base64.c 8.2 KB

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  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. * @file
  22. * @brief Base64 encode/decode
  23. * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)
  24. */
  25. #include "common.h"
  26. #include "base64.h"
  27. #include "intreadwrite.h"
  28. /* ---------------- private code */
  29. static const uint8_t map2[256] =
  30. {
  31. 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  32. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  33. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  34. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  35. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  36. 0xff, 0xff, 0xff,
  37. 0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
  38. 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
  39. 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0x00, 0x01,
  40. 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
  41. 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
  42. 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
  43. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
  44. 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
  45. 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
  46. 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33,
  47. 0xff, 0xff, 0xff, 0xff, 0xff,
  48. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  49. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  50. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  51. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  52. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  53. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  54. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  55. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  56. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  57. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  58. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  59. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  60. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  61. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  62. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  63. 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  64. };
  65. #define BASE64_DEC_STEP(i) do { \
  66. bits = map2[in[i]]; \
  67. if (bits & 0x80) \
  68. goto out ## i; \
  69. v = i ? (v << 6) + bits : bits; \
  70. } while(0)
  71. int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
  72. {
  73. uint8_t *dst = out;
  74. uint8_t *end = out + out_size;
  75. // no sign extension
  76. const uint8_t *in = in_str;
  77. unsigned bits = 0xff;
  78. unsigned v;
  79. while (end - dst > 3) {
  80. BASE64_DEC_STEP(0);
  81. BASE64_DEC_STEP(1);
  82. BASE64_DEC_STEP(2);
  83. BASE64_DEC_STEP(3);
  84. // Using AV_WB32 directly confuses compiler
  85. v = av_be2ne32(v << 8);
  86. AV_WN32(dst, v);
  87. dst += 3;
  88. in += 4;
  89. }
  90. if (end - dst) {
  91. BASE64_DEC_STEP(0);
  92. BASE64_DEC_STEP(1);
  93. BASE64_DEC_STEP(2);
  94. BASE64_DEC_STEP(3);
  95. *dst++ = v >> 16;
  96. if (end - dst)
  97. *dst++ = v >> 8;
  98. if (end - dst)
  99. *dst++ = v;
  100. in += 4;
  101. }
  102. while (1) {
  103. BASE64_DEC_STEP(0);
  104. in++;
  105. BASE64_DEC_STEP(0);
  106. in++;
  107. BASE64_DEC_STEP(0);
  108. in++;
  109. BASE64_DEC_STEP(0);
  110. in++;
  111. }
  112. out3:
  113. *dst++ = v >> 10;
  114. v <<= 2;
  115. out2:
  116. *dst++ = v >> 4;
  117. out1:
  118. out0:
  119. return bits & 1 ? AVERROR_INVALIDDATA : dst - out;
  120. }
  121. /*****************************************************************************
  122. * b64_encode: Stolen from VLC's http.c.
  123. * Simplified by Michael.
  124. * Fixed edge cases and made it work from data (vs. strings) by Ryan.
