[RFC] RFC4648 encoding

PHP already offers bin2hex()/hex2bin() and base64_encode()/base64_decode(). This covers part, but not all, of RFC 4648. I'd like to extend the coverage to include, at minimum, Base32. I'd also like to make these functions to be written to resist cache-timing attacks (i.e. when used to encode/decode encryption keys for long-term storage). Userland PoC: https://github.com/paragonie/constant_time_encoding http://blog.ircmaxell.com/2014/11/its-all-about-time.html These modifications can either be made in-place (at a negligble cost on the scale of nanoseconds) or they can be an alternative implementation. i.e. * bin2hex_ts() * base64_encode_ts() * base32_encode_ts() Does anyone have any questions or concerns? Scott Arciszewski Chief Development Officer Paragon Initiative Enterprises <https://paragonie.com>