Fix handling of server which follows a RCPT 452 with a 250. Bug 26092

[users/heiko/exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index b23f33d42d208dd8f5f5d80a4dbca3757f1c52b6..edba1232fabed75ad7b64834d58eb747178f29fc 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -161,6 +161,13 @@
 .macro index
 .echo "** Don't use .index; use .cindex or .oindex or .vindex"
 .endmacro
 .macro index
 .echo "** Don't use .index; use .cindex or .oindex or .vindex"
 .endmacro

+
+
+. use this for a concept-index entry for a header line
+.macro chindex
+.cindex "&'$1'& header line"
+.cindex "header lines" $1
+.endmacro

 . ////////////////////////////////////////////////////////////////////////////
 
 
 . ////////////////////////////////////////////////////////////////////////////
 
 


@@ -193,6 +200,8 @@
 . This chunk of literal XML implements index entries of the form "x, see y" and
 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
 . at the top level, so we have to put the .chapter directive first.
 . This chunk of literal XML implements index entries of the form "x, see y" and
 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
 . at the top level, so we have to put the .chapter directive first.

+
+. These do not turn up in the HTML output, unfortunately.  The PDF does get them.

 . /////////////////////////////////////////////////////////////////////////////
 
 .chapter "Introduction" "CHID1"
 . /////////////////////////////////////////////////////////////////////////////
 
 .chapter "Introduction" "CHID1"


@@ -318,6 +327,10 @@
   <primary>zero, binary</primary>
   <see><emphasis>binary zero</emphasis></see>
 </indexterm>
   <primary>zero, binary</primary>
   <see><emphasis>binary zero</emphasis></see>
 </indexterm>

+<indexterm role="concept">
+  <primary>headers</primary>
+  <see><emphasis>header lines</emphasis></see>
+</indexterm>

 
 .literal off
 
 
 .literal off
 


@@ -2683,10 +2696,8 @@ Exim through the local interface (see the &%-bm%& and &%-f%& options below).
 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
 users to set envelope senders.
 
 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
 users to set envelope senders.
 

-.cindex "&'From:'& header line"
-.cindex "&'Sender:'& header line"
-.cindex "header lines" "From:"
-.cindex "header lines" "Sender:"
+.chindex From:
+.chindex Sender:

 For a trusted user, there is never any check on the contents of the &'From:'&
 header line, and a &'Sender:'& line is never added. Furthermore, any existing
 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
 For a trusted user, there is never any check on the contents of the &'From:'&
 header line, and a &'Sender:'& line is never added. Furthermore, any existing
 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.


@@ -3885,7 +3896,9 @@ id, and the remaining ones must be email addresses. However, if the message is
 active (in the middle of a delivery attempt), it is not altered. This option
 can be used only by an admin user.
 
 active (in the middle of a delivery attempt), it is not altered. This option
 can be used only by an admin user.
 

-.vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
+.vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&&&
+       &~<&'host&~IP'&>&&&
+       &~<&'sequence&~number'&>&&&

         &~<&'message&~id'&>"
 .oindex "&%-MC%&"
 .cindex "SMTP" "passed connection"
         &~<&'message&~id'&>"
 .oindex "&%-MC%&"
 .cindex "SMTP" "passed connection"


@@ -4782,9 +4795,9 @@ recognized when Exim is run normally. It allows for the setting up of explicit
 .vitem &%-t%&
 .oindex "&%-t%&"
 .cindex "recipient" "extracting from header lines"
 .vitem &%-t%&
 .oindex "&%-t%&"
 .cindex "recipient" "extracting from header lines"

-.cindex "&'Bcc:'& header line"
-.cindex "&'Cc:'& header line"
-.cindex "&'To:'& header line"
+.chindex Bcc:
+.chindex Cc:
+.chindex To:

 When Exim is receiving a locally-generated, non-SMTP message on its standard
 input, the &%-t%& option causes the recipients of the message to be obtained
 from the &'To:'&, &'Cc:'&, and &'Bcc:'& header lines in the message instead of
 When Exim is receiving a locally-generated, non-SMTP message on its standard
 input, the &%-t%& option causes the recipients of the message to be obtained
 from the &'To:'&, &'Cc:'&, and &'Bcc:'& header lines in the message instead of


