C++BASE64 coding and decoding using the example _c language

Copy Code code as follows:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
static const char B64_TABLE[65] = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789+/";
static const char REVERSE_TABLE[128] =
{
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64
};

unsigned char *base64_encode (unsigned char *bindata,size_t inlen,unsigned char **out,size_t *outlen)
{
size_t _outlen = *outlen;
unsigned char *_out = NULL;
size_t out_pos = 0;

if (NULL = = *out)
{
_outlen = (Inlen/3 + (inlen%3!= 0)) * 4 + 1;
_out = malloc (_outlen);
}
Else
{
_outlen = *outlen;
_out = *out;
}

memset (_out, ' = ', _outlen);
_out[_outlen-1] = 0;

    unsigned int bits_collected = 0;
    unsigned int accumulator = 0;
    for (int i = 0; i < Inlen i++)
    {
         accumulator = (accumulator << 8) | (Bindata[i] & 0xffu);
        bits_collected + 8;
        while (bits_collected >= 6)
         {
            bits_collected-= 6;
            _out[out_pos++] = b64_table[(Accumulator > > bits_collected) & 0x3fu];
       }
   }

if (bits_collected >= 6)
{
if (NULL = = *out)
{
Free (_out);
}
return NULL;
}

if (bits_collected > 0)
{
Any trailing bits that are missing.
Accumulator <<= 6-bits_collected;
_out[out_pos++] = b64_table[accumulator & 0x3fu];
}

*outlen = _outlen;
*out = _out;
return _out;
}

unsigned char *base64_decode (unsigned char *bindata,size_t inlen,unsigned char **out,size_t *outlen)
{
size_t _outlen = *outlen;
unsigned char *_out = NULL;
int bits_collected = 0;
unsigned int accumulator = 0;
size_t out_pos = 0;

if (NULL = = *out)
{
_outlen = Inlen;
_out = malloc (_outlen);
}
Else
{
_outlen = *outlen;
_out = *out;
}

int c = 0;
for (int i = 0; i < Inlen; i++)
{
c = Bindata[i];
if (Isspace (c) | | | c = = ")
{
Skip whitespace and padding. Be liberal in what and you accept.
Continue
}
if ((C > 127) | | (c < 0) | | (Reverse_table[c] > 63))
{
return NULL;
}
Accumulator = (accumulator << 6) | REVERSE_TABLE[C];
bits_collected + 6;
if (bits_collected >= 8)
{
bits_collected-= 8;
_out[out_pos++] = (char) ((accumulator >> bits_collected) & 0xffu);
}
}

*outlen = _outlen;
*out = _out;
return _out;
}

int main (int argc,char *argv[])
{
unsigned char *str = argv[1];
unsigned char *out = 0;
size_t len = 0;
printf ("%s\n", Base64_encode (Str,strlen (str), &out,&len));
unsigned char *_out = 0;
size_t _len = 0;
printf ("%s\n", Base64_decode (Out,strlen (out), &_out,&_len));
return 0;
}