Open Source Projects

Open source projects I contribute to or am otherwise involved with. Most of this work grows directly out of running real mail and server infrastructure - fixes and features tend to start as something I needed in production, not as changes made in the abstract.

  • OpenBSD
    A security-focused, free Unix-like operating system known for its proactive security auditing, code correctness, and integrated cryptography. I've been an OpenBSD developer for years, working across base system tools, the packet filter (PF), and the ports tree - the kind of low-level work that shows up as a stable, predictable base for everything built on top of it.
  • Apache SpamAssassin
    The widely deployed mail filtering platform used to identify spam through a combination of header/body rules, Bayesian classification, DNS blocklists, and pluggable third-party checks. I'm a member of the SpamAssassin PMC and work on core rules, plugins, and releases, including the 3.4.x maintenance branch and the 4.0 rework - much of it driven by what actually shows up in production mail streams.
  • Apache httpd
    The Apache HTTP Server, one of the most widely deployed web servers on the Internet, powering a large share of sites and APIs worldwide. I contribute to the httpd project, with a particular focus on TLS and certificate automation - including ACME-related work such as mod_md - so that certificate issuance and renewal stay automatic instead of becoming a recurring source of outages.
  • MIMEDefang
    A flexible, Perl-based framework for filtering email at the MTA level, integrating with Sendmail and Postfix through their milter interfaces to scan, modify, or reject messages before final delivery. It's the layer that ties together antivirus scanning, SpamAssassin, and custom policy logic in a lot of the mail infrastructure I run and maintain.
  • Mail::SPF
    A Perl module implementing the Sender Policy Framework (SPF), used to validate that a message is being sent from a host the domain's administrators have actually authorized. It's a small but important piece of the anti-spoofing chain alongside DKIM and DMARC, and one I keep in good shape since so much of the filtering work above depends on it.
  • BTC Black
    A threat intelligence platform providing real-time DNS blocklists (RBLs) to identify and block malicious activity. It maintains four specialized, publicly queryable DNSBL databases: a Bitcoin RBL tracking wallet addresses tied to fraud, scams, and ransomware; an ESP Accounts RBL covering hashed email-service-provider accounts (Mailchimp, SendGrid, Amazon SES) confirmed for spam or abusive bulk campaigns; a Freemail Accounts RBL of hashed addresses from providers like Gmail and Yahoo confirmed as sources of spam or phishing; and a Fuzzy Hash RBL that uses locality-sensitive hashing to catch entire families of variants with a single entry. All lists are queried over standard DNS, so they drop straight into existing mail filters and security tooling.