reverse-proxy/tasks/fix/acme-contact-validation.md

id, name, status, depends_on, scope, risk, impact, level, review_findings

id	name	status	depends_on	scope	risk	impact	level	review_findings
fix/acme-contact-validation	Validate ACME contact email has non-empty address with @ sign (W2)	completed		single	trivial	isolated	implementation	W2

Description

The ACME contact validation only checks that contact.starts_with("mailto:") but doesn't verify there's an actual email address after the prefix. Values like mailto: (empty email) pass validation but will fail at the Let's Encrypt API at certificate provisioning time — after the proxy has already started.

The spec (config.md validation rule 19) now requires: "a valid mailto: URI with a non-empty email address containing an @ sign."

Changes Required

src/config/validation.rs — ACME contact validation (lines 148-153):

• After checking starts_with("mailto:"), validate the email part:

  let contact = &listener.tls.acme_contact;
  if contact.is_empty() || !contact.starts_with("mailto:") {
      errors.push(ValidationError::AcmeContactInvalid {
          bind_addr: listener.bind_addr.clone(),
      });
  } else {
      let email = &contact[7..]; // after "mailto:"
      if email.is_empty() || !email.contains('@') {
          errors.push(ValidationError::AcmeContactInvalid {
              bind_addr: listener.bind_addr.clone(),
          });
      }
  }
  

• Add tests for:
  • Valid: mailto:admin@example.com
  • Invalid: mailto: (empty), mailto:user (no @), empty string, non-mailto

Acceptance Criteria

• mailto: (empty email) is rejected by validation
• mailto:user (no @ sign) is rejected by validation
• mailto:admin@example.com still passes validation
• Non-mailto values still rejected
• New unit tests for the tightened validation
• cargo test passes
• cargo clippy passes with no warnings

References

• docs/architecture/config.md — validation rule 19
• docs/reviews/003-security-and-bug-review.md — W2 finding
• src/config/validation.rs — ACME contact validation, existing tests

Notes

To be filled on completion

Summary

To be filled on completion