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pcbc_enc.c 4.7 KB

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  1. /* crypto/des/pcbc_enc.c */
  2. /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  3. * All rights reserved.
  4. *
  5. * This package is an SSL implementation written
  6. * by Eric Young (eay@cryptsoft.com).
  7. * The implementation was written so as to conform with Netscapes SSL.
  8. *
  9. * This library is free for commercial and non-commercial use as long as
  10. * the following conditions are aheared to. The following conditions
  11. * apply to all code found in this distribution, be it the RC4, RSA,
  12. * lhash, DES, etc., code; not just the SSL code. The SSL documentation
  13. * included with this distribution is covered by the same copyright terms
  14. * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15. *
  16. * Copyright remains Eric Young's, and as such any Copyright notices in
  17. * the code are not to be removed.
  18. * If this package is used in a product, Eric Young should be given attribution
  19. * as the author of the parts of the library used.
  20. * This can be in the form of a textual message at program startup or
  21. * in documentation (online or textual) provided with the package.
  22. *
  23. * Redistribution and use in source and binary forms, with or without
  24. * modification, are permitted provided that the following conditions
  25. * are met:
  26. * 1. Redistributions of source code must retain the copyright
  27. * notice, this list of conditions and the following disclaimer.
  28. * 2. Redistributions in binary form must reproduce the above copyright
  29. * notice, this list of conditions and the following disclaimer in the
  30. * documentation and/or other materials provided with the distribution.
  31. * 3. All advertising materials mentioning features or use of this software
  32. * must display the following acknowledgement:
  33. * "This product includes cryptographic software written by
  34. * Eric Young (eay@cryptsoft.com)"
  35. * The word 'cryptographic' can be left out if the rouines from the library
  36. * being used are not cryptographic related :-).
  37. * 4. If you include any Windows specific code (or a derivative thereof) from
  38. * the apps directory (application code) you must include an acknowledgement:
  39. * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40. *
  41. * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44. * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51. * SUCH DAMAGE.
  52. *
  53. * The licence and distribution terms for any publically available version or
  54. * derivative of this code cannot be changed. i.e. this code cannot simply be
  55. * copied and put under another distribution licence
  56. * [including the GNU Public Licence.]
  57. */
  58. #include "des_locl.h"
  59. void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
  60. long length, DES_key_schedule *schedule,
  61. DES_cblock *ivec, int enc)
  62. {
  63. register DES_LONG sin0, sin1, xor0, xor1, tout0, tout1;
  64. DES_LONG tin[2];
  65. const unsigned char *in;
  66. unsigned char *out, *iv;
  67. in = input;
  68. out = output;
  69. iv = &(*ivec)[0];
  70. if (enc) {
  71. c2l(iv, xor0);
  72. c2l(iv, xor1);
  73. for (; length > 0; length -= 8) {
  74. if (length >= 8) {
  75. c2l(in, sin0);
  76. c2l(in, sin1);
  77. } else
  78. c2ln(in, sin0, sin1, length);
  79. tin[0] = sin0 ^ xor0;
  80. tin[1] = sin1 ^ xor1;
  81. DES_encrypt1((DES_LONG *)tin, schedule, DES_ENCRYPT);
  82. tout0 = tin[0];
  83. tout1 = tin[1];
  84. xor0 = sin0 ^ tout0;
  85. xor1 = sin1 ^ tout1;
  86. l2c(tout0, out);
  87. l2c(tout1, out);
  88. }
  89. } else {
  90. c2l(iv, xor0);
  91. c2l(iv, xor1);
  92. for (; length > 0; length -= 8) {
  93. c2l(in, sin0);
  94. c2l(in, sin1);
  95. tin[0] = sin0;
  96. tin[1] = sin1;
  97. DES_encrypt1((DES_LONG *)tin, schedule, DES_DECRYPT);
  98. tout0 = tin[0] ^ xor0;
  99. tout1 = tin[1] ^ xor1;
  100. if (length >= 8) {
  101. l2c(tout0, out);
  102. l2c(tout1, out);
  103. } else
  104. l2cn(tout0, tout1, out, length);
  105. xor0 = tout0 ^ sin0;
  106. xor1 = tout1 ^ sin1;
  107. }
  108. }
  109. tin[0] = tin[1] = 0;
  110. sin0 = sin1 = xor0 = xor1 = tout0 = tout1 = 0;
  111. }