draft-ietf-kitten-aes-cts-hmac-sha2-09.txt   draft-ietf-kitten-aes-cts-hmac-sha2-10.txt 
Network Working Group M. Jenkins Network Working Group M. Jenkins
Internet Draft National Security Agency Internet Draft National Security Agency
Intended Status: Informational M. Peck Intended Status: Informational M. Peck
Expires: July 28, 2016 The MITRE Corporation Expires: January 6, 2017 The MITRE Corporation
K. Burgin K. Burgin
January 25, 2016 July 5, 2016
AES Encryption with HMAC-SHA2 for Kerberos 5 AES Encryption with HMAC-SHA2 for Kerberos 5
draft-ietf-kitten-aes-cts-hmac-sha2-09 draft-ietf-kitten-aes-cts-hmac-sha2-10
Abstract Abstract
This document specifies two encryption types and two corresponding This document specifies two encryption types and two corresponding
checksum types for Kerberos 5. The new types use AES in CTS mode checksum types for Kerberos 5. The new types use AES in CTS mode
(CBC mode with ciphertext stealing) for confidentiality and HMAC with (CBC mode with ciphertext stealing) for confidentiality and HMAC with
a SHA-2 hash for integrity. a SHA-2 hash for integrity.
Status of this Memo Status of this Memo
skipping to change at page 1, line 35 skipping to change at page 1, line 35
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 28, 2016. This Internet-Draft will expire on January 6, 2017.
Copyright and License Notice Copyright and License Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 13 skipping to change at page 2, line 13
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Protocol Key Representation . . . . . . . . . . . . . . . . . 3 2. Protocol Key Representation . . . . . . . . . . . . . . . . . 3
3. Key Derivation Function . . . . . . . . . . . . . . . . . . . 3 3. Key Derivation Function . . . . . . . . . . . . . . . . . . . 3
4. Key Generation from Pass Phrases . . . . . . . . . . . . . . . 4 4. Key Generation from Pass Phrases . . . . . . . . . . . . . . . 4
5. Kerberos Algorithm Protocol Parameters . . . . . . . . . . . . 5 5. Kerberos Algorithm Protocol Parameters . . . . . . . . . . . . 5
6. Checksum Parameters . . . . . . . . . . . . . . . . . . . . . 7 6. Checksum Parameters . . . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
8. Security Considerations . . . . . . . . . . . . . . . . . . . 8 8. Security Considerations . . . . . . . . . . . . . . . . . . . 8
8.1. Random Values in Salt Strings . . . . . . . . . . . . . . 8 8.1. Random Values in Salt Strings . . . . . . . . . . . . . . 9
8.2. Algorithm Rationale . . . . . . . . . . . . . . . . . . . 9 8.2. Algorithm Rationale . . . . . . . . . . . . . . . . . . . 9
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 9 10.1. Normative References . . . . . . . . . . . . . . . . . . 10
10.2. Informative References . . . . . . . . . . . . . . . . . 9 10.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Test Vectors . . . . . . . . . . . . . . . . . . . . 10 Appendix A. Test Vectors . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
This document defines two encryption types and two corresponding This document defines two encryption types and two corresponding
checksum types for Kerberos 5 using AES with 128-bit or 256-bit keys. checksum types for Kerberos 5 using AES with 128-bit or 256-bit keys.
To avoid ciphertext expansion, we use a variation of the CBC-CS3 mode To avoid ciphertext expansion, we use a variation of the CBC-CS3 mode
defined in [SP800-38A+], also referred to as ciphertext stealing or defined in [SP800-38A+], also referred to as ciphertext stealing or
CTS mode. The new types conform to the framework specified in CTS mode. The new types conform to the framework specified in
[RFC3961], but do not use the simplified profile. [RFC3961], but do not use the simplified profile.
