-/* $OpenBSD: dh.c,v 1.35 2006/03/27 13:03:54 deraadt Exp $ */
+/* $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"
-#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"
int i;
int n = BN_num_bits(dh_pub);
int bits_set = 0;
+ BIGNUM *tmp;
if (dh_pub->neg) {
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;
+
logit("invalid public DH value (%d/%d)", bits_set, BN_num_bits(dh->p));
return 0;
}