From 61279f1fb6c38649f5bfc2f4c0cf8c68ebb1e74a Mon Sep 17 00:00:00 2001
From: Andreas Fischer <bantu@phpbb.com>
Date: Fri, 7 Jun 2013 01:03:03 +0200
Subject: [PATCH] [feature/elliptic-curve] Add comment for generator 2 and sha1
 hash function.

---
 phpseclib/Net/SSH2.php | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index 2807f839..9fb29c7c 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -1180,11 +1180,11 @@ class Net_SSH2 {
                 break;
         }
 
-        $kexHash = new Crypt_Hash('sha1');
-        $keyLength = min($keyLength, $kexHash->getLength());
-
+        // For both diffie-hellman-group1-sha1 and diffie-hellman-group14-sha1
+        // the generator field element is 2 (decimal) and the hash function is sha1.
         $g = new Math_BigInteger(2);
         $prime = new Math_BigInteger($prime, 16);
+        $kexHash = new Crypt_Hash('sha1');
         //$q = $p->bitwise_rightShift(1);
 
         /* To increase the speed of the key exchange, both client and server may
@@ -1195,6 +1195,7 @@ class Net_SSH2 {
 
            -- http://tools.ietf.org/html/rfc4419#section-6.2 */
         $one = new Math_BigInteger(1);
+        $keyLength = min($keyLength, $kexHash->getLength());
         $max = $one->bitwise_leftShift(16 * $keyLength)->subtract($one); // 2 * 8 * $keyLength
 
         $x = $one->random($one, $max);