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