libavutil/base64.c

   1 /*
   2  * Base64.c
   3  * Copyright (c) 2006 Ryan Martell. (rdm4@martellventures.com)
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23 * @file base64.c
  24  * @brief Base64 Encode/Decode
  25  * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)
  26  */
  27
  28 #include "common.h"
  29 #include "base64.h"
  30
  31 /* ---------------- private code */
  32 static uint8_t map2[] =
  33 {
  34     0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
  35     0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
  36     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x01,
  37     0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
  38     0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
  39     0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
  40     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
  41     0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
  42     0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
  43     0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33
  44 };
  45
  46 int av_base64_decode(uint8_t * out, const char *in, int out_length)
  47 {
  48     int i, v;
  49     uint8_t *dst = out;
  50
  51     v = 0;
  52     for (i = 0; in[i] && in[i] != '='; i++) {
  53         unsigned int index= in[i]-43;
  54         if (index>=(sizeof(map2)/sizeof(map2[0])) || map2[index] == 0xff)
  55             return -1;
  56         v = (v << 6) + map2[index];
  57         if (i & 3) {
  58             if (dst - out < out_length) {
  59                 *dst++ = v >> (6 - 2 * (i & 3));
  60             }
  61         }
  62     }
  63
  64     return (dst - out);
  65 }
  66
  67 /*****************************************************************************
  68 * b64_encode: stolen from VLC's http.c
  69 * simplified by michael
  70 * fixed edge cases and made it work from data (vs. strings) by ryan.
  71 *****************************************************************************/
  72
  73 char *av_base64_encode(char * buf, int buf_len, uint8_t * src, int len)
  74 {
  75     static const char b64[] =
  76         "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  77     char *ret, *dst;
  78     unsigned i_bits = 0;
  79     int i_shift = 0;
  80     int bytes_remaining = len;
  81
  82     if (len >= UINT_MAX / 4 ||
  83         buf_len < len * 4 / 3 + 12)
  84         return NULL;
  85     ret = dst = buf;
  86     if (len) {                  // special edge case, what should we really do here?
  87         while (bytes_remaining) {
  88             i_bits = (i_bits << 8) + *src++;
  89             bytes_remaining--;
  90             i_shift += 8;
  91
  92             do {
  93                 *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
  94                 i_shift -= 6;
  95             } while (i_shift > 6 || (bytes_remaining == 0 && i_shift > 0));
  96         }
  97         while ((dst - ret) & 3)
  98             *dst++ = '=';
  99     }
 100     *dst = '\0';
 101
 102     return ret;
 103 }
 104
 105 // #define TEST_BASE64
 106
 107 #ifdef TEST_BASE64
 108 #include "avutil.h"
 109
 110 int b64test()
 111 {
 112     int numerr = 0;
 113     int len;
 114     int numtest = 1;
 115     uint8_t decode[1000];
 116     struct test {
 117         void *data;
 118         int len;
 119         const char *result;
 120     } *t, tests[] = {
 121         {
 122         "", 0, ""}, {
 123         "1", 1, "MQ=="}, {
 124         "22", 2, "MjI="}, {
 125         "333", 3, "MzMz"}, {
 126         "4444", 4, "NDQ0NA=="}, {
 127         "55555", 5, "NTU1NTU="}, {
 128         "abc:def", 7, "YWJjOmRlZg=="}, {
 129         NULL}
 130     };
 131     for (t = tests; t->data; t++) {
 132         char *str;
 133
 134         av_log(NULL, AV_LOG_ERROR, "Encoding %s...\n", (char *) t->data);
 135         str = av_base64_encode(t->data, t->len);
 136         if (str) {
 137             av_log(NULL, AV_LOG_ERROR, "Encoded to %s...\n", str);
 138             if (strcmp(str, t->result) != 0) {
 139                 av_log(NULL, AV_LOG_ERROR, "failed test %d: %s != %s\n",
 140                        numtest, str, t->result);
 141                 numerr++;
 142             }
 143             av_free(str);
 144         }
 145
 146         av_log(NULL, AV_LOG_ERROR, "Done encoding, about to decode...\n");
 147         len = av_base64_decode(decode, t->result, sizeof(decode));
 148         if (len != t->len) {
 149             av_log(NULL, AV_LOG_ERROR, "failed test %d: len %d != %d\n",
 150                    numtest, len, t->len);
 151             numerr++;
 152         } else if (memcmp(decode, t->data, t->len) != 0) {
 153             av_log(NULL, AV_LOG_ERROR, "failed test %d: data\n", numtest);
 154             numerr++;
 155         } else {
 156             av_log(NULL, AV_LOG_ERROR, "Decoded to %s\n",
 157                    (char *) t->data);
 158         }
 159         numtest++;
 160     }
 161
 162 #undef srand
 163 #undef rand
 164
 165     {
 166         int test_count;
 167         srand(123141);          // time(NULL));
 168         for (test_count = 0; test_count < 100; test_count++) {
 169             int size = rand() % 1024;
 170             int ii;
 171             uint8_t *data;
 172             char *encoded_result;
 173
 174             av_log(NULL, AV_LOG_ERROR, "Test %d: Size %d bytes...",
 175                    test_count, size);
 176             data = (uint8_t *) av_malloc(size);
 177             for (ii = 0; ii < size; ii++) {
 178                 data[ii] = rand() % 255;
 179             }
 180
 181             encoded_result = av_base64_encode(data, size);
 182             if (encoded_result) {
 183                 int decode_buffer_size = size + 10;     // try without 10 as well
 184                 uint8_t *decode_buffer = av_malloc(decode_buffer_size);
 185                 if (decode_buffer) {
 186                     int decoded_size =
 187                         av_base64_decode(decode_buffer, encoded_result,
 188                                    decode_buffer_size);
 189
 190                     if (decoded_size != size) {
 191                         av_log(NULL, AV_LOG_ERROR,
 192                                "Decoded/Encoded size mismatch (%d != %d)\n",
 193                                decoded_size, size);
 194                     } else {
 195                         if (memcmp(decode_buffer, data, decoded_size) == 0) {
 196                             av_log(NULL, AV_LOG_ERROR, "Passed!\n");
 197                         } else {
 198                             av_log(NULL, AV_LOG_ERROR,
 199                                    "Failed (Data differs)!\n");
 200                         }
 201                     }
 202                     av_free(decode_buffer);
 203                 }
 204
 205                 av_free(encoded_result);
 206             }
 207         }
 208     }
 209
 210     // these are invalid strings, that it currently decodes (which it probably shouldn't?)
 211     {
 212         uint8_t str[32];
 213         if (av_base64_decode(str, "M=M=", sizeof(str)) != -1) {
 214             av_log(NULL, AV_LOG_ERROR,
 215                    "failed test %d: successful decode of `M=M='\n",
 216                    numtest++);
 217             numerr++;
 218         }
 219         if (av_base64_decode(str, "MQ===", sizeof(str)) != -1) {
 220             av_log(NULL, AV_LOG_ERROR,
 221                    "failed test %d: successful decode of `MQ==='\n",
 222                    numtest++);
 223             numerr++;
 224         }
 225     }
 226
 227     return numerr;
 228 }
 229 #endif
 230