Note: the GPG-related code is still under development, so please try the current implementation and feel free to report any issue you have encountered. Thanks!
First, verify that you have GPG 2.1+ installed:
$ gpg2 --version | head -n1
gpg (GnuPG) 2.1.11
Update you TREZOR firmware to the latest version (at least c720614).
Install latest trezor-agent
package from gpg-agent branch:
$ pip install --user git+https://github.com/romanz/trezor-agent.git
Define your GPG user ID as an environment variable:
$ export TREZOR_GPG_USER_ID="John Doe <[email protected]>"
There are two ways to generate TREZOR-based GPG public keys, as described below.
$ trezor-gpg create | gpg2 --import # use the TREZOR to confirm signing the primary key
gpg: key 5E4D684D: public key "John Doe <[email protected]>" imported
gpg: Total number processed: 1
gpg: imported: 1
$ gpg2 --edit "${TREZOR_GPG_USER_ID}" trust # set this key to ultimate trust (option #5)
$ gpg2 -k
/home/roman/.gnupg/pubring.kbx
------------------------------
pub nistp256/5E4D684D 2016-06-17 [SC]
uid [ultimate] John Doe <[email protected]>
sub nistp256/A31D9E25 2016-06-17 [E]
$ gpg2 -k # suppose there is already a GPG primary key
/home/roman/.gnupg/pubring.kbx
------------------------------
pub rsa2048/87BB07B4 2016-06-17 [SC]
uid [ultimate] John Doe <[email protected]>
sub rsa2048/7176D31F 2016-06-17 [E]
$ trezor-gpg create --subkey | gpg2 --import # use the TREZOR to confirm signing the subkey
gpg: key 87BB07B4: "John Doe <[email protected]>" 2 new signatures
gpg: key 87BB07B4: "John Doe <[email protected]>" 2 new subkeys
gpg: Total number processed: 1
gpg: new subkeys: 2
gpg: new signatures: 2
$ gpg2 -k
/home/roman/.gnupg/pubring.kbx
------------------------------
pub rsa2048/87BB07B4 2016-06-17 [SC]
uid [ultimate] John Doe <[email protected]>
sub rsa2048/7176D31F 2016-06-17 [E]
sub nistp256/DDE80B36 2016-06-17 [S]
sub nistp256/E3D0BA19 2016-06-17 [E]
$ trezor-gpg agent &
Note: this agent intercepts all GPG requests, so make sure to close it (e.g. by using killall trezor-gpg
),
when you are done with the TREZOR-based GPG operations.
$ echo "Hello World!" | gpg2 --sign | gpg2 --verify
gpg: Signature made Fri 17 Jun 2016 08:55:13 PM IDT using ECDSA key ID 5E4D684D
gpg: Good signature from "Roman Zeyde <[email protected]>" [ultimate]
$ date | gpg2 --encrypt -r "${TREZOR_GPG_USER_ID}" | gpg2 --decrypt
gpg: encrypted with 256-bit ECDH key, ID A31D9E25, created 2016-06-17
"Roman Zeyde <[email protected]>"
Fri Jun 17 20:55:31 IDT 2016
Git can use GPG to sign and verify commits and tags (see here):
$ git config --local gpg.program gpg2
$ git commit --gpg-sign # create GPG-signed commit
$ git log --show-signature -1 # verify commit signature
$ git tag --sign "TAG" # create GPG-signed tag
$ git verify-tag "TAG" # verify tag signature