Add sanity check to print_bin function

Add a sanity check to the print_bin function to ensure that the |off|
argument is positive. Thanks to Kevin Wojtysiak (Int3 Solutions) and
Paramjot Oberoi (Int3 Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit 3deeeeb61b0c5b9b5f0993a67b7967d2f85186da)

diff --git a/crypto/ec/eck_prn.c b/crypto/ec/eck_prn.c
index 515b262387df0f046f34434765fa5b7c7d43b7bc..df9b37a750d6251edca7a0fe15e431509d475c93 100644 (file)
--- a/crypto/ec/eck_prn.c
+++ b/crypto/ec/eck_prn.c
@@ -346,12 +346,14 @@ static int print_bin(BIO *fp, const char *name, const unsigned char *buf,
 
     if (buf == NULL)
         return 1;
-    if (off) {
+    if (off > 0) {
         if (off > 128)
             off = 128;
         memset(str, ' ', off);
         if (BIO_write(fp, str, off) <= 0)
             return 0;
+    } else {
+        off = 0;
     }
 
     if (BIO_printf(fp, "%s", name) <= 0)