X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/43a1dac4b63c228775d92cdc2861b6f1e76c6f1f..4341239037d5aac10b785f60f0e78570ab4ddebb:/doc/doc-docbook/spec.xfpt diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 493c094cd..d030a8411 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -8156,13 +8156,20 @@ option, you can still update it by a query of this form: ${lookup pgsql,servers=master/db/name/pw {UPDATE ...} } .endd -An older syntax places the servers specification before the query, +.new +A now-deprecated syntax places the servers specification before the query, semicolon separated: .code ${lookup mysql{servers=master; UPDATE ...} } .endd -The new version avoids potential issues with tainted -arguments in the query, for explicit expansion. +The new version avoids issues with tainted +arguments explicitly expanded as part of the query. +The entire string within the braces becomes tainted, +including the server sepcification - which is not permissible. +If the older sytax is used, a warning message will be logged. +This syntax will be removed in a future release. +.wen + &*Note*&: server specifications in list-style lookups are still problematic. @@ -8339,6 +8346,9 @@ type of match and is given below as the &*value*& information. .section "Expansion of lists" "SECTlistexpand" .cindex "expansion" "of lists" Each list is expanded as a single string before it is used. +.cindex "tainted data" tracking +&*Note*&: As a result, if any componend was tainted then the +entire result string becomes tainted. &'Exception: the router headers_remove option, where list-item splitting is done before string-expansion.'& @@ -9534,6 +9544,9 @@ start of a portion of the string that is interpreted and replaced as described below in section &<>& onwards. Backslash is used as an escape character, as described in the following section. +.cindex "tainted data" tracking +If any porttion of the result string is tainted, the entire result is. + Whether a string is expanded depends upon the context. Usually this is solely dependent upon the option for which a value is sought; in this documentation, options for which string expansion is performed are marked with † after @@ -14959,6 +14972,7 @@ See also the &'Policy controls'& section above. .row &%dsn_advertise_hosts%& "advertise DSN extensions to these hosts" .row &%ignore_fromline_hosts%& "allow &""From ""& from these hosts" .row &%ignore_fromline_local%& "allow &""From ""& from local SMTP" +.row &%limits_advertise_hosts%& "advertise LIMITS to these hosts" .row &%pipelining_advertise_hosts%& "advertise pipelining to these hosts" .row &%pipelining_connect_advertise_hosts%& "advertise pipelining to these hosts" .row &%prdr_enable%& "advertise PRDR to all hosts" @@ -15706,9 +15720,9 @@ the ACL once for each signature in the message. See section &<>&. -.option dmarc_forensic_sender main string&!! unset -.option dmarc_history_file main string unset -.option dmarc_tld_file main string unset +.option dmarc_forensic_sender main string&!! unset &&& + dmarc_history_file main string unset &&& + dmarc_tld_file main string unset .cindex DMARC "main section options" These options control DMARC processing. See section &<>& for details. @@ -16543,6 +16557,18 @@ has been built with LDAP support. +.new +.option limits_advertise_hosts main "host list&!!" * +.cindex LIMITS "suppressing advertising" +.cindex "ESMTP extensions" LIMITS +This option can be used to suppress the advertisement of the SMTP +LIMITS extension (RFC 9422) to specific hosts. +If permitted, Exim as a servier will advertise in the EHLO response +the limit for RCPT commands set by the &%recipients_max%& option (if it is set) +and the limit for MAIL commands set by the &%smtp_accept_max_per_connection%& +option. +,wen + .option local_from_check main boolean true .cindex "&'Sender:'& header line" "disabling addition of" .cindex "&'From:'& header line" "disabling checking of" @@ -17446,16 +17472,26 @@ or if the message was submitted locally (not using TCP/IP), and the &%-bnq%& option was not set. -.option recipients_max main integer 50000 +.option recipients_max main integer&!! 