Instead of using separate bad_record_mac and decryption_failed alerts,
use only bad_record_mac alert regardless of how the CBC decryption
failed. This provides less information to attackers that could modify
packets. In addition, instead of returning immediately on error, run
through the MAC check to make timing attacks more difficult.
When the received data will be decrypted, there is no need to first
copy it and then handle decryption in-place when decryption step can
take care of both operations.
TLS v1.0 and v1.1 RFCs were not exactly clear on the use of the
protocol version in record later. As such, accept any {03,xx} value
to remain compatible with existing implementations and new protocol
versions.
In addition, start ordering header file includes to be in more
consistent order: system header files, src/utils, src/*, same
directory as the *.c file.
