From 08e19e862af902b86d4b039b872f1cac049ec20a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Love=20H=C3=B6rnquist=20=C3=85strand?= <lha@kth.se>
Date: Fri, 7 Dec 2007 02:16:01 +0000
Subject: [PATCH] (krb5_generate_random_block): try to avoid the dead-lock in
 by not holding the lock while running RAND_file_name. From Hai Zaar.

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@22193 ec53bebd-3082-4978-b11e-865c3cabbd6b
---
 lib/krb5/crypto.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/krb5/crypto.c b/lib/krb5/crypto.c
index 2beff027d..3a35a2e80 100644
--- a/lib/krb5/crypto.c
+++ b/lib/krb5/crypto.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
+ * Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
  * (Royal Institute of Technology, Stockholm, Sweden). 
  * All rights reserved. 
  *
@@ -3452,13 +3452,13 @@ krb5_decrypt_EncryptedData(krb5_context context,
 #define ENTROPY_NEEDED 128
 
 static int
-seed_something(void)
+seed_something(const char *seedfile)
 {
-    char buf[1024], seedfile[256];
+    char buf[1024];
 
     /* If there is a seed file, load it. But such a file cannot be trusted,
        so use 0 for the entropy estimate */
-    if (RAND_file_name(seedfile, sizeof(seedfile))) {
+    if (seedfile[0]) {
 	int fd;
 	fd = open(seedfile, O_RDONLY);
 	if (fd >= 0) {
@@ -3467,10 +3467,8 @@ seed_something(void)
 	    if (ret > 0)
 		RAND_add(buf, ret, 0.0);
 	    close(fd);
-	} else
-	    seedfile[0] = '\0';
-    } else
-	seedfile[0] = '\0';
+	}
+    }
 
     /* Calling RAND_status() will try to use /dev/urandom if it exists so
        we do not have to deal with it. */
@@ -3505,7 +3503,13 @@ krb5_generate_random_block(void *buf, size_t len)
     
     HEIMDAL_MUTEX_lock(&crypto_mutex);
     if (!rng_initialized) {
-	if (seed_something())
+	char seedfile[256];
+
+	HEIMDAL_MUTEX_unlock(&crypto_mutex);
+	if (RAND_file_name(seedfile, sizeof(seedfile)) == 0)
+	    seedfile[0] = '\0';
+	HEIMDAL_MUTEX_lock(&crypto_mutex);
+	if (seed_something(seedfile))
 	    krb5_abortx(NULL, "Fatal: could not seed the "
 			"random number generator");