luizeof / dkimverify

a pure-Ruby library for validating/verifying DKIM signatures.

dkimverify

a gem for verifying DKIM signatures in Ruby

this gem does not sign mail messages (but a PR to enable it would likely be accepted, I just have no use for it.)

I'm pretty sure this actually works and I'm using it in production.

how to use

Dkim::Verifier.new(eml_filepath).verify!

the verify! method will return:

• true if the signature verifies
• false if no signature is present, and,
• raise Dkim::DkimError (or a child error) if the signature is present but does not verify.

with a debt of gratitude to:

• pydkim by @ghewgill which I used as a more-or-less literal source of translation
• carsonreinke's fork of the jhawthorne's dkim gem which I wish I had found before I started this.
• rfc6376 authors

not yet implemented

checking expiration dates (x=, t=) accounting for length limits (l= tag) tests (which I really ought to add) checking multiple dkim signature header lines (probably easy)

by

Jeremy B. Merrill The New York Times April 2017