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Versions: 00 draft-ietf-kitten-aes-cts-hmac-sha2

Network Working Group                                         M. Jenkins
Internet Draft                                  National Security Agency
Intended Status: Informational                                   M. Peck
Expires: April 4, 2014                             The MITRE Corporation
                                                               K. Burgin
                                                         October 1, 2013

              AES Encryption with HMAC-SHA2 for Kerberos 5
                 draft-ietf-kitten-aes-cbc-hmac-sha2-00

Abstract

   This document specifies two encryption types and two corresponding
   checksum types for Kerberos 5.  The new types use AES in CBC mode
   with plaintext padding for confidentiality and HMAC with a SHA-2 hash
   for integrity.

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
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   This Internet-Draft will expire on January 20, 2014.

Copyright and License Notice

   Copyright (c) 2013 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
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.



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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Protocol Key Representation  . . . . . . . . . . . . . . . . .  3
   3.  Key Generation from Pass Phrases . . . . . . . . . . . . . . .  3
   4.  Key Derivation Function  . . . . . . . . . . . . . . . . . . .  4
   5.  Kerberos Algorithm Protocol Parameters . . . . . . . . . . . .  5
   6.  Checksum Parameters  . . . . . . . . . . . . . . . . . . . . .  7
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  7
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . .  7
     8.1.  Random Values in Salt Strings  . . . . . . . . . . . . . .  8
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  8
   10.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  8
     10.1.  Normative References  . . . . . . . . . . . . . . . . . .  8
     10.2.  Informative References  . . . . . . . . . . . . . . . . .  8
   Appendix A.  Test Vectors  . . . . . . . . . . . . . . . . . . . .  9
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15


































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1.  Introduction

   This document defines two encryption types and two corresponding
   checksum types for Kerberos 5 using AES with 128-bit or 256-bit keys.
   The plaintext is padded to a multiple of the AES block size using the
   algorithm in Section 6.3 of [RFC5652].  The new types conform to the
   framework specified in [RFC3961], but do not use the simplified
   profile.

   The encryption and checksum types defined in this document are
   intended to support NSA's Suite B Profile for Kerberos [suiteb-
   kerberos] which requires the use of SHA-256 or SHA-384 as the hash
   algorithm.  Differences between the encryption and checksum types
   defined in this document and existing Kerberos encryption and
   checksum types are:

   *  The pseudorandom function used by PBKDF2 is HMAC-SHA-256 or HMAC-
      SHA-384.

   *  A key derivation function from [SP800-108] which uses the SHA-256
      or SHA-384 hash algorithm is used to produce keys for encryption,
      integrity protection, and checksum operations.

   *  The plaintext is padded so the resulting length is a multiple of
      the AES block length.  This allows for AES encryption using CBC
      mode as defined in [SP800-38A] instead of using ciphertext
      stealing (CTS) mode.

   *  The random nonce used during content encryption is sent as part of
      the ciphertext, instead of using a confounder. This saves one
      encryption and decryption operation per message.

   *  The HMAC is calculated over the random nonce concatenated with the
      AES output, instead of being calculated over the confounder and
      plaintext.  This allows the message receiver to verify the
      integrity of the message before decrypting the message.

   *  The HMAC algorithm uses the SHA-256 or SHA-384 hash algorithm for
      integrity protection and checksum operations.

2.  Protocol Key Representation

   The AES key space is dense, so we can use random or pseudorandom
   octet strings directly as keys.  The byte representation for the key
   is described in [FIPS197], where the first bit of the bit string is
   the high bit of the first byte of the byte string (octet string).

3.  Key Generation from Pass Phrases



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   The pseudorandom function used by PBKDF2 will be the SHA-256 or SHA-
   384 HMAC of the passphrase and salt. If the enctype is "aes128-cbc-
   hmac-sha256-128", then HMAC-SHA-256 is used as the PRF.  If the
   enctype is "aes256-cbc-hmac-sha384-192", then HMAC-SHA-384 is used as
   the PRF.

   The final key derivation step uses the algorithm KDF-HMAC-SHA2
   defined below in Section 4.

   If no string-to-key parameters are specified, the default number of
   iterations is 32,768.

