dropbear: genrsa.c annotate

annotate genrsa.c @ 1861:2b3a8026a6ce

Add re-exec for server This allows ASLR to re-randomize the address space for every connection, preventing some vulnerabilities from being exploitable by repeated probing. Overhead (memory and time) is yet to be confirmed. At present this is only enabled on Linux. Other BSD platforms with fexecve() would probably also work though have not been tested.

author	Matt Johnston <matt@ucc.asn.au>
date	Sun, 30 Jan 2022 10:14:56 +0800
parents	1051e4eea25a
children

rev	line source
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	1 /*
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	2 * Dropbear - a SSH2 server
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	3 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	4 * Copyright (c) 2002,2003 Matt Johnston
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	5 * All rights reserved.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	6 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	7 * Permission is hereby granted, free of charge, to any person obtaining a copy
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	8 * of this software and associated documentation files (the "Software"), to deal
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	9 * in the Software without restriction, including without limitation the rights
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	11 * copies of the Software, and to permit persons to whom the Software is
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	12 * furnished to do so, subject to the following conditions:
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	13 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	14 * The above copyright notice and this permission notice shall be included in
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	15 * all copies or substantial portions of the Software.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	16 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	23 * SOFTWARE. */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	24
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	25 #include "includes.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	26 #include "dbutil.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	27 #include "bignum.h"
858 220f55d540ae rename random.h to dbrandom.h since some OSes have a system random.h Matt Johnston <matt@ucc.asn.au> parents: 805 diff changeset	28 #include "dbrandom.h"
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	29 #include "rsa.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	30 #include "genrsa.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	31
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	32 #define RSA_E 65537
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	33
1295 750ec4ec4cbe Convert #ifdef to #if, other build changes Matt Johnston <matt@ucc.asn.au> parents: 892 diff changeset	34 #if DROPBEAR_RSA
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	35
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	36 static void getrsaprime(mp_int* prime, mp_int *primeminus,
794 d386defb5376 more ecdsa signkey work, not correct Matt Johnston <matt@ucc.asn.au> parents: 689 diff changeset	37 mp_int* rsa_e, unsigned int size_bytes);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	38
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	39 /* mostly taken from libtomcrypt's rsa key generation routine */
586 b50f0107e505 Rename rsa_key to dropbear_rsa_key (and same for dss too) so Matt Johnston <matt@ucc.asn.au> parents: 477 diff changeset	40 dropbear_rsa_key * gen_rsa_priv_key(unsigned int size) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	41
586 b50f0107e505 Rename rsa_key to dropbear_rsa_key (and same for dss too) so Matt Johnston <matt@ucc.asn.au> parents: 477 diff changeset	42 dropbear_rsa_key * key;
84 29a5c7c62350 default initialisers for mp_ints Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	43 DEF_MP_INT(pminus);
29a5c7c62350 default initialisers for mp_ints Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	44 DEF_MP_INT(qminus);
29a5c7c62350 default initialisers for mp_ints Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	45 DEF_MP_INT(lcm);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	46
794 d386defb5376 more ecdsa signkey work, not correct Matt Johnston <matt@ucc.asn.au> parents: 689 diff changeset	47 if (size < 512 \|\| size > 4096 \|\| (size % 8 != 0)) {
d386defb5376 more ecdsa signkey work, not correct Matt Johnston <matt@ucc.asn.au> parents: 689 diff changeset	48 dropbear_exit("Bits must satisfy 512 <= bits <= 4096, and be a"
d386defb5376 more ecdsa signkey work, not correct Matt Johnston <matt@ucc.asn.au> parents: 689 diff changeset	49 " multiple of 8");
d386defb5376 more ecdsa signkey work, not correct Matt Johnston <matt@ucc.asn.au> parents: 689 diff changeset	50 }
d386defb5376 more ecdsa signkey work, not correct Matt Johnston <matt@ucc.asn.au> parents: 689 diff changeset	51
586 b50f0107e505 Rename rsa_key to dropbear_rsa_key (and same for dss too) so Matt Johnston <matt@ucc.asn.au> parents: 477 diff changeset	52 key = m_malloc(sizeof(*key));
805 724c3e0c8734 Add m_mp_alloc_init_multi() helper Matt Johnston <matt@ucc.asn.au> parents: 794 diff changeset	53 m_mp_alloc_init_multi(&key->e, &key->n, &key->d, &key->p, &key->q, NULL);
724c3e0c8734 Add m_mp_alloc_init_multi() helper Matt Johnston <matt@ucc.asn.au> parents: 794 diff changeset	54 m_mp_init_multi(&pminus, &lcm, &qminus, NULL);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	55
1692 1051e4eea25a Update LibTomMath to 1.2.0 (#84) Steffen Jaeckel <s@jaeckel.eu> parents: 1655 diff changeset	56 mp_set_ul(key->e, RSA_E);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	57
892 ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	58 while (1) {
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	59 getrsaprime(key->p, &pminus, key->e, size/16);
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	60 getrsaprime(key->q, &qminus, key->e, size/16);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	61
892 ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	62 if (mp_mul(key->p, key->q, key->n) != MP_OKAY) {
