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authorDamien Miller <djm@mindrot.org>2001-03-30 10:50:10 +1000
committerDamien Miller <djm@mindrot.org>2001-03-30 10:50:10 +1000
commit9709f906844c86ec4db6fd8dd3ff377069c80573 (patch)
tree40fe09a5a23f2ad1f1b1546361ac00b0dd678997 /dh.c
parenta0ff466d804969067a684911269c380c664df21d (diff)
- OpenBSD CVS Sync
- markus@cvs.openbsd.org 2001/03/29 21:17:40 [dh.c dh.h kex.c kex.h] prepare for rekeying: move DH code to dh.c
Diffstat (limited to 'dh.c')
-rw-r--r--dh.c109
1 files changed, 108 insertions, 1 deletions
diff --git a/dh.c b/dh.c
index 636758fa..6c53b003 100644
--- a/dh.c
+++ b/dh.c
@@ -23,7 +23,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: dh.c,v 1.10 2001/03/28 22:04:57 provos Exp $");
+RCSID("$OpenBSD: dh.c,v 1.11 2001/03/29 21:17:39 markus Exp $");
#include "xmalloc.h"
@@ -166,3 +166,110 @@ choose_dh(int min, int wantbits, int max)
return (dh_new_group(dhg.g, dhg.p));
}
+
+/* diffie-hellman-group1-sha1 */
+
+int
+dh_pub_is_valid(DH *dh, BIGNUM *dh_pub)
+{
+ int i;
+ int n = BN_num_bits(dh_pub);
+ int bits_set = 0;
+
+ if (dh_pub->neg) {
+ log("invalid public DH value: negativ");
+ return 0;
+ }
+ for (i = 0; i <= n; i++)
+ if (BN_is_bit_set(dh_pub, i))
+ bits_set++;
+ debug("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))
+ return 1;
+ log("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;
+
+ if (dh->p == NULL)
+ fatal("dh_gen_key: dh->p == NULL");
+ if (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 {
+ if (dh->priv_key != NULL)
+ BN_free(dh->priv_key);
+ dh->priv_key = BN_new();
+ if (dh->priv_key == NULL)
+ fatal("dh_gen_key: BN_new failed");
+ /* generate a 2*need bits random private exponent */
+ if (!BN_rand(dh->priv_key, 2*need, 0, 0))
+ 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++)
+ if (BN_is_bit_set(dh->priv_key, i))
+ bits_set++;
+ debug("dh_gen_key: priv key bits set: %d/%d",
+ bits_set, BN_num_bits(dh->priv_key));
+ if (tries++ > 10)
+ fatal("dh_gen_key: too many bad keys: giving up");
+ } while (!dh_pub_is_valid(dh, dh->pub_key));
+}
+
+DH *
+dh_new_group_asc(const char *gen, const char *modulus)
+{
+ DH *dh;
+ int ret;
+
+ dh = DH_new();
+ if (dh == NULL)
+ fatal("DH_new");
+
+ if ((ret = BN_hex2bn(&dh->p, modulus)) < 0)
+ fatal("BN_hex2bn p");
+ if ((ret = BN_hex2bn(&dh->g, gen)) < 0)
+ fatal("BN_hex2bn g");
+
+ return (dh);
+}
+
+/*
+ * This just returns the group, we still need to generate the exchange
+ * value.
+ */
+
+DH *
+dh_new_group(BIGNUM *gen, BIGNUM *modulus)
+{
+ DH *dh;
+
+ dh = DH_new();
+ if (dh == NULL)
+ fatal("DH_new");
+ dh->p = modulus;
+ dh->g = gen;
+
+ return (dh);
+}
+
+DH *
+dh_new_group1(void)
+{
+ static char *gen = "2", *group1 =
+ "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" "ECE65381"
+ "FFFFFFFF" "FFFFFFFF";
+
+ return (dh_new_group_asc(gen, group1));
+}