   To ensure that different long-term keys are used with different
   enctypes, we prepend the enctype name to the salt string, separated
   by a null byte.  The enctype name is "aes128-cbc-hmac-sha256-128" or
   "aes256-cbc-hmac-sha384-192" (without the quotes). The user's long-
   term key is derived as follows

     saltp = enctype-name | 0x00 | salt
     tkey = random-to-key(PBKDF2(passphrase, saltp,
                              iter_count, keylength))
     key = KDF-HMAC-SHA2(tkey, "kerberos") where "kerberos" is the
           byte string {0x6b65726265726f73}.

   where the pseudorandom function used by PBKDF2 is HMAC-SHA-256 when
   the enctype is "aes128-cbc-hmac-sha256-128" and HMAC-SHA-384 when the
   enctype is "aes256-cbc-hmac-sha384-192", the value for keylength is
   the AES key length, and the algorithm KDF-HMAC-SHA2 is defined in
   Section 4.


4.  Key Derivation Function

   We use a key derivation function from Section 5.1 of [SP800-108]
   which uses the HMAC algorithm as the PRF.  The counter i is expressed
   as four octets in big-endian order.  The length of the output key in
   bits (denoted as k) is also represented as four octets in big-endian
   order.  The "Label" input to the KDF is the usage constant supplied
   to the key derivation function, and the "Context" input is null.
   Each application of the KDF only requires a single iteration of the
   PRF, so n = 1 in the notation of [SP800-108].

   In the following summary, | indicates concatenation.  The random-to-
   key function is the identity function, as defined in Section 3.  The
   k-truncate function is defined in [RFC3961], Section 5.1.

   When the encryption type is aes128-cbc-hmac-sha256-128, the output
   key length k is 128 bits for all applications of KDF-HMAC-SHA2(key,



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   constant) which is computed as follows:

     K1 = HMAC-SHA-256(key, 00 00 00 01 | constant | 0x00 | 00 00 00 80)
     KDF-HMAC-SHA2(key, constant) = random-to-key(k-truncate(K1))

   When the encryption type is aes256-cbc-hmac-sha384-192, the output
   key length k is 256 bits when computing the base-key and Ke, and the
   output key length k is 192 bits when deriving Kc and Ki.  KDF-HMAC-
   SHA2(key, constant) is computed as follows:

     If deriving Kc or Ki (the constant ends with 0x99 or 0x55):
     k = 192
     K1 = HMAC-SHA-384(key, 00 00 00 01 | constant | 0x00 | 00 00 00 C0)
     KDF-HMAC-SHA2(key, constant) = random-to-key(k-truncate(K1))

     Otherwise (if deriving Ke or deriving the base-key from a
                passphrase as described in Section 3):
     k = 256
     K1 = HMAC-SHA-384(key, 00 00 00 01 | constant | 0x00 | 00 00 01 00)
     KDF-HMAC-SHA2(key, constant) = random-to-key(k-truncate(K1))

   The constants used for key derivation are the same as those used in
   the simplified profile.

5.  Kerberos Algorithm Protocol Parameters

   Each encryption will use a 16-octet nonce generated at random by the
   message originator.  The initialization vector (IV) used by AES is
   obtained by xoring the random nonce with the cipherState.

   CBC mode [SP800-38A] requires the plaintext length be a multiple of
   the AES block size, so the plaintext is padded using the algorithm in
   Section 6.3 of [RFC5652].

   The ciphertext is the concatenation of the random nonce, the output
   of AES in CBC mode, and the HMAC of the nonce concatenated with the
   AES output.  The HMAC is computed using either SHA-256 or SHA-384.
   The output of HMAC-SHA-256 is truncated to 128 bits and the output of
   HMAC-SHA-384 is truncated to 192 bits. Sample test vectors are given
   in Appendix A.

   Decryption is performed by removing the HMAC, verifying the HMAC
   against the remainder, and then decrypting the remainder if the HMAC
   is correct.

   The following parameters apply to the encryption types aes128-cbc-
   hmac-sha256-128 and aes256-cbc-hmac-sha384-192.




