资 源 简 介
Base64 加密算法（Author 蒋柏良 Jerry Jiang)-*
* DESCRIPTION
* Base64 processes input in 24bit chunks by converting each chunk into 4
* bytes of output. It does so by splitting input into four 6bit groups and
* using these as indexes in the following substitution table-
* const char base64_map[] =
* "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
* "abcdefghijklmnopqrstuvwxyz"
* "0123456789+/"
* If an input is not a multiple of 3 bytes, it s padded with zeros. In
* this case the output bytes that consist entirely of the pad data are
* replaced with = .
*
* Example
* An input of 0x00 0x45 0xF2 is equivalent to 00000000 01000101 11110010
* bit sequence, which s then split into 000000 000100 010111 110010
* and these are substituted to produce the following base64 encoding
* A E X y
*
* RETURN VALUE
* b64_length() should return output length for the input of len bytes.
* b64_encode() should encode len bytes from src int
