aboutsummaryrefslogtreecommitdiff
path: root/crypto/dsa/dsa_asn1.c
blob: 6499e87ef31893886d47204021a1c3ee451f9ab8 (plain) (blame)
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
/*
 * Copyright 1999-2016 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 "dsa_locl.h"
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/rand.h>

ASN1_SEQUENCE(DSA_SIG) = {
        ASN1_SIMPLE(DSA_SIG, r, CBIGNUM),
        ASN1_SIMPLE(DSA_SIG, s, CBIGNUM)
} static_ASN1_SEQUENCE_END(DSA_SIG)

IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA_SIG, DSA_SIG, DSA_SIG)

DSA_SIG *DSA_SIG_new(void)
{
    DSA_SIG *sig = OPENSSL_zalloc(sizeof(*sig));
    if (sig == NULL)
        DSAerr(DSA_F_DSA_SIG_NEW, ERR_R_MALLOC_FAILURE);
    return sig;
}

void DSA_SIG_free(DSA_SIG *sig)
{
    if (sig == NULL)
        return;
    BN_clear_free(sig->r);
    BN_clear_free(sig->s);
    OPENSSL_free(sig);
}

void DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps)
{
    if (pr != NULL)
        *pr = sig->r;
    if (ps != NULL)
        *ps = sig->s;
}

int DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s)
{
    if (r == NULL || s == NULL)
        return 0;
    BN_clear_free(sig->r);
    BN_clear_free(sig->s);
    sig->r = r;
    sig->s = s;
    return 1;
}

/* Override the default free and new methods */
static int dsa_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                  void *exarg)
{
    if (operation == ASN1_OP_NEW_PRE) {
        *pval = (ASN1_VALUE *)DSA_new();
        if (*pval != NULL)
            return 2;
        return 0;
    } else if (operation == ASN1_OP_FREE_PRE) {
        DSA_free((DSA *)*pval);
        *pval = NULL;
        return 2;
    }
    return 1;
}

ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
        ASN1_EMBED(DSA, version, INT32),
        ASN1_SIMPLE(DSA, p, BIGNUM),
        ASN1_SIMPLE(DSA, q, BIGNUM),
        ASN1_SIMPLE(DSA, g, BIGNUM),
        ASN1_SIMPLE(DSA, pub_key, BIGNUM),
        ASN1_SIMPLE(DSA, priv_key, CBIGNUM)
} static_ASN1_SEQUENCE_END_cb(DSA, DSAPrivateKey)

IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPrivateKey, DSAPrivateKey)

ASN1_SEQUENCE_cb(DSAparams, dsa_cb) = {
        ASN1_SIMPLE(DSA, p, BIGNUM),
        ASN1_SIMPLE(DSA, q, BIGNUM),
        ASN1_SIMPLE(DSA, g, BIGNUM),
} static_ASN1_SEQUENCE_END_cb(DSA, DSAparams)

IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAparams, DSAparams)

ASN1_SEQUENCE_cb(DSAPublicKey, dsa_cb) = {
        ASN1_SIMPLE(DSA, pub_key, BIGNUM),
        ASN1_SIMPLE(DSA, p, BIGNUM),
        ASN1_SIMPLE(DSA, q, BIGNUM),
        ASN1_SIMPLE(DSA, g, BIGNUM)
} static_ASN1_SEQUENCE_END_cb(DSA, DSAPublicKey)

IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPublicKey, DSAPublicKey)

DSA *DSAparams_dup(DSA *dsa)
{
    return ASN1_item_dup(ASN1_ITEM_rptr(DSAparams), dsa);
}

int DSA_sign(int type, const unsigned char *dgst, int dlen,
             unsigned char *sig, unsigned int *siglen, DSA *dsa)
{
    DSA_SIG *s;

    s = DSA_do_sign(dgst, dlen, dsa);
    if (s == NULL) {
        *siglen = 0;
        return 0;
    }
    *siglen = i2d_DSA_SIG(s, &sig);
    DSA_SIG_free(s);
    return 1;
}

/* data has already been hashed (probably with SHA or SHA-1). */
/*-
 * returns
 *      1: correct signature
 *      0: incorrect signature
 *     -1: error
 */
int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
               const unsigned char *sigbuf, int siglen, DSA *dsa)
{
    DSA_SIG *s;
    const unsigned char *p = sigbuf;
    unsigned char *der = NULL;
    int derlen = -1;
    int ret = -1;

    s = DSA_SIG_new();
    if (s == NULL)
        return ret;
    if (d2i_DSA_SIG(&s, &p, siglen) == NULL)
        goto err;
    /* Ensure signature uses DER and doesn't have trailing garbage */
    derlen = i2d_DSA_SIG(s, &der);
    if (derlen != siglen || memcmp(sigbuf, der, derlen))
        goto err;
    ret = DSA_do_verify(dgst, dgst_len, s, dsa);
 err:
    OPENSSL_clear_free(der, derlen);
    DSA_SIG_free(s);
    return ret;
}