1 /* $OpenBSD: x_bignum.c,v 1.7 2014/07/12 16:42:47 miod Exp $ */ 2 /* Written by Dr Stephen N Henson (steve@openssl.org) 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 59 #include <stdio.h> 60 61 #include <openssl/asn1t.h> 62 #include <openssl/bn.h> 63 64 /* 65 * Custom primitive type for BIGNUM handling. This reads in an ASN1_INTEGER as a 66 * BIGNUM directly. Currently it ignores the sign which isn't a problem since 67 * all BIGNUMs used are non negative and anything that looks negative is 68 * normally due to an encoding error. 69 */ 70 71 static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it); 72 static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it); 73 74 static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, 75 const ASN1_ITEM *it); 76 static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 77 int utype, char *free_cont, const ASN1_ITEM *it); 78 79 static ASN1_PRIMITIVE_FUNCS bignum_pf = { 80 NULL, 81 0, 82 bn_new, 83 bn_free, 84 0, 85 bn_c2i, 86 bn_i2c 87 }; 88 89 ASN1_ITEM_start(BIGNUM) 90 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM" 91 ASN1_ITEM_end(BIGNUM) 92 93 ASN1_ITEM_start(CBIGNUM) 94 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM" 95 ASN1_ITEM_end(CBIGNUM) 96 97 static int 98 bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it) 99 { 100 *pval = (ASN1_VALUE *)BN_new(); 101 if (*pval) 102 return 1; 103 else 104 return 0; 105 } 106 107 static void 108 bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it) 109 { 110 if (*pval == NULL) 111 return; 112 BN_clear_free((BIGNUM *)*pval); 113 *pval = NULL; 114 } 115 116 static int 117 bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it) 118 { 119 BIGNUM *bn; 120 int pad, len; 121 122 if (*pval == NULL) 123 return -1; 124 bn = (BIGNUM *)*pval; 125 /* If MSB set in an octet we need a padding byte */ 126 if (BN_num_bits(bn) & 0x7) 127 pad = 0; 128 else 129 pad = 1; 130 if (cont) { 131 if (pad) 132 *cont++ = 0; 133 len = BN_bn2bin(bn, cont); 134 } else 135 len = BN_num_bytes(bn); 136 return pad + len; 137 } 138 139 static int 140 bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, 141 char *free_cont, const ASN1_ITEM *it) 142 { 143 BIGNUM *bn; 144 145 if (*pval == NULL) { 146 if (bn_new(pval, it) == 0) 147 return 0; 148 } 149 bn = (BIGNUM *)*pval; 150 if (!BN_bin2bn(cont, len, bn)) { 151 bn_free(pval, it); 152 return 0; 153 } 154 return 1; 155 } 156