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comparison ecc.c @ 756:bf9dc2d9c2b1 ecc

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more bits on ecc branch
author Matt Johnston <matt@ucc.asn.au>
date Wed, 27 Mar 2013 00:38:03 +0800
parents b07eb3dc23ec
children 230666086711
comparison
equal deleted inserted replaced
755:b07eb3dc23ec 756:bf9dc2d9c2b1
1 #include "includes.h"
2 #include "options.h"
3 #include "ecc.h"
4
1 #ifdef DROPBEAR_ECC 5 #ifdef DROPBEAR_ECC
2 6
7 #ifdef DROPBEAR_ECC_256
8 const struct ecc_curve_secp256r1 {
9 .ltc_set = &ltc_ecc_sets[0],
10 .hash_desc = sha256_desc,
11 .name = "secp256r1"
12 };
13 #endif
14
15
16 #ifdef DROPBEAR_ECC_384
17 const struct ecc_curve_secp384r1 {
18 .ltc_set = &ltc_ecc_sets[1],
19 .hash_desc = sha384_desc,
20 .name = "secp384r1"
21 };
22 #endif
23
24 #ifdef DROPBEAR_ECC_256
25 const struct ecc_curve_secp256r1 {
26 .ltc_set = &ltc_ecc_sets[0],
27 .hash_desc = sha256_desc,
28 .name = "secp256r1"
29 };
30 #endif
31
32
3 void buf_put_ecc_key_string(buffer *buf, ecc_key *key) { 33 void buf_put_ecc_key_string(buffer *buf, ecc_key *key) {
34 // XXX point compression
4 int len = key->dp->size*2 + 1; 35 int len = key->dp->size*2 + 1;
5 buf_putint(len); 36 buf_putint(len);
6 int err = ecc_ansi_x963_export(key, buf_getwriteptr(buf, len), &len); 37 int err = ecc_ansi_x963_export(key, buf_getwriteptr(buf, len), &len);
7 if (err != CRYPT_OK) { 38 if (err != CRYPT_OK) {
8 dropbear_exit("ECC error"); 39 dropbear_exit("ECC error");
11 } 42 }
12 43
13 int buf_get_ecc_key_string(buffer *buf, ecc_key *key) { 44 int buf_get_ecc_key_string(buffer *buf, ecc_key *key) {
14 } 45 }
15 46
47 // a modified version of libtomcrypt's "ecc_shared_secret" to output
48 // a mp_int instead.
49 mp_int * dropbear_ecc_shared_secret(ecc_key *public_key, ecc_key *private_key)
50 {
51 ecc_point *result = NULL
52 mp_int *prime = NULL, *shared_secret = NULL;
53 int ret = DROPBEAR_FAILURE;
54
55 /* type valid? */
56 if (private_key->type != PK_PRIVATE) {
57 goto done;
58 }
59
60 if (private_key->dp != public_key->dp) {
61 goto done;
62 }
63
64 #if 0
65 // XXX - possibly not neccessary tests?
66 if (ltc_ecc_is_valid_idx(private_key->idx) == 0 || ltc_ecc_is_valid_idx(public_key->idx) == 0) {
67 goto done;
68 }
69
70 if (XSTRCMP(private_key->dp->name, public_key->dp->name) != 0) {
71 goto done;
72 }
73 #endif
74
75 /* make new point */
76 result = ltc_ecc_new_point();
77 if (result == NULL) {
78 goto done;
79 }
80
81 prime = m_malloc(sizeof(*prime));
82 m_mp_init(prime);
83
84 if (mp_read_radix(prime, (char *)private_key->dp->prime, 16) != CRYPT_OK) {
85 goto done;
86 }
87 if (ltc_mp.ecc_ptmul(private_key->k, &public_key->pubkey, result, prime, 1) != CRYPT_OK) {
88 goto done;
89 }
90
91 err = DROPBEAR_SUCCESS;
92 done:
93 if (err == DROPBEAR_SUCCESS) {
94 shared_secret = prime;
95 prime = NULL;
96 }
97
98 if (prime) {
99 mp_clear(prime);
100 m_free(prime);
101 }
102 ltc_ecc_del_point(result);
103
104 if (err == DROPBEAR_FAILURE) {
105 dropbear_exit("ECC error");
106 }
107
108 return shared_secret;
109 return err;
110 }
111
112 }
16 113
17 #endif 114 #endif