Git error - gpg failed to sign data

Question

I just started using git and I install git and gpg via homebrew. For some reason, I get this error when i do git commit I looked at so many other stackoverflow

Answer 1

Solution:

Issue: Disabled loopback pinentry mode

To solve the problem, you need to enable loopback pinentry mode in ~/.gnupg/gpg.conf:

cat <<'EOF' >> ~/.gnupg/gpg.conf

use-agent 
pinentry-mode loopback

EOF

And also in ~/.gnupg/gpg-agent.conf (create the file if it doesn't already exist):

cat <<'EOF' >> ~/.gnupg/gpg-agent.conf

allow-loopback-pinentry

EOF

Then restart the agent with echo RELOADAGENT | gpg-connect-agent and you should be good to go!

Source

Answer 2

What solved it for me was making sure the key's name matched my git user name. I assume the emails have to match too. This might have to do with me using GPG KeyChain on my Mac. Not sure.

I thought I was naming the key when I filled this out, but I guess it was asking for my name (git user name).

Answer 3

In my case, I had to match the name stored in GitHub settings to the name and comment of the key.

So if gpg --list-keys returns uid [ultimate] Joe Blogs (fancy comment) <email@example.com> your name in .gitconfig should be Joe Blogs (fancy comment).

Initially, I had my name set as Joe Blogs and GPG would not find my key and show the "no secret key" error in strace. Unfortunately, that error didn't appear without strace and one would get the generic

error: gpg failed to sign the data
fatal: failed to write commit object

Answer 4

Git needs to know which key it is signing with.

After you have setup GPG, gpg-agent, and your gpg.conf files (see this guide), you need to run

git config --global user.signingkey EB11C755

Obviously, replace the public key at the end with your own. If you want every commit to be signed by default, use

git config --global commit.gpgsign true

Answer 5

In my case, this error occurred when running git commit on a small tmux window that was not able to fit the passphrase prompt.

$ echo "test" | gpg --clearsign
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

test
gpg: signing failed: Screen or window too small
gpg: [stdin]: clear-sign failed: Screen or window too small

Answer 6

In my case, I had mixed gpg configuration and smimesign configuration given in the commit signing documentation here: https://help.github.com/en/github/authenticating-to-github/telling-git-about-your-signing-key

After working on it for hours, I found the best way to correct it was unset everything related to gpg, and reconfiguring gpg.

As mentioned in @Jason Thrasher's answer, find all the git config related to gpg using:

git config -l | grep gpg

Then unset everything golablly as well as locally using:

git config --global --unset <config_name>
git config --local --unset <config_name>

Then reconfigure following the official documentation given above. Hope this helps.