The encryption and checksum types defined in this document are The encryption and checksum types defined in this document are
intended to support environments that desire to use SHA-256 or SHA- intended to support environments that desire to use SHA-256 or SHA-
384 as the hash algorithm. Differences between the encryption and 384 (defined in [FIPS180]) as the hash algorithm. Differences
checksum types defined in this document and the pre-existing Kerberos between the encryption and checksum types defined in this document
AES encryption and checksum types specified in [RFC3962] are: and the pre-existing Kerberos AES encryption and checksum types
specified in [RFC3962] are:
* The pseudorandom function used by PBKDF2 is HMAC-SHA-256 or HMAC- * The pseudorandom function used by PBKDF2 is HMAC-SHA-256 or HMAC-
SHA-384. SHA-384 (HMAC is defined in [RFC2104]).
* A key derivation function from [SP800-108] using the SHA-256 or * A key derivation function from [SP800-108] using the SHA-256 or
SHA-384 hash algorithm is used to produce keys for encryption, SHA-384 hash algorithm is used to produce keys for encryption,
integrity protection, and checksum operations. integrity protection, and checksum operations.
* The HMAC is calculated over the cipherstate concatenated with the * The HMAC is calculated over the cipherstate concatenated with the
AES output, instead of being calculated over the confounder and AES output, instead of being calculated over the confounder and
plaintext. This allows the message receiver to verify the plaintext. This allows the message receiver to verify the
integrity of the message before decrypting the message. integrity of the message before decrypting the message.
skipping to change at page 3, line 48 skipping to change at page 3, line 49
The AES key space is dense, so we can use random or pseudorandom The AES key space is dense, so we can use random or pseudorandom
octet strings directly as keys. The byte representation for the key octet strings directly as keys. The byte representation for the key
is described in [FIPS197], where the first bit of the bit string is 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). the high bit of the first byte of the byte string (octet string).
3. Key Derivation Function 3. Key Derivation Function
We use a key derivation function from Section 5.1 of [SP800-108] We use a key derivation function from Section 5.1 of [SP800-108]
which uses the HMAC algorithm as the PRF. which uses the HMAC algorithm as the PRF.
KDF-HMAC-SHA2(key, label, k) = k-truncate(K1) function KDF-HMAC-SHA2(key, label, [context,] k):
k-truncate(K1)
where the value of K1 is computed as below.
key: The source of entropy from which subsequent keys are derived key: The source of entropy from which subsequent keys are derived
(this is known as Ki in [SP800-108]). (this is known as Ki in [SP800-108]).
label: An octet string describing the intended usage of the derived label: An octet string describing the intended usage of the derived
key. key.
context: This parameter is optional. An octet string containing the
information related to the derived keying material. It may include
identities of parties who are deriving and/or using the derived key
material and, optionally, a nonce known by the parties who derive the
keys.
k: Length in bits of the key to be outputted, expressed in big-endian k: Length in bits of the key to be outputted, expressed in big-endian
binary representation in 4 bytes (this is known as L in [SP800-108]). binary representation in 4 bytes (this is called L in [SP800-108]).
(e.g. k = 128 is represented as 0x00000080, Specifically, k=128 is represented as 0x00000080, 192 as 0x000000C0,
k = 192 as 0x000000C0, k = 256 as 0x00000100, 256 as 0x00000100, and 384 as 0x00000180.
k = 384 as 0x00000180)
When the encryption type is aes128-cts-hmac-sha256-128, k must be no When the encryption type is aes128-cts-hmac-sha256-128, k must be no
greater than 256. When the encryption type is aes256-cts-hmac-sha384- greater than 256. When the encryption type is aes256-cts-hmac-sha384-
192, k must be no greater than 384. 192, k must be no greater than 384.
The k-truncate function is defined in [RFC3961], Section 5.1. The k-truncate function is defined in [RFC3961], Section 5.1. It
returns the 'k' leftmost bits of the bitstring input.
In all computations in this document, | indicates concatenation. In all computations in this document, | indicates concatenation.
