I originally defined the bytes() method for the String class, because it
made it obvious that it's a span of bytes instead of span of characters.
This commit makes this more consistent by defining a bytes() method when
the type of the span is known to be u8.
Additionaly, the cast operator to Bytes is overloaded for ByteBuffer and
such.
This is in preparation for the upcoming Galois/Counter mode, which
conventionally has 12 bytes of IV as opposed to CBC's 16 bytes.
...Also fixes a lot of style issues, since the author finally found the
project's clang config file in the repository root :^)
This commit fixes up the following:
- HMAC should not reuse a single hasher when successively updating
- AES Key should not assume its user key is valid signed char*
- Mode should have a virtual destructor
And adds a RFC5246 padding mode, which is required for TLS
