1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay (at) cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 8 * This library is free for commercial and non-commercial use as long as 9 * the following conditions are aheared to. The following conditions 10 * apply to all code found in this distribution, be it the RC4, RSA, 11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * included with this distribution is covered by the same copyright terms 13 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 14 * 15 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * the code are not to be removed. 17 * If this package is used in a product, Eric Young should be given attribution 18 * as the author of the parts of the library used. 19 * This can be in the form of a textual message at program startup or 20 * in documentation (online or textual) provided with the package. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * "This product includes cryptographic software written by 33 * Eric Young (eay (at) cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * The licence and distribution terms for any publically available version or 53 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * copied and put under another distribution licence 55 * [including the GNU Public Licence.] */ 56 57 #include <openssl/asn1.h> 58 59 #include <openssl/asn1t.h> 60 #include <openssl/bn.h> 61 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, const unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it); 76 77 static const ASN1_PRIMITIVE_FUNCS bignum_pf = { 78 NULL, 0, 79 bn_new, 80 bn_free, 81 0, 82 bn_c2i, 83 bn_i2c, 84 NULL /* prim_print */, 85 }; 86 87 ASN1_ITEM_start(BIGNUM) 88 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM" 89 ASN1_ITEM_end(BIGNUM) 90 91 ASN1_ITEM_start(CBIGNUM) 92 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, BN_SENSITIVE, "BIGNUM" 93 ASN1_ITEM_end(CBIGNUM) 94 95 static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it) 96 { 97 *pval = (ASN1_VALUE *)BN_new(); 98 if(*pval) return 1; 99 else return 0; 100 } 101 102 static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it) 103 { 104 if(!*pval) return; 105 if(it->size & BN_SENSITIVE) BN_clear_free((BIGNUM *)*pval); 106 else BN_free((BIGNUM *)*pval); 107 *pval = NULL; 108 } 109 110 static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it) 111 { 112 BIGNUM *bn; 113 int pad; 114 if(!*pval) return -1; 115 bn = (BIGNUM *)*pval; 116 /* If MSB set in an octet we need a padding byte */ 117 if(BN_num_bits(bn) & 0x7) pad = 0; 118 else pad = 1; 119 if(cont) { 120 if(pad) *cont++ = 0; 121 BN_bn2bin(bn, cont); 122 } 123 return pad + BN_num_bytes(bn); 124 } 125 126 static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, 127 int utype, char *free_cont, const ASN1_ITEM *it) 128 { 129 BIGNUM *bn; 130 if(!*pval) 131 { 132 if (!bn_new(pval, it)) 133 { 134 return 0; 135 } 136 } 137 bn = (BIGNUM *)*pval; 138 if(!BN_bin2bn(cont, len, bn)) { 139 bn_free(pval, it); 140 return 0; 141 } 142 return 1; 143 } 144