1 // SPDX-License-Identifier: BSD-2-Clause
2 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
3 *
4 * LibTomCrypt is a library that provides various cryptographic
5 * algorithms in a highly modular and flexible manner.
6 *
7 * The library is free for all purposes without any express
8 * guarantee it works.
9 */
10 #include "tomcrypt_private.h"
11
12
13 #ifdef LTC_MDSA
14
15 /**
16 Import DSA's p, q & g from dsaparam
17
18 dsaparam data: openssl dsaparam -outform DER -out dsaparam.der 2048
19
20 @param dsaparam The DSA param DER encoded data
21 @param dsaparamlen The length of dhparam data
22 @param key [out] the destination for the imported key
23 @return CRYPT_OK if successful.
24 */
dsa_set_pqg_dsaparam(const unsigned char * dsaparam,unsigned long dsaparamlen,dsa_key * key)25 int dsa_set_pqg_dsaparam(const unsigned char *dsaparam, unsigned long dsaparamlen,
26 dsa_key *key)
27 {
28 int err, stat;
29
30 LTC_ARGCHK(dsaparam != NULL);
31 LTC_ARGCHK(key != NULL);
32 LTC_ARGCHK(ltc_mp.name != NULL);
33
34 /* init key */
35 err = mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL);
36 if (err != CRYPT_OK) return err;
37
38 if ((err = der_decode_sequence_multi(dsaparam, dsaparamlen,
39 LTC_ASN1_INTEGER, 1UL, key->p,
40 LTC_ASN1_INTEGER, 1UL, key->q,
41 LTC_ASN1_INTEGER, 1UL, key->g,
42 LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
43 goto LBL_ERR;
44 }
45
46 key->qord = mp_unsigned_bin_size(key->q);
47
48 /* quick p, q, g validation, without primality testing */
49 if ((err = dsa_int_validate_pqg(key, &stat)) != CRYPT_OK) {
50 goto LBL_ERR;
51 }
52 if (stat == 0) {
53 err = CRYPT_INVALID_PACKET;
54 goto LBL_ERR;
55 }
56
57 return CRYPT_OK;
58
59 LBL_ERR:
60 dsa_free(key);
61 return err;
62 }
63
64 #endif
65
66 /* ref: $Format:%D$ */
67 /* git commit: $Format:%H$ */
68 /* commit time: $Format:%ai$ */
69