Page MenuHomec4science
Files F78173813

base64.c
No OneTemporary
Actions

File Metadata

Created
Sun, Aug 18, 22:24

base64.c
View Options

/**
* Copyright (c) 2006-2008 Apple Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
**/
#include "base64.h"
#include <stdlib.h>
#include <string.h>
// base64 tables
static char basis_64[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static signed char index_64[128] =
{
-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
-1, 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,-1, -1,-1,-1,-1,
-1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
};
#define CHAR64(c) (((c) < 0 || (c) > 127) ? -1 : index_64[(c)])
// base64_encode : base64 encode
//
// value : data to encode
// vlen : length of data
// (result) : new char[] - c-str of result
char *base64_encode(const unsigned char *value, int vlen)
{
char *result = (char *)malloc((vlen * 4) / 3 + 5);
char *out = result;
unsigned char oval;
while (vlen >= 3)
{
*out++ = basis_64[value[0] >> 2];
*out++ = basis_64[((value[0] << 4) & 0x30) | (value[1] >> 4)];
*out++ = basis_64[((value[1] << 2) & 0x3C) | (value[2] >> 6)];
*out++ = basis_64[value[2] & 0x3F];
value += 3;
vlen -= 3;
}
if (vlen > 0)
{
*out++ = basis_64[value[0] >> 2];
oval = (value[0] << 4) & 0x30;
if (vlen > 1) oval |= value[1] >> 4;
*out++ = basis_64[oval];
*out++ = (vlen < 2) ? '=' : basis_64[(value[1] << 2) & 0x3C];
*out++ = '=';
}
*out = '\0';
return result;
}
// base64_decode : base64 decode
//
// value : c-str to decode
// rlen : length of decoded result
// (result) : new unsigned char[] - decoded result
unsigned char *base64_decode(const char *value, int *rlen)
{
int c1, c2, c3, c4;
int vlen = (int)strlen(value);
unsigned char *result =(unsigned char *)malloc((vlen * 3) / 4 + 1);
unsigned char *out = result;
*rlen = 0;
while (1)
{
if (value[0]==0)
return result;
c1 = value[0];
if (CHAR64(c1) == -1)
goto base64_decode_error;;
c2 = value[1];
if (CHAR64(c2) == -1)
goto base64_decode_error;;
c3 = value[2];
if ((c3 != '=') && (CHAR64(c3) == -1))
goto base64_decode_error;;
c4 = value[3];
if ((c4 != '=') && (CHAR64(c4) == -1))
goto base64_decode_error;;
value += 4;
*out++ = (CHAR64(c1) << 2) | (CHAR64(c2) >> 4);
*rlen += 1;
if (c3 != '=')
{
*out++ = ((CHAR64(c2) << 4) & 0xf0) | (CHAR64(c3) >> 2);
*rlen += 1;
if (c4 != '=')
{
*out++ = ((CHAR64(c3) << 6) & 0xc0) | CHAR64(c4);
*rlen += 1;
}
}
}
base64_decode_error:
*result = 0;
*rlen = 0;
return result;
}

Event Timeline

c4science · Help