diff options
Diffstat (limited to 'pjlib-util/src/pjlib-util/base64.c')
| -rw-r--r-- | pjlib-util/src/pjlib-util/base64.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/pjlib-util/src/pjlib-util/base64.c b/pjlib-util/src/pjlib-util/base64.c new file mode 100644 index 0000000..d92339c --- /dev/null +++ b/pjlib-util/src/pjlib-util/base64.c @@ -0,0 +1,170 @@ +/* $Id: base64.c 3553 2011-05-05 06:14:19Z nanang $ */ +/* + * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) + * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <pjlib-util/base64.h> +#include <pj/assert.h> +#include <pj/errno.h> + +#define INV -1 +#define PADDING '=' + +const char base64_char[] = { + 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', + 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', + 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', + 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', + 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', + 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', '+', '/' +}; + +static int base256_char(char c) +{ + if (c >= 'A' && c <= 'Z') + return (c - 'A'); + else if (c >= 'a' && c <= 'z') + return (c - 'a' + 26); + else if (c >= '0' && c <= '9') + return (c - '0' + 52); + else if (c == '+') + return (62); + else if (c == '/') + return (63); + else { + /* It *may* happen on bad input, so this is not a good idea. + * pj_assert(!"Should not happen as '=' should have been filtered"); + */ + return INV; + } +} + + +static void base256to64(pj_uint8_t c1, pj_uint8_t c2, pj_uint8_t c3, + int padding, char *output) +{ + *output++ = base64_char[c1>>2]; + *output++ = base64_char[((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4)]; + switch (padding) { + case 0: + *output++ = base64_char[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)]; + *output = base64_char[c3 & 0x3F]; + break; + case 1: + *output++ = base64_char[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)]; + *output = PADDING; + break; + case 2: + default: + *output++ = PADDING; + *output = PADDING; + break; + } +} + + +PJ_DEF(pj_status_t) pj_base64_encode(const pj_uint8_t *input, int in_len, + char *output, int *out_len) +{ + const pj_uint8_t *pi = input; + pj_uint8_t c1, c2, c3; + int i = 0; + char *po = output; + + PJ_ASSERT_RETURN(input && output && out_len, PJ_EINVAL); + PJ_ASSERT_RETURN(*out_len >= PJ_BASE256_TO_BASE64_LEN(in_len), + PJ_ETOOSMALL); + + while (i < in_len) { + c1 = *pi++; + ++i; + + if (i == in_len) { + base256to64(c1, 0, 0, 2, po); + po += 4; + break; + } else { + c2 = *pi++; + ++i; + + if (i == in_len) { + base256to64(c1, c2, 0, 1, po); + po += 4; + break; + } else { + c3 = *pi++; + ++i; + base256to64(c1, c2, c3, 0, po); + } + } + + po += 4; + } + + *out_len = po - output; + return PJ_SUCCESS; +} + + +PJ_DEF(pj_status_t) pj_base64_decode(const pj_str_t *input, + pj_uint8_t *out, int *out_len) +{ + const char *buf = input->ptr; + int len = input->slen; + int i, j, k; + int c[4]; + + PJ_ASSERT_RETURN(input && out && out_len, PJ_EINVAL); + + while (buf[len-1] == '=' && len) + --len; + + PJ_ASSERT_RETURN(*out_len >= PJ_BASE64_TO_BASE256_LEN(len), + PJ_ETOOSMALL); + + for (i=0, j=0; i<len; ) { + /* Fill up c, silently ignoring invalid characters */ + for (k=0; k<4 && i<len; ++k) { + do { + c[k] = base256_char(buf[i++]); + } while (c[k]==INV && i<len); + } + + if (k<4) { + if (k > 1) { + out[j++] = (pj_uint8_t)((c[0]<<2) | ((c[1] & 0x30)>>4)); + if (k > 2) { + out[j++] = (pj_uint8_t) + (((c[1] & 0x0F)<<4) | ((c[2] & 0x3C)>>2)); + } + } + break; + } + + out[j++] = (pj_uint8_t)((c[0]<<2) | ((c[1] & 0x30)>>4)); + out[j++] = (pj_uint8_t)(((c[1] & 0x0F)<<4) | ((c[2] & 0x3C)>>2)); + out[j++] = (pj_uint8_t)(((c[2] & 0x03)<<6) | (c[3] & 0x3F)); + } + + pj_assert(j < *out_len); + *out_len = j; + + return PJ_SUCCESS; +} + + |