When the encryption type is aes128-cts-hmac-sha256-128, then K1 is When the encryption type is aes128-cts-hmac-sha256-128, then K1 is
computed as follows: computed as follows:
If the context parameter is not present:
K1 = HMAC-SHA-256(key, 0x00000001 | label | 0x00 | k) K1 = HMAC-SHA-256(key, 0x00000001 | label | 0x00 | k)
If the context parameter is present:
K1 = HMAC-SHA-256(key, 0x00000001 | label | 0x00 | context | k)
When the encryption type is aes256-cts-hmac-sha384-192, then K1 is When the encryption type is aes256-cts-hmac-sha384-192, then K1 is
computed as follows: computed as follows:
If the context parameter is not present:
K1 = HMAC-SHA-384(key, 0x00000001 | label | 0x00 | k) K1 = HMAC-SHA-384(key, 0x00000001 | label | 0x00 | k)
4. Key Generation from Pass Phrases If the context parameter is present:
K1 = HMAC-SHA-384(key, 0x00000001 | label | 0x00 | context | k)
In the definitions of K1 above, '0x00000001' is the i parameter (the
iteration counter) from Section 5.1 of [SP800-108].
4. Key Generation from Pass Phrases
As defined below, the string-to-key function uses PBKDF2 [RFC2898] As defined below, the string-to-key function uses PBKDF2 [RFC2898]
and KDF-HMAC-SHA2 to derive the base-key from a passphrase and salt. and KDF-HMAC-SHA2 to derive the base-key from a passphrase and salt.
The string-to-key parameter string is four octets indicating an The string-to-key parameter string is four octets indicating an
unsigned number in big-endian order, consistent with [RFC3962], unsigned number in big-endian order, consistent with [RFC3962],
except that the default is decimal 32768 if the parameter is not except that the default is decimal 32768 if the parameter is not
specified. specified.
To ensure that different long-term base-keys are used with different To ensure that different long-term base-keys are used with different
enctypes, we prepend the enctype name to the salt, separated by a enctypes, we prepend the enctype name to the salt, separated by a
null byte. The enctype-name is "aes128-cts-hmac-sha256-128" or null byte. The enctype-name is "aes128-cts-hmac-sha256-128" or
"aes256-cts-hmac-sha384-192" (without the quotes). "aes256-cts-hmac-sha384-192" (without the quotes).
The user's long-term base-key is derived as follows: The user's long-term base-key is derived as follows:
iter_count = string-to-key parameter, default is decimal 32768 iter_count = string-to-key parameter, default is decimal 32768
saltp = enctype-name | 0x00 | salt saltp = enctype-name | 0x00 | salt
tkey = random-to-key(PBKDF2(passphrase, saltp, tkey = random-to-key(PBKDF2(passphrase, saltp,
iter_count, keylength)) iter_count, keylength))
base-key = random-to-key(KDF-HMAC-SHA2(tkey, "kerberos", base-key = random-to-key(KDF-HMAC-SHA2(tkey, "kerberos",
keylength)) keylength))
where "kerberos" is the octet-string
0x6B65726265726F73
where the pseudorandom function used by PBKDF2 is HMAC-SHA-256 when where "kerberos" is the octet-string 0x6B65726265726F73.
the enctype is "aes128-cts-hmac-sha256-128" and HMAC-SHA-384 when the
enctype is "aes256-cts-hmac-sha384-192", the value for keylength is where PBKDF2 is the function of that name from RFC 2898, the
the AES key length (128 or 256 bits), and the algorithm KDF-HMAC-SHA2 pseudorandom function used by PBKDF2 is HMAC-SHA-256 when the enctype
is defined in Section 3. is "aes128-cts-hmac-sha256-128" and HMAC-SHA-384 when the enctype is
"aes256-cts-hmac-sha384-192", the value for keylength is the AES key
length (128 or 256 bits), and the algorithm KDF-HMAC-SHA2 is defined
in Section 3.
5. Kerberos Algorithm Protocol Parameters 5. Kerberos Algorithm Protocol Parameters
The cipherstate is used as the formal initialization vector (IV) The RFC 3961 cipher state that maintains cryptographic state across
input into CBC-CS3. The plaintext is prepended with a 16-octet different encryption operations using the same key is used as the
random nonce generated by the message originator, known as a formal initialization vector (IV) input into CBC-CS3. The plaintext
confounder. is prepended with a 16-octet random nonce generated by the message
originator, known as a confounder.
