BUG/MINOR: jwt: use CRYPTO_memcmp() to compare HMACs

As Tim reported in github issue #1414, we ought to use a constant-time
memcmp() when comparing hashes to avoid time-based attacks. Let's use
CRYPTO_memcmp() since this code already depends on openssl.

No backport is needed, this was just merged into 2.5.
1 file changed