X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/4ae6e648660146fd44e7aa00669d00e49c17c31a..36f7a17f69fe27a4c04a4ff98f80f780007db175:/doc/doc-docbook/spec.xfpt diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 63a78fc02..0d6c23907 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -9434,11 +9434,14 @@ letters appear. For example: &*$h_*&<&'header&~name'&>&*:*&" &&& "&*$bheader_*&<&'header&~name'&>&*:*&&~or&~&&& &*$bh_*&<&'header&~name'&>&*:*&" &&& + "&*$lheader_*&<&'header&~name'&>&*:*&&~or&~&&& + &*$lh_*&<&'header&~name'&>&*:*&" "&*$rheader_*&<&'header&~name'&>&*:*&&~or&~&&& &*$rh_*&<&'header&~name'&>&*:*&" .cindex "expansion" "header insertion" .vindex "&$header_$&" .vindex "&$bheader_$&" +.vindex "&$lheader_$&" .vindex "&$rheader_$&" .cindex "header lines" "in expansion strings" .cindex "header lines" "character sets" @@ -9451,7 +9454,7 @@ The newline that terminates a header line is not included in the expansion, but internal newlines (caused by splitting the header line over several physical lines) may be present. -The difference between &%rheader%&, &%bheader%&, and &%header%& is in the way +The difference between the four pairs of expansions is in the way the data in the header line is interpreted. .ilist @@ -9459,6 +9462,15 @@ the data in the header line is interpreted. &%rheader%& gives the original &"raw"& content of the header line, with no processing at all, and without the removal of leading and trailing white space. +.next +.cindex "list" "of header lines" +&%lheader%& gives a colon-separated list, one element per header when there +are multiple headers with a given name. +Any embedded colon characters within an element are doubled, so normal Exim +list-processing facilities can be used. +The terminating newline of each element is removed; in other respects +the content is &"raw"&. + .next .cindex "base64 encoding" "in header lines" &%bheader%& removes leading and trailing white space, and then decodes base64 @@ -15082,7 +15094,7 @@ server. This reduces security slightly, but improves interworking with older implementations of TLS. -option gnutls_allow_auto_pkcs11 main boolean unset +.option gnutls_allow_auto_pkcs11 main boolean unset This option will let GnuTLS (2.12.0 or later) autoload PKCS11 modules with the p11-kit configuration files in &_/etc/pkcs11/modules/_&. @@ -17369,7 +17381,7 @@ The ordering of the two lists must match. .cindex SSMTP .cindex SMTPS This option specifies a list of incoming SSMTP (aka SMTPS) ports that should -operate the obsolete SSMTP (SMTPS) protocol, where a TLS session is immediately +operate the SSMTP (SMTPS) protocol, where a TLS session is immediately set up without waiting for the client to issue a STARTTLS command. For further details, see section &<>&. @@ -30969,13 +30981,15 @@ rest of the ACL. The &%leaky%& (default) option means that the client's recorded rate is not updated if it is above the limit. The effect of this is that Exim measures the -client's average rate of successfully sent email, which cannot be greater than -the maximum allowed. If the client is over the limit it may suffer some -counter-measures (as specified in the ACL), but it will still be able to send -email at the configured maximum rate, whatever the rate of its attempts. This +client's average rate of successfully sent email, +.new +up to the given limit. +This is appropriate if the countermeasure when the condition is true +consists of refusing the message, and is generally the better choice if you have clients that retry automatically. -For example, it does not prevent a sender with an over-aggressive retry rate -from getting any email through. +If the action when true is anything more complex then this option is +likely not what is wanted. +.wen The &%strict%& option means that the client's recorded rate is always updated. The effect of this is that Exim measures the client's average rate @@ -39035,7 +39049,7 @@ tag value. Note that Exim does not check the value. This option sets the canonicalization method used when signing a message. The DKIM RFC currently supports two methods: "simple" and "relaxed". The option defaults to "relaxed" when unset. Note: the current implementation -only supports using the same canonicalization method for both headers and body. +only supports signing with the same canonicalization method for both headers and body. .option dkim_strict smtp string&!! unset This option defines how Exim behaves when signing a message that @@ -39069,22 +39083,28 @@ name will be appended. .section "Verifying DKIM signatures in incoming mail" "SECDKIMVFY" .cindex "DKIM" "verification" -Verification of DKIM signatures in SMTP incoming email is implemented via the -&%acl_smtp_dkim%& ACL. By default, this ACL is called once for each +.new +Verification of DKIM signatures in SMTP incoming email is done for all +messages for which an ACL control &%dkim_disable_verify%& has not been set. +.cindex authentication "expansion item" +Performing verification sets up information used by the +&$authresults$& expansion item. +.wen + +.new The results of that verification are then made available to the +&%acl_smtp_dkim%& ACL, &new(which can examine and modify them). +By default, this ACL is called once for each syntactically(!) correct signature in the incoming message. A missing ACL definition defaults to accept. If any ACL call does not accept, the message is not accepted. If a cutthrough delivery was in progress for the message, that is summarily dropped (having wasted the transmission effort). -To evaluate the signature in the ACL a large number of expansion variables +To evaluate the &new(verification result) in the ACL +a large number of expansion variables containing the signature status and its details are set up during the runtime of the ACL. -.cindex authentication "expansion item" -Performing verification sets up information used by the -&$authresults$& expansion item. - Calling the ACL only for existing signatures is not sufficient to build more advanced policies. For that reason, the global option &%dkim_verify_signers%&, and a global expansion variable