X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/0016d70b76e2706064b54c9dd24d45a45646b0de..f33ba69e92f389f5884eae5a586858a629a5260b:/sshrsa.c

diff --git a/sshrsa.c b/sshrsa.c
index e7fca008..f684c2af 100644
--- a/sshrsa.c
+++ b/sshrsa.c
@@ -54,7 +54,7 @@ int makekey(unsigned char *data, int len, struct RSAKey *result,
     }
 
     n = ssh1_read_bignum(p, len, result ? &result->modulus : NULL);
-    if (n < 0) return -1;
+    if (n < 0 || bignum_bitcount(result->modulus) == 0) return -1;
     if (result)
 	result->bytes = n - 2;
     if (keystr)