How do I decrypt a PGP email attachment in OSX?

March 30, 2013 8:37 AM

I have a PGP key and Thunderbird with Enigmail for OSX. A friend sent me an email with an encrypted attachment (filename ending in .pgp). While I know how to decrypt the email itself, I don't know how to decrypt the attachment.
posted by Spurious to Work & Money (2 answers total)

If you have Enigmail, you must have the helper application gpg (or something compatible). So, save the attachment from Thunderbird, then in a Terminal / Console window, do:

Spurious@MacName$ gpg Downloads/the-attachment-you-saved.pgp

GPG should be able to figure out what to do; it'll probably ask you for your passphrase, and may ask where to save the decrypted file. (I'm not really sure; I usually use other programs and workflows to encrypt and decrypt files.)

If you get an error along the lines of "gpg: command not found" then you'll need to figure out where the program was installed before you can run that terminal command. On my system, gpg is at /usr/local/bin/gpg, but I don't remember whether that's the default location, or just where I put it.

Once you find gpg, just put the full path name in the command above. E.g.:

spacewrench@MyMac$ /usr/local/bin/gpg attachment-name.pgp

(Actually, I just checked: enigmail itself knows where pgp/gpg is, and will tell you if you look in the settings / preferences.)
posted by spacewrench at 9:02 AM on March 30, 2013 [2 favorites]

Response by poster: Thanks! Worked like a charm!
posted by Spurious at 10:20 AM on March 30, 2013