For some reason, redmine:3.4 ships with ancient (2014) ruby-openid,
which is no longer compatible with the way how ruby handles HMAC.
Change-Id: I60f6f1ede059accf6b29891abcfe3b2529744e8a
From Holger:
Digest: This seems a bit of the magic of ruby but I vaguely remember having seen this before. I have
either patched or backported a fix. In newer Ruby versions "Digest" has been deprecated. The diff to
"stock" openid 2.3.0 is:
Change-Id: Idaca479140846481372ad0e1bff741bb09010847
Related: OS#3081
Harald Welte