python-imaplib2 needs to support SNI for OpenSSL 1.1.1

[Dimitri John Ledkov]

[Impact]

 * OpenSSL 1.1.1 performs SNI hostname verification, therefore hostname SSL context option must be set when establishing the connection, otherwise, validation of SNI certificates fail and thus resulting in lack of connectivity.

[Test Case]

 * use python-imaplib2 to connect to an SNI tls protected host

[Regression Potential]

 * change is compatible with pythons/openssl versions shipped in bionic-release
 * change is from upstream / tested in debian & disco
 * change improves security, and is compatible with deployed servers out there
 * hosts with certificates not matching their actual hostname will remain invalid/untrusted

[Additional info]
To install python & openssl 1.1.1 on Bionic you may enable and use the below silo, which will then exhibit the enforcement of SNI hostname verification.

sudo add-apt-repository ppa:ci-train-ppa-service/3473
sudo apt-get update

[Brian Murray (brian-murray)]

Hello Dimitri, or anyone else affected,

Accepted python-imaplib2 into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/python-imaplib2/2.57-1ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Dimitri John Ledkov (xnox)]

Established dummy connection to gmail using offlineimap, and received login failure. But there were no failures in establishing the TLS connection.

 offlineimap
OfflineIMAP 7.1.5
  Licensed under the GNU GPL v2 or any later version (with an OpenSSL exception)
imaplib2 v2.57 (system), Python v2.7.15+, OpenSSL 1.1.1 11 Sep 2018
Account sync Gmail-mine:
 *** Processing account Gmail-mine
 Establishing connection to imap.gmail.com:993 (Gmailserver-mine)
 PLAIN authentication failed: [AUTHENTICATIONFAILED] Invalid credentials (Failure)
 LOGIN authentication failed: [AUTHENTICATIONFAILED] Invalid credentials (Failure)

# dpkg-query -W python-imaplib2
python-imaplib2 2.57-1ubuntu0.1

All is good.

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for python-imaplib2 has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package python-imaplib2 - 2.57-1ubuntu0.1

---------------
python-imaplib2 (2.57-1ubuntu0.1) bionic; urgency=medium

  * Cherrypick 2.57-5 upload patch to use SSLContext if available so we
    send SNI. LP: #1815482

 -- Dimitri John Ledkov <email address hidden> Fri, 14 Dec 2018 15:26:07 +1100