This change updates the DTLS code to match the constant-time CBC
behaviour in the TLS.
(cherry picked from commit 9f27de17)

The previous CBC patch was bugged in that there was a path through enc()
in s3_pkt.c/d1_pkt.c which didn't set orig_len. orig_len would be left
at the previous value which could suggest that the packet was a
sufficient length when it wasn't.
(cherry picked from commit 6cb19b76)

This patch makes the decoding of SSLv3 and TLS CBC records constant
time. Without this, a timing side-channel can be used to build a padding
oracle and mount Vaudenay's attack.

This patch also disables the stitched AESNI+SHA mode pending a similar
fix to that code.

In order to be easy to backport, this change is implemented in ssl/,
rather than as a generic AEAD mode. In the future this should be changed
around so that HMAC isn't in ssl/, but crypto/ as FIPS expects.
(cherry picked from commit e130841b)

This change adds CRYPTO_memcmp, which compares two vectors of bytes in
an amount of time that's independent of their contents. It also changes
several MAC compares in the code to use this over the standard memcmp,
which may leak information about the size of a matching prefix.
(cherry picked from commit 2ee79888)

encrypted premaster secret value.
(cherry picked from commit ea34a583)

(cherry picked from commit 134c0065)

PR: 2963 and a number of others
(cherry picked from commit 4568182a)

PR: 2963 and a number of others

Submitted by: Dmitry Belyavsky, Seguei Leontiev
PR: 2821

Just a sample, real world applications would have to be cleverer.

from X509_STORE_CTX.

structures using HTTP. Add wrapper function to handle CRL download.

traditional format uses MD5 which is prohibited in FIPS mode.