1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@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@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@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@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
ASN1_ITEM_start(BIGNUM)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
bn_free(ASN1_VALUE ** pval,const ASN1_ITEM * it)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
bn_i2c(ASN1_VALUE ** pval,unsigned char * cont,int * putype,const ASN1_ITEM * it)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
bn_c2i(ASN1_VALUE ** pval,const unsigned char * cont,int len,int utype,char * free_cont,const ASN1_ITEM * it)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