1 /*
2 * Copyright 2020-2023 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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 /*
11 * DSA low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <openssl/core_names.h>
17 #include <openssl/err.h>
18 #ifndef FIPS_MODULE
19 # include <openssl/x509.h>
20 #endif
21 #include "crypto/dsa.h"
22 #include "dsa_local.h"
23
24 /*
25 * The intention with the "backend" source file is to offer backend support
26 * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
27 * implementations alike.
28 */
29
ossl_dsa_key_fromdata(DSA * dsa,const OSSL_PARAM params[],int include_private)30 int ossl_dsa_key_fromdata(DSA *dsa, const OSSL_PARAM params[],
31 int include_private)
32 {
33 const OSSL_PARAM *param_priv_key = NULL, *param_pub_key;
34 BIGNUM *priv_key = NULL, *pub_key = NULL;
35
36 if (dsa == NULL)
37 return 0;
38
39 if (include_private) {
40 param_priv_key =
41 OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
42 }
43 param_pub_key =
44 OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);
45
46 /* It's ok if neither half is present */
47 if (param_priv_key == NULL && param_pub_key == NULL)
48 return 1;
49
50 if (param_pub_key != NULL && !OSSL_PARAM_get_BN(param_pub_key, &pub_key))
51 goto err;
52 if (param_priv_key != NULL && !OSSL_PARAM_get_BN(param_priv_key, &priv_key))
53 goto err;
54
55 if (!DSA_set0_key(dsa, pub_key, priv_key))
56 goto err;
57
58 return 1;
59
60 err:
61 BN_clear_free(priv_key);
62 BN_free(pub_key);
63 return 0;
64 }
65
ossl_dsa_is_foreign(const DSA * dsa)66 int ossl_dsa_is_foreign(const DSA *dsa)
67 {
68 #ifndef FIPS_MODULE
69 if (dsa->engine != NULL || DSA_get_method((DSA *)dsa) != DSA_OpenSSL())
70 return 1;
71 #endif
72 return 0;
73 }
74
dsa_bn_dup_check(BIGNUM ** out,const BIGNUM * f)75 static ossl_inline int dsa_bn_dup_check(BIGNUM **out, const BIGNUM *f)
76 {
77 if (f != NULL && (*out = BN_dup(f)) == NULL)
78 return 0;
79 return 1;
80 }
81
ossl_dsa_dup(const DSA * dsa,int selection)82 DSA *ossl_dsa_dup(const DSA *dsa, int selection)
83 {
84 DSA *dupkey = NULL;
85
86 /* Do not try to duplicate foreign DSA keys */
87 if (ossl_dsa_is_foreign(dsa))
88 return NULL;
89
90 if ((dupkey = ossl_dsa_new(dsa->libctx)) == NULL)
91 return NULL;
92
93 if ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) != 0
94 && !ossl_ffc_params_copy(&dupkey->params, &dsa->params))
95 goto err;
96
97 dupkey->flags = dsa->flags;
98
99 if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0
100 && ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) == 0
101 || !dsa_bn_dup_check(&dupkey->pub_key, dsa->pub_key)))
102 goto err;
103
104 if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0
105 && ((selection & OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS) == 0
106 || !dsa_bn_dup_check(&dupkey->priv_key, dsa->priv_key)))
107 goto err;
108
109 #ifndef FIPS_MODULE
110 if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_DSA,
111 &dupkey->ex_data, &dsa->ex_data))
112 goto err;
113 #endif
114
115 return dupkey;
116
117 err:
118 DSA_free(dupkey);
119 return NULL;
120 }
121
122 #ifndef FIPS_MODULE
ossl_dsa_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO * p8inf,OSSL_LIB_CTX * libctx,const char * propq)123 DSA *ossl_dsa_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
124 OSSL_LIB_CTX *libctx, const char *propq)
125 {
126 const unsigned char *p, *pm;
127 int pklen, pmlen;
128 int ptype;
129 const void *pval;
130 const ASN1_STRING *pstr;
131 const X509_ALGOR *palg;
132 ASN1_INTEGER *privkey = NULL;
133 const BIGNUM *dsa_p, *dsa_g;
134 BIGNUM *dsa_pubkey = NULL, *dsa_privkey = NULL;
135 BN_CTX *ctx = NULL;
136
137 DSA *dsa = NULL;
138
139 if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8inf))
140 return 0;
141 X509_ALGOR_get0(NULL, &ptype, &pval, palg);
142
143 if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
144 goto decerr;
145 if (privkey->type == V_ASN1_NEG_INTEGER || ptype != V_ASN1_SEQUENCE)
146 goto decerr;
147
148 pstr = pval;
149 pm = pstr->data;
150 pmlen = pstr->length;
151 if ((dsa = d2i_DSAparams(NULL, &pm, pmlen)) == NULL)
152 goto decerr;
153 /* We have parameters now set private key */
154 if ((dsa_privkey = BN_secure_new()) == NULL
155 || !ASN1_INTEGER_to_BN(privkey, dsa_privkey)) {
156 ERR_raise(ERR_LIB_DSA, DSA_R_BN_ERROR);
157 goto dsaerr;
158 }
159 /* Calculate public key */
160 if ((dsa_pubkey = BN_new()) == NULL) {
161 ERR_raise(ERR_LIB_DSA, ERR_R_BN_LIB);
162 goto dsaerr;
163 }
164 if ((ctx = BN_CTX_new()) == NULL) {
165 ERR_raise(ERR_LIB_DSA, ERR_R_BN_LIB);
166 goto dsaerr;
167 }
168
169 dsa_p = DSA_get0_p(dsa);
170 dsa_g = DSA_get0_g(dsa);
171 BN_set_flags(dsa_privkey, BN_FLG_CONSTTIME);
172 if (!BN_mod_exp(dsa_pubkey, dsa_g, dsa_privkey, dsa_p, ctx)) {
173 ERR_raise(ERR_LIB_DSA, DSA_R_BN_ERROR);
174 goto dsaerr;
175 }
176 if (!DSA_set0_key(dsa, dsa_pubkey, dsa_privkey)) {
177 ERR_raise(ERR_LIB_DSA, ERR_R_INTERNAL_ERROR);
178 goto dsaerr;
179 }
180
181 goto done;
182
183 decerr:
184 ERR_raise(ERR_LIB_DSA, DSA_R_DECODE_ERROR);
185 dsaerr:
186 BN_free(dsa_privkey);
187 BN_free(dsa_pubkey);
188 DSA_free(dsa);
189 dsa = NULL;
190 done:
191 BN_CTX_free(ctx);
192 ASN1_STRING_clear_free(privkey);
193 return dsa;
194 }
195 #endif
196
