Ticket bz1525628 - invalid password migration causes unauth bind

Ticket bz1525628 - invalid password migration causes unauth bind

Bug Description:  Slapi_ct_memcmp expects both inputs to be
at LEAST size n. If they are not, we only compared UP to n.

Invalid migrations of passwords (IE {CRYPT}XX) would create
a pw which is just salt and no hash. ct_memcmp would then
only verify the salt bits and would allow the authentication.

This relies on an administrative mistake both of allowing
password migration (nsslapd-allow-hashed-passwords) and then
subsequently migrating an INVALID password to the server.

Fix Description:  slapi_ct_memcmp now access n1, n2 size
and will FAIL if they are not the same, but will still compare
n bytes, where n is the "longest" memory, to the first byte
of the other to prevent length disclosure of the shorter
value (generally the mis-migrated password)

https://bugzilla.redhat.com/show_bug.cgi?id=1525628

Author: wibrown

Review by: ???

Gbp-Pq: Name CVE-2017-15135.patch