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192.168.1.100 / R306 / 2dbc1526a2b84342aa5d5d2a0b7c25c960d13710 / . / ap / lib / libssl / openssl-1.1.1o / crypto / asn1 / x_bignum.c
blob: c6b3accd3a105defe9b43d83e3c48e964086da23 [file] [log] [blame]
yuezonghe824eb0c2024-06-27 02:32:26 -0700[diff] [blame]1/*
2 * Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <stdio.h>
11#include "internal/cryptlib.h"
12#include <openssl/asn1t.h>
13#include <openssl/bn.h>
14
15/*
16 * Custom primitive type for BIGNUM handling. This reads in an ASN1_INTEGER
17 * as a BIGNUM directly. Currently it ignores the sign which isn't a problem
18 * since all BIGNUMs used are non negative and anything that looks negative
19 * is normally due to an encoding error.
20 */
21
22#define BN_SENSITIVE 1
23
24static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
25static int bn_secure_new(ASN1_VALUE **pval, const ASN1_ITEM *it);
26static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it);
27
28static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
29 const ASN1_ITEM *it);
30static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
31 int utype, char *free_cont, const ASN1_ITEM *it);
32static int bn_secure_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
33 int utype, char *free_cont, const ASN1_ITEM *it);
34static int bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it,
35 int indent, const ASN1_PCTX *pctx);
36
37static ASN1_PRIMITIVE_FUNCS bignum_pf = {
38 NULL, 0,
39 bn_new,
40 bn_free,
41 0,
42 bn_c2i,
43 bn_i2c,
44 bn_print
45};
46
47static ASN1_PRIMITIVE_FUNCS cbignum_pf = {
48 NULL, 0,
49 bn_secure_new,
50 bn_free,
51 0,
52 bn_secure_c2i,
53 bn_i2c,
54 bn_print
55};
56
57ASN1_ITEM_start(BIGNUM)
58 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &bignum_pf, 0, "BIGNUM"
59ASN1_ITEM_end(BIGNUM)
60
61ASN1_ITEM_start(CBIGNUM)
62 ASN1_ITYPE_PRIMITIVE, V_ASN1_INTEGER, NULL, 0, &cbignum_pf, BN_SENSITIVE, "CBIGNUM"
63ASN1_ITEM_end(CBIGNUM)
64
65static int bn_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
66{
67 *pval = (ASN1_VALUE *)BN_new();
68 if (*pval != NULL)
69 return 1;
70 else
71 return 0;
72}
73
74static int bn_secure_new(ASN1_VALUE **pval, const ASN1_ITEM *it)
75{
76 *pval = (ASN1_VALUE *)BN_secure_new();
77 if (*pval != NULL)
78 return 1;
79 else
80 return 0;
81}
82
83static void bn_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
84{
85 if (*pval == NULL)
86 return;
87 if (it->size & BN_SENSITIVE)
88 BN_clear_free((BIGNUM *)*pval);
89 else
90 BN_free((BIGNUM *)*pval);
91 *pval = NULL;
92}
93
94static int bn_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype,
95 const ASN1_ITEM *it)
96{
97 BIGNUM *bn;
98 int pad;
99 if (*pval == NULL)
100 return -1;
101 bn = (BIGNUM *)*pval;
102 /* If MSB set in an octet we need a padding byte */
103 if (BN_num_bits(bn) & 0x7)
104 pad = 0;
105 else
106 pad = 1;
107 if (cont) {
108 if (pad)
109 *cont++ = 0;
110 BN_bn2bin(bn, cont);
111 }
112 return pad + BN_num_bytes(bn);
113}
114
115static int bn_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
116 int utype, char *free_cont, const ASN1_ITEM *it)
117{
118 BIGNUM *bn;
119
120 if (*pval == NULL && !bn_new(pval, it))
121 return 0;
122 bn = (BIGNUM *)*pval;
123 if (!BN_bin2bn(cont, len, bn)) {
124 bn_free(pval, it);
125 return 0;
126 }
127 return 1;
128}
129
130static int bn_secure_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
131 int utype, char *free_cont, const ASN1_ITEM *it)
132{
133 int ret;
134 BIGNUM *bn;
135
136 if (*pval == NULL && !bn_secure_new(pval, it))
137 return 0;
138
139 ret = bn_c2i(pval, cont, len, utype, free_cont, it);
140 if (!ret)
141 return 0;
142
143 /* Set constant-time flag for all secure BIGNUMS */
144 bn = (BIGNUM *)*pval;
145 BN_set_flags(bn, BN_FLG_CONSTTIME);
146 return ret;
147}
148
149static int bn_print(BIO *out, ASN1_VALUE **pval, const ASN1_ITEM *it,
150 int indent, const ASN1_PCTX *pctx)
151{
152 if (!BN_print(out, *(BIGNUM **)pval))
153 return 0;
154 if (BIO_puts(out, "\n") <= 0)
155 return 0;
156 return 1;
157}