The ciphertext is a concatenation of the output of AES in CBC-CS3 The ciphertext is a concatenation of the output of AES in CBC-CS3
mode and the HMAC of the cipherstate concatenated with the AES mode and the HMAC of the cipher state concatenated with the AES
output. The HMAC is computed using either SHA-256 or SHA-384 output. The HMAC is computed using either SHA-256 or SHA-384
depending on the encryption type. The output of HMAC-SHA-256 is depending on the encryption type. The output of HMAC-SHA-256 is
truncated to 128 bits and the output of HMAC-SHA-384 is truncated to truncated to 128 bits and the output of HMAC-SHA-384 is truncated to
192 bits. Sample test vectors are given in Appendix A. 192 bits. Sample test vectors are given in Appendix A.
Decryption is performed by removing the HMAC, verifying the HMAC Decryption is performed by removing the HMAC, verifying the HMAC
against the cipherstate concatenated with the ciphertext, and then against the cipher state concatenated with the ciphertext, and then
decrypting the ciphertext if the HMAC is correct. Finally, the first decrypting the ciphertext if the HMAC is correct. Finally, the first
16 octets of the decryption output (the confounder) is discarded, and 16 octets of the decryption output (the confounder) is discarded, and
the remainder is returned as the plaintext decryption output. the remainder is returned as the plaintext decryption output.
The following parameters apply to the encryption types aes128-cts- The following parameters apply to the encryption types aes128-cts-
hmac-sha256-128 and aes256-cts-hmac-sha384-192. hmac-sha256-128 and aes256-cts-hmac-sha384-192.
protocol key format: as defined in Section 2. protocol key format: as defined in Section 2.
specific key structure: three derived keys: { Kc, Ke, Ki }. specific key structure: three derived keys: { Kc, Ke, Ki }.
skipping to change at page 6, line 26 skipping to change at page 6, line 47
If the enctype is aes128-cts-hmac-sha256-128: If the enctype is aes128-cts-hmac-sha256-128:
Kc = KDF-HMAC-SHA2(base-key, usage | 0x99, 128) Kc = KDF-HMAC-SHA2(base-key, usage | 0x99, 128)
Ke = KDF-HMAC-SHA2(base-key, usage | 0xAA, 128) Ke = KDF-HMAC-SHA2(base-key, usage | 0xAA, 128)
Ki = KDF-HMAC-SHA2(base-key, usage | 0x55, 128) Ki = KDF-HMAC-SHA2(base-key, usage | 0x55, 128)
If the enctype is aes256-cts-hmac-sha384-192: If the enctype is aes256-cts-hmac-sha384-192:
Kc = KDF-HMAC-SHA2(base-key, usage | 0x99, 192) Kc = KDF-HMAC-SHA2(base-key, usage | 0x99, 192)
Ke = KDF-HMAC-SHA2(base-key, usage | 0xAA, 256) Ke = KDF-HMAC-SHA2(base-key, usage | 0xAA, 256)
Ki = KDF-HMAC-SHA2(base-key, usage | 0x55, 192) Ki = KDF-HMAC-SHA2(base-key, usage | 0x55, 192)
cipherstate: a 128-bit CBC initialization vector derived from cipher state: a 128-bit CBC initialization vector derived from a
the ciphertext. previous (if any) ciphertext using the same encryption key, as
specified below.
initial cipherstate: all bits zero. initial cipher state: all bits zero.
encryption function: as follows, where E() is AES encryption in encryption function: as follows, where E() is AES encryption in
CBC-CS3 mode, and h is the size of truncated HMAC (128 bits or CBC-CS3 mode, and h is the size of truncated HMAC (128 bits or
192 bits as described above). 192 bits as described above).
