[Bro-Dev] md5_hash vs. md5_hmac

[Vern Paxson]

> The implementation of md5_hash(...) and md5_hmac(...) in bro.bif is
> identical:
> 
>     %{
>     unsigned char digest[16];
>     hmac_md5_val(@ARG@, digest);
>     return new StringVal(md5_digest_print(digest));
>     %}

They're not identical.  (At least, not in 1.5, which is what I can easily
check.)  md5_hash() calls hash_md5_val() rather than hmac_md5_val().
Per the CHANGES:

- The new built-in md5_hmac() returns an HMAC-MD5 hash of the given string
  (Ruoming Pang).  The HMAC secret key is generated from available entropy
  when Bro starts up, or it can be specified for repeatability using
  the new -K flag.

		Vern