consttime_memequal is the same as the old consttime_bcmp.
explicit_memset is to memset as explicit_bzero was to bcmp.
Passes amd64 release and i386/ALL, but I'm sure I missed some spots,
so please let me know.
abd userland, as proposed on tech-security, with explicit_bzero using
a volatile function pointer as suggested by Alan Barrett.
Both do what the name says. For userland, both are prefixed by "__"
to keep them out of the user namespace.
Change some memset/memcmp uses to the new functions where it makes
sense -- these are just some examples, more to come.
in the NetBSD build
since the libc version of MD5Final zeroes out the context, replace
the bzero introduced in the previous commit by comments telling that
The algorithm used is essentially PBKDF1 from RFC 2898 but using
hmac_sha1 rather than SHA1 directly (suggested by smb@research.att.com).
* The format of the encrypted password is:
* $<tag>$<iterations>$<salt>$<digest>
*
* where:
* <tag> is "sha1"
* <iterations> is an unsigned int identifying how many rounds
* have been applied to <digest>. The number
* should vary slightly for each password to make
* it harder to generate a dictionary of
* pre-computed hashes. See crypt_sha1_iterations.
* <salt> up to 64 bytes of random data, 8 bytes is
* currently considered more than enough.
* <digest> the hashed password.
hmac.c implementes HMAC as defined in RFC 2104 and includes a unit
test for both hmac_sha1 and hmac_sha1 using a selection of the Known
Answer Tests from RFC 2202.
It is worth noting that to be FIPS compliant the hmac key (password)
should be 10-20 chars.