Linux gpg

Import Public/Private Key

It doesn't make a difference if its a private key or public key, this is the correct way to import a key.

 gpg --import file.gpg

Export Public Key

This is the command to export your public key, using the armor command will convert the key from binary to ascii, so you can email it or post it.

 gpg --armor --export you@example.com > mykey.asc

Another way

 gpg --output mykey_pub.gpg --armor --export me@email.com

If you have more then one key another way where ABAACA is the hash.

 gpg --output mykey_pub.gpg --armor --export ABAACA

Export a base64 output of your public key.

 gpg --export me@email.com | base64

Export Private Key

To export your private key.

 gpg --output mykey_sec.gpg --armor --export-secret-key me@email.com

another way, where ABAACA is the hash

 gpg --output mykey_sec.gpg --armor --export-secret-key ABAACA

Base64 export of your private key.

  gpg --export-secret-key me@email.com | base64

List Keys

To see a list of all the keys in the system.

 gpg --list-keys

Sign a file

This will create a single file called text.sig that will contain both the file and the signature.

 gpg --clear-sig --output text.sig text.txt

This will create a single file called text.sig that contains an ascii file with just the signature.

 gpg --detach-sign --armor --output text.sig text.txt

This will create a single file called text.sig with a binary signature.

 gpg --detach-sign --output text.sig text.txt

This will create an binary file with a signature and original document.

 gpg --sign --output text.txt.sig text.txt

Backup

I read somewhere to back up the GPG file system, you can just copy ~/. gnupg but I have not tried this before.

Resources

https://www.debuntu.org/how-to-importexport-gpg-key-pair/

Encrypt a File with Password

To encrypt a file with a password with gpg use the following

 gpg -c filename

This will create a new encrypted file with the extension .gpg, you can delete the unencrypted file.

To decrypt the file.

 gpg -d filename

Extend the expiration date of a key

If you key expires you can extend the expiration date of the key

Command

 gpg --quick-set-expire {key_id} {extended_amount}

key_id=the key id extended_amount=The amount of time to add, d, m, y

example

 gpg --quick-set-expire 38D3CD66D0671E54B78001B43FD6190BCDE08D11 2y

https://www.gnupg.org/documentation/manuals/gnupg/OpenPGP-Key-Management.html