Alexandre Lision | 8af73cb | 2013-12-10 14:11:20 -0500 | [diff] [blame] | 1 | /* $Id$ */ |
| 2 | /* |
| 3 | * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| 4 | * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 19 | */ |
| 20 | #include <pjlib-util/base64.h> |
| 21 | #include <pj/assert.h> |
| 22 | #include <pj/errno.h> |
| 23 | |
| 24 | #define INV -1 |
| 25 | #define PADDING '=' |
| 26 | |
| 27 | const char base64_char[] = { |
| 28 | 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', |
| 29 | 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', |
| 30 | 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', |
| 31 | 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', |
| 32 | 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', |
| 33 | 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', |
| 34 | '8', '9', '+', '/' |
| 35 | }; |
| 36 | |
| 37 | static int base256_char(char c) |
| 38 | { |
| 39 | if (c >= 'A' && c <= 'Z') |
| 40 | return (c - 'A'); |
| 41 | else if (c >= 'a' && c <= 'z') |
| 42 | return (c - 'a' + 26); |
| 43 | else if (c >= '0' && c <= '9') |
| 44 | return (c - '0' + 52); |
| 45 | else if (c == '+') |
| 46 | return (62); |
| 47 | else if (c == '/') |
| 48 | return (63); |
| 49 | else { |
| 50 | /* It *may* happen on bad input, so this is not a good idea. |
| 51 | * pj_assert(!"Should not happen as '=' should have been filtered"); |
| 52 | */ |
| 53 | return INV; |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | |
| 58 | static void base256to64(pj_uint8_t c1, pj_uint8_t c2, pj_uint8_t c3, |
| 59 | int padding, char *output) |
| 60 | { |
| 61 | *output++ = base64_char[c1>>2]; |
| 62 | *output++ = base64_char[((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4)]; |
| 63 | switch (padding) { |
| 64 | case 0: |
| 65 | *output++ = base64_char[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)]; |
| 66 | *output = base64_char[c3 & 0x3F]; |
| 67 | break; |
| 68 | case 1: |
| 69 | *output++ = base64_char[((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6)]; |
| 70 | *output = PADDING; |
| 71 | break; |
| 72 | case 2: |
| 73 | default: |
| 74 | *output++ = PADDING; |
| 75 | *output = PADDING; |
| 76 | break; |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | |
| 81 | PJ_DEF(pj_status_t) pj_base64_encode(const pj_uint8_t *input, int in_len, |
| 82 | char *output, int *out_len) |
| 83 | { |
| 84 | const pj_uint8_t *pi = input; |
| 85 | pj_uint8_t c1, c2, c3; |
| 86 | int i = 0; |
| 87 | char *po = output; |
| 88 | |
| 89 | PJ_ASSERT_RETURN(input && output && out_len, PJ_EINVAL); |
| 90 | PJ_ASSERT_RETURN(*out_len >= PJ_BASE256_TO_BASE64_LEN(in_len), |
| 91 | PJ_ETOOSMALL); |
| 92 | |
| 93 | while (i < in_len) { |
| 94 | c1 = *pi++; |
| 95 | ++i; |
| 96 | |
| 97 | if (i == in_len) { |
| 98 | base256to64(c1, 0, 0, 2, po); |
| 99 | po += 4; |
| 100 | break; |
| 101 | } else { |
| 102 | c2 = *pi++; |
| 103 | ++i; |
| 104 | |
| 105 | if (i == in_len) { |
| 106 | base256to64(c1, c2, 0, 1, po); |
| 107 | po += 4; |
| 108 | break; |
| 109 | } else { |
| 110 | c3 = *pi++; |
| 111 | ++i; |
| 112 | base256to64(c1, c2, c3, 0, po); |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | po += 4; |
| 117 | } |
| 118 | |
| 119 | *out_len = (int)(po - output); |
| 120 | return PJ_SUCCESS; |
| 121 | } |
| 122 | |
| 123 | |
| 124 | PJ_DEF(pj_status_t) pj_base64_decode(const pj_str_t *input, |
| 125 | pj_uint8_t *out, int *out_len) |
| 126 | { |
| 127 | const char *buf = input->ptr; |
| 128 | int len = (int)input->slen; |
| 129 | int i, j, k; |
| 130 | int c[4]; |
| 131 | |
| 132 | PJ_ASSERT_RETURN(input && out && out_len, PJ_EINVAL); |
| 133 | |
| 134 | while (buf[len-1] == '=' && len) |
| 135 | --len; |
| 136 | |
| 137 | PJ_ASSERT_RETURN(*out_len >= PJ_BASE64_TO_BASE256_LEN(len), |
| 138 | PJ_ETOOSMALL); |
| 139 | |
| 140 | for (i=0, j=0; i<len; ) { |
| 141 | /* Fill up c, silently ignoring invalid characters */ |
| 142 | for (k=0; k<4 && i<len; ++k) { |
| 143 | do { |
| 144 | c[k] = base256_char(buf[i++]); |
| 145 | } while (c[k]==INV && i<len); |
| 146 | } |
| 147 | |
| 148 | if (k<4) { |
| 149 | if (k > 1) { |
| 150 | out[j++] = (pj_uint8_t)((c[0]<<2) | ((c[1] & 0x30)>>4)); |
| 151 | if (k > 2) { |
| 152 | out[j++] = (pj_uint8_t) |
| 153 | (((c[1] & 0x0F)<<4) | ((c[2] & 0x3C)>>2)); |
| 154 | } |
| 155 | } |
| 156 | break; |
| 157 | } |
| 158 | |
| 159 | out[j++] = (pj_uint8_t)((c[0]<<2) | ((c[1] & 0x30)>>4)); |
| 160 | out[j++] = (pj_uint8_t)(((c[1] & 0x0F)<<4) | ((c[2] & 0x3C)>>2)); |
| 161 | out[j++] = (pj_uint8_t)(((c[2] & 0x03)<<6) | (c[3] & 0x3F)); |
| 162 | } |
| 163 | |
| 164 | pj_assert(j < *out_len); |
| 165 | *out_len = j; |
| 166 | |
| 167 | return PJ_SUCCESS; |
| 168 | } |
| 169 | |
| 170 | |