+/* $OpenBSD: dh.c,v 1.42 2006/08/03 03:34:42 deraadt Exp $ */
/*
* Copyright (c) 2000 Niels Provos. All rights reserved.
*
*/
#include "includes.h"
-RCSID("$OpenBSD: dh.c,v 1.23 2002/11/21 22:22:50 markus Exp $");
-#include "xmalloc.h"
+#include <sys/param.h>
#include <openssl/bn.h>
#include <openssl/dh.h>
-#include <openssl/evp.h>
-#include "buffer.h"
-#include "cipher.h"
-#include "kex.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
#include "dh.h"
#include "pathnames.h"
#include "log.h"
{
char *cp, *arg;
char *strsize, *gen, *prime;
+ const char *errstr = NULL;
cp = line;
- arg = strdelim(&cp);
+ if ((arg = strdelim(&cp)) == NULL)
+ return 0;
/* Ignore leading whitespace */
if (*arg == '\0')
arg = strdelim(&cp);
goto fail;
strsize = strsep(&cp, " "); /* size */
if (cp == NULL || *strsize == '\0' ||
- (dhg->size = atoi(strsize)) == 0)
+ (dhg->size = (u_int)strtonum(strsize, 0, 64*1024, &errstr)) == 0 ||
+ errstr)
goto fail;
/* The whole group is one bit larger */
dhg->size++;
if (BN_num_bits(dhg->p) != dhg->size)
goto failclean;
+ if (BN_is_zero(dhg->g) || BN_is_one(dhg->g))
+ goto failclean;
+
return (1);
failclean:
choose_dh(int min, int wantbits, int max)
{
FILE *f;
- char line[2048];
+ char line[4096];
int best, bestcount, which;
int linenum;
struct dhgroup dhg;
if ((f = fopen(_PATH_DH_MODULI, "r")) == NULL &&
(f = fopen(_PATH_DH_PRIMES, "r")) == NULL) {
- log("WARNING: %s does not exist, using old modulus", _PATH_DH_MODULI);
- return (dh_new_group1());
+ logit("WARNING: %s does not exist, using fixed modulus",
+ _PATH_DH_MODULI);
+ return (dh_new_group14());
}
linenum = 0;
if (bestcount == 0) {
fclose(f);
- log("WARNING: no suitable primes in %s", _PATH_DH_PRIMES);
- return (NULL);
+ logit("WARNING: no suitable primes in %s", _PATH_DH_PRIMES);
+ return (dh_new_group14());
}
linenum = 0;
return (dh_new_group(dhg.g, dhg.p));
}
-/* diffie-hellman-group1-sha1 */
+/* diffie-hellman-groupN-sha1 */
int
dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
int i;
int n = BN_num_bits(dh_pub);
int bits_set = 0;
+ BIGNUM *tmp;
if (dh_pub->neg) {
- log("invalid public DH value: negativ");
+ logit("invalid public DH value: negativ");
+ return 0;
+ }
+ if (BN_cmp(dh_pub, BN_value_one()) != 1) { /* pub_exp <= 1 */
+ logit("invalid public DH value: <= 1");
return 0;
}
+
+ if ((tmp = BN_new()) == NULL)
+ return (-1);
+ if (!BN_sub(tmp, dh->p, BN_value_one()) ||
+ BN_cmp(dh_pub, tmp) != -1) { /* pub_exp > p-2 */
+ BN_clear_free(tmp);
+ logit("invalid public DH value: >= p-1");
+ return 0;
+ }
+ BN_clear_free(tmp);
+
for (i = 0; i <= n; i++)
if (BN_is_bit_set(dh_pub, i))
bits_set++;
debug2("bits set: %d/%d", bits_set, BN_num_bits(dh->p));
/* if g==2 and bits_set==1 then computing log_g(dh_pub) is trivial */
- if (bits_set > 1 && (BN_cmp(dh_pub, dh->p) == -1))
+ if (bits_set > 1)
return 1;
- log("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
+
+ logit("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
return 0;
}
void
dh_gen_key(DH *dh, int need)
{
- int i, bits_set = 0, tries = 0;
+ int i, bits_set, tries = 0;
if (dh->p == NULL)
fatal("dh_gen_key: dh->p == NULL");
- if (2*need >= BN_num_bits(dh->p))
+ if (need > INT_MAX / 2 || 2 * need >= BN_num_bits(dh->p))
fatal("dh_gen_key: group too small: %d (2*need %d)",
BN_num_bits(dh->p), 2*need);
do {
fatal("dh_gen_key: BN_rand failed");
if (DH_generate_key(dh) == 0)
fatal("DH_generate_key");
- for (i = 0; i <= BN_num_bits(dh->priv_key); i++)
+ for (i = 0, bits_set = 0; i <= BN_num_bits(dh->priv_key); i++)
if (BN_is_bit_set(dh->priv_key, i))
bits_set++;
debug2("dh_gen_key: priv key bits set: %d/%d",
return (dh_new_group_asc(gen, group1));
}
+DH *
+dh_new_group14(void)
+{
+ static char *gen = "2", *group14 =
+ "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
+ "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
+ "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
+ "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
+ "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE45B3D"
+ "C2007CB8" "A163BF05" "98DA4836" "1C55D39A" "69163FA8" "FD24CF5F"
+ "83655D23" "DCA3AD96" "1C62F356" "208552BB" "9ED52907" "7096966D"
+ "670C354E" "4ABC9804" "F1746C08" "CA18217C" "32905E46" "2E36CE3B"
+ "E39E772C" "180E8603" "9B2783A2" "EC07A28F" "B5C55DF0" "6F4C52C9"
+ "DE2BCBF6" "95581718" "3995497C" "EA956AE5" "15D22618" "98FA0510"
+ "15728E5A" "8AACAA68" "FFFFFFFF" "FFFFFFFF";
+
+ return (dh_new_group_asc(gen, group14));
+}
+
/*
* Estimates the group order for a Diffie-Hellman group that has an
* attack complexity approximately the same as O(2**bits). Estimate
dh_estimate(int bits)
{
- if (bits < 64)
- return (512); /* O(2**63) */
- if (bits < 128)
+ if (bits <= 128)
return (1024); /* O(2**86) */
- if (bits < 192)
+ if (bits <= 192)
return (2048); /* O(2**116) */
return (4096); /* O(2**156) */
}