Installing certbot from jessie-backports gives authentication error

[rschulman]

The gen script currently fails when installing certbot (and associated python dependencies) from backports.

Error:

WARNING: The following packages cannot be authenticated!
  python-cffi-backend python-pkg-resources python-configargparse python-six python-idna
  python-ipaddress python-pyasn1 python-setuptools python-cryptography python-dialog
  python-dnspython python-funcsigs python-openssl python-ndg-httpsclient python-pbr
  python-psutil python-urllib3 python-requests python-rfc3339 python-mock python-acme
  python-certbot certbot

As far as I can tell, backports does not have a different signing key from the jessie stable packages.

[rschulman]

Things tried so far:

• Including the PGP signing key for Debian (in case only the Raspbian signing key is included by default)
• Calling apt-key update before update and dist-upgrade

[dhowe]

Same problem

[rschulman]

@dhowe: Check the certbox_fix branch in this repo that appears to fix the problem, although I have no idea what I did differently from when I opened the issue to make it work, sadly. Waiting to close this until I merge in that branch.