The current version invokes undefined behavior when the count is negative, zero, or equal to or greater than the width of the operand. The new version masks the count to avoid these situations. Although branchless, it is relatively inefficient if the compiler does not recognize it and translate it to a rol or ror instruction. Empirical tests show that both clang and gcc get it right for constant counts, and recent versions of clang (but not gcc) get it right for variable counts as well. Note that our current code base has no instances of rolN / rorN with a variable count.
- Use the new vector byte-order conversion functions where appropriate.
- Use memset_s() instead of memset() where appropriate.
- Use consistent names and types for function arguments.
- Reindent, rename and reorganize to conform to Cryb style and idiom.
SHA224 and SHA256 were left mostly unchanged. MD2 and MD4 were completely rewritten as the previous versions (taken from XySSL) seem to have been copied from RSAREF.
This breaks the ABI as some context structures have grown or shrunk and some function arguments have been changed from int to size_t.
Single-DES is now a special case of triple-DES with all three keys being the same. This is significantly slower than a pure single-DES implementation, but that's fine since nobody should be using it anyway.
We now have separate encryption and decryption methods, and can process an arbitrary amount of plaintext or ciphertext per call, rounded down to the block size (if applicable). For stream ciphers, we also have a keystream method which fills the provided buffer with an arbitrary amount of keystream (once again, rounded down if applicable).
Not only is this a slightly more logical name, but it allows us to expose the verbose flag, previously private to cryb_t_main.c, as the equally logically named t_verbose.
The rk pointer in struct aes_ctx always pointed to the context's buffer and served no purpose whatsoever, but the compiler had no way of knowing that and could therefore not optimize away assignments to and from it.
Note that the removal of rk breaks the ABI, since it changes the size of struct aes_ctx, but we allow ourselves that because neither the API nor the ABI have been fixed yet.
Unlike assert(3), which uses abort(3), this has no other side effects (before raising SIGABRT) than an fprintf() call. The test framework will catch the SIGABRT, report that the test case failed, and proceed with the next case.
