Please ship ec2-instance-connect.conf instead of creating it in postinst

[Balint Reczey]

[Impact]

 * The ssh.service drop-in is placed and removed in maintainer scripts based on the current ssh configuration checks which are incomplete. The drop-in is also not owned by the package.

[Test Case]

 * Install the fixed package. The drop-in should be listed among the package's files:
$ dpkg -L ec2-instance-connect
...
/lib/systemd/system/ssh.service.d/ec2-instance-connect.conf
...

* Upgrade package from previous version. The drop-in should replace the old one.

* Change /etc/ssh/sshd_config to set AuthorizedKeysCommand
  Install the fixed package. A warning should appear and sshd should not be restarted by the package's maintainer scripts.

[Regression Potential]

* The change is made to make installation and upgrades more reliable. The test cases check package installs and upgrades where regressions could happen due to implementation mistakes.
* The unfixed version of the package did not place the drop-in when it detected setting AuthorizedKeysCommand in sshd_conf, while the fixed version installs the drop-in, just does not restart the ssh service. This can block users from logging in via ssh if only the sshd_conf's AuthorizedKeysCommand configuration enabled their login and the ssh service got restarted after installing/upgrading ec2-instance-connect.
This is a known change in behavior and is mitigated by showing a warning when this potentially problematic configuration is detected. It is also worth noting that in case the drop-in overrides the configuration in sshd_conf it is still possible to log in via EC2 Instance Connect, the login method the package enables.

[Other Info]

[Launchpad Janitor (janitor)]

This bug was fixed in the package ec2-instance-connect - 1.1.12+dfsg1-0ubuntu2

---------------
ec2-instance-connect (1.1.12+dfsg1-0ubuntu2) focal; urgency=medium

  * Ship ssh.service drop-in instead of handling placement in maintainer scripts
    (LP: #1861909)

 -- Balint Reczey <email address hidden> Tue, 04 Feb 2020 18:39:50 +0100

[Łukasz Zemczak (sil2100)]

Hello Balint, or anyone else affected,

Accepted ec2-instance-connect into eoan-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/ec2-instance-connect/1.1.12+dfsg1-0ubuntu3~19.10.0 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-eoan to verification-done-eoan. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-eoan. 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.

[Łukasz Zemczak (sil2100)]

Hello Balint, or anyone else affected,

Accepted ec2-instance-connect into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/ec2-instance-connect/1.1.12+dfsg1-0ubuntu3~18.04.0 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.

[Łukasz Zemczak (sil2100)]

Hello Balint, or anyone else affected,

Accepted ec2-instance-connect into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/ec2-instance-connect/1.1.12+dfsg1-0ubuntu3~16.04.0 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-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. 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.

[Balint Reczey (rbalint)]

Verified on Bionic:

ubuntu@ip-172-31-42-192:~$ dpkg -l ec2-instance-connect
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=====================================-=======================-=======================-================================================================================
ii ec2-instance-connect 1.1.12+dfsg1-0ubuntu3~1 all Configures ssh daemon to accept EC2 Instance Connect ssh keys
ubuntu@ip-172-31-42-192:~$ dpkg -L ec2-instance-connect | grep conf
/lib/systemd/system/ssh.service.d/ec2-instance-connect.conf
ubuntu@ip-172-31-42-192:~$

[Balint Reczey (rbalint)]

Verified on Eoan:

root@ee-proposed:~# dpkg -l ec2-instance-connect
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-====================-=============================-============-=============================================================
ii ec2-instance-connect 1.1.12+dfsg1-0ubuntu3~19.10.0 all Configures ssh daemon to accept EC2 Instance Connect ssh keys
root@ee-proposed:~# dpkg -L ec2-instance-connect | grep conf
/lib/systemd/system/ssh.service.d/ec2-instance-connect.conf
root@ee-proposed:~#

[Balint Reczey (rbalint)]

Verified on Xenial:

root@x-proposed:~# dpkg -l ec2-instance-connect | cat
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-====================-=============================-============-=============================================================
ii ec2-instance-connect 1.1.12+dfsg1-0ubuntu3~16.04.0 all Configures ssh daemon to accept EC2 Instance Connect ssh keys
root@x-proposed:~# dpkg -L ec2-instance-connect | grep conf
/lib/systemd/system/ssh.service.d/ec2-instance-connect.conf

[Łukasz Zemczak (sil2100)]

I assume a full verification has been done here, along with the upgrade scenario and change of /etc/ssh/sshd_config ?

