网上找的base64解码算法,中间停止解码,不知道是不是字符串太大,有592个字符,从base64解码到ASCII的字符串大小有限制.
预期结果:
Lorem ipsum dolor sit amet,consectetur adipiscing elit,sed do eiusmod tempor incididunt ut labore et dolore magna aliqua。Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat。Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur。Exceptioneur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est labourum
实际结果:
Lorem ipsum dolor sit amet,consectetur adipiscing elit,sed do eiusmod tempor incididunt ut labore et dolore magna aliqua。Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat。杜伊斯·奥特·伊鲁
unsigned char *base64_decode(const char *data, size_t input_length, size_t *output_length) {
unsigned char *decoded_data;
int i, j = 0;
if (decoding_table == NULL) build_decoding_table();
if (input_length % 4 != 0) return NULL;
*output_length = input_length / 4 * 3;
if (data[input_length - 1] == '=') (*output_length)--;
if (data[input_length - 2] == '=') (*output_length)--;
decoded_data = (unsigned char*)malloc(*output_length +1);
if (decoded_data == NULL) return NULL;
for (i = 0, j = 0; i < input_length;) {
uint32_t sextet_a = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
uint32_t sextet_b = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
uint32_t sextet_c = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
uint32_t sextet_d = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
uint32_t triple = (sextet_a << 3 * 6)
+ (sextet_b << 2 * 6)
+ (sextet_c << 1 * 6)
+ (sextet_d << 0 * 6);
if (j < *output_length) decoded_data[j++] = (triple >> 2 * 8) & 0xFF;
if (j < *output_length) decoded_data[j++] = (triple >> 1 * 8) & 0xFF;
if (j < *output_length) decoded_data[j++] = (triple >> 0 * 8) & 0xFF;
}
return decoded_data;
}
int main(int argc, _TCHAR* argv[]){
const char* data64 = "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";
size_t input_length = strlen(data64);
size_t output_length;
char * output = (char *) base64_decode(data64, input_length, &output_length);
char * result = (char*)calloc(output_length, sizeof(char));
strncpy(result, output, output_length);
result[output_length] = 0;
printf(result);
printf("\n");
base64_cleanup();
system("pause");
return 0;
}