From ab076e024dead93707ab637800ddcdad0a289e0a Mon Sep 17 00:00:00 2001
From: simon <simon@cda61777-01e9-0310-a592-d414129be87e>
Date: Sat, 22 Jan 2005 14:51:29 +0000
Subject: [PATCH] Owen's just pointed out that random_stir() is capable of
 recursion. I'm sure I didn't mean that to happen! Added a lock to stop it.

git-svn-id: svn://svn.tartarus.org/sgt/putty@5166 cda61777-01e9-0310-a592-d414129be87e
---
 sshrand.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/sshrand.c b/sshrand.c
index 43b81234..26fcfe52 100644
--- a/sshrand.c
+++ b/sshrand.c
@@ -40,6 +40,8 @@ struct RandPool {
 
     unsigned char incomingb[HASHINPUT];
     int incomingpos;
+
+    int stir_pending;
 };
 
 static struct RandPool pool;
@@ -52,6 +54,14 @@ static void random_stir(void)
     word32 digest[HASHSIZE / sizeof(word32)];
     int i, j, k;
 
+    /*
+     * noise_get_light will call random_add_noise, which may call
+     * back to here. Prevent recursive stirs.
+     */
+    if (pool.stir_pending)
+	return;
+    pool.stir_pending = TRUE;
+
     noise_get_light(random_add_noise);
 
     SHATransform((word32 *) pool.incoming, (word32 *) pool.incomingb);
@@ -115,6 +125,8 @@ static void random_stir(void)
     memcpy(pool.incoming, digest, sizeof(digest));
 
     pool.poolpos = sizeof(pool.incoming);
+
+    pool.stir_pending = FALSE;
 }
 
 void random_add_noise(void *noise, int length)
-- 
2.11.0