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
bn_new(ASN1_VALUE ** pval,const ASN1_ITEM * it)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
bn_free(ASN1_VALUE ** pval,const ASN1_ITEM * it)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
bn_i2c(ASN1_VALUE ** pval,unsigned char * cont,int * putype,const ASN1_ITEM * it)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
bn_c2i(ASN1_VALUE ** pval,const unsigned char * cont,int len,int utype,char * free_cont,const ASN1_ITEM * it)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
bn_print(BIO * out,ASN1_VALUE ** pval,const ASN1_ITEM * it,int indent,const ASN1_PCTX * pctx)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