diff options
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..a4edf49 --- /dev/null +++ b/src/base64.c @@ -0,0 +1,127 @@ +/* This file is part of GDBM, the GNU data base manager. + Copyright (C) 2011, 2013 Free Software Foundation, Inc. + + GDBM is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. + + GDBM 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GDBM. If not, see <http://www.gnu.org/licenses/>. */ + +# include "autoconf.h" +# include "gdbmdefs.h" +# include "gdbm.h" + +static char b64tab[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; +static int b64val[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 +}; + +int +_gdbm_base64_encode (const unsigned char *input, size_t input_len, + unsigned char **output, size_t *output_size, + size_t *nbytes) +{ + size_t olen = 4 * (input_len + 2) / 3 + 1; + unsigned char *out; + + if (olen > *output_size) + { + out = realloc (*output, olen); + if (!out) + return GDBM_MALLOC_ERROR; + *output = out; + *output_size = olen; + } + else + out = *output; + + while (input_len >= 3) + { + *out++ = b64tab[input[0] >> 2]; + *out++ = b64tab[((input[0] << 4) & 0x30) | (input[1] >> 4)]; + *out++ = b64tab[((input[1] << 2) & 0x3c) | (input[2] >> 6)]; + *out++ = b64tab[input[2] & 0x3f]; + input_len -= 3; + input += 3; + } + + if (input_len > 0) + { + unsigned char c = (input[0] << 4) & 0x30; + *out++ = b64tab[input[0] >> 2]; + if (input_len > 1) + c |= input[1] >> 4; + *out++ = b64tab[c]; + *out++ = (input_len < 2) ? '=' : b64tab[(input[1] << 2) & 0x3c]; + *out++ = '='; + } + *out = 0; + *nbytes = out - *output; + return 0; +} + +int +_gdbm_base64_decode (const unsigned char *input, size_t input_len, + unsigned char **output, size_t *output_size, + size_t *inbytes, size_t *outbytes) +{ + int rc = 0; + int olen = input_len; + unsigned char *out; + size_t ins = 0; + + if (olen > *output_size) + { + out = realloc (*output, olen); + if (!out) + return GDBM_MALLOC_ERROR; + *output = out; + *output_size = olen; + } + else + out = *output; + + do + { + if (input_len < 4) + break; + if (input[0] > 127 || b64val[input[0]] == -1 + || input[1] > 127 || b64val[input[1]] == -1 + || input[2] > 127 || ((input[2] != '=') && (b64val[input[2]] == -1)) + || input[3] > 127 || ((input[3] != '=') + && (b64val[input[3]] == -1))) + { + rc = GDBM_ILLEGAL_DATA; + break; + } + *out++ = (b64val[input[0]] << 2) | (b64val[input[1]] >> 4); + if (input[2] != '=') + { + *out++ = ((b64val[input[1]] << 4) & 0xf0) | (b64val[input[2]] >> 2); + if (input[3] != '=') + *out++ = ((b64val[input[2]] << 6) & 0xc0) | b64val[input[3]]; + } + input += 4; + input_len -= 4; + ins += 4; + } + while (input_len > 0); + *inbytes = ins; + *outbytes = out - *output; + return rc; +} |