1 /*
2 * Copyright 1995-2023 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 <stdio.h>
17 #include "internal/cryptlib.h"
18 #include <openssl/bn.h>
19 #include "dsa_local.h"
20 #include "crypto/dsa.h"
21
ossl_dsa_check_params(const DSA * dsa,int checktype,int * ret)22 int ossl_dsa_check_params(const DSA *dsa, int checktype, int *ret)
23 {
24 if (checktype == OSSL_KEYMGMT_VALIDATE_QUICK_CHECK)
25 return ossl_ffc_params_simple_validate(dsa->libctx, &dsa->params,
26 FFC_PARAM_TYPE_DSA, ret);
27 else
28 /*
29 * Do full FFC domain params validation according to FIPS-186-4
30 * - always in FIPS_MODULE
31 * - only if possible (i.e., seed is set) in default provider
32 */
33 return ossl_ffc_params_full_validate(dsa->libctx, &dsa->params,
34 FFC_PARAM_TYPE_DSA, ret);
35 }
36
37 /*
38 * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Full public key validation.
39 */
ossl_dsa_check_pub_key(const DSA * dsa,const BIGNUM * pub_key,int * ret)40 int ossl_dsa_check_pub_key(const DSA *dsa, const BIGNUM *pub_key, int *ret)
41 {
42 return ossl_ffc_validate_public_key(&dsa->params, pub_key, ret)
43 && *ret == 0;
44 }
45
46 /*
47 * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Partial public key validation.
48 * To only be used with ephemeral FFC public keys generated using the approved
49 * safe-prime groups.
50 */
ossl_dsa_check_pub_key_partial(const DSA * dsa,const BIGNUM * pub_key,int * ret)51 int ossl_dsa_check_pub_key_partial(const DSA *dsa, const BIGNUM *pub_key, int *ret)
52 {
53 return ossl_ffc_validate_public_key_partial(&dsa->params, pub_key, ret)
54 && *ret == 0;
55 }
56
ossl_dsa_check_priv_key(const DSA * dsa,const BIGNUM * priv_key,int * ret)57 int ossl_dsa_check_priv_key(const DSA *dsa, const BIGNUM *priv_key, int *ret)
58 {
59 *ret = 0;
60
61 return (dsa->params.q != NULL
62 && ossl_ffc_validate_private_key(dsa->params.q, priv_key, ret));
63 }
64
65 /*
66 * FFC pairwise check from SP800-56A R3.
67 * Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency
68 */
ossl_dsa_check_pairwise(const DSA * dsa)69 int ossl_dsa_check_pairwise(const DSA *dsa)
70 {
71 int ret = 0;
72 BN_CTX *ctx = NULL;
73 BIGNUM *pub_key = NULL;
74
75 if (dsa->params.p == NULL
76 || dsa->params.g == NULL
77 || dsa->priv_key == NULL
78 || dsa->pub_key == NULL)
79 return 0;
80
81 ctx = BN_CTX_new_ex(dsa->libctx);
82 if (ctx == NULL)
83 goto err;
84 pub_key = BN_new();
85 if (pub_key == NULL)
86 goto err;
87
88 /* recalculate the public key = (g ^ priv) mod p */
89 if (!ossl_dsa_generate_public_key(ctx, dsa, dsa->priv_key, pub_key))
90 goto err;
91 /* check it matches the existing pubic_key */
92 ret = BN_cmp(pub_key, dsa->pub_key) == 0;
93 err:
94 BN_free(pub_key);
95 BN_CTX_free(ctx);
96 return ret;
97 }
98