1 /* $OpenBSD: x_bignum.c,v 1.15 2024/07/08 16:24:22 beck 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 #include "asn1_local.h"
65 #include "bytestring.h"
66
67 /*
68 * Custom primitive type for that reads an ASN.1 INTEGER into a BIGNUM.
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 static void bn_clear(ASN1_VALUE **pval, const ASN1_ITEM *it);
74
75 static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
76 const ASN1_ITEM *it);
77 static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
78 int utype, char *free_cont, const ASN1_ITEM *it);
79 static int bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it,
80 int indent, const ASN1_PCTX *pctx);
81
82 static const ASN1_PRIMITIVE_FUNCS bignum_pf = {
83 .app_data = NULL,
84 .flags = 0,
85 .prim_new = bn_new,
86 .prim_free = bn_free,
87 .prim_clear = bn_clear,
88 .prim_c2i = bn_c2i,
89 .prim_i2c = bn_i2c,
90 .prim_print = bn_print,
91 };
92
93 const ASN1_ITEM BIGNUM_it = {
94 .itype = ASN1_ITYPE_PRIMITIVE,
95 .utype = V_ASN1_INTEGER,
96 .templates = NULL,
97 .tcount = 0,
98 .funcs = &bignum_pf,
99 .size = 0,
100 .sname = "BIGNUM",
101 };
102 LCRYPTO_ALIAS(BIGNUM_it);
103
104 const ASN1_ITEM CBIGNUM_it = {
105 .itype = ASN1_ITYPE_PRIMITIVE,
106 .utype = V_ASN1_INTEGER,
107 .templates = NULL,
108 .tcount = 0,
109 .funcs = &bignum_pf,
110 .size = 0,
111 .sname = "BIGNUM",
112 };
113 LCRYPTO_ALIAS(CBIGNUM_it);
114
115 static int
bn_new(ASN1_VALUE ** pval,const ASN1_ITEM * it)116 bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
117 {
118 if ((*pval = (ASN1_VALUE *)BN_new()) == NULL)
119 return 0;
120
121 return 1;
122 }
123
124 static void
bn_clear(ASN1_VALUE ** pval,const ASN1_ITEM * it)125 bn_clear(ASN1_VALUE **pval, const ASN1_ITEM *it)
126 {
127 BN_free((BIGNUM *)*pval);
128 *pval = NULL;
129 }
130
131 static void
bn_free(ASN1_VALUE ** pval,const ASN1_ITEM * it)132 bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
133 {
134 if (*pval == NULL)
135 return;
136
137 bn_clear(pval, it);
138 }
139
140 static int
bn_i2c(ASN1_VALUE ** pval,unsigned char * content,int * putype,const ASN1_ITEM * it)141 bn_i2c(ASN1_VALUE **pval, unsigned char *content, int *putype, const ASN1_ITEM *it)
142 {
143 ASN1_INTEGER *aint = NULL;
144 unsigned char **pp = NULL;
145 const BIGNUM *bn;
146 int ret;
147
148 if (*pval == NULL)
149 return -1;
150
151 bn = (const BIGNUM *)*pval;
152
153 if ((aint = BN_to_ASN1_INTEGER(bn, NULL)) == NULL)
154 return -1;
155
156 if (content != NULL)
157 pp = &content;
158
159 ret = i2c_ASN1_INTEGER(aint, pp);
160
161 ASN1_INTEGER_free(aint);
162
163 return ret;
164 }
165
166 static int
bn_c2i(ASN1_VALUE ** pval,const unsigned char * content,int len,int utype,char * free_content,const ASN1_ITEM * it)167 bn_c2i(ASN1_VALUE **pval, const unsigned char *content, int len, int utype,
168 char *free_content, const ASN1_ITEM *it)
169 {
170 ASN1_INTEGER *aint = NULL;
171 BIGNUM *bn;
172 CBS cbs;
173 int ret = 0;
174
175 bn_clear(pval, it);
176
177 if (len < 0)
178 goto err;
179 CBS_init(&cbs, content, len);
180 if (!c2i_ASN1_INTEGER_cbs(&aint, &cbs))
181 goto err;
182
183 if ((bn = ASN1_INTEGER_to_BN(aint, NULL)) == NULL)
184 goto err;
185 *pval = (ASN1_VALUE *)bn;
186
187 ret = 1;
188
189 err:
190 ASN1_INTEGER_free(aint);
191
192 return ret;
193 }
194
195 static int
bn_print(BIO * out,ASN1_VALUE ** pval,const ASN1_ITEM * it,int indent,const ASN1_PCTX * pctx)196 bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it, int indent,
197 const ASN1_PCTX *pctx)
198 {
199 const BIGNUM *bn = (BIGNUM *)*pval;
200
201 if (!BN_print(out, bn))
202 return 0;
203 if (BIO_printf(out, "\n") <= 0)
204 return 0;
205
206 return 1;
207 }
208