gpg: Can't check signature: No public key

Question

I can decrypt file on one machine, but on another one it says "can't check signature" (but still decrypts file).

$ sudo gpg --lock-never -o update.tar -r my@email.com --decrypt myfile.sig
gpg: Signature made <DATETIME>
gpg:                using RSA key <KEY>
gpg: Can't check signature: No public key

How can I find public key on a machine where it works?

---

Decryption works, i.e. I am seeing update.tar and it is not corrupted. The only problem only is error message about signature check. On one machine I have it and on another I don't. I.e. another machine has public key to check signature somewhere. How to find it?

Answer 1

You may need to reimport/export your keys and import them:

run this in a file, make sure you run chmod +x file first.

#!/bin/bash
your_id_here="$@"
#your_id_here is your ID.:

#Export keys and ownertrust:
exportkey() {
gpg --export --armor $your_id_here > $your_id_here.pub.asc
gpg --export-secret-keys --armor $your_id_here > $your_id_here.priv.asc
gpg --export-secret-subkeys --armor $your_id_here > $your_id_here.sub_priv.asc
gpg --export-ownertrust > $your_id_here.ownertrust.txt
}
exportkey

Run as ./file id on the commandline, or modify this as you will.

To make it easier to move around, run this in a folder and then tar it.

To import them:

#!/bin/bash
your_id_here="$@"
importkey() {
gpg --import $your_id_here.pub.asc
gpg --import $your_id_here.priv.asc
gpg --import $your_id_here.sub_priv.asc
gpg --import-ownertrust $your_id_here.ownertrust.txt
}
importkey

Same thing as above ./file2 id.

Of course, do untar them first before running this.

PS:

• It will obviously prompt you for your password, which you usually have when it come to gpg.

• Just bear in mind it might ask you for your password more than once (think 2 times) because of the two priv key, the rest won't ask for it i believe (unless of course you have the cache setting set in the gpg-agent.conf, in which case it will ask either once or none).

• Lastly, this only work as a per-id cases. So you'd have to list the ids of your keys yourself by using gpg -k then copy pasting the id that you'd want to backup...