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Makefile.in contains updated files required
author Matt Johnston <matt@ucc.asn.au>
date Tue, 01 Jun 2004 02:46:09 +0000
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children 29a5c7c62350
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-1:000000000000 4:fe6bca95afa7
1 /*
2 * Dropbear - a SSH2 server
3 *
4 * Copyright (c) 2002,2003 Matt Johnston
5 * All rights reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE. */
24
25 #include "includes.h"
26 #include "dbutil.h"
27 #include "bignum.h"
28 #include "random.h"
29 #include "rsa.h"
30 #include "genrsa.h"
31
32 #define RSA_E 65537
33
34 #ifdef DROPBEAR_RSA
35
36 static void getrsaprime(mp_int* prime, mp_int *primeminus,
37 mp_int* rsa_e, unsigned int size);
38
39 /* mostly taken from libtomcrypt's rsa key generation routine */
40 rsa_key * gen_rsa_priv_key(unsigned int size) {
41
42 rsa_key * key;
43 mp_int pminus, qminus, lcm;
44
45 key = (rsa_key*)m_malloc(sizeof(rsa_key));
46
47 key->e = (mp_int*)m_malloc(sizeof(mp_int));
48 key->n = (mp_int*)m_malloc(sizeof(mp_int));
49 key->d = (mp_int*)m_malloc(sizeof(mp_int));
50 key->p = (mp_int*)m_malloc(sizeof(mp_int));
51 key->q = (mp_int*)m_malloc(sizeof(mp_int));
52
53 m_mp_init_multi(key->e, key->n, key->d, key->p, key->q,
54 &pminus, &lcm, &qminus, NULL);
55
56 seedrandom();
57
58 if (mp_set_int(key->e, RSA_E) != MP_OKAY) {
59 fprintf(stderr, "rsa generation failed\n");
60 exit(1);
61 }
62
63 /* PuTTY doesn't like it if the modulus isn't a multiple of 8 bits,
64 * so we just generate them until we get one which is OK */
65 getrsaprime(key->p, &pminus, key->e, size/2);
66 do {
67 getrsaprime(key->q, &qminus, key->e, size/2);
68
69 if (mp_mul(key->p, key->q, key->n) != MP_OKAY) {
70 fprintf(stderr, "rsa generation failed\n");
71 exit(1);
72 }
73 } while (mp_count_bits(key->n) % 8 != 0);
74
75 /* lcm(p-1, q-1) */
76 if (mp_lcm(&pminus, &qminus, &lcm) != MP_OKAY) {
77 fprintf(stderr, "rsa generation failed\n");
78 exit(1);
79 }
80
81 /* de = 1 mod lcm(p-1,q-1) */
82 /* therefore d = (e^-1) mod lcm(p-1,q-1) */
83 if (mp_invmod(key->e, &lcm, key->d) != MP_OKAY) {
84 fprintf(stderr, "rsa generation failed\n");
85 exit(1);
86 }
87
88 mp_clear_multi(&pminus, &qminus, &lcm, NULL);
89
90 return key;
91 }
92
93 /* return a prime suitable for p or q */
94 static void getrsaprime(mp_int* prime, mp_int *primeminus,
95 mp_int* rsa_e, unsigned int size) {
96
97 unsigned char *buf;
98 mp_int temp_gcd;
99
100 buf = (unsigned char*)m_malloc(size+1);
101
102 m_mp_init(&temp_gcd);
103 do {
104 /* generate a random odd number with MSB set, then find the
105 the next prime above it */
106 genrandom(buf, size+1);
107 buf[0] |= 0x80; /* MSB set */
108
109 if (mp_read_unsigned_bin(prime, buf, size+1) != MP_OKAY) {
110 fprintf(stderr, "rsa generation failed\n");
111 exit(1);
112 }
113
114 /* find the next integer which is prime, 8 round of miller-rabin */
115 if (mp_prime_next_prime(prime, 8, 0) != MP_OKAY) {
116 fprintf(stderr, "rsa generation failed\n");
117 exit(1);
118 }
119
120 /* subtract one to get p-1 */
121 if (mp_sub_d(prime, 1, primeminus) != MP_OKAY) {
122 fprintf(stderr, "rsa generation failed\n");
123 exit(1);
124 }
125 /* check relative primality to e */
126 if (mp_gcd(primeminus, rsa_e, &temp_gcd) != MP_OKAY) {
127 fprintf(stderr, "rsa generation failed\n");
128 exit(1);
129 }
130 } while (mp_cmp_d(&temp_gcd, 1) != MP_EQ); /* while gcd(p-1, e) != 1 */
131
132 /* now we have a good value for result */
133 mp_clear(&temp_gcd);
134 m_burn(buf, size+1);
135 m_free(buf);
136 }
137
138 #endif /* DROPBEAR_RSA */