Working around SHA1 signatures in keyring

alejandro Cortez alejacortez69 at
Fri Mar 26 22:54:51 CET 2021

For a few years, using gpg (GnuPG) 2.0.22 / libgcrypt 1.5.3 from
ubuntu-14.04 I signed coworker keys using Preferences: AES256 SHA512
BZIP2 ZLIB ZIP in gpg.conf. I am currently setting up an ubuntu-20.04
workstation with gpg (GnuPG) 2.2.19 / libgcrypt 1.8.5 and it would
seem that my config got wiped at some point because the last two keys
I signed (several months ago) give the following error when checking
sigs on my new workstation:

gpg: Note: third-party key signatures using the SHA1 algorithm are rejected

I should point out that I had to add no-self-sigs-only to the
keyserver-options as I guess the default workaround to poisoned keys
(either in the original source or something debian or ubuntu added) is
a scorched earth policy, which is fine but unworkable to our web of
trust. I created some test keys to mimic the same situation and did
the following to try to fix it:

gpg --cert-digest-algo SHA512 --expert --edit-key <key to resign>

I deleted my original signature and signed again. Then I pushed the
test key to the keyservers and added import-clean to gpg.conf and
refreshed the keys from a different test user and it _seems_ to work.
Is this a sane fix? Is there a better or more proper fix?


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