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
11 #include "tomcrypt_private.h"
12
13 #ifdef LTC_MDH
14
15 /**
16 Import DH key parts p and g from dhparam
17
18 dhparam data: openssl dhparam -outform DER -out dhparam.der 2048
19
20 @param dhparam The DH param DER encoded data
21 @param dhparamlen The length of dhparam data
22 @param key [out] Where the newly created DH key will be stored
23 @return CRYPT_OK if successful, note: on error all allocated memory will be freed automatically.
24 */
dh_set_pg_dhparam(const unsigned char * dhparam,unsigned long dhparamlen,dh_key * key)25 int dh_set_pg_dhparam(const unsigned char *dhparam, unsigned long dhparamlen, dh_key *key)
26 {
27 int err;
28
29 LTC_ARGCHK(key != NULL);
30 LTC_ARGCHK(ltc_mp.name != NULL);
31 LTC_ARGCHK(dhparam != NULL);
32 LTC_ARGCHK(dhparamlen > 0);
33
34 if ((err = mp_init_multi(&key->x, &key->y, &key->base, &key->prime, NULL)) != CRYPT_OK) {
35 return err;
36 }
37 if ((err = der_decode_sequence_multi(dhparam, dhparamlen,
38 LTC_ASN1_INTEGER, 1UL, key->prime,
39 LTC_ASN1_INTEGER, 1UL, key->base,
40 LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
41 goto LBL_ERR;
42 }
43
44 return CRYPT_OK;
45
46 LBL_ERR:
47 dh_free(key);
48 return err;
49 }
50
51 #endif /* LTC_MDH */
52
53 /* ref: $Format:%D$ */
54 /* git commit: $Format:%H$ */
55 /* commit time: $Format:%ai$ */
56