X-Git-Url: https://git.exim.org/users/heiko/exim.git/blobdiff_plain/1899bab2d862898cb92c3ec9765f3357acb2bfc9..237b2cf2b5bd2539026ce0038d084595589559dd:/doc/doc-txt/experimental-spec.txt?ds=sidebyside diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt index d58f3961b..a5024d827 100644 --- a/doc/doc-txt/experimental-spec.txt +++ b/doc/doc-txt/experimental-spec.txt @@ -92,10 +92,25 @@ is requested and required for the connection to proceed. The host(s) should also be in "hosts_require_tls", and "tls_verify_certificates" configured for the transport. +For the client to be able to verify the stapled OCSP the server must +also supply, in its stapled information, any intermediate +certificates for the chain leading to the OCSP proof from the signer +of the server certificate. There may be zero or one such. These +intermediate certificates should be added to the server OCSP stapling +file (named by tls_ocsp_file). + At this point in time, we're gathering feedback on use, to determine if it's worth adding complexity to the Exim daemon to periodically re-fetch OCSP files and somehow handling multiple files. + A helper script "ocsp_fetch.pl" for fetching a proof from a CA + OCSP server is supplied. The server URL may be included in the + server certificate, if the CA is helpful. + + One fail mode seen was the OCSP Signer cert expiring before the end + of vailidity of the OCSP proof. The checking done by Exim/OpenSSL + noted this as invalid overall, but the re-fetch script did not. + @@ -697,7 +712,7 @@ use standard conditions such as hosts, senders, etc, to decide that DMARC verification should *not* be performed for them and disable DMARC with a control setting: - control = dmarc_verify_disable + control = dmarc_disable_verify A DMARC record can also specify a "forensic address", which gives exim an email address to submit reports about failed alignment. @@ -740,11 +755,13 @@ mean, refer to the DMARC website above. Valid strings are: rejecting the email. o quarantine The DMARC check failed and the library recommends keeping it for further inspection. + o none The DMARC check passed and the library recommends + no specific action, neutral. o norecord No policy section in the DMARC record for this sender domain. o nofrom Unable to determine the domain of the sender. - o none There is no DMARC record for this sender domain. - o error Library error or dns error. + o temperror Library error or dns error. + o off The DMARC check was disabled for this email. You can prefix each string with an exclamation mark to invert its meaning, for example "!accept" will match all results but @@ -803,7 +820,7 @@ b. Configure, somewhere before the DATA ACL, the control option to (RCPT ACL) warn domains = +local_domains hosts = +local_hosts - control = dmarc_verify_disable + control = dmarc_disable_verify warn !domains = +screwed_up_dmarc_records control = dmarc_enable_forensic @@ -829,6 +846,175 @@ b. Configure, somewhere before the DATA ACL, the control option to +Transport post-delivery actions +-------------------------------------------------------------- + +An arbitrary per-transport string can be expanded on successful delivery, +and (for SMTP transports) a second string on deferrals caused by a host error. +This feature may be used, for example, to write exim internal log information +(not available otherwise) into a database. + +In order to use the feature, you must set + +EXPERIMENTAL_TPDA=yes + +in your Local/Makefile + +and define the expandable strings in the runtime config file, to +be executed at end of delivery. + +Additionally, there are 6 more variables, available at end of +delivery: + +tpda_delivery_ip IP of host, which has accepted delivery +tpda_delivery_port Port of remote host which has accepted delivery +tpda_delivery_fqdn FQDN of host, which has accepted delivery +tpda_delivery_local_part local part of address being delivered +tpda_delivery_domain domain part of address being delivered +tpda_delivery_confirmation SMTP confirmation message + +In case of a deferral caused by a host-error: +tpda_defer_errno Error number +tpda_defer_errstr Error string possibly containing more details + +The $router_name and $transport_name variables are also usable. + + +To take action after successful deliveries, set the following option +on any transport of interest. + +tpda_delivery_action + +An example might look like: + +tpda_delivery_action = \ +${lookup pgsql {SELECT * FROM record_Delivery( \ + '${quote_pgsql:$sender_address_domain}',\ + '${quote_pgsql:${lc:$sender_address_local_part}}', \ + '${quote_pgsql:$tpda_delivery_domain}', \ + '${quote_pgsql:${lc:$tpda_delivery_local_part}}', \ + '${quote_pgsql:$tpda_delivery_ip}', \ + '${quote_pgsql:${lc:$tpda_delivery_fqdn}}', \ + '${quote_pgsql:$message_exim_id}')}} + +The string is expanded after the delivery completes and any +side-effects will happen. The result is then discarded. +Note that for complex operations an ACL expansion can be used. + + +In order to log host deferrals, add the following option to an SMTP +transport: + +tpda_host_defer_action + +This is a private option of the SMTP transport. It is intended to +log failures of remote hosts. It is executed only when exim has +attempted to deliver a message to a remote host and failed due to +an error which doesn't seem to be related to the individual +message, sender, or recipient address. +See section 45.2 of the exim documentation for more details on how +this is determined. + +Example: + +tpda_host_defer_action = \ +${lookup mysql {insert into delivlog set \ + msgid = '${quote_mysql:$message_exim_id}', \ + senderlp = '${quote_mysql:${lc:$sender_address_local_part}}', \ + senderdom = '${quote_mysql:$sender_address_domain}', \ + delivlp = '${quote_mysql:${lc:$tpda_delivery_local_part}}', \ + delivdom = '${quote_mysql:$tpda_delivery_domain}', \ + delivip = '${quote_mysql:$tpda_delivery_ip}', \ + delivport = '${quote_mysql:$tpda_delivery_port}', \ + delivfqdn = '${quote_mysql:$tpda_delivery_fqdn}', \ + deliverrno = '${quote_mysql:$tpda_defer_errno}', \ + deliverrstr = '${quote_mysql:$tpda_defer_errstr}' \ + }} + + +Redis Lookup +-------------------------------------------------------------- + +Redis is open source advanced key-value data store. This document +does not explain the fundamentals, you should read and understand how +it works by visiting the website at http://www.redis.io/. + +Redis lookup support is added via the hiredis library. Visit: + + https://github.com/redis/hiredis + +to obtain a copy, or find it in your operating systems package repository. +If building from source, this description assumes that headers will be in +/usr/local/include, and that the libraries are in /usr/local/lib. + +1. In order to build exim with Redis lookup support add + +EXPERIMENTAL_REDIS=yes + +to your Local/Makefile. (Re-)build/install exim. exim -d should show +Experimental_Redis in the line "Support for:". + +EXPERIMENTAL_REDIS=yes +LDFLAGS += -lhiredis +# CFLAGS += -I/usr/local/include +# LDFLAGS += -L/usr/local/lib + +The first line sets the feature to include the correct code, and +the second line says to link the hiredis libraries into the +exim binary. The commented out lines should be uncommented if you +built hiredis from source and installed in the default location. +Adjust the paths if you installed them elsewhere, but you do not +need to uncomment them if an rpm (or you) installed them in the +package controlled locations (/usr/include and /usr/lib). + + +2. Use the following global settings to configure Redis lookup support: + +Required: +redis_servers This option provides a list of Redis servers + and associated connection data, to be used in + conjunction with redis lookups. The option is + only available if Exim is configured with Redis + support. + +For example: + +redis_servers = 127.0.0.1/10/ - using database 10 with no password +redis_servers = 127.0.0.1//password - to make use of the default database of 0 with a password +redis_servers = 127.0.0.1// - for default database of 0 with no password + +3. Once you have the Redis servers defined you can then make use of the +experimental Redis lookup by specifying ${lookup redis{}} in a lookup query. + +4. Example usage: + +(Host List) +hostlist relay_from_ips = <\n ${lookup redis{SMEMBERS relay_from_ips}} + +Where relay_from_ips is a Redis set which contains entries such as "192.168.0.0/24" "10.0.0.0/8" and so on. +The result set is returned as +192.168.0.0/24 +10.0.0.0/8 +.. +. + +(Domain list) +domainlist virtual_domains = ${lookup redis {HGET $domain domain}} + +Where $domain is a hash which includes the key 'domain' and the value '$domain'. + +(Adding or updating an existing key) +set acl_c_spammer = ${if eq{${lookup redis{SPAMMER_SET}}}{OK}} + +Where SPAMMER_SET is a macro and it is defined as + +"SET SPAMMER " + +(Getting a value from Redis) + +set acl_c_spam_host = ${lookup redis{GET...}} + + -------------------------------------------------------------- End of file