x_bignum.c 4.7 KB

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  1. /* x_bignum.c */
  2. /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
  3. * project 2000.
  4. */
  5. /* ====================================================================
  6. * Copyright (c) 2000 The OpenSSL Project. All rights reserved.
  7. *
  8. * Redistribution and use in source and binary forms, with or without
  9. * modification, are permitted provided that the following conditions
  10. * are met:
  11. *
  12. * 1. Redistributions of source code must retain the above copyright
  13. * notice, this list of conditions and the following disclaimer.
  14. *
  15. * 2. Redistributions in binary form must reproduce the above copyright
  16. * notice, this list of conditions and the following disclaimer in
  17. * the documentation and/or other materials provided with the
  18. * distribution.
  19. *
  20. * 3. All advertising materials mentioning features or use of this
  21. * software must display the following acknowledgment:
  22. * "This product includes software developed by the OpenSSL Project
  23. * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24. *
  25. * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26. * endorse or promote products derived from this software without
  27. * prior written permission. For written permission, please contact
  28. * licensing@OpenSSL.org.
  29. *
  30. * 5. Products derived from this software may not be called "OpenSSL"
  31. * nor may "OpenSSL" appear in their names without prior written
  32. * permission of the OpenSSL Project.
  33. *
  34. * 6. Redistributions of any form whatsoever must retain the following
  35. * acknowledgment:
  36. * "This product includes software developed by the OpenSSL Project
  37. * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38. *
  39. * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40. * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42. * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43. * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44. * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45. * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46. * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48. * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50. * OF THE POSSIBILITY OF SUCH DAMAGE.
  51. * ====================================================================
  52. *
  53. * This product includes cryptographic software written by Eric Young
  54. * (eay@cryptsoft.com). This product includes software written by Tim
  55. * Hudson (tjh@cryptsoft.com).
  56. *
  57. */
  58. #include <stdio.h>
  59. #include "cryptlib.h"
  60. #include <openssl/asn1t.h>
  61. #include <openssl/bn.h>
  62. /* Custom primitive type for BIGNUM handling. This reads in an ASN1_INTEGER as a
  63. * BIGNUM directly. Currently it ignores the sign which isn't a problem since all
  64. * BIGNUMs used are non negative and anything that looks negative is normally due
  65. * to an encoding error.
  66. */
  67. #define BN_SENSITIVE 1
  68. static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
  69. static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
  70. static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it);
  71. static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it);
  72. static ASN1_PRIMITIVE_FUNCS bignum_pf = {
  73. NULL, 0,
  74. bn_new,
  75. bn_free,
  76. 0,
  77. bn_c2i,
  78. bn_i2c
  79. };
  80. ASN1_ITEM_start(BIGNUM)
  81. ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM"
  82. ASN1_ITEM_end(BIGNUM)
  83. ASN1_ITEM_start(CBIGNUM)
  84. ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, BN_SENSITIVE, "BIGNUM"
  85. ASN1_ITEM_end(CBIGNUM)
  86. static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
  87. {
  88. *pval = (ASN1_VALUE *)BN_new();
  89. if(*pval) return 1;
  90. else return 0;
  91. }
  92. static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
  93. {
  94. if(!*pval) return;
  95. if(it->size & BN_SENSITIVE) BN_clear_free((BIGNUM *)*pval);
  96. else BN_free((BIGNUM *)*pval);
  97. *pval = NULL;
  98. }
  99. static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it)
  100. {
  101. BIGNUM *bn;
  102. int pad;
  103. if(!*pval) return -1;
  104. bn = (BIGNUM *)*pval;
  105. /* If MSB set in an octet we need a padding byte */
  106. if(BN_num_bits(bn) & 0x7) pad = 0;
  107. else pad = 1;
  108. if(cont) {
  109. if(pad) *cont++ = 0;
  110. BN_bn2bin(bn, cont);
  111. }
  112. return pad + BN_num_bytes(bn);
  113. }
  114. static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
  115. int utype, char *free_cont, const ASN1_ITEM *it)
  116. {
  117. BIGNUM *bn;
  118. if(!*pval) bn_new(pval, it);
  119. bn = (BIGNUM *)*pval;
  120. if(!BN_bin2bn(cont, len, bn)) {
  121. bn_free(pval, it);
  122. return 0;
  123. }
  124. return 1;
  125. }