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   protocol key format: as defined in Section 2.

   specific key structure: three protocol-format keys: { Kc, Ke, Ki }.

   required checksum mechanism: as defined in Section 6.

   key-generation seed length: key size (128 or 256 bits).

   string-to-key function: as defined in Section 3.

   default string-to-key parameters: 00 00 80 00.

   random-to-key function: identity function.

   key-derivation function: KDF-HMAC-SHA2 as defined in Section 4.  The
   key usage number is expressed as four octets in big-endian order.

   Kc = KDF-HMAC-SHA2(base-key, usage | 0x99)
   Ke = KDF-HMAC-SHA2(base-key, usage | 0xAA)
   Ki = KDF-HMAC-SHA2(base-key, usage | 0x55)

   cipherState: a 128-bit random nonce.

   initial cipherState: all bits zero.

   encryption function: as follows, where E() is AES encryption in CBC
   mode, h is the size of truncated HMAC, and c is the AES block size.

      N = random nonce of length c (128 bits)
      IV = N XOR cipherState
      pad = Shortest string of non-zero length to bring the plaintext
            to a length that is a multiple of c.  The value of each
            added octet equals the number of octets that are added.
      C = E(Ke, plaintext | pad, IV)
      H = HMAC(Ki, N | C)
      ciphertext =  N | C | H[1..h]
      cipherState = N

   decryption function: as follows, where D() is AES encryption in CBC
   mode, and h is the size of truncated HMAC.

      (N, C, H) = ciphertext
      if H != HMAC(Ki, N | C)[1..h]
          stop, report error
      IV = N XOR cipherState
      P | pad = D(Ke, C, IV)
      cipherState = N




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   pseudo-random function:
      Kp  = KDF-HMAC-SHA2(protocol-key, "prf")
      PRF = HMAC(Kp, octet-string)

6.  Checksum Parameters

   The following parameters apply to the checksum types hmac-sha256-128-
   aes128 and hmac-sha384-192-aes256, which are the associated checksums
   for aes128-cbc-hmac-sha256-128 and aes256-cbc-hmac-sha384-192,
   respectively.

   associated cryptosystem: AES-128-CBC or AES-256-CBC as appropriate.

   get_mic: HMAC(Kc, message)[1..h].

   verify_mic: get_mic and compare.

7.  IANA Considerations

   IANA is requested to assign:

   Encryption type numbers for aes128-cbc-hmac-sha256-128 and
   aes256-cbc-hmac-sha384-192 in the Kerberos Encryption Type Numbers
   registry.

      Etype   encryption type              Reference
      -----   ---------------              ---------
      TBD1    aes128-cbc-hmac-sha256-128   [this document]
      TBD2    aes256-cbc-hmac-sha384-192   [this document]

   Checksum type numbers for hmac-sha256-128-aes128 and hmac-sha384-192-
   aes256 in the Kerberos Checksum Type Numbers registry.

      Sumtype   Checksum type            Size   Reference
      -------   -------------            ----   ---------
      TBD3      hmac-sha256-128-aes128   16     [this document]
      TBD4      hmac-sha384-192-aes256   24     [this document]

8.  Security Considerations

   This specification requires implementations to generate random
   values.  The use of inadequate pseudo-random number generators
   (PRNGs) can result in little or no security.  The generation of
   quality random numbers is difficult.  [RFC4086] offers random number
   generation guidance.

   This document specifies a mechanism for generating keys from pass
   phrases or passwords.  The salt and iteration count resist brute



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   force and dictionary attacks, however, it is still important to
   choose or generate strong passphrases.

8.1.  Random Values in Salt Strings

   NIST guidance in Section 5.1 of [SP800-132] requires the salt used as
   input to the PBKDF to contain at least 128 bits of random.  Some
   known issues with including random values in Kerberos encryption type
   salt strings are:

   *  Cross-realm TGTs are currently managed by entering the same
      password at two KDCs to get the same keys.  If each KDC uses a
      random salt, they won't have the same keys.

   *  The string-to-key function as defined in [RFC3961] requires the
      salt to be valid UTF-8 strings.  Not every 128-bit random string
      will be valid UTF-8.

   *  Current implementations of password history checking will not
      work.

   *  ktutil's add_entry command assumes the default salt.

9.  Acknowledgements

   Kelley Burgin was employed at the National Security Agency during
   much of the work on this document.

