base64.c 6.8 KB

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  1. /*
  2. * RFC 1521 base64 encoding/decoding
  3. *
  4. * Copyright (C) 2006-2010, Brainspark B.V.
  5. *
  6. * This file is part of PolarSSL (http://www.polarssl.org)
  7. * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
  8. *
  9. * All rights reserved.
  10. *
  11. * This program is free software; you can redistribute it and/or modify
  12. * it under the terms of the GNU General Public License as published by
  13. * the Free Software Foundation; either version 2 of the License, or
  14. * (at your option) any later version.
  15. *
  16. * This program is distributed in the hope that it will be useful,
  17. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19. * GNU General Public License for more details.
  20. *
  21. * You should have received a copy of the GNU General Public License along
  22. * with this program; if not, write to the Free Software Foundation, Inc.,
  23. * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24. */
  25. #include "config.h"
  26. #if defined(POLARSSL_BASE64_C)
  27. #include "polarssl/base64.h"
  28. static const unsigned char base64_enc_map[64] =
  29. {
  30. 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
  31. 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
  32. 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
  33. 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
  34. 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
  35. 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
  36. '8', '9', '+', '/'
  37. };
  38. static const unsigned char base64_dec_map[128] =
  39. {
  40. 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  41. 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  42. 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  43. 127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  44. 127, 127, 127, 62, 127, 127, 127, 63, 52, 53,
  45. 54, 55, 56, 57, 58, 59, 60, 61, 127, 127,
  46. 127, 64, 127, 127, 127, 0, 1, 2, 3, 4,
  47. 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
  48. 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
  49. 25, 127, 127, 127, 127, 127, 127, 26, 27, 28,
  50. 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
  51. 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
  52. 49, 50, 51, 127, 127, 127, 127, 127
  53. };
  54. /*
  55. * Encode a buffer into base64 format
  56. */
  57. int base64_encode( unsigned char *dst, size_t *dlen,
  58. const unsigned char *src, size_t slen )
  59. {
  60. size_t i, n;
  61. int C1, C2, C3;
  62. unsigned char *p;
  63. if( slen == 0 )
  64. return( 0 );
  65. n = (slen << 3) / 6;
  66. switch( (slen << 3) - (n * 6) )
  67. {
  68. case 2: n += 3; break;
  69. case 4: n += 2; break;
  70. default: break;
  71. }
  72. if( *dlen < n + 1 )
  73. {
  74. *dlen = n + 1;
  75. return( POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL );
  76. }
  77. n = (slen / 3) * 3;
  78. for( i = 0, p = dst; i < n; i += 3 )
  79. {
  80. C1 = *src++;
  81. C2 = *src++;
  82. C3 = *src++;
  83. *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
  84. *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
  85. *p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F];
  86. *p++ = base64_enc_map[C3 & 0x3F];
  87. }
  88. if( i < slen )
  89. {
  90. C1 = *src++;
  91. C2 = ((i + 1) < slen) ? *src++ : 0;
  92. *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
  93. *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
  94. if( (i + 1) < slen )
