Increased security of TLS encryption

This commit is contained in:
Philipp Dörfler 2017-09-19 23:54:40 +02:00 committed by GitHub
parent 7c1e153d85
commit 46d14bcdf0

View file

@ -83,6 +83,21 @@ in
smtpd_sasl_path = private/auth smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes smtpd_sasl_auth_enable = yes
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
# TLS settings, inspired by https://github.com/jeaye/nix-files
smtpd_tls_security_level = may # Submission by mail clients is handled in submissionOptions
smtpd_tls_eecdh_grade = ultra # strong might suffice and is computationally less expensive
smtpd_tls_protocols = !SSLv2, !SSLv3 # Disable predecessors to TLS
smtpd_tls_auth_only = yes # Allowing AUTH on a non encrypted connection poses a security risk
smtpd_tls_loglevel = 1 # Log only a summary message on TLS handshake completion
# Disable weak ciphers as reported by https://ssl-tools.net
# https://serverfault.com/questions/744168/how-to-disable-rc4-on-postfix
smtpd_tls_exclude_ciphers = RC4, aNULL
smtp_tls_exclude_ciphers = RC4, aNULL
# Configure a non blocking source of randomness
tls_random_source = dev:/dev/urandom
''; '';
submissionOptions = submissionOptions =