10.  References

10.1.  Normative References

   [RFC3961]    Raeburn, K., "Encryption and Checksum Specifications for
                Kerberos 5", RFC 3961, February 2005.

   [RFC5652]    Housley, R., "Cryptographic Message Syntax (CMS)",
                RFC5652, September 2009.

   [FIPS197]    National Institute of Standards and Technology,
                "Advanced Encryption Standard (AES)", FIPS PUB 197,
                November 2001.

10.2.  Informative References


   [RFC4086]    Eastlake 3rd, D., Schiller, J., and S. Crocker,
                "Randomness Requirements for Security", BCP 106, RFC
                4086, June 2005.



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   [SP800-38A]  National Institute of Standards and Technology,
                "Recommendation for Block Cipher Modes of Operation:
                Methods and Techniques", NIST Special Publication
                800-38A, December 2001.

   [SP800-108]  National Institute of Standards and Technology,
                "Recommendation for Key Derivation Using Pseudorandom
                Functions", NIST Special Publication 800-108, October
                2009.

   [SP800-132]  National Institute of Standards and Technology,
                "Recommendation for Password-Based Key Derivation, Part
                1: Storage Applications", NIST Special Publication 800-
                132, June 2010.

   [suiteb-kerberos]
                Burgin, K. and K. Igoe, "Suite B Profile for
                Kerberos 5", internet-draft draft-burgin-kerberos-
                suiteb-01, Work In Progress, 2012.

Appendix A.  Test Vectors

   Sample results for string-to-key conversion:
   --------------------------------------------

   Iteration count = 32768
   Pass phrase = "password"
   Saltp for creating 128-bit master key:
      61 65 73 31 32 38 2D 63 62 63 2D 68 6D 61 63 2D
      73 68 61 32 35 36 2D 31 32 38 00 10 DF 9D D7 83
      E5 BC 8A CE A1 73 0E 74 35 5F 61 41 54 48 45 4E
      41 2E 4D 49 54 2E 45 44 55 72 61 65 62 75 72 6E
   (The saltp is "aes128-cbc-hmac-sha256-128" | 0x00 |
    random 16 byte valid UTF-8 sequence | "ATHENA.MIT.EDUraeburn")
   128-bit master key:
      C3 19 22 E2 EA 3A 67 05 E0 B9 AC 57 08 82 48 28

   Saltp for creating 256-bit master key:
      61 65 73 32 35 36 2D 63 62 63 2D 68 6D 61 63 2D
      73 68 61 33 38 34 2D 31 39 32 00 10 DF 9D D7 83
      E5 BC 8A CE A1 73 0E 74 35 5F 61 41 54 48 45 4E
      41 2E 4D 49 54 2E 45 44 55 72 61 65 62 75 72 6E
   (The saltp is "aes256-cbc-hmac-sha384-192" | 0x00 |
    random 16 byte valid UTF-8 sequence | "ATHENA.MIT.EDUraeburn")
   256-bit master key:
      77 73 83 E7 C4 76 1D CE FC 5B D8 F8 A7 28 37 8A
      5E 63 BC B2 0E B9 A2 BB C5 1E 73 56 8A FC CD E6




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   Sample results for key derivation:
   ----------------------------------

   enctype aes128-cbc-hmac-sha256-128:
   128-bit master key:
      37 05 D9 60 80 C1 77 28 A0 E8 00 EA B6 E0 D2 3C
   Kc value for key usage 2 (constant = 0x0000000299):
      B3 1A 01 8A 48 F5 47 76 F4 03 E9 A3 96 32 5D C3
   Ke value for key usage 2 (constant = 0x00000002AA):
      9B 19 7D D1 E8 C5 60 9D 6E 67 C3 E3 7C 62 C7 2E
   Ki value for key usage 2 (constant = 0x0000000255):
      9F DA 0E 56 AB 2D 85 E1 56 9A 68 86 96 C2 6A 6C

