From 26d755bc9a2f4ed57aa8a678c7babed52e01dae9 Mon Sep 17 00:00:00 2001
From: simon <simon@cda61777-01e9-0310-a592-d414129be87e>
Date: Tue, 13 Jan 2009 18:18:35 +0000
Subject: [PATCH] Check the two popen() calls in noise_get_heavy for NULL.

git-svn-id: svn://svn.tartarus.org/sgt/putty@8411 cda61777-01e9-0310-a592-d414129be87e
---
 unix/uxnoise.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/unix/uxnoise.c b/unix/uxnoise.c
index b563f7cb..7ebb9a58 100644
--- a/unix/uxnoise.c
+++ b/unix/uxnoise.c
@@ -4,6 +4,9 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
 #include <fcntl.h>
 #include <unistd.h>
 #include <sys/time.h>
@@ -47,19 +50,34 @@ void noise_get_heavy(void (*func) (void *, int))
     char buf[512];
     FILE *fp;
     int ret;
+    int got_dev_urandom = 0;
 
-    if (read_dev_urandom(buf, 32))
+    if (read_dev_urandom(buf, 32)) {
+	got_dev_urandom = 1;
 	func(buf, 32);
+    }
 
     fp = popen("ps -axu 2>/dev/null", "r");
-    while ( (ret = fread(buf, 1, sizeof(buf), fp)) > 0)
-	func(buf, ret);
-    pclose(fp);
+    if (fp) {
+	while ( (ret = fread(buf, 1, sizeof(buf), fp)) > 0)
+	    func(buf, ret);
+	pclose(fp);
+    } else if (!got_dev_urandom) {
+	fprintf(stderr, "popen: %s\n"
+		"Unable to access fallback entropy source\n", strerror(errno));
+	exit(1);
+    }
 
     fp = popen("ls -al /tmp 2>/dev/null", "r");
-    while ( (ret = fread(buf, 1, sizeof(buf), fp)) > 0)
-	func(buf, ret);
-    pclose(fp);
+    if (fp) {
+	while ( (ret = fread(buf, 1, sizeof(buf), fp)) > 0)
+	    func(buf, ret);
+	pclose(fp);
+    } else if (!got_dev_urandom) {
+	fprintf(stderr, "popen: %s\n"
+		"Unable to access fallback entropy source\n", strerror(errno));
+	exit(1);
+    }
 
     read_random_seed(func);
     random_save_seed();
-- 
2.11.0