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 const ASN1_ITEM BIGNUM_it = { 90 .itype = ASN1_ITYPE_PRIMITIVE, 91 .utype = V_ASN1_INTEGER, 92 .templates = NULL, 93 .tcount = 0, 94 .funcs = &bignum_pf, 95 .size = 0, 96 .sname = "BIGNUM", 97 }; 98 99 const ASN1_ITEM CBIGNUM_it = { 100 .itype = ASN1_ITYPE_PRIMITIVE, 101 .utype = V_ASN1_INTEGER, 102 .templates = NULL, 103 .tcount = 0, 104 .funcs = &bignum_pf, 105 .size = 0, 106 .sname = "BIGNUM", 107 }; 108 109 static int 110 bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it) 111 { 112 *pval = (ASN1_VALUE *)BN_new(); 113 if (*pval) 114 return 1; 115 else 116 return 0; 117 } 118 119 static void 120 bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it) 121 { 122 if (*pval == NULL) 123 return; 124 BN_clear_free((BIGNUM *)*pval); 125 *pval = NULL; 126 } 127 128 static int 129 bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it) 130 { 131 BIGNUM *bn; 132 int pad, len; 133 134 if (*pval == NULL) 135 return -1; 136 bn = (BIGNUM *)*pval; 137 /* If MSB set in an octet we need a padding byte */ 138 if (BN_num_bits(bn) & 0x7) 139 pad = 0; 140 else 141 pad = 1; 142 if (cont) { 143 if (pad) 144 *cont++ = 0; 145 len = BN_bn2bin(bn, cont); 146 } else 147 len = BN_num_bytes(bn); 148 return pad + len; 149 } 150 151 static int 152 bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, 153 char *free_cont, const ASN1_ITEM *it) 154 { 155 BIGNUM *bn; 156 157 if (*pval == NULL) { 158 if (bn_new(pval, it) == 0) 159 return 0; 160 } 161 bn = (BIGNUM *)*pval; 162 if (!BN_bin2bn(cont, len, bn)) { 163 bn_free(pval, it); 164 return 0; 165 } 166 return 1; 167 } 168