   enctype aes256-cbc-hmac-sha384-192:
   256-bit master key:
      6D 40 4D 37 FA F7 9F 9D F0 D3 35 68 D3 20 66 98
      00 EB 48 36 47 2E A8 A0 26 D1 6B 71 82 46 0C 52
   Kc value for key usage 2 (constant = 0x0000000299):
      EF 57 18 BE 86 CC 84 96 3D 8B BB 50 31 E9 F5 C4
      BA 41 F2 8F AF 69 E7 3D
   Ke value for key usage 2 (constant = 0x00000002AA):
      56 AB 22 BE E6 3D 82 D7 BC 52 27 F6 77 3F 8E A7
      A5 EB 1C 82 51 60 C3 83 12 98 0C 44 2E 5C 7E 49
   Ki value for key usage 2 (constant = 0x0000000255):
      69 B1 65 14 E3 CD 8E 56 B8 20 10 D5 C7 30 12 B6
      22 C4 D0 0F FC 23 ED 1F

   Sample encryptions (using the default cipher state):
   ----------------------------------------------------

   Plaintext: (empty)
   Nonce:
      7E 58 95 EA F2 67 24 35 BA D8 17 F5 45 A3 71 48
   128-bit AES key:
      9B 19 7D D1 E8 C5 60 9D 6E 67 C3 E3 7C 62 C7 2E
   128-bit HMAC key:
      9F DA 0E 56 AB 2D 85 E1 56 9A 68 86 96 C2 6A 6C
   AES Output:
      9E 30 E1 7A 01 BC E8 5B 59 90 C8 90 1A 55 1D 8C
   HMAC Output:
      0C 80 06 07 A4 6E 35 2C A7 73 CE 52 69 51 63 57
   Ciphertext:
      7E 58 95 EA F2 67 24 35 BA D8 17 F5 45 A3 71 48
      9E 30 E1 7A 01 BC E8 5B 59 90 C8 90 1A 55 1D 8C
      0C 80 06 07 A4 6E 35 2C A7 73 CE 52 69 51 63 57

   Plaintext: (length less than block size)
      00 01 02 03 04 05



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   Nonce:
      7B CA 28 5E 2F D4 13 0F B5 5B 1A 5C 83 BC 5B 24
   128-bit AES key:
      4E FD A6 52 4E 6B 56 B4 F2 12 61 FB FC 93 21 AB
   128-bit HMAC key:
      29 1B 0C 37 73 D7 6E E6 BA 2C CF 1E 03 93 F6 3E
   AES Output:
      2B E8 63 D7 B1 D4 F0 4D 95 F2 17 D6 9E C2 14 23
   HMAC Output:
      5F D1 CB B9 C0 6E 42 6E F9 95 05 B5 FB 42 6F 6A
   Ciphertext:
      7B CA 28 5E 2F D4 13 0F B5 5B 1A 5C 83 BC 5B 24
      2B E8 63 D7 B1 D4 F0 4D 95 F2 17 D6 9E C2 14 23
      5F D1 CB B9 C0 6E 42 6E F9 95 05 B5 FB 42 6F 6A

   Plaintext: (length equals block size)
      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
   Nonce:
      56 AB 21 71 3F F6 2C 0A 14 57 20 0F 6F A9 94 8F
   128-bit AES key:
      FF 82 40 42 4B CC BA 05 56 50 C0 39 3B 83 DF 3B
   128-bit HMAC key:
      ED 15 62 8B 45 35 8C BF 7F 50 E7 64 C2 6B 8A 1A
   AES Output:
      AD 5D 0C E8 93 48 A8 16 07 11 09 75 6A 83 FB 09
      D2 3F 29 30 68 F9 D4 E5 1F B8 92 B0 61 C7 43 BF
   HMAC Output:
      3A 40 51 A4 8B 7A 11 B3 91 F1 36 67 98 16 24 AD
   Ciphertext:
      56 AB 21 71 3F F6 2C 0A 14 57 20 0F 6F A9 94 8F
      AD 5D 0C E8 93 48 A8 16 07 11 09 75 6A 83 FB 09
      D2 3F 29 30 68 F9 D4 E5 1F B8 92 B0 61 C7 43 BF
      3A 40 51 A4 8B 7A 11 B3 91 F1 36 67 98 16 24 AD