N = random nonce of length 128 bits (the AES block size) N = random nonce of length 128 bits (the AES block size)
IV = cipherstate IV = cipher state
C = E(Ke, N | plaintext, IV) C = E(Ke, N | plaintext, IV)
H = HMAC(Ki, IV | C) H = HMAC(Ki, IV | C)
ciphertext = C | H[1..h] ciphertext = C | H[1..h]
Steps to compute the 128-bit cipherstate: Steps to compute the 128-bit cipher state:
L = length of C in bits L = length of C in bits
portion C into 128-bit blocks, placing any remainder portion C into 128-bit blocks, placing any remainder
of less than 128 bits into a final block of less than 128 bits into a final block
if L == 128: cipherstate = C if L == 128: cipher state = C
else if L mod 128 > 0: cipherstate = last full (128-bit) else if L mod 128 > 0: cipher state = last full (128-bit)
block of C (the block of C (the
next-to-last block) next-to-last block)
else if L mod 128 == 0: cipherstate = next-to-last block else if L mod 128 == 0: cipher state = next-to-last block
of C of C
(note that L will never be less than 128 because of the
presence of N in the encryption input)
decryption function: as follows, where D() is AES decryption in decryption function: as follows, where D() is AES decryption in
CBC-CS3 mode, and h is the size of truncated HMAC. CBC-CS3 mode, and h is the size of truncated HMAC.
(C, H) = ciphertext (C, H) = ciphertext (Note: H is the last h bits of the ciphertext)
IV = cipherstate IV = cipher state
if H != HMAC(Ki, IV | C)[1..h] if H != HMAC(Ki, IV | C)[1..h]
stop, report error stop, report error
(N, P) = D(Ke, C, IV) (N, P) = D(Ke, C, IV)
Note: N is set to the first block of the decryption output, Note: N is set to the first block of the decryption output,
P is set to the rest of the output. P is set to the rest of the output.
cipherstate = same as described above in encryption function cipher state = same as described above in encryption function
pseudo-random function: pseudo-random function:
If the enctype is aes128-cts-hmac-sha256-128: If the enctype is aes128-cts-hmac-sha256-128:
PRF = KDF-HMAC-SHA2(base-key, "prf" | octet-string, 256) PRF = KDF-HMAC-SHA2(input-key, "prf", octet-string, 256)
If the enctype is aes256-cts-hmac-sha384-192: If the enctype is aes256-cts-hmac-sha384-192:
PRF = KDF-HMAC-SHA2(base-key, "prf" | octet-string, 384) PRF = KDF-HMAC-SHA2(input-key, "prf", octet-string, 384)
where "prf" is the octet-string 0x707266 where "prf" is the octet-string 0x707266
6. Checksum Parameters 6. Checksum Parameters
The following parameters apply to the checksum types hmac-sha256-128- The following parameters apply to the checksum types hmac-sha256-128-
aes128 and hmac-sha384-192-aes256, which are the associated checksums aes128 and hmac-sha384-192-aes256, which are the associated checksums
for aes128-cts-hmac-sha256-128 and aes256-cts-hmac-sha384-192, for aes128-cts-hmac-sha256-128 and aes256-cts-hmac-sha384-192,
respectively. respectively.
associated cryptosystem: AES-128-CTS or AES-256-CTS as appropriate. associated cryptosystem: aes128-cts-hmac-sha256-128 or aes256-cts-
hmac-sha384-192 as appropriate.
get_mic: HMAC(Kc, message)[1..h]. get_mic: HMAC(Kc, message)[1..h].
where h is 128 bits for checksum type hmac-sha256-128-aes128 where h is 128 bits for checksum type hmac-sha256-128-aes128
and 192 bits for checksum type hmac-sha384-192-aes256 and 192 bits for checksum type hmac-sha384-192-aes256
verify_mic: get_mic and compare. verify_mic: get_mic and compare.
