/*
  * Copyright (c) 2006 Ryan Martell. (rdm4@martellventures.com)
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**

  * @file libavutil/base64.c

  * @brief Base64 encode/decode

  * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)
  */
 
 #include "common.h"
 #include "base64.h"
 
 /* ---------------- private code */

 static const uint8_t map2[] =

 {
     0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
     0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x01,
     0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
     0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
     0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
     0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
     0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
     0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33
 };
 

 int av_base64_decode(uint8_t *out, const char *in, int out_size)

 {
     int i, v;
     uint8_t *dst = out;
 
     v = 0;
     for (i = 0; in[i] && in[i] != '='; i++) {
         unsigned int index= in[i]-43;

         if (index>=FF_ARRAY_ELEMS(map2) || map2[index] == 0xff)

             return -1;
         v = (v << 6) + map2[index];
         if (i & 3) {

             if (dst - out < out_size) {

                 *dst++ = v >> (6 - 2 * (i & 3));
             }
         }
     }
 

     return dst - out;

 }
 
 /*****************************************************************************

 * b64_encode: Stolen from VLC's http.c.
 * Simplified by Michael.
 * Fixed edge cases and made it work from data (vs. strings) by Ryan.

 *****************************************************************************/
 

 char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)

 {
     static const char b64[] =
         "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
     char *ret, *dst;
     unsigned i_bits = 0;
     int i_shift = 0;

     int bytes_remaining = in_size;

     if (in_size >= UINT_MAX / 4 ||
         out_size < (in_size+2) / 3 * 4 + 1)

         return NULL;

     ret = dst = out;

     while (bytes_remaining) {

         i_bits = (i_bits << 8) + *in++;

         bytes_remaining--;
         i_shift += 8;

         do {
             *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
             i_shift -= 6;
         } while (i_shift > 6 || (bytes_remaining == 0 && i_shift > 0));
     }
     while ((dst - ret) & 3)
         *dst++ = '=';

     *dst = '\0';
 
     return ret;
 }

 
 #ifdef TEST
 
 #undef printf
 
 #define MAX_DATA_SIZE    1024
 #define MAX_ENCODED_SIZE 2048
 
 int test_encode_decode(const uint8_t *data, unsigned int data_size, const char *encoded_ref)
 {
     char  encoded[MAX_ENCODED_SIZE];
     uint8_t data2[MAX_DATA_SIZE];
     int data2_size, max_data2_size = MAX_DATA_SIZE;
 
     if (!av_base64_encode(encoded, MAX_ENCODED_SIZE, data, data_size)) {
         printf("Failed: cannot encode the input data\n");
         return 1;
     }
     if (encoded_ref && strcmp(encoded, encoded_ref)) {
         printf("Failed: encoded string differs from reference\n"
                "Encoded:\n%s\nReference:\n%s\n", encoded, encoded_ref);
         return 1;
     }
 
     if ((data2_size = av_base64_decode(data2, encoded, max_data2_size)) < 0) {
         printf("Failed: cannot decode the encoded string\n"
                "Encoded:\n%s\n", encoded);
         return 1;
     }
     if (memcmp(data2, data, data_size)) {
         printf("Failed: encoded/decoded data differs from original data\n");
         return 1;
     }
 
     printf("Passed!\n");
     return 0;
 }
 
 int main(void)
 {
     int i, error_count = 0;
     struct test {
         const uint8_t *data;
         const char *encoded_ref;
     } tests[] = {
         { "",        ""},
         { "1",       "MQ=="},
         { "22",      "MjI="},
         { "333",     "MzMz"},
         { "4444",    "NDQ0NA=="},
         { "55555",   "NTU1NTU="},
         { "666666",  "NjY2NjY2"},
         { "abc:def", "YWJjOmRlZg=="},
     };
 
     printf("Encoding/decoding tests\n");
     for (i = 0; i < FF_ARRAY_ELEMS(tests); i++)
         error_count += test_encode_decode(tests[i].data, strlen(tests[i].data), tests[i].encoded_ref);
 
     return error_count;
 }
 
 #endif