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Diffstat (limited to 'src/base64.c')
| -rw-r--r-- | src/base64.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/src/base64.c b/src/base64.c new file mode 100644 index 0000000..066494e --- /dev/null +++ b/src/base64.c @@ -0,0 +1,127 @@ +/* + * base64.c + * base64 encode/decode implementation + * + * Copyright (c) 2011 Nikias Bassen, All Rights Reserved. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ +#include <string.h> +#include "base64.h" + +static const char base64_str[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; +static const char base64_pad = '='; + +static const int8_t base64_table[256] = { + -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, + -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, -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, -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 +}; + +char *base64encode(const unsigned char *buf, size_t *size) +{ + if (!buf || !size || !(*size > 0)) return NULL; + int outlen = (*size / 3) * 4; + char *outbuf = (char*)malloc(outlen+5); // 4 spare bytes + 1 for '\0' + size_t n = 0; + size_t m = 0; + unsigned char input[3]; + unsigned int output[4]; + while (n < *size) { + input[0] = buf[n++]; + input[1] = (n < *size) ? buf[n++] : 0; + input[2] = (n < *size) ? buf[n++] : 0; + output[0] = input[0] >> 2; + output[1] = ((input[0] & 3) << 4) + (input[1] >> 4); + output[2] = ((input[1] & 15) << 2) + (input[2] >> 6); + output[3] = input[2] & 63; + outbuf[m++] = base64_str[(int)output[0]]; + outbuf[m++] = base64_str[(int)output[1]]; + outbuf[m++] = base64_str[(int)output[2]]; + outbuf[m++] = base64_str[(int)output[3]]; + } + while ((m % 4) != 0) { + outbuf[m++] = base64_pad; + } + outbuf[m] = 0; // 0-termination! + *size = m; + return outbuf; +} + +static int base64decode_block(unsigned char *target, const char *data, size_t data_size) +{ + int w1,w2,w3,w4; + int n,i; + + if (!data || (data_size <= 0)) { + return 0; + } + + n = 0; + i = 0; + while (n < data_size-3) { + w1 = base64_table[(int)data[n]]; + w2 = base64_table[(int)data[n+1]]; + w3 = base64_table[(int)data[n+2]]; + w4 = base64_table[(int)data[n+3]]; + + if (w2 >= 0) { + target[i++] = (char)((w1*4 + (w2 >> 4)) & 255); + } + if (w3 >= 0) { + target[i++] = (char)((w2*16 + (w3 >> 2)) & 255); + } + if (w4 >= 0) { + target[i++] = (char)((w3*64 + w4) & 255); + } + n+=4; + } + return i; +} + +unsigned char *base64decode(const char *buf, size_t *size) +{ + if (!buf) return; + size_t len = strlen(buf); + if (len <= 0) return; + unsigned char *outbuf = (unsigned char*)malloc((len/4)*3+3); + + unsigned char *line; + int p = 0; + + line = (unsigned char*)strtok((char*)buf, "\r\n\t "); + while (line) { + p+=base64decode_block(outbuf+p, line, strlen((char*)line)); + + // get next line of base64 encoded block + line = (unsigned char*)strtok(NULL, "\r\n\t "); + } + outbuf[p] = 0; + *size = p; + return outbuf; +} |