7. IANA Considerations 7. IANA Considerations
IANA is requested to assign: IANA is requested to assign:
skipping to change at page 8, line 48 skipping to change at page 9, line 26
8.1. Random Values in Salt Strings 8.1. Random Values in Salt Strings
NIST guidance in Section 5.1 of [SP800-132] requires at least 128 NIST guidance in Section 5.1 of [SP800-132] requires at least 128
bits of the salt to be randomly generated. The string-to-key function bits of the salt to be randomly generated. The string-to-key function
as defined in [RFC3961] requires the salt to be valid UTF-8 strings. as defined in [RFC3961] requires the salt to be valid UTF-8 strings.
Not every 128-bit random string will be valid UTF-8, so a UTF-8 Not every 128-bit random string will be valid UTF-8, so a UTF-8
compatible encoding would be needed to encapsulate the random bits. compatible encoding would be needed to encapsulate the random bits.
However, using a salt containing a random portion may have the However, using a salt containing a random portion may have the
following issues with some implementations: following issues with some implementations:
* Cross-realm TGTs are typically managed by entering the same * Cross-realm krbtgt keys are typically managed by entering the
password at two KDCs to get the same keys. If each KDC uses a same password at two KDCs to get the same keys. If each KDC uses
random salt, they won't have the same keys. a random salt, they won't have the same keys.
* Random salts may interfere with password history checking. * Random salts may interfere with password history checking.
8.2. Algorithm Rationale 8.2. Algorithm Rationale
This document has been written to be consistent with common This document has been written to be consistent with common
implementations of AES and SHA-2. The encryption and hash algorithm implementations of AES and SHA-2. The encryption and hash algorithm
sizes have been chosen to create a consistent level of protection, sizes have been chosen to create a consistent level of protection,
with consideration to implementation efficiencies. So, for instance, with consideration to implementation efficiencies. So, for instance,
SHA-384, which would normally be matched to AES-192, is instead SHA-384, which would normally be matched to AES-192, is instead
skipping to change at page 9, line 26 skipping to change at page 10, line 4
enc-type name "aes256-cts-hmac-sha384-192", the truncation of the enc-type name "aes256-cts-hmac-sha384-192", the truncation of the
HMAC-SHA-384 output to 192-bits results in an overall 192-bit level HMAC-SHA-384 output to 192-bits results in an overall 192-bit level
of security. of security.
9. Acknowledgements 9. Acknowledgements
Kelley Burgin was employed at the National Security Agency during Kelley Burgin was employed at the National Security Agency during
much of the work on this document. much of the work on this document.
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC2104] Krawczyk, H. et al., "HMAC: Keyed-Hashing for Message
Authentication", RFC 2104, February 1997.
[RFC2898] Kaliski, B., "PKCS #5: Password-Based Cryptography [RFC2898] Kaliski, B., "PKCS #5: Password-Based Cryptography
Specification Version 2.0", RFC 2898, September 2000. Specification Version 2.0", RFC 2898, September 2000.
[RFC3961] Raeburn, K., "Encryption and Checksum Specifications for [RFC3961] Raeburn, K., "Encryption and Checksum Specifications for
Kerberos 5", RFC 3961, February 2005. Kerberos 5", RFC 3961, February 2005.
[RFC3962] Raeburn, K., "Advanced Encryption Standard (AES) [RFC3962] Raeburn, K., "Advanced Encryption Standard (AES)
Encryption for Kerberos 5", RFC 3962, February 2005. Encryption for Kerberos 5", RFC 3962, February 2005.
[FIPS180] National Institute of Standards and Technology, "Secure
Hash Standard", FIPS PUB 180-4, August 2015.
[FIPS197] National Institute of Standards and Technology, [FIPS197] National Institute of Standards and Technology,
"Advanced Encryption Standard (AES)", FIPS PUB 197, "Advanced Encryption Standard (AES)", FIPS PUB 197,
November 2001. November 2001.
[SP800-38A+] National Institute of Standards and Technology, [SP800-38A+] National Institute of Standards and Technology,
"Recommendation for Block Cipher Modes of Operation: "Recommendation for Block Cipher Modes of Operation:
Three Variants of Ciphertext Stealing for CBC Mode", Three Variants of Ciphertext Stealing for CBC Mode",
NIST Special Publication 800-38A Addendum, October 2010. NIST Special Publication 800-38A Addendum, October 2010.
