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Policy Considerations. Phill Hallam Baker. We have a choice. Choice 1. If it works don’t break it. Choice 2. Do the job right. An Architecture. A master plan. If we have to change. Layered Architecture Reusable Policy Statements Reusable discovery strategy.
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Policy Considerations Phill Hallam Baker
If we have to change • Layered Architecture • Reusable Policy Statements • Reusable discovery strategy
SSL • Should I use security? • HTTPS://
S/MIME, PGP • No policy layer • Authentication has limited use
STARTTLS • The best email encryption we have • Should be used 100% • Vulnerable to a downgrade attack
We can fix discovery Without changing the DNS infrastructure Or waiting for it to change
Three step discovery 1) policy = lookup (TXT, "_dkim.alice.example.com") IF policy <> NULL THEN RETURN policy 2) pointer = lookup (PTR, “alice.example.com") IF pointer == NULL THEN RETURN NULL 3) policy = lookup (TXT, "_dkim." + pointer) return policy To specify a wildcard use: *.example.com PTR _default.example.com