To assist our users in verifying the authenticity of our software releases, we digitally sign them. As of Fedora 3.3, this is part of the Fedora Release Process, and requires that the committer doing the final build for distribution uses their code signing key.
We have borrowed heavily from the release signing policy used by the ASF.
When generating your code signing key:
- Use a 4096 bit RSA key with SHA512 hash
- Use your real name, preferred email address, and "CODE SIGNING KEY" as the comment.
- Use a strong password to protect your key
Once generated, you should:
- Keep your private key file on a safe, secure computer, and make sure you have a secure backup.
- Never use this key for purposes other than code signing or signing other keys.
1. Generate Your Key
Carefully follow the instructions here to generate your key and check that SHA1 is avoided.
Tip: Popular binaries for GnuPG 2.x can be found here:
Note: After initially generating your key with GnuPG 2.x (gpg2), you can work with it using the more commonly-available 1.4.9 release (gpg).
2. Publish Your Public Key
To enable people to find your public key, you should publish it to a well-known keyserver. This is a simple command with gpg:
gpg --send-key [yourKeyID]
...where yourKeyID is the last 8 digits of your public key fingerprint.
This will upload your public key to a well-known keyserver, which will then trigger other connected keyservers to get a copy. Afterward, you can verify the general availability of your public key by searching for your name in one of the keyservers in the SKS network.
3. Publish Your Key Fingerprint
Add your fingerprint to the Fedora Contributors page.
4. Sign Others Committers' Keys
For each fingerprint on the Fedora Contributors page:
- Download the key via:
gpg --recv-keys [fingerprint]
- Sign it via:
gpg -u [yourKeyID] --sign-key [fingerprint]
- Upload the signature via:
gpg --send-key [fingerprint]
5. Ask Other Committers to Sign Your Key
Email the other committers, notifying them that you've signed their key and uploaded the signature, and they should run:
...then ask them to sign your key as indicated above.
After they have had a chance to sign your key and upload the signature, you should also do a --refresh-keys so your local web of trust is up to date.
6. Optional: Sign Your Own Key
If you have another key you use for normal communication, you can improve the web of trust by signing your other key with with your code signing key, and vice-versa.