[SP800-108] National Institute of Standards and Technology, [SP800-108] National Institute of Standards and Technology,
skipping to change at page 11, line 4 skipping to change at page 11, line 36
random 16 byte valid UTF-8 sequence | "ATHENA.MIT.EDUraeburn") random 16 byte valid UTF-8 sequence | "ATHENA.MIT.EDUraeburn")
256-bit base-key: 256-bit base-key:
45 BD 80 6D BF 6A 83 3A 9C FF C1 C9 45 89 A2 22 45 BD 80 6D BF 6A 83 3A 9C FF C1 C9 45 89 A2 22
36 7A 79 BC 21 C4 13 71 89 06 E9 F5 78 A7 84 67 36 7A 79 BC 21 C4 13 71 89 06 E9 F5 78 A7 84 67
Sample results for key derivation: Sample results for key derivation:
---------------------------------- ----------------------------------
enctype aes128-cts-hmac-sha256-128: enctype aes128-cts-hmac-sha256-128:
128-bit base-key: 128-bit base-key:
37 05 D9 60 80 C1 77 28 A0 E8 00 EA B6 E0 D2 3C 37 05 D9 60 80 C1 77 28 A0 E8 00 EA B6 E0 D2 3C
Kc value for key usage 2 (constant = 0x0000000299): Kc value for key usage 2 (label = 0x0000000299):
B3 1A 01 8A 48 F5 47 76 F4 03 E9 A3 96 32 5D C3 B3 1A 01 8A 48 F5 47 76 F4 03 E9 A3 96 32 5D C3
Ke value for key usage 2 (constant = 0x00000002AA): Ke value for key usage 2 (label = 0x00000002AA):
9B 19 7D D1 E8 C5 60 9D 6E 67 C3 E3 7C 62 C7 2E 9B 19 7D D1 E8 C5 60 9D 6E 67 C3 E3 7C 62 C7 2E
Ki value for key usage 2 (constant = 0x0000000255): Ki value for key usage 2 (label = 0x0000000255):
9F DA 0E 56 AB 2D 85 E1 56 9A 68 86 96 C2 6A 6C 9F DA 0E 56 AB 2D 85 E1 56 9A 68 86 96 C2 6A 6C
enctype aes256-cts-hmac-sha384-192: enctype aes256-cts-hmac-sha384-192:
256-bit base-key: 256-bit base-key:
6D 40 4D 37 FA F7 9F 9D F0 D3 35 68 D3 20 66 98 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 00 EB 48 36 47 2E A8 A0 26 D1 6B 71 82 46 0C 52
Kc value for key usage 2 (constant = 0x0000000299): Kc value for key usage 2 (label = 0x0000000299):
EF 57 18 BE 86 CC 84 96 3D 8B BB 50 31 E9 F5 C4 EF 57 18 BE 86 CC 84 96 3D 8B BB 50 31 E9 F5 C4
BA 41 F2 8F AF 69 E7 3D BA 41 F2 8F AF 69 E7 3D
Ke value for key usage 2 (constant = 0x00000002AA): Ke value for key usage 2 (label = 0x00000002AA):
56 AB 22 BE E6 3D 82 D7 BC 52 27 F6 77 3F 8E A7 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 A5 EB 1C 82 51 60 C3 83 12 98 0C 44 2E 5C 7E 49
Ki value for key usage 2 (constant = 0x0000000255): Ki value for key usage 2 (label = 0x0000000255):
69 B1 65 14 E3 CD 8E 56 B8 20 10 D5 C7 30 12 B6 69 B1 65 14 E3 CD 8E 56 B8 20 10 D5 C7 30 12 B6
22 C4 D0 0F FC 23 ED 1F 22 C4 D0 0F FC 23 ED 1F
Sample encryptions (all using the default cipher state): Sample encryptions (all using the default cipher state):
-------------------------------------------------------- --------------------------------------------------------
These sample encryptions use the above sample key These sample encryptions use the above sample key
derivation results, including use of the same derivation results, including use of the same
base-key and key usage values. base-key and key usage values.
