X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/c6940f12e2ad6ba778324f50b9a779db36238518..32f46b5c30131a9ba5bbadd28da6425434aca47f:/cmdgen.c

diff --git a/cmdgen.c b/cmdgen.c
index d8d5a946..ae405208 100644
--- a/cmdgen.c
+++ b/cmdgen.c
@@ -119,7 +119,7 @@ void sk_cleanup(void)
 void showversion(void)
 {
     char *verstr = dupstr(ver);
-    verstr[0] = tolower(verstr[0]);
+    verstr[0] = tolower((unsigned char)verstr[0]);
     printf("PuTTYgen %s\n", verstr);
     sfree(verstr);
 }
@@ -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);