WebPG for Mozilla Firefox on Linux is the same extension for other operating systems.
The (current) requirements are:
- gpg
- A working key agent
- gnupg2
A working key agent is absolutely necessary, as, the web browser client should never be asking for the passphrase to unlock a private key - I have this belief for the following reasons
- The user should not be encouraged to type their passphrase into anything other than the key agent (ESPECIALLY NOT THE BROWSER)
- Passing around the passphrase within the browser is a dangerous proposition
The gnupg2 package is required because it provides gpgconf - which is used to control aspects of gpg during operations such signing. (without gpgconf, the gpg configuration cannot be modified through libgpgme)