From: jacob <jacob@cda61777-01e9-0310-a592-d414129be87e>
Date: Tue, 13 Mar 2007 14:43:14 +0000 (+0000)
Subject: get_random_data() can return NULL (for instance, if we can't open /dev/random
X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/commitdiff_plain/7da629c2abc50b798dbb25c2badd0e98ee702f79

get_random_data() can return NULL (for instance, if we can't open /dev/random
on Unix), yet cmdgen failed to deal with this. Spotted by Darren Tucker.


git-svn-id: svn://svn.tartarus.org/sgt/putty@7396 cda61777-01e9-0310-a592-d414129be87e
---

diff --git a/cmdgen.c b/cmdgen.c
index d8d5a946..9aa585f3 100644
--- a/cmdgen.c
+++ b/cmdgen.c
@@ -640,6 +640,11 @@ int main(int argc, char **argv)
 
 	random_ref();
 	entropy = get_random_data(bits / 8);
+	if (!entropy) {
+	    fprintf(stderr, "puttygen: failed to collect entropy, "
+		    "could not generate key\n");
+	    return 1;
+	}
 	random_add_heavynoise(entropy, bits / 8);
 	memset(entropy, 0, bits/8);
 	sfree(entropy);