50000 .cindex "limit" "number of recipients" .cindex "recipient" "maximum number" -If this option is set greater than zero, it specifies the maximum number of +If the value resulting from expanding this option +is set greater than zero, it specifies the maximum number of original recipients for any message. Additional recipients that are generated by aliasing or forwarding do not count. SMTP messages get a 452 response for all recipients over the limit; earlier recipients are delivered as normal. Non-SMTP messages with too many recipients are failed, and no deliveries are done. +.new +For SMTP message the expansion is done after the connection is +accepted (but before any SMTP conversation) and may depend on +the IP addresses and port numbers of the connection. +&*Note*&: If an expansion is used for the option, +care should be taken that a resonable value results for +non-SMTP messages. +.wen + .cindex "RCPT" "maximum number of incoming" &*Note*&: The RFCs specify that an SMTP server should accept at least 100 RCPT commands in a single message. @@ -25343,6 +25379,13 @@ over a single TCP/IP connection. If the value is zero, there is no limit. For testing purposes, this value can be overridden by the &%-oB%& command line option. +.new +.cindex "ESMTP extensions" LIMITS +If the peer advertises a LIMITS extension with a MAILMAX value, +and either TLSS is in use or was not advertised, +that value also constrains the result of this option. +.wen + .option dane_require_tls_ciphers smtp string&!! unset .cindex "TLS" "requiring specific ciphers for DANE" @@ -25919,6 +25962,14 @@ each set of addresses is treated independently, and so can cause parallel connections to the same host if &%remote_max_parallel%& permits this. +.new +.cindex "ESMTP extensions" LIMITS +If the peer advertises a LIMITS extension with a RCPTMAX value, +and either TLSS is in use or was not advertised, +that value also constrains the result of this option +and no parallel connections will be caused on meeting the RCPTMAX limit. +.wen + .option message_linelength_limit smtp integer 998 .cindex "line length" limit @@ -25950,6 +26001,14 @@ If the connection is DANE-enabled then this option is ignored; only messages having the domain used for the DANE TLSA lookup are sent on the connection. +.new +.cindex "ESMTP extensions" LIMITS +If the peer advertises a LIMITS extension with a RCPTDOMAINMAX value, +and either TLSS is in use or was not advertised, +this option is regarded as being false. +.wen + + .option port smtp string&!! "see below" .cindex "port" "sending TCP/IP" .cindex "TCP/IP" "setting outgoing port" @@ -30706,6 +30765,10 @@ and the &%acl_smtp_mime%& ACLs. The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support enabled (which is the default). +If, for a specific message, an ACL control +&*dkim_disable_verify*& +has been set, this &%acl_smtp_dkim%& ACL is not called. + The ACL test specified by &%acl_smtp_dkim%& happens after a message has been received, and is executed for each DKIM signature found in a message. If not otherwise specified, the default action is to accept. @@ -41537,8 +41600,11 @@ Exim's DKIM implementation allows for .olist Signing outgoing messages: This function is implemented in the SMTP transport. It can co-exist with all other Exim features -(including transport filters) -except cutthrough delivery. +(including transport filters) except cutthrough delivery. +.new +However, signing options may not depend on headers modified by +routers, the transport or a transport filter. +.wen .next Verifying signatures in incoming messages: This is implemented by an additional ACL (acl_smtp_dkim), which can be called several times per message, with @@ -41746,10 +41812,11 @@ name will be appended. .option dkim_timestamps smtp integer&!! unset This option controls the inclusion of timestamp information in the signature. If not set, no such information will be included. -Otherwise, must be an unsigned number giving an offset in seconds from the current time -for the expiry tag -(eg. 1209600 for two weeks); -both creation (t=) and expiry (x=) tags will be included. +.new +Otherwise, must be an unsigned number giving an offset in seconds from the +current time for the expiry tag (e.g. 1209600 for two weeks); both creation +(t=) and expiry (x=) tags will be included unless the offset is 0 (no expiry). +.wen RFC 6376 lists these tags as RECOMMENDED.