mbedtls works very differently from BoringSSL, and many changes had to
be made in the details of AES decryption to accomodate this.
Beyond the basic changes required for mbedtls, part of the CTS padding
implementation had to be rewritten. I believe this is because of an
assumption that held for BoringSSL, but not for mbedtls. I was unable to
determine what it was, so I rewrote the CTS decryption using reference
materials. After this, tests passed.
The deterministc PRNG I used with mbedtls in the RSA tests differs
somewhat from the old one, so the expected vectors had to be
regenerated. The old determinstic tests were also disabled, and are now
re-enabled.
Since cryptography is sensitive code, and because there were far more
changes needed here than just updating some headers and utility function
calls, this has been split into its own PR for separate review from the
rest of the media/base porting work.
Issue #1047 (CMake porting)
Issue #346 (absl porting)