   Plaintext: (length greater than block size)
      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
      10 11 12 13 14
   Nonce:
      A7 A4 E2 9A 47 28 CE 10 66 4F B6 4E 49 AD 3F AC
   128-bit AES key:
      B5 9B 88 75 AD 5D CA FF F7 79 4D 93 F8 19 9D 79
   128-bit HMAC key:
      0A 42 1D 72 2F 8F C2 D6 84 8B 1C DA D1 5A 49 C9
   AES Output:
      DA A3 99 2E 39 5C 5D E1 34 EB 1A CC 73 8D CE 02
      35 B9 D6 5A 63 0B 8D 84 BC 78 E9 38 75 79 5E DF
   HMAC Output:
      CF 68 74 07 12 22 6C 61 C1 E4 A6 78 A9 7C 86 60



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   Ciphertext:
      A7 A4 E2 9A 47 28 CE 10 66 4F B6 4E 49 AD 3F AC
      DA A3 99 2E 39 5C 5D E1 34 EB 1A CC 73 8D CE 02
      35 B9 D6 5A 63 0B 8D 84 BC 78 E9 38 75 79 5E DF
      CF 68 74 07 12 22 6C 61 C1 E4 A6 78 A9 7C 86 60

   Plaintext: (empty)
   Nonce:
      F7 64 E9 FA 15 C2 76 47 8B 2C 7D 0C 4E 5F 58 E4
   256-bit AES key:
      0F A2 0D 7D 03 33 EE 65 16 2C DA 67 E7 AD 0D 3C
      5E 03 1F 3B 66 70 E0 31 28 2F AC C2 87 9C 21 C7
   192-bit HMAC key:
      53 BF 30 6A 68 33 A3 25 18 FC B8 5F 63 1D 03 D5
      2E E3 1B 39 75 2F 57 ED
   AES Output:
      73 1E 56 A3 D9 DA 70 87 5C 74 C7 67 73 C2 F7 EB
   HMAC Output:
      FA F7 49 55 33 7E 20 98 C4 B4 F7 8F 35 5B 8A B9
      72 6D 40 AC F3 5D B3 7B
   Ciphertext:
      F7 64 E9 FA 15 C2 76 47 8B 2C 7D 0C 4E 5F 58 E4
      73 1E 56 A3 D9 DA 70 87 5C 74 C7 67 73 C2 F7 EB
      FA F7 49 55 33 7E 20 98 C4 B4 F7 8F 35 5B 8A B9
      72 6D 40 AC F3 5D B3 7B

   Plaintext: (length less than block size)
      00 01 02 03 04 05
   Nonce:
      B8 0D 32 51 C1 F6 47 14 94 25 6F FE 71 2D 0B 9A
   256-bit AES key:
      47 DA 4C A2 8B D1 C1 14 D5 50 7E 55 81 86 CA 4F
      DB A0 DA E5 B2 4F 6D 68 89 D5 3A FB F1 D0 B8 36
   192-bit HMAC key:
      13 6B 5C 83 C9 53 AE 29 E2 C2 31 6A 7B 34 B8 C2
      AD 26 E4 66 7F AB 42 6E
   AES Output:
      EF DE 87 A1 14 2D B5 C7 4A 42 52 A7 A7 77 5A 3E
   HMAC Output:
      45 02 19 E4 A8 C6 3E 8F E6 DB F5 08 78 E4 28 40
      E9 36 DD 0A 66 1C A9 9C
   Ciphertext:
      B8 0D 32 51 C1 F6 47 14 94 25 6F FE 71 2D 0B 9A
      EF DE 87 A1 14 2D B5 C7 4A 42 52 A7 A7 77 5A 3E
      45 02 19 E4 A8 C6 3E 8F E6 DB F5 08 78 E4 28 40
      E9 36 DD 0A 66 1C A9 9C

   Plaintext: (length equals block size)



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Internet-Draft      AES-CBC HMAC-SHA2 For Kerberos 5     October 1, 2013


