clean up ssl.py; expose unwrap and add test for it

Lib/ssl.py

@@ -75,10 +75,10 @@
     SSL_ERROR_INVALID_ERROR_CODE,
     )
 
-from socket import socket, AF_INET, SOCK_STREAM, error
 from socket import getnameinfo as _getnameinfo
 from socket import error as socket_error
 from socket import dup as _dup
+from socket import socket, AF_INET, SOCK_STREAM
 import base64        # for DER-to-PEM translation
 import traceback
 
@@ -296,6 +296,14 @@ def shutdown(self, how):
         self._sslobj = None
         socket.shutdown(self, how)
 
+    def unwrap (self):
+        if self._sslobj:
+            s = self._sslobj.shutdown()
+            self._sslobj = None
+            return s
+        else:
+            raise ValueError("No SSL wrapper around " + str(self))
+
     def _real_close(self):
         self._sslobj = None
         # self._closed = True

Lib/test/test_ssl.py

@@ -279,6 +279,15 @@ def run (self):
                             self.write("OK\n".encode("ASCII", "strict"))
                             if not self.wrap_conn():
                                 return
+                        elif (self.server.starttls_server and self.sslconn
+                              and amsg.strip() == 'ENDTLS'):
+                            if support.verbose and self.server.connectionchatty:
+                                sys.stdout.write(" server: read ENDTLS from client, sending OK...\n")
+                            self.write("OK\n".encode("ASCII", "strict"))
+                            self.sock = self.sslconn.unwrap()
+                            self.sslconn = None
+                            if support.verbose and self.server.connectionchatty:
+                                sys.stdout.write(" server: connection is now unencrypted...\n")
                         else:
                             if (support.verbose and
                                 self.server.connectionchatty):
@@ -868,7 +877,7 @@ def testProtocolTLS1(self):
 
         def testSTARTTLS (self):
 
-            msgs = ("msg 1", "MSG 2", "STARTTLS", "MSG 3", "msg 4")
+            msgs = ("msg 1", "MSG 2", "STARTTLS", "MSG 3", "msg 4", "ENDTLS", "msg 5", "msg 6")
 
             server = ThreadedEchoServer(CERTFILE,
                                         ssl_version=ssl.PROTOCOL_TLSv1,
@@ -910,8 +919,16 @@ def testSTARTTLS (self):
                                     " client:  read %s from server, starting TLS...\n"
                                     % repr(msg))
                             conn = ssl.wrap_socket(s, ssl_version=ssl.PROTOCOL_TLSv1)
-
                             wrapped = True
+                        elif (indata == "ENDTLS" and
+                              str(outdata, 'ASCII', 'replace').strip().lower().startswith("ok")):
+                            if support.verbose:
+                                msg = str(outdata, 'ASCII', 'replace')
+                                sys.stdout.write(
+                                    " client:  read %s from server, ending TLS...\n"
+                                    % repr(msg))
+                            s = conn.unwrap()
+                            wrapped = False
                         else:
                             if support.verbose:
                                 msg = str(outdata, 'ASCII', 'replace')
@@ -922,7 +939,7 @@ def testSTARTTLS (self):
                     if wrapped:
                         conn.write("over\n".encode("ASCII", "strict"))
                     else:
-                        s.send("over\n")
+                        s.send("over\n".encode("ASCII", "strict"))
                 if wrapped:
                     conn.close()
                 else:

Modules/_ssl.c

@@ -1370,6 +1370,42 @@ PyDoc_STRVAR(PySSL_SSLread_doc,
 \n\
 Read up to len bytes from the SSL socket.");
 
+static PyObject *PySSL_SSLshutdown(PySSLObject *self)
+{
+	int err;
+        PySocketSockObject *sock
+          = (PySocketSockObject *) PyWeakref_GetObject(self->Socket);
+
+	/* Guard against closed socket */
+        if ((((PyObject*)sock) == Py_None) || (sock->sock_fd < 0)) {
+                _setSSLError("Underlying socket connection gone",
+                             PY_SSL_ERROR_NO_SOCKET, __FILE__, __LINE__);
+                return NULL;
+        }
+
+	PySSL_BEGIN_ALLOW_THREADS
+	err = SSL_shutdown(self->ssl);
+	if (err == 0) {
+		/* we need to call it again to finish the shutdown */
+		err = SSL_shutdown(self->ssl);
+	}
+	PySSL_END_ALLOW_THREADS
+
+	if (err < 0)
+		return PySSL_SetError(self, err, __FILE__, __LINE__);
+	else {
+                Py_INCREF(sock);
+                return (PyObject *) sock;
+	}
+}
+
+PyDoc_STRVAR(PySSL_SSLshutdown_doc,
+"shutdown(s) -> socket\n\
+\n\
+Does the SSL shutdown handshake with the remote end, and returns\n\
+the underlying socket object.");
+
+
 static PyMethodDef PySSLMethods[] = {
 	{"do_handshake", (PyCFunction)PySSL_SSLdo_handshake, METH_NOARGS},
 	{"write", (PyCFunction)PySSL_SSLwrite, METH_VARARGS,
@@ -1381,6 +1417,8 @@ static PyMethodDef PySSLMethods[] = {
 	{"peer_certificate", (PyCFunction)PySSL_peercert, METH_VARARGS,
 	 PySSL_peercert_doc},
 	{"cipher", (PyCFunction)PySSL_cipher, METH_NOARGS},
+	{"shutdown", (PyCFunction)PySSL_SSLshutdown, METH_NOARGS,
+	 PySSL_SSLshutdown_doc},
 	{NULL, NULL}
 };
 
@@ -1480,6 +1518,8 @@ fails or if it does provide enough data to seed PRNG.");
 
 #endif
 
+
+
 /* List of functions exported by this module. */
 
 static PyMethodDef PySSL_methods[] = {