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	63 fprintf(stderr, "RSA generation failed\n");
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	64 exit(1);
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	65 }
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	66
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	67 if ((unsigned int)mp_count_bits(key->n) == size) {
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	68 break;
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	69 }
477 657c045054ab Remove workaround forcing rsa mpint to exactly a 8 bits multiple for putty (see Matt Johnston <matt@ucc.asn.au> parents: 188 diff changeset	70 }
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	71
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	72 /* lcm(p-1, q-1) */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	73 if (mp_lcm(&pminus, &qminus, &lcm) != MP_OKAY) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 586 diff changeset	74 fprintf(stderr, "RSA generation failed\n");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	75 exit(1);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	76 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	77
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	78 /* de = 1 mod lcm(p-1,q-1) */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	79 /* therefore d = (e^-1) mod lcm(p-1,q-1) */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	80 if (mp_invmod(key->e, &lcm, key->d) != MP_OKAY) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 586 diff changeset	81 fprintf(stderr, "RSA generation failed\n");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	82 exit(1);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	83 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	84
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	85 mp_clear_multi(&pminus, &qminus, &lcm, NULL);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	86
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	87 return key;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	88 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	89
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	90 /* return a prime suitable for p or q */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	91 static void getrsaprime(mp_int* prime, mp_int *primeminus,
794 d386defb5376 more ecdsa signkey work, not correct Matt Johnston <matt@ucc.asn.au> parents: 689 diff changeset	92 mp_int* rsa_e, unsigned int size_bytes) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	93
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	94 unsigned char *buf;
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1295 diff changeset	95 int trials;
84 29a5c7c62350 default initialisers for mp_ints Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	96 DEF_MP_INT(temp_gcd);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	97
892 ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	98 buf = (unsigned char*)m_malloc(size_bytes);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	99
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	100 m_mp_init(&temp_gcd);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	101 do {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	102 /* generate a random odd number with MSB set, then find the
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	103 the next prime above it */
892 ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	104 genrandom(buf, size_bytes);
ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	105 buf[0] \|= 0x80;
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	106
892 ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	107 bytes_to_mp(prime, buf, size_bytes);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	108
1655 f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1295 diff changeset	109 /* find the next integer which is prime */
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1295 diff changeset	110 trials = mp_prime_rabin_miller_trials(mp_count_bits(prime));
f52919ffd3b1 update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) Steffen Jaeckel <s_jaeckel@gmx.de> parents: 1295 diff changeset	111 if (mp_prime_next_prime(prime, trials, 0) != MP_OKAY) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 586 diff changeset	112 fprintf(stderr, "RSA generation failed\n");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	113 exit(1);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	114 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	115
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	116 /* subtract one to get p-1 */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	117 if (mp_sub_d(prime, 1, primeminus) != MP_OKAY) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 586 diff changeset	118 fprintf(stderr, "RSA generation failed\n");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	119 exit(1);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	120 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	121 /* check relative primality to e */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	122 if (mp_gcd(primeminus, rsa_e, &temp_gcd) != MP_OKAY) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 586 diff changeset	123 fprintf(stderr, "RSA generation failed\n");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	124 exit(1);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	125 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	126 } while (mp_cmp_d(&temp_gcd, 1) != MP_EQ); /* while gcd(p-1, e) != 1 */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	127
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	128 /* now we have a good value for result */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	129 mp_clear(&temp_gcd);
892 ae766a2c8fa7 generate RSA keys of exact length Matt Johnston <matt@ucc.asn.au> parents: 858 diff changeset	130 m_burn(buf, size_bytes);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	131 m_free(buf);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	132 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	133
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	134 #endif /* DROPBEAR_RSA */

Mercurial > dropbear

annotate genrsa.c @ 1861:2b3a8026a6ce