rc4_skey.c 5.5 KB

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  1. /* crypto/rc4/rc4_skey.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 <openssl/rc4.h>
  59. #include "rc4_locl.h"
  60. #include <openssl/opensslv.h>
  61. const char *RC4_version="RC4" OPENSSL_VERSION_PTEXT;
  62. const char *RC4_options(void)
  63. {
  64. #ifdef RC4_INDEX
  65. if (sizeof(RC4_INT) == 1)
  66. return("rc4(idx,char)");
  67. else
  68. return("rc4(idx,int)");
  69. #else
  70. if (sizeof(RC4_INT) == 1)
  71. return("rc4(ptr,char)");
  72. else
  73. return("rc4(ptr,int)");
  74. #endif
  75. }
  76. /* RC4 as implemented from a posting from
  77. * Newsgroups: sci.crypt
  78. * From: sterndark@netcom.com (David Sterndark)
  79. * Subject: RC4 Algorithm revealed.
  80. * Message-ID: <sternCvKL4B.Hyy@netcom.com>
  81. * Date: Wed, 14 Sep 1994 06:35:31 GMT
  82. */
  83. void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
  84. {
  85. register RC4_INT tmp;
  86. register int id1,id2;
  87. register RC4_INT *d;
  88. unsigned int i;
  89. d= &(key->data[0]);
  90. key->x = 0;
  91. key->y = 0;
  92. id1=id2=0;
  93. #define SK_LOOP(d,n) { \
  94. tmp=d[(n)]; \
  95. id2 = (data[id1] + tmp + id2) & 0xff; \
  96. if (++id1 == len) id1=0; \
  97. d[(n)]=d[id2]; \
  98. d[id2]=tmp; }
  99. #if defined(OPENSSL_CPUID_OBJ) && !defined(OPENSSL_NO_ASM)
  100. # if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
  101. defined(__INTEL__) || \
  102. defined(__x86_64) || defined(__x86_64__) || defined(_M_AMD64)
  103. if (sizeof(RC4_INT) > 1) {
  104. /*
  105. * Unlike all other x86 [and x86_64] implementations,
  106. * Intel P4 core [including EM64T] was found to perform
  107. * poorly with wider RC4_INT. Performance improvement
  108. * for IA-32 hand-coded assembler turned out to be 2.8x
  109. * if re-coded for RC4_CHAR! It's however inappropriate
  110. * to just switch to RC4_CHAR for x86[_64], as non-P4
  111. * implementations suffer from significant performance
  112. * losses then, e.g. PIII exhibits >2x deterioration,
  113. * and so does Opteron. In order to assure optimal
  114. * all-round performance, let us [try to] detect P4 at
  115. * run-time by checking upon HTT bit in CPU capability
  116. * vector and set up compressed key schedule, which is
  117. * recognized by correspondingly updated assembler
  118. * module...
  119. * <appro@fy.chalmers.se>
  120. */
  121. if (OPENSSL_ia32cap_P & (1<<28)) {
  122. unsigned char *cp=(unsigned char *)d;
  123. for (i=0;i<256;i++) cp[i]=i;
  124. for (i=0;i<256;i++) SK_LOOP(cp,i);
  125. /* mark schedule as compressed! */
  126. d[256/sizeof(RC4_INT)]=-1;
  127. return;
  128. }
  129. }
  130. # endif
  131. #endif
  132. for (i=0; i < 256; i++) d[i]=i;
  133. for (i=0; i < 256; i+=4)
  134. {
  135. SK_LOOP(d,i+0);
  136. SK_LOOP(d,i+1);
  137. SK_LOOP(d,i+2);
  138. SK_LOOP(d,i+3);
  139. }
  140. }