Fill the TLS padding extension with zero bytes instead of spaces.

net/third_party/nss/ssl/ssl3ext.c

 /*
  * SSL3 Protocol
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /* TLS extension code moved here from ssl3ecc.c */
 
 #include "nssrenam.h"
@@ skipping 2349 matching lines @@
         extensionLen > maxBytes ||
         paddingLen > sizeof(padding)) {
         PORT_Assert(0);
         return -1;
     }
 
     if (SECSuccess != ssl3_AppendHandshakeNumber(ss, ssl_padding_xtn, 2))
         return -1;
     if (SECSuccess != ssl3_AppendHandshakeNumber(ss, paddingLen, 2))
         return -1;
-    memset(padding, ' ', paddingLen);
+    memset(padding, 0, paddingLen);
     if (SECSuccess != ssl3_AppendHandshake(ss, padding, paddingLen))
         return -1;
 
     return extensionLen;
 }
 
 /* ssl3_ClientSendSignedCertTimestampXtn sends the signed_certificate_timestamp
  * extension for TLS ClientHellos. */
 static PRInt32
 ssl3_ClientSendSignedCertTimestampXtn(sslSocket *ss, PRBool append,
@@ skipping 47 matching lines @@
 
     if (!data->len) {
         /* Empty extension data: RFC 6962 mandates non-empty contents. */
         return SECFailure;
     }
     *scts = *data;
     /* Keep track of negotiated extensions. */
     ss->xtnData.negotiated[ss->xtnData.numNegotiated++] = ex_type;
     return SECSuccess;
 }