[Balint Reczey (rbalint)]

@sil2100 Oh, no, I've missed that! Thanks for catching that!

[Balint Reczey (rbalint)]

Verified maintainer script warning on all releases:

root@bb-proposed:~# grep AuthorizedKeysCommand /etc/ssh/sshd_config
AuthorizedKeysCommand /bin/false
#AuthorizedKeysCommandUser nobody
root@bb-proposed:~# apt install -qq ec2-instance-connect
The following package was automatically installed and is no longer required:
  libfreetype6
Use 'apt autoremove' to remove it.
The following NEW packages will be installed:
  ec2-instance-connect
0 upgraded, 1 newly installed, 0 to remove and 76 not upgraded.
Need to get 12.6 kB of archives.
After this operation, 57.3 kB of additional disk space will be used.
Selecting previously unselected package ec2-instance-connect.
(Reading database ... 36957 files and directories currently installed.)
Preparing to unpack .../ec2-instance-connect_1.1.12+dfsg1-0ubuntu3~18.04.0_all.deb ...
Created system user ec2-instance-connect
Unpacking ec2-instance-connect (1.1.12+dfsg1-0ubuntu3~18.04.0) ...
Setting up ec2-instance-connect (1.1.12+dfsg1-0ubuntu3~18.04.0) ...
Created symlink /etc/systemd/system/multi-user.target.wants/ec2-instance-connect.service → /lib/systemd/system/ec2-
instance-connect.service.
Job for ec2-instance-connect.service failed because the control process exited with error code.
See "systemctl status ec2-instance-connect.service" and "journalctl -xe" for details.
ERROR: Not restarting ssh because /etc/ssh/sshd_config already sets
ERROR: AuthorizedKeysCommand*, which is also set by
ERROR: /lib/systemd/system/ssh.service.d/ec2-instance-connect.conf.
Please restart ssh manually if the configuration is correct.
root@bb-proposed:~#

root@ee-proposed:~# grep AuthorizedKeysCommand /etc/ssh/sshd_config
AuthorizedKeysCommand /bin/false
#AuthorizedKeysCommandUser nobody
root@ee-proposed:~# apt install -qq ec2-instance-connect
The following packages were automatically installed and are no longer required:
  command-not-found-data libdumbnet1 libidn11 libip4tc0 libip6tc0 multiarch-support
Use 'apt autoremove' to remove them.
The following NEW packages will be installed:
  ec2-instance-connect
0 upgraded, 1 newly installed, 0 to remove and 34 not upgraded.
Need to get 12.6 kB of archives.
After this operation, 57.3 kB of additional disk space will be used.
Selecting previously unselected package ec2-instance-connect.
(Reading database ... 32593 files and directories currently installed.)
Preparing to unpack .../ec2-instance-connect_1.1.12+dfsg1-0ubuntu3~19.10.0_all.deb ...
Created system user ec2-instance-connect
Unpacking ec2-instance-connect (1.1.12+dfsg1-0ubuntu3~19.10.0) ...
Setting up ec2-instance-connect (1.1.12+dfsg1-0ubuntu3~19.10.0) ...
Created symlink /etc/systemd/system/multi-user.target.wants/ec2-instance-connect.service → /lib/systemd/system/ec2-
instance-connect.service.
Job for ec2-instance-connect.service failed because the control process exited with error code.
See "systemctl status ec2-instance-connect.service" and "journalctl -xe" for details.
ERROR: Not restarting ssh because /etc/ssh/sshd_config already sets
ERROR: AuthorizedKeysCommand*, which is also set by
ERROR: /lib/systemd/system/ssh.service.d/ec2-instance-connect.conf.
Please restart ssh manually if the configuration is correct.
root...

[Launchpad Janitor (janitor)]

This bug was fixed in the package ec2-instance-connect - 1.1.12+dfsg1-0ubuntu3~19.10.0

---------------
ec2-instance-connect (1.1.12+dfsg1-0ubuntu3~19.10.0) eoan; urgency=medium

