SECTION(global, bounce)m4_dnl
delay_warning = 1h : 24h : 2d
+SECTION(global, tls)m4_dnl
+tls_certificate = CONF_sysconf_dir/server.cert
+tls_privatekey = CONF_sysconf_dir/server.key
+tls_advertise_hosts = ${if exists {CONF_sysconf_dir/server.key} {*}{}}
+tls_dhparam = CONF_ca_dir/dh-param-2048.pem
+tls_require_ciphers = ${if or {{={$received_port}{CONF_submission_port}} \
+ {match_ip {$sender_host_address}{+trusted}}} \
+ {CONF_good_ciphers} \
+ {CONF_acceptable_ciphers}}
+tls_verify_certificates = CONF_ca_dir/ca.cert
+tls_verify_hosts = ${if eq{$acl_c_mode}{submission} {} {+allnets}}
+
DIVERT(null)
###--------------------------------------------------------------------------
### Access control lists.
{CONF_sysconf_dir/helo.conf} \
{${if match_ip \
{$sender_host_address} \
- {$value}}}}}}
+ {<; $value}}}}}}
!verify = helo
set acl_c_helo_warning = true
## Reject if the client isn't allowed to relay and the recipient
## isn't in one of our known domains.
- deny message = Relaying not permitted
- !hosts = CONF_relay_clients
- !authenticated = *
- !domains = +known
+ require message = Relaying not permitted
+ acl = check_relay
## Ensure that the recipient is routable.
require message = Invalid recipient \
($recipient_verify_failure; $acl_verify_message)
verify = recipient
+SECTION(acl, misc)m4_dnl
+check_relay:
+ ## Accept either if the client is allowed to relay through us, or if
+ ## we're the correct place to send this mail.
+
+ ## Known clients and authenticated users are OK.
+ accept hosts = CONF_relay_clients
+ accept authenticated = *
+
+ ## Known domains are OK.
+ accept domains = +public
+
+ ## Finally, domains in our table are OK, unless they say they aren't.
+ accept domains = \
+ ${if exists{CONF_sysconf_dir/domains.conf} \
+ {partial0-lsearch; CONF_sysconf_dir/domains.conf}}
+ condition = DOMKV(service, {$value}{true})
+
+ ## Nope, that's not allowed.
+ deny
+
SECTION(acl, rcpt-tail)m4_dnl
## Everything checks out OK: let this one go through.
accept
warn set acl_c_user = $authenticated_id
hosts = +thishost
!authenticated = *
+ condition = ${if def:sender_ident}
set acl_c_user = $sender_ident
- ## User must be authenticated.
+ ## User must be authenticated by now.
deny message = Sender not authenticated
- !hosts = +thishost
- !authenticated = *
+ condition = ${if !def:acl_c_user}
## Make sure that the local part is one that the authenticated sender
## is allowed to claim.
deny message = Sender address forbidden to calling user
+ !condition = \
+ ${if exists {CONF_sysconf_dir/auth-sender.conf} \
+ {${lookup {$acl_c_user} \
+ lsearch \
+ {CONF_sysconf_dir/auth-sender.conf} \
+ {${if match_address \
+ {$sender_address} \
+ {+value}}} \
+ {false}}}}
!condition = ${LOOKUP_DOMAIN($sender_address_domain,
{${if and {{match_local_part \
{$acl_c_user} \
return_path_add = true:>)
SECTION(transports)m4_dnl
-## A standard transport for remote delivery. Try to do TLS, and don't worry
-## too much if it's not very secure: the alternative is sending in plaintext
-## anyway.
+## A standard transport for remote delivery. By default, try to do TLS, and
+## don't worry too much if it's not very secure: the alternative is sending
+## in plaintext anyway. But all of this can be overridden from the
+## `domains.conf' file. Annoyingly, the `tls_dh_min_bits' setting isn't
+## expanded before use, so we can't set it the obvious way. Instead, encode
+## it into the transport name. This is very unpleasant, of course.
smtp:
driver = smtp
tls_require_ciphers = CONF_acceptable_ciphers
tls_dh_min_bits = 1020
tls_tempfail_tryclear = true
+m4_define(<:SMTP_TRANS_DHBITS:>,
+ <:driver = smtp
+ hosts_try_auth = *
+ hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
+ hosts_require_auth = \
+ ${if bool {DOMKV(require-auth, {$value}{false})} {*}{}}
+ tls_certificate = DOMKV(tls-certificate, {${expand:$value}}fail)
+ tls_privatekey = DOMKV(tls-private-key, {${expand:$value}}fail)
+ tls_verify_certificates = DOMKV(tls-peer-ca, {${expand:$value}}fail)
+ tls_require_ciphers = \
+ DOMKV(tls-ciphers,
+ {${extract {${expand:$value}} \
+ { good = CONF_good_ciphers \
+ any = CONF_acceptable_ciphers } \
+ {$value} \
+ {${expand:$value}}}} \
+ {CONF_acceptable_ciphers})
+ tls_dh_min_bits = $1
+ tls_tempfail_tryclear = true:>)m4_dnl
+smtp_dhbits_1024:
+ SMTP_TRANS_DHBITS(1020)
+smtp_dhbits_2048:
+ SMTP_TRANS_DHBITS(2046)
+
## Transport to a local SMTP server; use TLS and perform client
## authentication.
smtp_local:
~mdw / exim-config / blobdiff