This module implements the HMAC-MD5 authentication algorithm using the MD5 message-digest algorithm and the HMAC technique documented in RFC 2104. The authmd5h module has the following properties:

key size

128 bits

digest size

96 bits (truncated from 128)

See attributes(5) for descriptions of the following attributes:

ipseckey(1M), attributes(5), pf_key(7P), ipsec(7P), ipsecah(7P), ipsecesp(7P)

Krawczyk, H., Ballare, M., and Canetti, R., RFC 2104, HMAC: Keyed-Hashing for Message Authentication, The Internet Society, 1997

Madsen, C. and Glenn, R., RFC 2403, The Use of HMAC-MD5-96 within ESP and AH, The Internet Society, 1998.

Rivest, R., RFC 1321, The MD5 Message-Digest Algorithm, The Internet Society, 1992.