@@ -9716,7 +9729,7 @@ If the ACL returns defer the result is a forced-fail.  Otherwise the expansion f
 
 .vitem "&*${authresults{*&<&'authserv-id'&>&*}}*&"
 .cindex authentication "results header"
 
 .vitem "&*${authresults{*&<&'authserv-id'&>&*}}*&"
 .cindex authentication "results header"

-.cindex headers "authentication-results:"
+.chindex Authentication-Results:

 .cindex authentication "expansion item"
 This item returns a string suitable for insertion as an
 &'Authentication-Results:'&
 .cindex authentication "expansion item"
 This item returns a string suitable for insertion as an
 &'Authentication-Results:'&


@@ -11719,6 +11732,7 @@ users' filter files may be locked out by the system administrator.
 .new
 &*Note:*& Testing a path using this condition is not a sufficient way of
 de-tainting it.
 .new
 &*Note:*& Testing a path using this condition is not a sufficient way of
 de-tainting it.

+Consider using a dsearch lookup.

 .wen
 
 .vitem &*first_delivery*&
 .wen
 
 .vitem &*first_delivery*&


@@ -12324,7 +12338,7 @@ to the relevant file.
 When, as a result of aliasing or forwarding, a message is directed to a pipe,
 this variable holds the pipe command when the transport is running.
 
 When, as a result of aliasing or forwarding, a message is directed to a pipe,
 this variable holds the pipe command when the transport is running.
 

-.vitem "&$auth1$& &-- &$auth3$&"
+.vitem "&$auth1$& &-- &$auth4$&"

 .vindex "&$auth1$&, &$auth2$&, etc"
 These variables are used in SMTP authenticators (see chapters
 &<<CHAPplaintext>>&&--&<<CHAPtlsauth>>&). Elsewhere, they are empty.
 .vindex "&$auth1$&, &$auth2$&, etc"
 These variables are used in SMTP authenticators (see chapters
 &<<CHAPplaintext>>&&--&<<CHAPtlsauth>>&). Elsewhere, they are empty.


@@ -16981,7 +16995,7 @@ not count as protocol errors (see &%smtp_max_synprot_errors%&).
 .option pipelining_connect_advertise_hosts main "host list&!!" *
 .cindex "pipelining" "early connection"
 .cindex "pipelining" PIPE_CONNECT
 .option pipelining_connect_advertise_hosts main "host list&!!" *
 .cindex "pipelining" "early connection"
 .cindex "pipelining" PIPE_CONNECT

-.cindex "ESMTP extensions" X_PIPE_CONNECT
+.cindex "ESMTP extensions" PIPE_CONNECT

 If Exim is built with the SUPPORT_PIPE_CONNECT build option
 this option controls which hosts the facility is advertised to
 and from which pipeline early-connection (before MAIL) SMTP
 If Exim is built with the SUPPORT_PIPE_CONNECT build option
 this option controls which hosts the facility is advertised to
 and from which pipeline early-connection (before MAIL) SMTP


@@ -16990,7 +17004,9 @@ When used, the pipelining saves on roundtrip times.
 
 See also the &%hosts_pipe_connect%& smtp transport option.
 
 
 See also the &%hosts_pipe_connect%& smtp transport option.
 

-Currently the option name &"X_PIPE_CONNECT"& is used.
+.new
+The SMTP service extension keyword advertised is &"PIPE_CONNECT"&.
+.wen

 
 
 .option prdr_enable main boolean false
 
 
 .option prdr_enable main boolean false


@@ -22579,7 +22595,7 @@ This defaults to the incoming sender address, but can be changed by setting
 
 
 .option return_path_add transports boolean false
 
 
 .option return_path_add transports boolean false

-.cindex "&'Return-path:'& header line"
+.chindex Return-path:

 If this option is true, a &'Return-path:'& header is added to the message.
 Although the return path is normally available in the prefix line of BSD
 mailboxes, this is commonly not displayed by MUAs, and so the user does not
 If this option is true, a &'Return-path:'& header is added to the message.
 Although the return path is normally available in the prefix line of BSD
 mailboxes, this is commonly not displayed by MUAs, and so the user does not


@@ -25717,7 +25733,7 @@ If this option is set to &"smtps"&, the default value for the &%port%& option
 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 The Internet standards bodies used to strongly discourage use of this mode,
 changes to &"smtps"&, and the transport initiates TLS immediately after
 connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 The Internet standards bodies used to strongly discourage use of this mode,

-but as of RFC 8314 it is perferred over STARTTLS for message submission
+but as of RFC 8314 it is preferred over STARTTLS for message submission

 (as distinct from MTA-MTA communication).
 
