libavutil/base64.c

   1 /*
   2  * Copyright (c) 2006 Ryan Martell. (rdm4@martellventures.com)
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file libavutil/base64.c
  23  * @brief Base64 encode/decode
  24  * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)
  25  */
  26
  27 #include "common.h"
  28 #include "base64.h"
  29
  30 /* ---------------- private code */
  31 static const uint8_t map2[] =
  32 {
  33     0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
  34     0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
  35     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x01,
  36     0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
  37     0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
  38     0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
  39     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
  40     0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
  41     0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
  42     0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33
  43 };
  44
  45 int av_base64_decode(uint8_t *out, const char *in, int out_size)
  46 {
  47     int i, v;
  48     uint8_t *dst = out;
  49
  50     v = 0;
  51     for (i = 0; in[i] && in[i] != '='; i++) {
  52         unsigned int index= in[i]-43;
  53         if (index>=FF_ARRAY_ELEMS(map2) || map2[index] == 0xff)
  54             return -1;
  55         v = (v << 6) + map2[index];
  56         if (i & 3) {
  57             if (dst - out < out_size) {
  58                 *dst++ = v >> (6 - 2 * (i & 3));
  59             }
  60         }
  61     }
  62
  63     return dst - out;
  64 }
  65
  66 /*****************************************************************************
  67 * b64_encode: Stolen from VLC's http.c.
  68 * Simplified by Michael.
  69 * Fixed edge cases and made it work from data (vs. strings) by Ryan.
  70 *****************************************************************************/
  71
  72 char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
  73 {
  74     static const char b64[] =
  75         "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  76     char *ret, *dst;
  77     unsigned i_bits = 0;
  78     int i_shift = 0;
  79     int bytes_remaining = in_size;
  80
  81     if (in_size >= UINT_MAX / 4 ||
  82         out_size < (in_size+2) / 3 * 4 + 1)
  83         return NULL;
  84     ret = dst = out;
  85     while (bytes_remaining) {
  86         i_bits = (i_bits << 8) + *in++;
  87         bytes_remaining--;
  88         i_shift += 8;
  89
  90         do {
  91             *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
  92             i_shift -= 6;
  93         } while (i_shift > 6 || (bytes_remaining == 0 && i_shift > 0));
  94     }
  95     while ((dst - ret) & 3)
  96         *dst++ = '=';
  97     *dst = '\0';
  98
  99     return ret;
 100 }
 101
 102 #ifdef TEST
 103
 104 #undef printf
 105
 106 #define MAX_DATA_SIZE    1024
 107 #define MAX_ENCODED_SIZE 2048
 108
 109 static int test_encode_decode(const uint8_t *data, unsigned int data_size,
 110                               const char *encoded_ref)
 111 {
 112     char  encoded[MAX_ENCODED_SIZE];
 113     uint8_t data2[MAX_DATA_SIZE];
 114     int data2_size, max_data2_size = MAX_DATA_SIZE;
 115
 116     if (!av_base64_encode(encoded, MAX_ENCODED_SIZE, data, data_size)) {
 117         printf("Failed: cannot encode the input data\n");
 118         return 1;
 119     }
 120     if (encoded_ref && strcmp(encoded, encoded_ref)) {
 121         printf("Failed: encoded string differs from reference\n"
 122                "Encoded:\n%s\nReference:\n%s\n", encoded, encoded_ref);
 123         return 1;
 124     }
 125
 126     if ((data2_size = av_base64_decode(data2, encoded, max_data2_size)) < 0) {
 127         printf("Failed: cannot decode the encoded string\n"
 128                "Encoded:\n%s\n", encoded);
 129         return 1;
 130     }
 131     if (memcmp(data2, data, data_size)) {
 132         printf("Failed: encoded/decoded data differs from original data\n");
 133         return 1;
 134     }
 135
 136     printf("Passed!\n");
 137     return 0;
 138 }
 139
 140 int main(void)
 141 {
 142     int i, error_count = 0;
 143     struct test {
 144         const uint8_t *data;
 145         const char *encoded_ref;
 146     } tests[] = {
 147         { "",        ""},
 148         { "1",       "MQ=="},
 149         { "22",      "MjI="},
 150         { "333",     "MzMz"},
 151         { "4444",    "NDQ0NA=="},
 152         { "55555",   "NTU1NTU="},
 153         { "666666",  "NjY2NjY2"},
 154         { "abc:def", "YWJjOmRlZg=="},
 155     };
 156
 157     printf("Encoding/decoding tests\n");
 158     for (i = 0; i < FF_ARRAY_ELEMS(tests); i++)
 159         error_count += test_encode_decode(tests[i].data, strlen(tests[i].data), tests[i].encoded_ref);
 160
 161     return error_count;
 162 }
 163
 164 #endif