  95. *p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F];
  96. else *p++ = '=';
  97. *p++ = '=';
  98. }
  99. *dlen = p - dst;
  100. *p = 0;
  101. return( 0 );
  102. }
  103. /*
  104. * Decode a base64-formatted buffer
  105. */
  106. int base64_decode( unsigned char *dst, size_t *dlen,
  107. const unsigned char *src, size_t slen )
  108. {
  109. size_t i, j, n;
  110. unsigned long x;
  111. unsigned char *p;
  112. for( i = j = n = 0; i < slen; i++ )
  113. {
  114. if( ( slen - i ) >= 2 &&
  115. src[i] == '\r' && src[i + 1] == '\n' )
  116. continue;
  117. if( src[i] == '\n' )
  118. continue;
  119. if( src[i] == '=' && ++j > 2 )
  120. return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
  121. if( src[i] > 127 || base64_dec_map[src[i]] == 127 )
  122. return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
  123. if( base64_dec_map[src[i]] < 64 && j != 0 )
  124. return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
  125. n++;
  126. }
  127. if( n == 0 )
  128. return( 0 );
  129. n = ((n * 6) + 7) >> 3;
  130. if( *dlen < n )
  131. {
  132. *dlen = n;
  133. return( POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL );
  134. }
  135. for( j = 3, n = x = 0, p = dst; i > 0; i--, src++ )
  136. {
  137. if( *src == '\r' || *src == '\n' )
  138. continue;
  139. j -= ( base64_dec_map[*src] == 64 );
  140. x = (x << 6) | ( base64_dec_map[*src] & 0x3F );
  141. if( ++n == 4 )
  142. {
  143. n = 0;
  144. if( j > 0 ) *p++ = (unsigned char)( x >> 16 );
  145. if( j > 1 ) *p++ = (unsigned char)( x >> 8 );
  146. if( j > 2 ) *p++ = (unsigned char)( x );
  147. }
  148. }
  149. *dlen = p - dst;
  150. return( 0 );
  151. }
  152. #if defined(POLARSSL_SELF_TEST)
  153. #include <string.h>
  154. #ifdef PRINTF_STDLIB
  155. #include <stdio.h>
  156. #endif
  157. #ifdef PRINTF_CUSTOM
  158. #include "tinystdio.h"
  159. #endif
  160. static const unsigned char base64_test_dec[64] =
  161. {
  162. 0x24, 0x48, 0x6E, 0x56, 0x87, 0x62, 0x5A, 0xBD,
  163. 0xBF, 0x17, 0xD9, 0xA2, 0xC4, 0x17, 0x1A, 0x01,
  164. 0x94, 0xED, 0x8F, 0x1E, 0x11, 0xB3, 0xD7, 0x09,
  165. 0x0C, 0xB6, 0xE9, 0x10, 0x6F, 0x22, 0xEE, 0x13,
  166. 0xCA, 0xB3, 0x07, 0x05, 0x76, 0xC9, 0xFA, 0x31,
  167. 0x6C, 0x08, 0x34, 0xFF, 0x8D, 0xC2, 0x6C, 0x38,
  168. 0x00, 0x43, 0xE9, 0x54, 0x97, 0xAF, 0x50, 0x4B,
  169. 0xD1, 0x41, 0xBA, 0x95, 0x31, 0x5A, 0x0B, 0x97
  170. };
  171. static const unsigned char base64_test_enc[] =
  172. "JEhuVodiWr2/F9mixBcaAZTtjx4Rs9cJDLbpEG8i7hPK"
  173. "swcFdsn6MWwINP+Nwmw4AEPpVJevUEvRQbqVMVoLlw==";
  174. /*
  175. * Checkup routine
  176. */
  177. int base64_self_test( int verbose )
  178. {
  179. size_t len;
  180. unsigned char *src, buffer[128];
  181. if( verbose != 0 )
  182. printf( " Base64 encoding test: " );
  183. len = sizeof( buffer );
  184. src = (unsigned char *) base64_test_dec;
  185. if( base64_encode( buffer, &len, src, 64 ) != 0 ||
  186. memcmp( base64_test_enc, buffer, 88 ) != 0 )
  187. {
  188. if( verbose != 0 )
  189. printf( "failed\n" );
  190. return( 1 );
  191. }
  192. if( verbose != 0 )
  193. printf( "passed\n Base64 decoding test: " );
  194. len = sizeof( buffer );
  195. src = (unsigned char *) base64_test_enc;
  196. if( base64_decode( buffer, &len, src, 88 ) != 0 ||
  197. memcmp( base64_test_dec, buffer, 64 ) != 0 )
  198. {
  199. if( verbose != 0 )
  200. printf( "failed\n" );
  201. return( 1 );
  202. }
  203. if( verbose != 0 )
  204. printf( "passed\n\n" );
  205. return( 0 );
  206. }
  207. #endif
  208. #endif