Index: Lib/ftplib.py
===================================================================
--- Lib/ftplib.py	(revisione 60910)
+++ Lib/ftplib.py	(copia locale)
@@ -33,6 +33,7 @@
 # Modified by Jack to work on the mac.
 # Modified by Siebren to support docstrings and PASV.
 # Modified by Phil Schwartz to add storbinary and storlines callbacks.
+# Modified by Giampaolo Rodola' to add TLS/SSL support.
 #
 
 import os
@@ -576,6 +577,92 @@
             self.file = self.sock = None
 
 
+try:
+    import ssl
+except ImportError:
+    pass
+else:
+    class FTP_TLS(FTP):
+        """A FTP subclass which adds TLS support to FTP as described
+        in RFC-4217.
+
+        Connect as usual to port 21 leaving control and data channels
+        implicitly unprotected.
+        Securing control and data channels requires user to explicitly
+        ask for it by using auth_tls() and prot_p() methods.
+
+        Usage example:
+        >>> from ftplib import FTP_TLS
+        >>> ftps = FTP_TLS('ftp.python.org')
+        >>> ftps.auth_tls()  # switch to secure control connection
+        '234 Using authentication type TLS'
+        >>> ftps.login()  # login anonimously
+        '230 Guest login ok, access restrictions apply.'
+        >>> ftps.prot_p()  # switch to secure data connection
+        '200 Protection level set to P'
+        >>> ftps.retrlines('LIST')  # list directory content securely
+        total 9
+        drwxr-xr-x   8 root     wheel        1024 Jan  3  1994 .
+        drwxr-xr-x   8 root     wheel        1024 Jan  3  1994 ..
+        drwxr-xr-x   2 root     wheel        1024 Jan  3  1994 bin
+        drwxr-xr-x   2 root     wheel        1024 Jan  3  1994 etc
+        d-wxrwxr-x   2 ftp      wheel        1024 Sep  5 13:43 incoming
+        drwxr-xr-x   2 root     wheel        1024 Nov 17  1993 lib
+        drwxr-xr-x   6 1094     wheel        1024 Sep 13 19:07 pub
+        drwxr-xr-x   3 root     wheel        1024 Jan  3  1994 usr
+        -rw-r--r--   1 root     root          312 Aug  1  1994 welcome.msg
+        '226 Transfer complete.'
+        >>> ftps.quit()
+        '221 Goodbye.'
+        >>>
+        """
+
+        def __init__(self, host='', user='', passwd='', acct='', keyfile=None,
+                     certfile=None, timeout=None):
+            FTP.__init__(self, host=host, user=user, passwd=passwd, acct=acct,
+                         timeout=timeout)
+            self.keyfile = keyfile
+            self.certfile = certfile
+            self.prot_private = False
+
+        def auth_tls(self):
+            """Set up secure control connection by using TLS."""
+            resp = self.voidcmd('AUTH SSL')
+            self.sock = ssl.wrap_socket(self.sock, self.keyfile, self.certfile)
+            self.file = self.sock.makefile(mode='rb')
+            return resp
+
+        def prot_p(self):
+            """Set up secure data connection."""
+            # PROT defines whether or not the data channel is to be protected.
+            # Though RFC-2228 defines four possible protection levels,
+            # RFC-4217 only recommends two, Clear and Private.
+            # Clear (PROT C) means that no security is to be used on the
+            # data-channel, Private (PROT P) means that the data-channel
+            # should be protected by TLS.
+            # PBSZ command MUST still be issued, but must have a parameter of
+            # '0' to indicate that no buffering is taking place and the data
+            # connection should not be encapsulated.
+            self.voidcmd('PBSZ 0')
+            resp = self.voidcmd('PROT P')
+            self.prot_private = True
+            return resp
+
+        def prot_c(self):
+            """Set up clear text data channel."""
+            resp = self.voidcmd('PROT C')
+            self.prot_private = False
+            return resp
+
+        def ntransfercmd(self, cmd, rest=None):
+            conn, size = FTP.ntransfercmd(self, cmd, rest)
+            if self.prot_private:
+                conn = ssl.wrap_socket(conn, self.keyfile, self.certfile)
+            return conn, size
+        
+    __all__.append("FTP_TLS")
+
+
 _150_re = None
 
 def parse150(resp):