60 0a 00 3c 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 f2 88 a6 24 61 45
     b0 1d a7 4b f0 12 ff ff af 92 00 00 02 04 05 a0
     01 03 03 08 04 02 08 0a 17 82 24 5b 14 27 5b 3b
     1d 14 54 3d

   MAC:

      da 1d 61 57 9f 6f c6 41 e9 98 91 89 88 5d 3b 11
A.4.2.3. Send (Client) Non-SYN (Omits Options) 
   Send_other_traffic_key:

      a1 04 09 79 51 2f 15 43 c9 0a c8 f5 e7 30 9c 86
      c4 86 16 18 a1 f7 d4 ad 11 e6 73 1b dc e3 3f 9d

   IPv6/TCP:
     6e 09 3d 76 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 f2 88 00 b3 b0 1d a7 4b
     a6 24 61 46 d0 18 01 00 6e 3c 00 00 01 01 08 0a
     14 27 5b 4f 17 82 24 5b 1d 14 3d 54 25 1c 01 3f
     a6 d3 38 1e 84 c0 33 c4 da f7 2a d8 ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      25 1c 01 3f a6 d3 38 1e 84 c0 33 c4 da f7 2a d8
A.4.2.4. Receive (Server) Non-SYN (Omits Options) 
   Receive_other_traffic_key:

      fa b8 f8 8f 4c 4a ed 05 ff 0d 1e 8a d5 3b 25 ba
      59 2d 0e ae fb 4b a2 70 77 3b 43 9e fc 7c 0d 04

   IPv6/TCP:
     6e 0c 60 0a 00 77 06 40 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00
     00 00 00 00 00 00 00 01 00 b3 f2 88 a6 24 61 46
     b0 1d a7 8e d0 18 01 00 20 e0 00 00 01 01 08 0a
     17 82 24 65 14 27 5b 4f 1d 14 54 3d 8e 7f f5 06
     98 77 24 e1 cd fe 77 ab 72 e5 00 58 ff ff ff ff
     ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04
     fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00
     01 02 02 80 00 02 02 02 00 02 02 42 00 02 06

   MAC:

      8e 7f f5 06 98 77 24 e1 cd fe 77 ab 72 e5 00 58

Authors' Addresses

Ron Bonica
HPE
United States of America
Tony Li
HPE
United States of America
Ping Chen
HPE
Canada
Prashant Kumar
HPE
India
Reji Thomas
Arista Networks
India
Sujeet Nayak Ammunje
Cisco Systems
India
Ayan Banerjee
Cisco Systems
United States of America