1/* x_bignum.c */ 2/* 3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project 4 * 2000. 5 */ 6/* ==================================================================== 7 * Copyright (c) 2000 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * licensing@OpenSSL.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59 60#include <stdio.h> 61#include "cryptlib.h" 62#include <openssl/asn1t.h> 63#include <openssl/bn.h> 64 65/* 66 * Custom primitive type for BIGNUM handling. This reads in an ASN1_INTEGER 67 * as a BIGNUM directly. Currently it ignores the sign which isn't a problem 68 * since all BIGNUMs used are non negative and anything that looks negative 69 * is normally due to an encoding error. 70 */ 71 72#define BN_SENSITIVE 1 73 74static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it); 75static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it); 76 77static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, 78 const ASN1_ITEM *it); 79static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 80 int utype, char *free_cont, const ASN1_ITEM *it); 81 82static ASN1_PRIMITIVE_FUNCS bignum_pf = { 83 NULL, 0, 84 bn_new, 85 bn_free, 86 0, 87 bn_c2i, 88 bn_i2c 89}; 90 91ASN1_ITEM_start(BIGNUM) 92 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM" 93ASN1_ITEM_end(BIGNUM) 94 95ASN1_ITEM_start(CBIGNUM) 96 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, BN_SENSITIVE, "BIGNUM" 97ASN1_ITEM_end(CBIGNUM) 98 99static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it) 100{ 101 *pval = (ASN1_VALUE *)BN_new(); 102 if (*pval) 103 return 1; 104 else 105 return 0; 106} 107 108static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it) 109{ 110 if (!*pval) 111 return; 112 if (it->size & BN_SENSITIVE) 113 BN_clear_free((BIGNUM *)*pval); 114 else 115 BN_free((BIGNUM *)*pval); 116 *pval = NULL; 117} 118 119static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, 120 const ASN1_ITEM *it) 121{ 122 BIGNUM *bn; 123 int pad; 124 if (!*pval) 125 return -1; 126 bn = (BIGNUM *)*pval; 127 /* If MSB set in an octet we need a padding byte */ 128 if (BN_num_bits(bn) & 0x7) 129 pad = 0; 130 else 131 pad = 1; 132 if (cont) { 133 if (pad) 134 *cont++ = 0; 135 BN_bn2bin(bn, cont); 136 } 137 return pad + BN_num_bytes(bn); 138} 139 140static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 141 int utype, char *free_cont, const ASN1_ITEM *it) 142{ 143 BIGNUM *bn; 144 145 if (*pval == NULL && !bn_new(pval, it)) 146 return 0; 147 bn = (BIGNUM *)*pval; 148 if (!BN_bin2bn(cont, len, bn)) { 149 bn_free(pval, it); 150 return 0; 151 } 152 return 1; 153} 154