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The Secure List Server: an OpenPGP & S/MIME aware Mailman (Cernko, Patrick; Endner-Dühr, Frederic; Herrmann, Jörg)

The Secure List Server Project developed a patch for the Mailman Mailinglist server that enabled it to handle PGP and S/MIME signed resp. encrypted mails. This patch includes:

  • Signature verification for incoming mails
  • Decryption of incoming encrypted mails
  • Encryption and Signing of outgoing mails

While deploying the software on our server, I recognized, that it only had limited support for S/MIME encryption. In order to improve this, we extended the patch with:

  • Complete S/MIME support
    • WebUI for uploading list's certificate and key for list admins
    • WebUI for members to upload their certificate
    • Fixed handling of MIME messages
    • Using system's trusted CAs instead of single CA
    • Eleminated anonymize list workaround by replacing From: mail address with list's address when encrypting
  • several bugfixes and overall code review

The updated patch, based on the original one can be found here: