--- a/security/nss/lib/ssl/sslcert.c
+++ b/security/nss/lib/ssl/sslcert.c
@@ -446,17 +446,18 @@ ssl_ConfigCertByUsage(sslSocket *ss, CER
     }
 
     /* Check that we successfully picked an authType */
     if (arg.authType == ssl_auth_null) {
         PORT_SetError(SEC_ERROR_INVALID_ARGS);
         return SECFailure;
     }
     /* |data->authType| has to either agree or be ssl_auth_null. */
-    if (data->authType != ssl_auth_null && data->authType != arg.authType) {
+    if (data && data->authType != ssl_auth_null &&
+        data->authType != arg.authType) {
         PORT_SetError(SEC_ERROR_INVALID_ARGS);
         return SECFailure;
     }
     return ssl_ConfigCert(ss, cert, keyPair, &arg);
 }
 
 /* This function adopts pubKey and destroys it if things go wrong. */
 static ssl3KeyPair *