AES-CMAC Test Vectors

Test vectors for AES-CMAC from NIST SP 800-38B and RFC 4493.

Source

• NIST SP 800-38B: Recommendation for Block Cipher Modes of Operation: The CMAC Mode for Authentication
• URL: https://csrc.nist.gov/pubs/sp/800-38b/upd1/final
• RFC 4493: The AES-CMAC Algorithm
• URL: https://www.rfc-editor.org/rfc/rfc4493

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AES-128-CMAC

Key: 2b7e1516 28aed2a6 abf71588 09cf4f3c

Subkeys

L  = 7df76b0c 1ab899b3 3e42f047 b91b546f
K1 = fbeed618 357133667c85e08f 7236a8de
K2 = f7ddac30 6ae266cc f90bc11e e46d513b

Example 1 — Empty Message

Data:    (empty)
CMAC:    bb1d6929 e9593728 7fa37d12 9b756746

Example 2 — 16-byte Message (Complete Block)

Data:    6bc1bee2 2e409f96 e93d7e11 7393172a
CMAC:    070a16b4 6b4d4144 f79bdd9d d04a287c

Example 3 — 40-byte Message (Incomplete Final Block)

Data:    6bc1bee2 2e409f96 e93d7e11 7393172a
         ae2d8a57 1e03ac9c 9eb76fac 45af8e51
         30c81c46 a35ce411
CMAC:    dfa66747 de9ae630 30ca3261 1497c827

Example 4 — 64-byte Message (4 Complete Blocks)

Data:    6bc1bee2 2e409f96 e93d7e11 7393172a
         ae2d8a57 1e03ac9c 9eb76fac 45af8e51
         30c81c46 a35ce411 e5fbc119 1a0a52ef
         f69f2445 df4f9b17 ad2b417b e66c3710
CMAC:    51f0bebf 7e3b9d92 fc497417 79363cfe

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AES-256-CMAC

Key: 603deb10 15ca71be 2b73aef0 857d7781 1f352c07 3b6108d7 2d9810a3 0914dff4

Example 1 — Empty Message

Data:    (empty)
CMAC:    028962f6 1b7bf89e fc6b551f 4667d983

Example 2 — 16-byte Message

Data:    6bc1bee2 2e409f96 e93d7e11 7393172a
CMAC:    28a7023f 452e8f82 bd4bf28d 8c37c35c

Example 3 — 64-byte Message

Data:    6bc1bee2 2e409f96 e93d7e11 7393172a
         ae2d8a57 1e03ac9c 9eb76fac 45af8e51
         30c81c46 a35ce411 e5fbc119 1a0a52ef
         f69f2445 df4f9b17 ad2b417b e66c3710
CMAC:    e1992190 549f6ed5 696a2c05 6c315410

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AES-GMAC

AES-GMAC does not have standalone test vectors in NIST SP 800-38B. Instead, GMAC is validated by comparing against AES-GCM with empty plaintext, using the test vectors from NIST SP 800-38D.

The NUnit test suite cross-validates GMAC against AesGcm128, AesGcm192, and AesGcm256 with empty plaintext to ensure consistent results.

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Validation

The NUnit test suite in tests/Security/Cryptography/Mac/Cmac/CmacTests.cs validates all NIST SP 800-38B test vectors and additionally cross-validates against BouncyCastle CMac(AesEngine) for:

• Empty messages
• Short messages
• Messages spanning multiple blocks
• AES-128 and AES-256 key sizes

The GMAC tests in tests/Security/Cryptography/Mac/Gmac/GmacTests.cs validate against the CryptoHives AES-GCM implementation with empty plaintext and test tag verification behavior.