1 /* $OpenBSD: x_bignum.c,v 1.10 2019/04/01 15:49:22 jsing 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 static int bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it, 79 int indent, const ASN1_PCTX *pctx); 80 81 static ASN1_PRIMITIVE_FUNCS bignum_pf = { 82 .app_data = NULL, 83 .flags = 0, 84 .prim_new = bn_new, 85 .prim_free = bn_free, 86 .prim_clear = NULL, /* XXX */ 87 .prim_c2i = bn_c2i, 88 .prim_i2c = bn_i2c, 89 .prim_print = bn_print, 90 }; 91 92 const ASN1_ITEM BIGNUM_it = { 93 .itype = ASN1_ITYPE_PRIMITIVE, 94 .utype = V_ASN1_INTEGER, 95 .templates = NULL, 96 .tcount = 0, 97 .funcs = &bignum_pf, 98 .size = 0, 99 .sname = "BIGNUM", 100 }; 101 102 const ASN1_ITEM CBIGNUM_it = { 103 .itype = ASN1_ITYPE_PRIMITIVE, 104 .utype = V_ASN1_INTEGER, 105 .templates = NULL, 106 .tcount = 0, 107 .funcs = &bignum_pf, 108 .size = 0, 109 .sname = "BIGNUM", 110 }; 111 112 static int 113 bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it) 114 { 115 *pval = (ASN1_VALUE *)BN_new(); 116 if (*pval) 117 return 1; 118 else 119 return 0; 120 } 121 122 static void 123 bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it) 124 { 125 if (*pval == NULL) 126 return; 127 BN_clear_free((BIGNUM *)*pval); 128 *pval = NULL; 129 } 130 131 static int 132 bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it) 133 { 134 BIGNUM *bn; 135 int pad, len; 136 137 if (*pval == NULL) 138 return -1; 139 bn = (BIGNUM *)*pval; 140 /* If MSB set in an octet we need a padding byte */ 141 if (BN_num_bits(bn) & 0x7) 142 pad = 0; 143 else 144 pad = 1; 145 if (cont) { 146 if (pad) 147 *cont++ = 0; 148 len = BN_bn2bin(bn, cont); 149 } else 150 len = BN_num_bytes(bn); 151 return pad + len; 152 } 153 154 static int 155 bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, 156 char *free_cont, const ASN1_ITEM *it) 157 { 158 BIGNUM *bn; 159 160 if (*pval == NULL) { 161 if (bn_new(pval, it) == 0) 162 return 0; 163 } 164 bn = (BIGNUM *)*pval; 165 if (!BN_bin2bn(cont, len, bn)) { 166 bn_free(pval, it); 167 return 0; 168 } 169 return 1; 170 } 171 172 static int 173 bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it, int indent, 174 const ASN1_PCTX *pctx) 175 { 176 BIGNUM *bn = (BIGNUM *)*pval; 177 178 if (!BN_print(out, bn)) 179 return 0; 180 if (BIO_printf(out, "\n") <= 0) 181 return 0; 182 183 return 1; 184 } 185