Diffstat (limited to 'libetpan/src/data-types/base64.c') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | libetpan/src/data-types/base64.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/libetpan/src/data-types/base64.c b/libetpan/src/data-types/base64.c new file mode 100644 index 0000000..58a2c04 --- a/dev/null +++ b/libetpan/src/data-types/base64.c @@ -0,0 +1,143 @@ +/* + * libEtPan! -- a mail stuff library + * + * Copyright (C) 2001, 2005 - Juergen Graf + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the libEtPan! project nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * $Id$ + */ + +#include "base64.h" + +#include <stdlib.h> + +#define OUTPUT_SIZE 513 +#define CHAR64(c) (((c) < 0 || (c) > 127) ? -1 : index_64[(c)]) + +static 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 +}; + +static char basis_64[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +char * encode_base64(const char * in, int len) +{ + char * output, * tmp; + unsigned char oval; + int out_len; + + out_len = ((len + 2) / 3 * 4) + 1; + + if ((len > 0) && (in == NULL)) + return NULL; + + output = malloc(out_len); + if (!output) + return NULL; + + tmp = output; + while (len >= 3) { + *tmp++ = basis_64[in[0] >> 2]; + *tmp++ = basis_64[((in[0] << 4) & 0x30) | (in[1] >> 4)]; + *tmp++ = basis_64[((in[1] << 2) & 0x3c) | (in[2] >> 6)]; + *tmp++ = basis_64[in[2] & 0x3f]; + in += 3; + len -= 3; + } + if (len > 0) { + *tmp++ = basis_64[in[0] >> 2]; + oval = (in[0] << 4) & 0x30; + if (len > 1) oval |= in[1] >> 4; + *tmp++ = basis_64[oval]; + *tmp++ = (len < 2) ? '=' : basis_64[(in[1] << 2) & 0x3c]; + *tmp++ = '='; + } + + *tmp = '\0'; + + return output; +} + +char * decode_base64(const char * in, int len) +{ + char * output, * out; + int i, c1, c2, c3, c4, out_len; + + out_len = 0; + + output = malloc(OUTPUT_SIZE); + if (output == NULL) + return NULL; + out = output; + + if (in[0] == '+' && in[1] == ' ') + in += 2; + + for (i = 0; i < (len / 4); i++) { + c1 = in[0]; + c2 = in[1]; + c3 = in[2]; + c4 = in[3]; + if (CHAR64(c1) == -1 || CHAR64(c2) == -1 || + (c3 != '=' && CHAR64(c3) == -1) || + (c4 != '=' && CHAR64(c4) == -1)) + return NULL; + + in += 4; + *output++ = (CHAR64(c1) << 2) | (CHAR64(c2) >> 4); + if (++out_len >= OUTPUT_SIZE) + return NULL; + + if (c3 != '=') { + *output++ = ((CHAR64(c2) << 4) & 0xf0) | (CHAR64(c3) >> 2); + if (++out_len >= OUTPUT_SIZE) + return NULL; + + if (c4 != '=') { + *output++ = ((CHAR64(c3) << 6) & 0xc0) | CHAR64(c4); + if (++out_len >= OUTPUT_SIZE) + return NULL; + } + } + } + + *output = 0; + + return out; +} + + |