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/*
public domain BASE64 code
modified for cocos2d-iphone: http://www.cocos2d-iphone.org
*/
#include <stdio.h>
#include <stdlib.h>
#include "base64.h"
unsigned char alphabet[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int _base64Decode( unsigned char *input, unsigned int input_len, unsigned char *output, unsigned int *output_len );
int _base64Decode( unsigned char *input, unsigned int input_len, unsigned char *output, unsigned int *output_len )
{
static char inalphabet[256], decoder[256];
int i, bits, c, char_count, errors = 0;
unsigned int input_idx = 0;
unsigned int output_idx = 0;
for (i = (sizeof alphabet) - 1; i >= 0 ; i--) {
inalphabet[alphabet[i]] = 1;
decoder[alphabet[i]] = i;
}
char_count = 0;
bits = 0;
for( input_idx=0; input_idx < input_len ; input_idx++ ) {
c = input[ input_idx ];
if (c == '=')
break;
if (c > 255 || ! inalphabet[c])
continue;
bits += decoder[c];
char_count++;
if (char_count == 4) {
output[ output_idx++ ] = (bits >> 16);
output[ output_idx++ ] = ((bits >> 8) & 0xff);
output[ output_idx++ ] = ( bits & 0xff);
bits = 0;
char_count = 0;
} else {
bits <<= 6;
}
}
if( c == '=' ) {
switch (char_count) {
case 1:
fprintf(stderr, "base64Decode: encoding incomplete: at least 2 bits missing");
errors++;
break;
case 2:
output[ output_idx++ ] = ( bits >> 10 );
break;
case 3:
output[ output_idx++ ] = ( bits >> 16 );
output[ output_idx++ ] = (( bits >> 8 ) & 0xff);
break;
}
} else if ( input_idx < input_len ) {
if (char_count) {
fprintf(stderr, "base64 encoding incomplete: at least %d bits truncated",
((4 - char_count) * 6));
errors++;
}
}
*output_len = output_idx;
return errors;
}
int base64Decode(unsigned char *in, unsigned int inLength, unsigned char **out)
{
unsigned int outLength = 0;
//should be enough to store 6-bit buffers in 8-bit buffers
*out = malloc( inLength * 3.0f / 4.0f + 1 );
if( *out ) {
int ret = _base64Decode(in, inLength, *out, &outLength);
if (ret > 0 )
{
printf("Base64Utils: error decoding");
free(*out);
*out = NULL;
outLength = 0;
}
}
return outLength;
}
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