Issue 12139: add CCC command support to FTP_TLS class to revert the SSL connection back to clear-text.

2 files changed, 19 insertions, 0 deletions

diff --git a/Doc/library/ftplib.rst b/Doc/library/ftplib.rst
index f4205f4..087e200 100644
--- a/Doc/library/ftplib.rst
+++ b/Doc/library/ftplib.rst
@@ -426,6 +426,14 @@ FTP_TLS Objects
 
    Set up secure control connection by using TLS or SSL, depending on what specified in :meth:`ssl_version` attribute.
 
+.. method:: FTP_TLS.ccc()
+
+   Revert control channel back to plaintex.  This can be useful to take
+   advantage of firewalls that know how to handle NAT with non-secure FTP
+   without opening fixed ports.
+
+   .. versionadded:: 3.3
+
 .. method:: FTP_TLS.prot_p()
 
    Set up secure data connection.
diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst
index 4374d02..63f8b15 100644
--- a/Doc/whatsnew/3.3.rst
+++ b/Doc/whatsnew/3.3.rst
@@ -192,6 +192,17 @@ The :mod:`ssl` module has new functions:
   * :func:`~ssl.RAND_pseudo_bytes`: generate pseudo-random bytes.
 
 
+ftplib
+------
+
+The :class:`~ftplib.FTP_TLS` class now provides a new
+:func:`~ftplib.FTP_TLS.ccc` function to revert control channel back to
+plaintex.  This can be useful to take advantage of firewalls that know how to
+handle NAT with non-secure FTP without opening fixed ports.
+
+(Patch submitted by Giampaolo Rodolà in :issue:`12139`.)
+
+
 Optimizations
 =============