x_bignum.c revision 356290
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) 2000-2019 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); 81static int bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it, 82 int indent, const ASN1_PCTX *pctx); 83 84static ASN1_PRIMITIVE_FUNCS bignum_pf = { 85 NULL, 0, 86 bn_new, 87 bn_free, 88 0, 89 bn_c2i, 90 bn_i2c, 91 bn_print 92}; 93 94ASN1_ITEM_start(BIGNUM) 95 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM" 96ASN1_ITEM_end(BIGNUM) 97 98ASN1_ITEM_start(CBIGNUM) 99 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, BN_SENSITIVE, "BIGNUM" 100ASN1_ITEM_end(CBIGNUM) 101 102static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it) 103{ 104 *pval = (ASN1_VALUE *)BN_new(); 105 if (*pval != NULL) 106 return 1; 107 else 108 return 0; 109} 110 111static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it) 112{ 113 if (*pval == NULL) 114 return; 115 if (it->size & BN_SENSITIVE) 116 BN_clear_free((BIGNUM *)*pval); 117 else 118 BN_free((BIGNUM *)*pval); 119 *pval = NULL; 120} 121 122static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, 123 const ASN1_ITEM *it) 124{ 125 BIGNUM *bn; 126 int pad; 127 if (*pval == NULL) 128 return -1; 129 bn = (BIGNUM *)*pval; 130 /* If MSB set in an octet we need a padding byte */ 131 if (BN_num_bits(bn) & 0x7) 132 pad = 0; 133 else 134 pad = 1; 135 if (cont) { 136 if (pad) 137 *cont++ = 0; 138 BN_bn2bin(bn, cont); 139 } 140 return pad + BN_num_bytes(bn); 141} 142 143static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 144 int utype, char *free_cont, const ASN1_ITEM *it) 145{ 146 BIGNUM *bn; 147 148 if (*pval == NULL && !bn_new(pval, it)) 149 return 0; 150 bn = (BIGNUM *)*pval; 151 if (!BN_bin2bn(cont, len, bn)) { 152 bn_free(pval, it); 153 return 0; 154 } 155 return 1; 156} 157 158static int bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it, 159 int indent, const ASN1_PCTX *pctx) 160{ 161 if (!BN_print(out, *(BIGNUM **)pval)) 162 return 0; 163 if (BIO_puts(out, "\n") <= 0) 164 return 0; 165 return 1; 166} 167