Hello, by default kolab use smtp with SSLv3 support. SSLv3 bugged and should be disabled by default. Read http://disablessl3.com for more info.
Quickfix :
https://cgit.kolab.org/pykolab/tree/pykolab/setup/setup_mta.py#n252
OLD:
postfix_main_settings = {
"inet_interfaces": "all",
"recipient_delimiter": "+",
"local_recipient_maps": "ldap:/etc/postfix/ldap/local_recipient_maps.cf",
"mydestination": "ldap:/etc/postfix/ldap/mydestination.cf",
"transport_maps": "ldap:/etc/postfix/ldap/transport_maps.cf, hash:/etc/postfix/transport",
"virtual_alias_maps": "$alias_maps, ldap:/etc/postfix/ldap/virtual_alias_maps.cf, ldap:/etc/postfix/ldap/virtual_alias_maps_mailforwarding.cf, ldap:/etc/postfix/ldap/virtual_alias_maps_sharedfolders.cf, ldap:/etc/postfix/ldap/mailenabled_distgroups.cf, ldap:/etc/postfix/ldap/mailenabled_dynamic_distgroups.cf",
"smtpd_tls_auth_only": "yes",
"smtpd_tls_security_level": "may",
"smtp_tls_security_level": "may",
"smtpd_sasl_auth_enable": "yes",
"smtpd_sender_login_maps": "$local_recipient_maps",
"smtpd_sender_restrictions": "permit_mynetworks, reject_sender_login_mismatch",
"smtpd_recipient_restrictions": "permit_mynetworks, reject_unauth_pipelining, reject_rbl_client zen.spamhaus.org, reject_non_fqdn_recipient, reject_invalid_helo_hostname, reject_unknown_recipient_domain, reject_unauth_destination, check_policy_service unix:private/recipient_policy_inc
oming, permit",
"smtpd_sender_restrictions": "permit_mynetworks, check_policy_service unix:private/sender_policy_incoming",
"submission_recipient_restrictions": "check_policy_service unix:private/submission_policy, permit_sasl_authenticated, reject",
"submission_sender_restrictions": "reject_non_fqdn_sender, check_policy_service unix:private/submission_policy, permit_sasl_authenticated, reject",
"submission_data_restrictions": "check_policy_service unix:private/submission_policy",
"content_filter": "smtp-amavis:[127.0.0.1]:10024"
}NEW:
postfix_main_settings = {
"inet_interfaces": "all",
"recipient_delimiter": "+",
"local_recipient_maps": "ldap:/etc/postfix/ldap/local_recipient_maps.cf",
"mydestination": "ldap:/etc/postfix/ldap/mydestination.cf",
"transport_maps": "ldap:/etc/postfix/ldap/transport_maps.cf, hash:/etc/postfix/transport",
"virtual_alias_maps": "$alias_maps, ldap:/etc/postfix/ldap/virtual_alias_maps.cf, ldap:/etc/postfix/ldap/virtual_alias_maps_mailforwarding.cf, ldap:/etc/postfix/ldap/virtual_alias_maps_sharedfolders.cf, ldap:/etc/postfix/ldap/mailenabled_distgroups.cf, ldap:/etc/postfix/ldap/mailenabled_dynamic_distgroups.cf",
"smtpd_tls_auth_only": "yes",
"smtpd_tls_security_level": "may",
"smtp_tls_security_level": "may",
"smtpd_sasl_auth_enable": "yes",
"smtpd_sender_login_maps": "$local_recipient_maps",
"smtpd_sender_restrictions": "permit_mynetworks, reject_sender_login_mismatch",
"smtpd_recipient_restrictions": "permit_mynetworks, reject_unauth_pipelining, reject_rbl_client zen.spamhaus.org, reject_non_fqdn_recipient, reject_invalid_helo_hostname, reject_unknown_recipient_domain, reject_unauth_destination, check_policy_service unix:private/recipient_policy_incoming, permit",
"smtpd_sender_restrictions": "permit_mynetworks, check_policy_service unix:private/sender_policy_incoming",
"submission_recipient_restrictions": "check_policy_service unix:private/submission_policy, permit_sasl_authenticated, reject",
"submission_sender_restrictions": "reject_non_fqdn_sender, check_policy_service unix:private/submission_policy, permit_sasl_authenticated, reject",
"submission_data_restrictions": "check_policy_service unix:private/submission_policy",
"content_filter": "smtp-amavis:[127.0.0.1]:10024",
"# Disable SSLv3 ",
"smtpd_tls_protocols = !SSLv2 !SSLv3 ",
"smtp_tls_protocols = !SSLv2 !SSLv3 ",
"lmtp_tls_protocols = !SSLv2 !SSLv3 ",
"smtpd_tls_mandatory_protocols = !SSLv2 !SSLv3 ",
"smtp_tls_mandatory_protocols = !SSLv2 !SSLv3 ",
"lmtp_tls_mandatory_protocols = !SSLv2 !SSLv3 "
}how to check:
openssl s_client -starttls smtp -crlf -ssl3 -connect localhost:25
Answers:
SSLv3 disabled:
[root@mail etc]# openssl s_client -starttls smtp -crlf -ssl3 -connect localhost:25 CONNECTED(00000003) 139792975714208:error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failure:s3_pkt.c:1259:SSL alert number 40 139792975714208:error:1409E0E5:SSL routines:SSL3_WRITE_BYTES:ssl handshake failure:s3_pkt.c:598:
SSLv3 ENABLED:
[root@mail etc]# openssl s_client -starttls smtp -crlf -ssl3 -connect localhost:25 CONNECTED(00000003) depth=0 C = --, ST = SomeState, L = SomeCity, O = SomeOrganization, OU = SomeOrganizationalUnit, CN = localhost.localdomain, emailAddress = root@localhost.localdomain verify error:num=18:self signed certificate verify return:1 depth=0 C = --, ST = SomeState, L = SomeCity, O = SomeOrganization, OU = SomeOrganizationalUnit, CN = localhost.localdomain, emailAddress = root@localhost.localdomain verify return:1 Certificate chain 0 s:/C=--/ST=SomeState/L=SomeCity/O=SomeOrganization/OU=SomeOrganizationalUnit/CN=localhost.localdomain/emailAddress=root@localhost.localdomain i:/C=/ST=SomeState/L=SomeCity/O=SomeOrganization/OU=SomeOrganizationalUnit/CN=localhost.localdomain/emailAddress=root@localhost.localdomain Server certificate -----BEGIN CERTIFICATE-----