  * Rebuild for Eoan

ec2-instance-connect (1.1.12+dfsg1-0ubuntu3) focal; urgency=medium

  * debian/preinst: Don't remove ec2-instance-connect.conf manually on upgrade
  * debian/prerm: Drop obsolete file

ec2-instance-connect (1.1.12+dfsg1-0ubuntu2) focal; urgency=medium

  * Ship ssh.service drop-in instead of handling placement in maintainer scripts
    (LP: #1861909)

ec2-instance-connect (1.1.12+dfsg1-0ubuntu1) focal; urgency=medium

  [ Balint Reczey ]
  * New upstream version 1.1.11:
    - Removing errant write to /tmp
    - Cleaning up bad bash practices, including umask race condition
    - Fix for an update to openssl (or dependencies) affecting behavior
      of CApath option on openssl verify
    - Fixing Nitro behavior of hostkey harvesting
    - Adding additional licensing headers
  * New upstream version 1.1.12 (LP: #1860142):
    - Adding support for Instance Metadata Service Version 2
    - Modifying cURL invocation to avoid need for eval
    - Cleaning up shellcheck catches
  * debian/install: Adjust for new upstream source layout
  * Suppress systemctl messages and ignore error in maintainer scripts
  * Bump compat level to 10

  [ LordAlfredo ]
  * Rely on debhelper to enable and start systemd service

 -- Balint Reczey <email address hidden> Mon, 10 Feb 2020 21:26:44 +0100

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for ec2-instance-connect has completed successfully and the package is now being 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 ec2-instance-connect - 1.1.12+dfsg1-0ubuntu3~18.04.0

---------------
ec2-instance-connect (1.1.12+dfsg1-0ubuntu3~18.04.0) bionic; urgency=medium

  * Rebuild for Bionic

ec2-instance-connect (1.1.12+dfsg1-0ubuntu3) focal; urgency=medium

  * debian/preinst: Don't remove ec2-instance-connect.conf manually on upgrade
  * debian/prerm: Drop obsolete file

ec2-instance-connect (1.1.12+dfsg1-0ubuntu2) focal; urgency=medium

  * Ship ssh.service drop-in instead of handling placement in maintainer scripts
    (LP: #1861909)

ec2-instance-connect (1.1.12+dfsg1-0ubuntu1) focal; urgency=medium

  [ Balint Reczey ]
  * New upstream version 1.1.11:
    - Removing errant write to /tmp
    - Cleaning up bad bash practices, including umask race condition
    - Fix for an update to openssl (or dependencies) affecting behavior
      of CApath option on openssl verify
    - Fixing Nitro behavior of hostkey harvesting
    - Adding additional licensing headers
  * New upstream version 1.1.12 (LP: #1860142):
    - Adding support for Instance Metadata Service Version 2
    - Modifying cURL invocation to avoid need for eval
    - Cleaning up shellcheck catches
  * debian/install: Adjust for new upstream source layout
  * Suppress systemctl messages and ignore error in maintainer scripts
  * Bump compat level to 10

  [ LordAlfredo ]
  * Rely on debhelper to enable and start systemd service

 -- Balint Reczey <email address hidden> Mon, 10 Feb 2020 21:26:44 +0100

[Launchpad Janitor (janitor)]

This bug was fixed in the package ec2-instance-connect - 1.1.12+dfsg1-0ubuntu3~16.04.0

---------------
ec2-instance-connect (1.1.12+dfsg1-0ubuntu3~16.04.0) xenial; urgency=medium

  * Rebuild for Xenial

ec2-instance-connect (1.1.12+dfsg1-0ubuntu3) focal; urgency=medium

  * debian/preinst: Don't remove ec2-instance-connect.conf manually on upgrade
  * debian/prerm: Drop obsolete file

ec2-instance-connect (1.1.12+dfsg1-0ubuntu2) focal; urgency=medium

  * Ship ssh.service drop-in instead of handling placement in maintainer scripts
    (LP: #1861909)

ec2-instance-connect (1.1.12+dfsg1-0ubuntu1) focal; urgency=medium

  [ Balint Reczey ]
  * New upstream version 1.1.11:
    - Removing errant write to /tmp
    - Cleaning up bad bash practices, including umask race condition
    - Fix for an update to openssl (or dependencies) affecting behavior
      of CApath option on openssl verify
    - Fixing Nitro behavior of hostkey harvesting
    - Adding additional licensing headers
  * New upstream version 1.1.12 (LP: #1860142):
    - Adding support for Instance Metadata Service Version 2
    - Modifying cURL invocation to avoid need for eval
    - Cleaning up shellcheck catches
  * debian/install: Adjust for new upstream source layout
  * Suppress systemctl messages and ignore error in maintainer scripts
  * Bump compat level to 10

  [ LordAlfredo ]
  * Rely on debhelper to enable and start systemd service

 -- Balint Reczey <email address hidden> Mon, 10 Feb 2020 21:26:44 +0100