The following test vectors are for The following test vectors are for
skipping to change at page 15, line 30 skipping to change at page 16, line 13
Checksum type: hmac-sha384-192-aes256 Checksum type: hmac-sha384-192-aes256
192-bit HMAC key (Kc): 192-bit HMAC key (Kc):
EF 57 18 BE 86 CC 84 96 3D 8B BB 50 31 E9 F5 C4 EF 57 18 BE 86 CC 84 96 3D 8B BB 50 31 E9 F5 C4
BA 41 F2 8F AF 69 E7 3D BA 41 F2 8F AF 69 E7 3D
Plaintext: Plaintext:
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
10 11 12 13 14 10 11 12 13 14
Checksum: Checksum:
45 EE 79 15 67 EE FC A3 7F 4A C1 E0 22 2D E8 0D 45 EE 79 15 67 EE FC A3 7F 4A C1 E0 22 2D E8 0D
43 C3 BF A0 66 99 67 2A 43 C3 BF A0 66 99 67 2A
Sample pseudorandom function (PRF) invocations: Sample pseudorandom function (PRF) invocations:
---------------------------------------- ----------------------------------------
PRF input octet-string: "test" (0x74657374) PRF input octet-string: "test" (0x74657374)
enctype aes128-cts-hmac-sha256-128: enctype aes128-cts-hmac-sha256-128:
base-key value / HMAC-SHA-256 key: input-key value / HMAC-SHA-256 key:
37 05 D9 60 80 C1 77 28 A0 E8 00 EA B6 E0 D2 3C 37 05 D9 60 80 C1 77 28 A0 E8 00 EA B6 E0 D2 3C
HMAC-SHA-256 input message: HMAC-SHA-256 input message:
00 00 00 01 70 72 66 74 65 73 74 00 00 00 01 00 00 00 00 01 70 72 66 00 74 65 73 74 00 00 01 00
PRF output: PRF output:
14 11 15 B0 A6 CB 9A 1D CB B4 C7 E2 5B 43 32 22 9D 18 86 16 F6 38 52 FE 86 91 5B B8 40 B4 A8 86
52 DE 58 11 21 85 C5 DC F5 12 5E 7B 81 54 8D 39 FF 3E 6B B0 F8 19 B4 9B 89 33 93 D3 93 85 42 95
enctype aes256-cts-hmac-sha384-192: enctype aes256-cts-hmac-sha384-192:
base-key value / HMAC-SHA-384 key: input-key value / HMAC-SHA-384 key:
6D 40 4D 37 FA F7 9F 9D F0 D3 35 68 D3 20 66 98 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 00 EB 48 36 47 2E A8 A0 26 D1 6B 71 82 46 0C 52
HMAC-SHA-384 input message: HMAC-SHA-384 input message:
00 00 00 01 70 72 66 74 65 73 74 00 00 00 01 80 00 00 00 01 70 72 66 00 74 65 73 74 00 00 01 80
PRF output: PRF output:
31 0A 4B 5C D2 90 F7 04 33 B2 A1 A1 D0 93 FD F7 98 01 F6 9A 36 8C 2B F6 75 E5 95 21 E1 77 D9 A0
8C 6C 9D AE 5C AC D3 A7 BD 45 CB 67 44 41 99 43 7F 67 EF E1 CF DE 8D 3C 8D 6F 6A 02 56 E3 B1 7D
0D 36 19 06 44 E8 A2 16 66 43 AE AD E9 63 87 52 B3 C1 B6 2A D1 B8 55 33 60 D1 73 67 EB 15 14 D2
Authors' Addresses Authors' Addresses
Michael J. Jenkins Michael J. Jenkins
National Security Agency National Security Agency
EMail: mjjenki@tycho.ncsc.mil EMail: mjjenki@tycho.ncsc.mil
Michael A. Peck Michael A. Peck
The MITRE Corporation The MITRE Corporation
 End of changes. 53 change blocks. 
67 lines changed or deleted 97 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/