      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
   Nonce:
      53 BF 8A 0D 10 52 65 D4 E2 76 42 86 24 CE 5E 63
   256-bit AES key:
      5E A6 16 D8 FD A2 33 F1 B4 99 79 A4 B9 FA 01 D3
      21 B1 3D 6F BD 6E 3B B7 2E 54 B4 85 E2 36 AF 23
   192-bit HMAC key:
      AD D3 8D C9 86 83 C5 CC 14 E3 C7 37 EA A7 06 47
      B3 19 71 0E 87 6A 38 77
   AES Output:
      E4 09 FF 7A 93 60 E9 72 7B 3F 88 35 28 73 E0 CF
      B3 21 90 09 69 7D 79 6A 51 9C A3 86 DF 84 5D AD
   HMAC Output:
      60 75 75 AA D0 05 9F 9A C8 16 EA E0 B9 B5 00 2E
      42 33 AA 53 89 9F AB 39
   Ciphertext:
      53 BF 8A 0D 10 52 65 D4 E2 76 42 86 24 CE 5E 63
      E4 09 FF 7A 93 60 E9 72 7B 3F 88 35 28 73 E0 CF
      B3 21 90 09 69 7D 79 6A 51 9C A3 86 DF 84 5D AD
      60 75 75 AA D0 05 9F 9A C8 16 EA E0 B9 B5 00 2E
      42 33 AA 53 89 9F AB 39

   Plaintext: (length greater than block size)
      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
      10 11 12 13 14
   Nonce:
      76 3E 65 36 7E 86 4F 02 F5 51 53 C7 E3 B5 8A F1
   256-bit AES key:
      B3 A8 02 E3 40 61 3E F1 E0 EC E9 1A 15 7C 59 12
      6F BD C4 B8 C2 4C 8D 0B 2E 5A 30 F0 1E 7E 34 88
   192-bit HMAC key:
      FC 0B 49 9B 83 55 A3 2A C3 C9 AC B6 64 93 63 EB
      5D BB A4 25 1A 75 B2 0A
   AES Output:
      F6 2D D7 FF 39 A8 EE D2 4C C5 A8 CF 84 15 71 1C
      F5 05 05 2F 9B AD 75 C8 27 9D 05 D4 81 CF A9 73
   HMAC Output:
      DB 3B C2 37 0F 9D A6 F1 F7 99 32 A0 A6 4F 7A 7A
      BD B9 B3 35 47 DD 9B 62
   Ciphertext:
      76 3E 65 36 7E 86 4F 02 F5 51 53 C7 E3 B5 8A F1
      F6 2D D7 FF 39 A8 EE D2 4C C5 A8 CF 84 15 71 1C
      F5 05 05 2F 9B AD 75 C8 27 9D 05 D4 81 CF A9 73
      DB 3B C2 37 0F 9D A6 F1 F7 99 32 A0 A6 4F 7A 7A
      BD B9 B3 35 47 DD 9B 62

   Sample checksums:
   -----------------



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Internet-Draft      AES-CBC HMAC-SHA2 For Kerberos 5     October 1, 2013


   Checksum type: hmac-sha256-128-aes128
   128-bit master key:
      37 05 D9 60 80 C1 77 28 A0 E8 00 EA B6 E0 D2 3C
   128-bit HMAC key (Kc, key usage 2):
      B3 1A 01 8A 48 F5 47 76 F4 03 E9 A3 96 32 5D C3
   Plaintext:
      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
      10 11 12 13 14
   Checksum:
      D7 83 67 18 66 43 D6 7B 41 1C BA 91 39 FC 1D EE

   Checksum type: hmac-sha384-192-aes256
   256-bit master key:
      6D 40 4D 37 FA F7 9F 9D F0 D3 35 68 D3 20 66 98
      00 EB 48 36 47 2E A8 A0 26 D1 6B 71 82 46 0C 52
   192-bit HMAC key (Kc, key usage 2):
      EF 57 18 BE 86 CC 84 96 3D 8B BB 50 31 E9 F5 C4
      BA 41 F2 8F AF 69 E7 3D
   Plaintext:
      00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
      10 11 12 13 14
   Checksum:
      45 EE 79 15 67 EE FC A3 7F 4A C1 E0 22 2D E8 0D
      43 C3 BF A0 66 99 67 2A



























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Internet-Draft      AES-CBC HMAC-SHA2 For Kerberos 5     October 1, 2013


Authors' Addresses

   Michael J. Jenkins
   National Security Agency

   EMail: mjjenki@tycho.ncsc.mil

   Michael A. Peck
   The MITRE Corporation

   EMail: mpeck@mitre.org

   Kelley W. Burgin

   Email: kelley.burgin@gmail.com




































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