This module implements the HMAC-SHA-1 authentication algorithm, using the SHA-1 hash algorithm and the HMAC technique set forth in RFC 2104. The authshal module has the following properties

key size

160 bits

digest size

96 bits (truncated from 160).

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

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

NIST, FIPS PUB 180-1: Secure Hash Standard, April 1995.

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 2404, The Use of HMAC-SHA-1-96 within ESP and AH, The Internet Society, 1998.