Summarized Changelog:
- Fix a bug in ECDSA which could occur when the group size and hash length differ
- Fix a bug in ECDSA verification when the public key was chosen to be a small multiple of the group generator
- SIV's functionality of supporting multiple associated data inputs has been generalized onto the AEAD_Mode interface
- Fix a bug parsing deeply nested cipher names
- Small optimizations in the non-hardware assisted AES key generation code path
- Prevent requesting DER encoding of signatures when the algorithm did not support it