add ssl_peek functionality

OpenSSL/SSL.py

@@ -1,3 +1,4 @@
+import socket
 from sys import platform
 from functools import wraps, partial
 from itertools import count, chain
@@ -1311,12 +1312,15 @@ def recv(self, bufsiz, flags=None):
         method again with the SAME buffer.
 
         :param bufsiz: The maximum number of bytes to read
-        :param flags: (optional) Included for compatibility with the socket
-                      API, the value is ignored
+        :param flags: (optional) The only supported flag is
+                      socket.MSG_PEEK. All other flags are ignored.
         :return: The string read from the Connection
         """
         buf = _ffi.new("char[]", bufsiz)
-        result = _lib.SSL_read(self._ssl, buf, bufsiz)
+        if flags and flags & socket.MSG_PEEK:
+            result = _lib.SSL_peek(self._ssl, buf, bufsiz)
+        else:
+            result = _lib.SSL_read(self._ssl, buf, bufsiz)
         self._raise_ssl_error(self._ssl, result)
         return _ffi.buffer(buf, result)[:]
     read = recv

OpenSSL/test/test_ssl.py

@@ -8,7 +8,7 @@
 from gc import collect, get_referrers
 from errno import ECONNREFUSED, EINPROGRESS, EWOULDBLOCK, EPIPE, ESHUTDOWN
 from sys import platform, getfilesystemencoding
-from socket import SHUT_RDWR, error, socket
+from socket import MSG_PEEK, SHUT_RDWR, error, socket
 from os import makedirs
 from os.path import join
 from unittest import main
@@ -2171,6 +2171,16 @@ def test_pending_wrong_args(self):
         connection = Connection(Context(TLSv1_METHOD), None)
         self.assertRaises(TypeError, connection.pending, None)
 
+    def test_peek(self):
+        """
+        :py:obj:`Connection.recv` peeks into the connect if :py:obj:`socket.MSG_PEEK` is passed.
+        """
+        server, client = self._loopback()
+        server.send(b('xy'))
+        self.assertEquals(client.recv(2, MSG_PEEK), b('xy'))
+        self.assertEquals(client.recv(2, MSG_PEEK), b('xy'))
+        self.assertEquals(client.recv(2), b('xy'))
+
 
     def test_connect_wrong_args(self):
         """