When using hmac-md5, the intermediate key length is the output of the hash function (128 bits), not the input key length. Relevant if the input key is not an RC4 key. http://src.mit.edu/fisheye/changelog/krb5/?cs=25418 Commit By: ghudson Revision: 25418 Changed Files: U trunk/src/lib/crypto/krb/checksum_hmac_md5.c