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comparison libtomcrypt/src/pk/dh/dh_set.c @ 1471:6dba84798cd5

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Update to libtomcrypt 1.18.1, merged with Dropbear changes
author Matt Johnston <matt@ucc.asn.au>
date Fri, 09 Feb 2018 21:44:05 +0800
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1470:8bba51a55704 1471:6dba84798cd5
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 */
9
10 #include "tomcrypt.h"
11
12 #ifdef LTC_MDH
13
14 /**
15 Import DH key parts p and g from raw numbers
16
17 @param p DH's p (prime)
18 @param plen DH's p's length
19 @param g DH's g (group)
20 @param glen DH's g's length
21 @param key [out] the destination for the imported key
22 @return CRYPT_OK if successful
23 */
24 int dh_set_pg(const unsigned char *p, unsigned long plen,
25 const unsigned char *g, unsigned long glen,
26 dh_key *key)
27 {
28 int err;
29
30 LTC_ARGCHK(key != NULL);
31 LTC_ARGCHK(p != NULL);
32 LTC_ARGCHK(g != NULL);
33 LTC_ARGCHK(ltc_mp.name != NULL);
34
35 if ((err = mp_init_multi(&key->x, &key->y, &key->base, &key->prime, NULL)) != CRYPT_OK) {
36 return err;
37 }
38
39 if ((err = mp_read_unsigned_bin(key->base, (unsigned char*)g, glen)) != CRYPT_OK) { goto LBL_ERR; }
40 if ((err = mp_read_unsigned_bin(key->prime, (unsigned char*)p, plen)) != CRYPT_OK) { goto LBL_ERR; }
41
42 return CRYPT_OK;
43
44 LBL_ERR:
45 dh_free(key);
46 return err;
47 }
48
49 /**
50 Import DH key parts p and g from built-in DH groups
51
52 @param groupsize The size of the DH group to use
53 @param key [out] Where the newly created DH key will be stored
54 @return CRYPT_OK if successful, note: on error all allocated memory will be freed automatically.
55 */
56 int dh_set_pg_groupsize(int groupsize, dh_key *key)
57 {
58 int err, i;
59
60 LTC_ARGCHK(key != NULL);
61 LTC_ARGCHK(ltc_mp.name != NULL);
62 LTC_ARGCHK(groupsize > 0);
63
64 for (i = 0; (groupsize > ltc_dh_sets[i].size) && (ltc_dh_sets[i].size != 0); i++);
65 if (ltc_dh_sets[i].size == 0) return CRYPT_INVALID_KEYSIZE;
66
67 if ((err = mp_init_multi(&key->x, &key->y, &key->base, &key->prime, NULL)) != CRYPT_OK) {
68 return err;
69 }
70 if ((err = mp_read_radix(key->base, ltc_dh_sets[i].base, 16)) != CRYPT_OK) { goto LBL_ERR; }
71 if ((err = mp_read_radix(key->prime, ltc_dh_sets[i].prime, 16)) != CRYPT_OK) { goto LBL_ERR; }
72
73 return CRYPT_OK;
74
75 LBL_ERR:
76 dh_free(key);
77 return err;
78 }
79
80 /**
81 Import DH public or private key part from raw numbers
82
83 NB: The p & g parts must be set beforehand
84
85 @param in The key-part to import, either public or private.
86 @param inlen The key-part's length
87 @param type Which type of key (PK_PRIVATE or PK_PUBLIC)
88 @param key [out] the destination for the imported key
89 @return CRYPT_OK if successful
90 */
91 int dh_set_key(const unsigned char *in, unsigned long inlen, int type, dh_key *key)
92 {
93 int err;
94
95 LTC_ARGCHK(key != NULL);
96 LTC_ARGCHK(ltc_mp.name != NULL);
97
98 if (type == PK_PRIVATE) {
99 key->type = PK_PRIVATE;
100 if ((err = mp_read_unsigned_bin(key->x, (unsigned char*)in, inlen)) != CRYPT_OK) { goto LBL_ERR; }
101 if ((err = mp_exptmod(key->base, key->x, key->prime, key->y)) != CRYPT_OK) { goto LBL_ERR; }
102 }
103 else {
104 key->type = PK_PUBLIC;
105 if ((err = mp_read_unsigned_bin(key->y, (unsigned char*)in, inlen)) != CRYPT_OK) { goto LBL_ERR; }
106 }
107
108 /* check public key */
109 if ((err = dh_check_pubkey(key)) != CRYPT_OK) {
110 goto LBL_ERR;
111 }
112
113 return CRYPT_OK;
114
115 LBL_ERR:
116 dh_free(key);
117 return err;
118 }
119
120 #endif /* LTC_MDH */
121
122 /* ref: $Format:%D$ */
123 /* git commit: $Format:%H$ */
124 /* commit time: $Format:%ai$ */