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 raw numbers
17 @param p DSA's p in binary representation
18 @param plen The length of p
19 @param q DSA's q in binary representation
20 @param qlen The length of q
21 @param g DSA's g in binary representation
22 @param glen The length of g
23 @param key [out] the destination for the imported key
24 @return CRYPT_OK if successful.
25 */
dsa_set_pqg(const unsigned char * p,unsigned long plen,const unsigned char * q,unsigned long qlen,const unsigned char * g,unsigned long glen,dsa_key * key)26 int dsa_set_pqg(const unsigned char *p, unsigned long plen,
27 const unsigned char *q, unsigned long qlen,
28 const unsigned char *g, unsigned long glen,
29 dsa_key *key)
30 {
31 int err, stat;
32
33 LTC_ARGCHK(p != NULL);
34 LTC_ARGCHK(q != NULL);
35 LTC_ARGCHK(g != NULL);
36 LTC_ARGCHK(key != NULL);
37 LTC_ARGCHK(ltc_mp.name != NULL);
38
39 /* init key */
40 err = mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL);
41 if (err != CRYPT_OK) return err;
42
43 if ((err = mp_read_unsigned_bin(key->p, (unsigned char *)p , plen)) != CRYPT_OK) { goto LBL_ERR; }
44 if ((err = mp_read_unsigned_bin(key->g, (unsigned char *)g , glen)) != CRYPT_OK) { goto LBL_ERR; }
45 if ((err = mp_read_unsigned_bin(key->q, (unsigned char *)q , qlen)) != CRYPT_OK) { goto LBL_ERR; }
46
47 key->qord = mp_unsigned_bin_size(key->q);
48
49 /* do only a quick validation, without primality testing */
50 if ((err = dsa_int_validate_pqg(key, &stat)) != CRYPT_OK) { goto LBL_ERR; }
51 if (stat == 0) {
52 err = CRYPT_INVALID_PACKET;
53 goto LBL_ERR;
54 }
55
56 return CRYPT_OK;
57
58 LBL_ERR:
59 dsa_free(key);
60 return err;
61 }
62
63 /**
64 Import DSA public or private key-part from raw numbers
65
66 NB: The p, q & g parts must be set beforehand
67
68 @param in The key-part to import, either public or private.
69 @param inlen The key-part's length
70 @param type Which type of key (PK_PRIVATE or PK_PUBLIC)
71 @param key [out] the destination for the imported key
72 @return CRYPT_OK if successful.
73 */
dsa_set_key(const unsigned char * in,unsigned long inlen,int type,dsa_key * key)74 int dsa_set_key(const unsigned char *in, unsigned long inlen, int type, dsa_key *key)
75 {
76 int err, stat = 0;
77
78 LTC_ARGCHK(key != NULL);
79 LTC_ARGCHK(key->x != NULL);
80 LTC_ARGCHK(key->y != NULL);
81 LTC_ARGCHK(key->p != NULL);
82 LTC_ARGCHK(key->g != NULL);
83 LTC_ARGCHK(key->q != NULL);
84 LTC_ARGCHK(ltc_mp.name != NULL);
85
86 if (type == PK_PRIVATE) {
87 key->type = PK_PRIVATE;
88 if ((err = mp_read_unsigned_bin(key->x, (unsigned char *)in, inlen)) != CRYPT_OK) { goto LBL_ERR; }
89 if ((err = mp_exptmod(key->g, key->x, key->p, key->y)) != CRYPT_OK) { goto LBL_ERR; }
90 }
91 else {
92 key->type = PK_PUBLIC;
93 if ((err = mp_read_unsigned_bin(key->y, (unsigned char *)in, inlen)) != CRYPT_OK) { goto LBL_ERR; }
94 }
95
96 if ((err = dsa_int_validate_xy(key, &stat)) != CRYPT_OK) { goto LBL_ERR; }
97 if (stat == 0) {
98 err = CRYPT_INVALID_PACKET;
99 goto LBL_ERR;
100 }
101
102 return CRYPT_OK;
103
104 LBL_ERR:
105 dsa_free(key);
106 return err;
107 }
108
109 #endif
110
111 /* ref: $Format:%D$ */
112 /* git commit: $Format:%H$ */
113 /* commit time: $Format:%ai$ */
114