1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */
2 /* SPDX-License-Identifier: Unlicense */
3 #include "tomcrypt_private.h"
4
5
6 #ifdef LTC_MDSA
7
8 /**
9 Import DSA's p, q & g from raw numbers
10 @param p DSA's p in binary representation
11 @param plen The length of p
12 @param q DSA's q in binary representation
13 @param qlen The length of q
14 @param g DSA's g in binary representation
15 @param glen The length of g
16 @param key [out] the destination for the imported key
17 @return CRYPT_OK if successful.
18 */
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)19 int dsa_set_pqg(const unsigned char *p, unsigned long plen,
20 const unsigned char *q, unsigned long qlen,
21 const unsigned char *g, unsigned long glen,
22 dsa_key *key)
23 {
24 int err, stat;
25
26 LTC_ARGCHK(p != NULL);
27 LTC_ARGCHK(q != NULL);
28 LTC_ARGCHK(g != NULL);
29 LTC_ARGCHK(key != NULL);
30 LTC_ARGCHK(ltc_mp.name != NULL);
31
32 /* init key */
33 err = mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL);
34 if (err != CRYPT_OK) return err;
35
36 if ((err = mp_read_unsigned_bin(key->p, (unsigned char *)p , plen)) != CRYPT_OK) { goto LBL_ERR; }
37 if ((err = mp_read_unsigned_bin(key->g, (unsigned char *)g , glen)) != CRYPT_OK) { goto LBL_ERR; }
38 if ((err = mp_read_unsigned_bin(key->q, (unsigned char *)q , qlen)) != CRYPT_OK) { goto LBL_ERR; }
39
40 key->qord = mp_unsigned_bin_size(key->q);
41
42 /* do only a quick validation, without primality testing */
43 if ((err = dsa_int_validate_pqg(key, &stat)) != CRYPT_OK) { goto LBL_ERR; }
44 if (stat == 0) {
45 err = CRYPT_INVALID_PACKET;
46 goto LBL_ERR;
47 }
48
49 return CRYPT_OK;
50
51 LBL_ERR:
52 dsa_free(key);
53 return err;
54 }
55
56 /**
57 Import DSA public or private key-part from raw numbers
58
59 NB: The p, q & g parts must be set beforehand
60
61 @param in The key-part to import, either public or private.
62 @param inlen The key-part's length
63 @param type Which type of key (PK_PRIVATE or PK_PUBLIC)
64 @param key [out] the destination for the imported key
65 @return CRYPT_OK if successful.
66 */
dsa_set_key(const unsigned char * in,unsigned long inlen,int type,dsa_key * key)67 int dsa_set_key(const unsigned char *in, unsigned long inlen, int type, dsa_key *key)
68 {
69 int err, stat = 0;
70
71 LTC_ARGCHK(key != NULL);
72 LTC_ARGCHK(key->x != NULL);
73 LTC_ARGCHK(key->y != NULL);
74 LTC_ARGCHK(key->p != NULL);
75 LTC_ARGCHK(key->g != NULL);
76 LTC_ARGCHK(key->q != NULL);
77 LTC_ARGCHK(ltc_mp.name != NULL);
78
79 if (type == PK_PRIVATE) {
80 key->type = PK_PRIVATE;
81 if ((err = mp_read_unsigned_bin(key->x, (unsigned char *)in, inlen)) != CRYPT_OK) { goto LBL_ERR; }
82 if ((err = mp_exptmod(key->g, key->x, key->p, key->y)) != CRYPT_OK) { goto LBL_ERR; }
83 }
84 else {
85 key->type = PK_PUBLIC;
86 if ((err = mp_read_unsigned_bin(key->y, (unsigned char *)in, inlen)) != CRYPT_OK) { goto LBL_ERR; }
87 }
88
89 if ((err = dsa_int_validate_xy(key, &stat)) != CRYPT_OK) { goto LBL_ERR; }
90 if (stat == 0) {
91 err = CRYPT_INVALID_PACKET;
92 goto LBL_ERR;
93 }
94
95 return CRYPT_OK;
96
97 LBL_ERR:
98 dsa_free(key);
99 return err;
100 }
101
102 #endif
103