  125. *****************************************************************************/
  126. char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
  127. {
  128. static const char b64[] =
  129. "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  130. char *ret, *dst;
  131. unsigned i_bits = 0;
  132. int i_shift = 0;
  133. int bytes_remaining = in_size;
  134. if (in_size >= UINT_MAX / 4 ||
  135. out_size < AV_BASE64_SIZE(in_size))
  136. return NULL;
  137. ret = dst = out;
  138. while (bytes_remaining > 3) {
  139. i_bits = AV_RB32(in);
  140. in += 3; bytes_remaining -= 3;
  141. *dst++ = b64[ i_bits>>26 ];
  142. *dst++ = b64[(i_bits>>20) & 0x3F];
  143. *dst++ = b64[(i_bits>>14) & 0x3F];
  144. *dst++ = b64[(i_bits>>8 ) & 0x3F];
  145. }
  146. i_bits = 0;
  147. while (bytes_remaining) {
  148. i_bits = (i_bits << 8) + *in++;
  149. bytes_remaining--;
  150. i_shift += 8;
  151. }
  152. while (i_shift > 0) {
  153. *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
  154. i_shift -= 6;
  155. }
  156. while ((dst - ret) & 3)
  157. *dst++ = '=';
  158. *dst = '\0';
  159. return ret;
  160. }
  161. #ifdef TEST
  162. // LCOV_EXCL_START
  163. #define MAX_DATA_SIZE 1024
  164. #define MAX_ENCODED_SIZE 2048
  165. static int test_encode_decode(const uint8_t *data, unsigned int data_size,
  166. const char *encoded_ref)
  167. {
  168. char encoded[MAX_ENCODED_SIZE];
  169. uint8_t data2[MAX_DATA_SIZE];
  170. int data2_size, max_data2_size = MAX_DATA_SIZE;
  171. if (!av_base64_encode(encoded, MAX_ENCODED_SIZE, data, data_size)) {
  172. printf("Failed: cannot encode the input data\n");
  173. return 1;
  174. }
  175. if (encoded_ref && strcmp(encoded, encoded_ref)) {
  176. printf("Failed: encoded string differs from reference\n"
  177. "Encoded:\n%s\nReference:\n%s\n", encoded, encoded_ref);
  178. return 1;
  179. }
  180. if ((data2_size = av_base64_decode(data2, encoded, max_data2_size)) != data_size) {
  181. printf("Failed: cannot decode the encoded string\n"
  182. "Encoded:\n%s\n", encoded);
  183. return 1;
  184. }
  185. if ((data2_size = av_base64_decode(data2, encoded, data_size)) != data_size) {
  186. printf("Failed: cannot decode with minimal buffer\n"
  187. "Encoded:\n%s\n", encoded);
  188. return 1;
  189. }
  190. if (memcmp(data2, data, data_size)) {
  191. printf("Failed: encoded/decoded data differs from original data\n");
  192. return 1;
  193. }
  194. if (av_base64_decode(NULL, encoded, 0) != 0) {
  195. printf("Failed: decode to NULL buffer\n");
  196. return 1;
  197. }
  198. if (strlen(encoded)) {
  199. char *end = strchr(encoded, '=');
  200. if (!end)
  201. end = encoded + strlen(encoded) - 1;
  202. *end = '%';
  203. if (av_base64_decode(NULL, encoded, 0) >= 0) {
  204. printf("Failed: error detection\n");
  205. return 1;
  206. }
  207. }
  208. printf("Passed!\n");
  209. return 0;
  210. }
  211. int main(int argc, char ** argv)
  212. {
  213. int i, error_count = 0;
  214. struct test {
  215. const uint8_t *data;
  216. const char *encoded_ref;
  217. } tests[] = {
  218. { "", ""},
  219. { "1", "MQ=="},
  220. { "22", "MjI="},
  221. { "333", "MzMz"},
  222. { "4444", "NDQ0NA=="},
  223. { "55555", "NTU1NTU="},
  224. { "666666", "NjY2NjY2"},
  225. { "abc:def", "YWJjOmRlZg=="},
  226. };
  227. char in[1024], out[2048];
  228. printf("Encoding/decoding tests\n");
  229. for (i = 0; i < FF_ARRAY_ELEMS(tests); i++)
  230. error_count += test_encode_decode(tests[i].data, strlen(tests[i].data), tests[i].encoded_ref);
  231. if (argc>1 && !strcmp(argv[1], "-t")) {
  232. memset(in, 123, sizeof(in));
  233. for(i=0; i<10000; i++){
  234. START_TIMER
  235. av_base64_encode(out, sizeof(out), in, sizeof(in));
  236. STOP_TIMER("encode")
  237. }
  238. for(i=0; i<10000; i++){
  239. START_TIMER
  240. av_base64_decode(in, out, sizeof(in));
  241. STOP_TIMER("decode")
  242. }
  243. for(i=0; i<10000; i++){
  244. START_TIMER
  245. av_base64_decode(NULL, out, 0);
  246. STOP_TIMER("syntax check")
  247. }
  248. }
  249. return error_count;
  250. }
  251. // LCOV_EXCL_STOP
  252. #endif