Offer modern AEAD ciphers on Caddy

Why it matters

The server offers only older CBC ciphers for TLS 1.2 and no TLS 1.3, so no client gets the modern authenticated ciphers (AES-GCM or ChaCha20). CBC suites have a history of attacks and are slower.

Staged change. Do this in stages and check each one before the next, so a mistake does not break your site or your mail.

The fix

1. Caddy offers AEAD ciphers and TLS 1.3 by default. If you see this finding, a custom ciphers or protocols setting overrides the defaults, so remove it and reload.
2. Keep a copy of the previous Caddyfile, so you can restore it and reload if a client you need breaks.

Read the documentation ↗(opens in a new tab)

Related

• Reported by the cipher suites check
• Disable the RC4 cipher
• Disable the 3DES cipher
• Require forward-secret ciphers
• Retire the old TLS versions that use CBC ciphers