X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/5c58ad2d1527936b4d30891497eef48bde0fe1f3..a52f067e0510f49ff0473878280521bd11cd3c78:/sshbn.c

diff --git a/sshbn.c b/sshbn.c
index adb88243..dbf223d6 100644
--- a/sshbn.c
+++ b/sshbn.c
@@ -324,6 +324,9 @@ int ssh1_read_bignum(unsigned char *data, Bignum *result) {
     b = (w+7)/8;                       /* bits -> bytes */
     w = (w+15)/16;		       /* bits -> words */
 
+    if (!result)                       /* just return length */
+        return b + 2;
+
     bn = newbn(w);
 
     for (i=1; i<=w; i++)