summaryrefslogtreecommitdiffstats
path: root/crypto/dsa/dsa_backend.c
blob: f3e54aeb131b0d922419bf6cc58c5c5ebcdc957e (plain)
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
/*
 * Copyright 2020-2021 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (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
 */

/*
 * DSA low level APIs are deprecated for public use, but still ok for
 * internal use.
 */
#include "internal/deprecated.h"

#include <openssl/core_names.h>
#include <openssl/err.h>
#include "crypto/dsa.h"

/*
 * The intention with the "backend" source file is to offer backend support
 * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
 * implementations alike.
 */

int ossl_dsa_key_fromdata(DSA *dsa, const OSSL_PARAM params[])
{
    const OSSL_PARAM *param_priv_key, *param_pub_key;
    BIGNUM *priv_key = NULL, *pub_key = NULL;

    if (dsa == NULL)
        return 0;

    param_priv_key =
        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
    param_pub_key =
        OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);

    /* It's ok if neither half is present */
    if (param_priv_key == NULL && param_pub_key == NULL)
        return 1;

    if (param_pub_key != NULL && !OSSL_PARAM_get_BN(param_pub_key, &pub_key))
        goto err;
    if (param_priv_key != NULL && !OSSL_PARAM_get_BN(param_priv_key, &priv_key))
        goto err;

    if (!DSA_set0_key(dsa, pub_key, priv_key))
        goto err;

    return 1;

 err:
    BN_clear_free(priv_key);
    BN_free(pub_key);
    return 0;
}

#ifndef FIPS_MODULE
DSA *ossl_dsa_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
                             OSSL_LIB_CTX *libctx, const char *propq)
{
    const unsigned char *p, *pm;
    int pklen, pmlen;
    int ptype;
    const void *pval;
    const ASN1_STRING *pstr;
    const X509_ALGOR *palg;
    ASN1_INTEGER *privkey = NULL;
    const BIGNUM *dsa_p, *dsa_g;
    BIGNUM *dsa_pubkey = NULL, *dsa_privkey = NULL;
    BN_CTX *ctx = NULL;

    DSA *dsa = NULL;

    if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8inf))
        return 0;
    X509_ALGOR_get0(NULL, &ptype, &pval, palg);

    if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
        goto decerr;
    if (privkey->type == V_ASN1_NEG_INTEGER || ptype != V_ASN1_SEQUENCE)
        goto decerr;

    pstr = pval;
    pm = pstr->data;
    pmlen = pstr->length;
    if ((dsa = d2i_DSAparams(NULL, &pm, pmlen)) == NULL)
        goto decerr;
    /* We have parameters now set private key */
    if ((dsa_privkey = BN_secure_new()) == NULL
        || !ASN1_INTEGER_to_BN(privkey, dsa_privkey)) {
        ERR_raise(ERR_LIB_DSA, DSA_R_BN_ERROR);
        goto dsaerr;
    }
    /* Calculate public key */
    if ((dsa_pubkey = BN_new()) == NULL) {
        ERR_raise(ERR_LIB_DSA, ERR_R_MALLOC_FAILURE);
        goto dsaerr;
    }
    if ((ctx = BN_CTX_new()) == NULL) {
        ERR_raise(ERR_LIB_DSA, ERR_R_MALLOC_FAILURE);
        goto dsaerr;
    }

    dsa_p = DSA_get0_p(dsa);
    dsa_g = DSA_get0_g(dsa);
    BN_set_flags(dsa_privkey, BN_FLG_CONSTTIME);
    if (!BN_mod_exp(dsa_pubkey, dsa_g, dsa_privkey, dsa_p, ctx)) {
        ERR_raise(ERR_LIB_DSA, DSA_R_BN_ERROR);
        goto dsaerr;
    }
    DSA_set0_key(dsa, dsa_pubkey, dsa_privkey);

    goto done;

 decerr:
    ERR_raise(ERR_LIB_DSA, DSA_R_DECODE_ERROR);
 dsaerr:
    BN_free(dsa_privkey);
    BN_free(dsa_pubkey);
    DSA_free(dsa);
    dsa = NULL;
 done:
    BN_CTX_free(ctx);
    ASN1_STRING_clear_free(privkey);
    return dsa;
}
#endif