annotate dsa_make_key.c @ 0:d7da3b1e1540 libtomcrypt

put back the 0.95 makefile which was inadvertently merged over
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:21:40 +0000
parents
children 5d99163f7e32
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
2 *
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
3 * LibTomCrypt is a library that provides various cryptographic
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
4 * algorithms in a highly modular and flexible manner.
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
5 *
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
6 * The library is free for all purposes without any express
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
7 * guarantee it works.
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
8 *
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
9 * Tom St Denis, [email protected], http://libtomcrypt.org
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
10 */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
11 #include "mycrypt.h"
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 #ifdef MDSA
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
14
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
15 int dsa_make_key(prng_state *prng, int wprng, int group_size, int modulus_size, dsa_key *key)
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
16 {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
17 mp_int tmp, tmp2;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18 int err, res;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19 unsigned char buf[512];
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21 _ARGCHK(key != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
22
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23 /* check prng */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24 if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 return err;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
26 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
28 /* check size */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29 if (group_size >= 1024 || group_size <= 15 ||
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
30 group_size >= modulus_size || (modulus_size - group_size) >= (int)sizeof(buf)) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
31 return CRYPT_INVALID_ARG;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
32 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
33
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
34 /* init mp_ints */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
35 if ((err = mp_init_multi(&tmp, &tmp2, &key->g, &key->q, &key->p, &key->x, &key->y, NULL)) != MP_OKAY) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
36 return mpi_to_ltc_error(err);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
37 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
38
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
39 /* make our prime q */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
40 if ((err = rand_prime(&key->q, group_size*8, prng, wprng)) != CRYPT_OK) { goto error2; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
41
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
42 /* double q */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
43 if ((err = mp_mul_2(&key->q, &tmp)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
44
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
45 /* now make a random string and multply it against q */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
46 if (prng_descriptor[wprng].read(buf+1, modulus_size - group_size, prng) != (unsigned long)(modulus_size - group_size)) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
47 err = CRYPT_ERROR_READPRNG;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
48 goto error2;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
49 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
50
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
51 /* force magnitude */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
52 buf[0] = 1;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
53
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
54 /* force even */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
55 buf[modulus_size - group_size] &= ~1;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
56
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
57 if ((err = mp_read_unsigned_bin(&tmp2, buf, modulus_size - group_size+1)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
58 if ((err = mp_mul(&key->q, &tmp2, &key->p)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
59 if ((err = mp_add_d(&key->p, 1, &key->p)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
60
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
61 /* now loop until p is prime */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
62 for (;;) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
63 if ((err = is_prime(&key->p, &res)) != CRYPT_OK) { goto error2; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
64 if (res == MP_YES) break;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
65
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
66 /* add 2q to p and 2 to tmp2 */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
67 if ((err = mp_add(&tmp, &key->p, &key->p)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
68 if ((err = mp_add_d(&tmp2, 2, &tmp2)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
69 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
70
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
71 /* now p = (q * tmp2) + 1 is prime, find a value g for which g^tmp2 != 1 */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
72 mp_set(&key->g, 1);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
73
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
74 do {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
75 if ((err = mp_add_d(&key->g, 1, &key->g)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
76 if ((err = mp_exptmod(&key->g, &tmp2, &key->p, &tmp)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
77 } while (mp_cmp_d(&tmp, 1) == MP_EQ);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
78
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
79 /* at this point tmp generates a group of order q mod p */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
80 mp_exch(&tmp, &key->g);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
81
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
82 /* so now we have our DH structure, generator g, order q, modulus p
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
83 Now we need a random exponent [mod q] and it's power g^x mod p
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
84 */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
85 do {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
86 if (prng_descriptor[wprng].read(buf, group_size, prng) != (unsigned long)group_size) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
87 err = CRYPT_ERROR_READPRNG;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
88 goto error2;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
89 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
90 if ((err = mp_read_unsigned_bin(&key->x, buf, group_size)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
91 } while (mp_cmp_d(&key->x, 1) != MP_GT);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
92 if ((err = mp_exptmod(&key->g, &key->x, &key->p, &key->y)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
93
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
94 key->type = PK_PRIVATE;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
95 key->qord = group_size;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
96
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
97 /* shrink the ram required */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
98 if ((err = mp_shrink(&key->g)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
99 if ((err = mp_shrink(&key->p)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
100 if ((err = mp_shrink(&key->q)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
101 if ((err = mp_shrink(&key->x)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
102 if ((err = mp_shrink(&key->y)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
103
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
104 err = CRYPT_OK;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
105
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
106 #ifdef CLEAN_STACK
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
107 zeromem(buf, sizeof(buf));
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
108 #endif
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
109
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
110 goto done;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
111 error : err = mpi_to_ltc_error(err);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
112 error2: mp_clear_multi(&key->g, &key->q, &key->p, &key->x, &key->y, NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
113 done : mp_clear_multi(&tmp, &tmp2, NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
114 return err;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
115 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
116
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
117 #endif