##
## SSL settings
##

# SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>
#ssl = yes

# PEM encoded X.509 SSL/TLS certificate and private key. They're opened before
# dropping root privileges, so keep the key file unreadable by anyone but root.
# These [snakeoil files actually exist](https://askubuntu.com/questions/396120/what-is-the-purpose-of-the-ssl-cert-snakeoil-key), but shouldn't ever be used in production!
# As `SSL_TYPE` env is required by docker-mailserver, these "snakeoil" files will be replaced on container startup.
ssl_server_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem
ssl_server_key_file = /etc/ssl/private/ssl-cert-snakeoil.key
# Fallback/Hybrid cert support. docker-mailserver will enable these when using ENV vars `SSL_ALT_CERT_PATH` and `SSL_ALT_KEY_PATH`.
#ssl_alt_cert = </path/to/alternative/cert.pem
#ssl_alt_key = </path/to/alternative/key.pem

# If key file is password protected, give the password here. Alternatively
# give it when starting dovecot with -p parameter. Since this file is often
# world-readable, you may want to place this setting instead to a different
# root owned 0600 file by using ssl_key_password = <path.
#ssl_key_password =

# PEM encoded trusted certificate authority. Set this only if you intend to use
# ssl_verify_client_cert=yes. The file should contain the CA certificate(s)
# followed by the matching CRL(s). (e.g. ssl_ca = </etc/ssl/certs/ca.pem)
#ssl_ca =

# Require that CRL check succeeds for client certificates.
#ssl_require_crl = yes

# Directory and/or file for trusted SSL CA certificates. These are used only
# when Dovecot needs to act as an SSL client (e.g. imapc backend). The
# directory is usually /etc/ssl/certs in Debian-based systems and the file is
# /etc/pki/tls/cert.pem in RedHat-based systems.
#ssl_client_ca_dir =
#ssl_client_ca_file =

# Request client to send a certificate. If you also want to require it, set
# auth_ssl_require_client_cert=yes in auth section.
#ssl_verify_client_cert = no

# Which field from certificate to use for username. commonName and
# x500UniqueIdentifier are the usual choices. You'll also need to set
# auth_ssl_username_from_cert=yes.
#ssl_cert_username_field = commonName

# SSL DH parameters
# Since v2.3.3+ Diffie-Hellman parameters have been made optional, and you are encouraged to disable non-ECC DH algorithms completely.
# `docker-mailserver` is configured to use the recommended pre-defined 4096-bit DHE Group at https://github.com/internetstandards/dhe_groups
ssl_server_dh_file = /etc/dovecot/dh.pem

# Minimum SSL protocol version to use. Potentially recognized values are SSLv3,
# TLSv1, TLSv1.1, and TLSv1.2, depending on the OpenSSL version used.
ssl_min_protocol = TLSv1.2

# SSL ciphers to use
ssl_cipher_list = ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384

# ref: https://doc.dovecot.org/main/core/summaries/settings.html#ssl_server_prefer_ciphers
ssl_server_prefer_ciphers = server

# SSL crypto device to use, for valid values run "openssl engine"
#ssl_crypto_device =