From df62d71e64d29d1054e7a53d1a801075ef70335f Mon Sep 17 00:00:00 2001
From: Darren Tucker <dtucker@zip.com.au>
Date: Thu, 10 Oct 2013 10:32:39 +1100
Subject:    - dtucker@cvs.openbsd.org 2013/10/08 11:42:13      [dh.c dh.h]    
  Increase the size of the Diffie-Hellman groups requested for a each     
 symmetric key size.  New values from NIST Special Publication 800-57 with    
  the upper limit specified by RFC4419.  Pointed out by Peter Backes, ok     
 djm@.

---
 dh.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

(limited to 'dh.c')

diff --git a/dh.c b/dh.c
index 449dd385..d33af1fa 100644
--- a/dh.c
+++ b/dh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh.c,v 1.51 2013/07/02 12:31:43 markus Exp $ */
+/* $OpenBSD: dh.c,v 1.52 2013/10/08 11:42:13 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  *
@@ -352,17 +352,20 @@ dh_new_group14(void)
 
 /*
  * Estimates the group order for a Diffie-Hellman group that has an
- * attack complexity approximately the same as O(2**bits).  Estimate
- * with:  O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3)))
+ * attack complexity approximately the same as O(2**bits).
+ * Values from NIST Special Publication 800-57: Recommendation for Key
+ * Management Part 1 (rev 3) limited by the recommended maximum value
+ * from RFC4419 section 3.
  */
 
 int
 dh_estimate(int bits)
 {
-
+	if (bits <= 112)
+		return 2048;
 	if (bits <= 128)
-		return (1024);	/* O(2**86) */
+		return 3072;
 	if (bits <= 192)
-		return (2048);	/* O(2**116) */
-	return (4096);		/* O(2**156) */
+		return 7680;
+	return 8192;
 }
-- 
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