2 * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
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
11 * DSA low level APIs are deprecated for public use, but still ok for
14 #include "internal/deprecated.h"
18 #include "internal/cryptlib.h"
19 #include <openssl/bn.h>
20 #include <openssl/self_test.h>
21 #include "prov/providercommon.h"
22 #include "crypto/dsa.h"
23 #include "dsa_local.h"
26 # define MIN_STRENGTH 112
28 # define MIN_STRENGTH 80
31 static int dsa_keygen(DSA
*dsa
);
33 int DSA_generate_key(DSA
*dsa
)
36 if (dsa
->meth
->dsa_keygen
!= NULL
)
37 return dsa
->meth
->dsa_keygen(dsa
);
39 return dsa_keygen(dsa
);
42 int ossl_dsa_generate_public_key(BN_CTX
*ctx
, const DSA
*dsa
,
43 const BIGNUM
*priv_key
, BIGNUM
*pub_key
)
46 BIGNUM
*prk
= BN_new();
50 BN_with_flags(prk
, priv_key
, BN_FLG_CONSTTIME
);
52 /* pub_key = g ^ priv_key mod p */
53 if (!BN_mod_exp(pub_key
, dsa
->params
.g
, prk
, dsa
->params
.p
, ctx
))
63 * Refer: FIPS 140-3 IG 10.3.A Additional Comment 1
64 * Perform a KAT by duplicating the public key generation.
66 * NOTE: This issue requires a background understanding, provided in a separate
67 * document; the current IG 10.3.A AC1 is insufficient regarding the PCT for
68 * the key agreement scenario.
70 * Currently IG 10.3.A requires PCT in the mode of use prior to use of the
71 * key pair, citing the PCT defined in the associated standard. For key
72 * agreement, the only PCT defined in SP 800-56A is that of Section 5.6.2.4:
73 * the comparison of the original public key to a newly calculated public key.
75 static int dsa_keygen_knownanswer_test(DSA
*dsa
, BN_CTX
*ctx
,
76 OSSL_CALLBACK
*cb
, void *cbarg
)
79 OSSL_SELF_TEST
*st
= NULL
;
80 unsigned char bytes
[512] = {0};
81 BIGNUM
*pub_key2
= BN_new();
86 st
= OSSL_SELF_TEST_new(cb
, cbarg
);
90 OSSL_SELF_TEST_onbegin(st
, OSSL_SELF_TEST_TYPE_PCT_KAT
,
91 OSSL_SELF_TEST_DESC_PCT_DSA
);
93 if (!ossl_dsa_generate_public_key(ctx
, dsa
, dsa
->priv_key
, pub_key2
))
96 if (BN_num_bytes(pub_key2
) > (int)sizeof(bytes
))
98 len
= BN_bn2bin(pub_key2
, bytes
);
99 OSSL_SELF_TEST_oncorrupt_byte(st
, bytes
);
100 if (BN_bin2bn(bytes
, len
, pub_key2
) != NULL
)
101 ret
= !BN_cmp(dsa
->pub_key
, pub_key2
);
104 OSSL_SELF_TEST_onend(st
, ret
);
105 OSSL_SELF_TEST_free(st
);
111 * FIPS 140-2 IG 9.9 AS09.33
112 * Perform a sign/verify operation.
114 static int dsa_keygen_pairwise_test(DSA
*dsa
, OSSL_CALLBACK
*cb
, void *cbarg
)
117 unsigned char dgst
[16] = {0};
118 unsigned int dgst_len
= (unsigned int)sizeof(dgst
);
120 OSSL_SELF_TEST
*st
= NULL
;
122 st
= OSSL_SELF_TEST_new(cb
, cbarg
);
126 OSSL_SELF_TEST_onbegin(st
, OSSL_SELF_TEST_TYPE_PCT
,
127 OSSL_SELF_TEST_DESC_PCT_DSA
);
129 sig
= DSA_do_sign(dgst
, (int)dgst_len
, dsa
);
133 OSSL_SELF_TEST_oncorrupt_byte(st
, dgst
);
135 if (DSA_do_verify(dgst
, dgst_len
, sig
, dsa
) != 1)
140 OSSL_SELF_TEST_onend(st
, ret
);
141 OSSL_SELF_TEST_free(st
);
145 #endif /* FIPS_MODULE */
147 static int dsa_keygen(DSA
*dsa
)
151 BIGNUM
*pub_key
= NULL
, *priv_key
= NULL
;
153 if ((ctx
= BN_CTX_new_ex(dsa
->libctx
)) == NULL
)
156 if (dsa
->priv_key
== NULL
) {
157 if ((priv_key
= BN_secure_new()) == NULL
)
160 priv_key
= dsa
->priv_key
;
163 /* Do a partial check for invalid p, q, g */
164 if (!ossl_ffc_params_simple_validate(dsa
->libctx
, &dsa
->params
,
165 FFC_PARAM_TYPE_DSA
, NULL
))
169 * For FFC FIPS 186-4 keygen
170 * security strength s = 112,
171 * Max Private key size N = len(q)
173 if (!ossl_ffc_generate_private_key(ctx
, &dsa
->params
,
174 BN_num_bits(dsa
->params
.q
),
175 MIN_STRENGTH
, priv_key
))
178 if (dsa
->pub_key
== NULL
) {
179 if ((pub_key
= BN_new()) == NULL
)
182 pub_key
= dsa
->pub_key
;
185 if (!ossl_dsa_generate_public_key(ctx
, dsa
, priv_key
, pub_key
))
188 dsa
->priv_key
= priv_key
;
189 dsa
->pub_key
= pub_key
;
194 OSSL_CALLBACK
*cb
= NULL
;
197 OSSL_SELF_TEST_get_callback(dsa
->libctx
, &cb
, &cbarg
);
198 ok
= dsa_keygen_pairwise_test(dsa
, cb
, cbarg
)
199 && dsa_keygen_knownanswer_test(dsa
, ctx
, cb
, cbarg
);
201 ossl_set_error_state(OSSL_SELF_TEST_TYPE_PCT
);
202 BN_free(dsa
->pub_key
);
203 BN_clear_free(dsa
->priv_key
);
205 dsa
->priv_key
= NULL
;
214 if (pub_key
!= dsa
->pub_key
)
216 if (priv_key
!= dsa
->priv_key
)