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 59 #include <stdio.h> 60 #include "cryptlib.h" 61 #include <openssl/asn1t.h> 62 63 /* Custom primitive type for BIGNUM handling. This reads in an ASN1_INTEGER as a 64 * BIGNUM directly. Currently it ignores the sign which isn't a problem since all 65 * BIGNUMs used are non negative and anything that looks negative is normally due 66 * to an encoding error. 67 */ 68 69 #define BN_SENSITIVE 1 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, const ASN1_ITEM *it); 75 static int bn_c2i(ASN1_VALUE **pval, unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it); 76 77 static ASN1_PRIMITIVE_FUNCS bignum_pf = { 78 NULL, 0, 79 bn_new, 80 bn_free, 81 0, 82 bn_c2i, 83 bn_i2c 84 }; 85 86 ASN1_ITEM_start(BIGNUM) 87 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM" 88 ASN1_ITEM_end(BIGNUM) 89 90 ASN1_ITEM_start(CBIGNUM) 91 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, BN_SENSITIVE, "BIGNUM" 92 ASN1_ITEM_end(CBIGNUM) 93 94 static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it) 95 { 96 *pval = (ASN1_VALUE *)BN_new(); 97 if(*pval) return 1; 98 else return 0; 99 } 100 101 static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it) 102 { 103 if(!*pval) return; 104 if(it->size & BN_SENSITIVE) BN_clear_free((BIGNUM *)*pval); 105 else BN_free((BIGNUM *)*pval); 106 *pval = NULL; 107 } 108 109 static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it) 110 { 111 BIGNUM *bn; 112 int pad; 113 if(!*pval) return -1; 114 bn = (BIGNUM *)*pval; 115 /* If MSB set in an octet we need a padding byte */ 116 if(BN_num_bits(bn) & 0x7) pad = 0; 117 else pad = 1; 118 if(cont) { 119 if(pad) *cont++ = 0; 120 BN_bn2bin(bn, cont); 121 } 122 return pad + BN_num_bytes(bn); 123 } 124 125 static int bn_c2i(ASN1_VALUE **pval, unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it) 126 { 127 BIGNUM *bn; 128 if(!*pval) bn_new(pval, it); 129 bn = (BIGNUM *)*pval; 130 if(!BN_bin2bn(cont, len, bn)) { 131 bn_free(pval, it); 132 return 0; 133 } 134 return 1; 135 } 136 137 138