 
 (as distinct from MTA-MTA communication).
 
 


@@ -27820,7 +27836,14 @@ fixed_plain:
   client_send = ^username^mysecret
 .endd
 The lack of colons means that the entire text is sent with the AUTH
   client_send = ^username^mysecret
 .endd
 The lack of colons means that the entire text is sent with the AUTH

-command, with the circumflex characters converted to NULs. A similar example
+command, with the circumflex characters converted to NULs.
+.new
+Note that due to the ambiguity of parsing three consectutive circumflex characters
+there is no way to provide a password having a leading circumflex.
+.wen
+
+
+A similar example

 that uses the LOGIN mechanism is:
 .code
 fixed_login:
 that uses the LOGIN mechanism is:
 .code
 fixed_login:


@@ -28144,6 +28167,12 @@ realease for the SCRAM-SHA-256 method.
 The macro _HAVE_AUTH_GSASL_SCRAM_SHA_256 will be defined
 when this happens.
 
 The macro _HAVE_AUTH_GSASL_SCRAM_SHA_256 will be defined
 when this happens.
 

+.new
+To see the list of mechanisms supported by the library run Exim with "auth" debug
+enabled and look for a line containing "GNU SASL supports".
+Note however that some may not have been tested from Exim.
+.wen
+

 
 .option client_authz gsasl string&!! unset
 This option can be used to supply an &'authorization id'&
 
 .option client_authz gsasl string&!! unset
 This option can be used to supply an &'authorization id'&


@@ -28163,21 +28192,44 @@ the password to be used, in clear.
 This option is exapanded before use, and should result in
 the account name to be used.
 
 This option is exapanded before use, and should result in
 the account name to be used.
 

+

 .option client_spassword gsasl string&!! unset
 .option client_spassword gsasl string&!! unset

+.new
+This option is only supported for library versions 1.9.1 and greater.
+The macro _HAVE_AUTH_GSASL_SCRAM_S_KEY will be defined when this is so.
+.wen
+

 If a SCRAM mechanism is being used and this option is set
 If a SCRAM mechanism is being used and this option is set

+and correctly sized

 it is used in preference to &%client_password%&.
 The value after expansion should be
 a 40 (for SHA-1) or 64 (for SHA-256) character string
 with the PBKDF2-prepared password, hex-encoded.
 it is used in preference to &%client_password%&.
 The value after expansion should be
 a 40 (for SHA-1) or 64 (for SHA-256) character string
 with the PBKDF2-prepared password, hex-encoded.

+

 Note that this value will depend on the salt and iteration-count
 supplied by the server.
 Note that this value will depend on the salt and iteration-count
 supplied by the server.

-
+The option is expanded before use.
+.new
+During the expansion &$auth1$& is set with the client username,
+&$auth2$& with the iteration count, and
+&$auth3$& with the salt.
+
+The intent of this option
+is to support clients that can cache thes salted password
+to save on recalculation costs.
+The cache lookup should return an unusable value
+(eg. an empty string)
+if the salt or iteration count has changed
+
+If the authentication succeeds then the above variables are set,
+.vindex "&$auth4$&"
+plus the calculated salted password value value in &$auth4$&,
+during the expansion of the &%client_set_id%& option.
+A side-effect of this expansion can be used to prime the cache.
+.wen

 
 
 .option server_channelbinding gsasl boolean false
 
 
 .option server_channelbinding gsasl boolean false

-Do not set this true and rely on the properties
-without consulting a cryptographic engineer.
-

 Some authentication mechanisms are able to use external context at both ends
 of the session to bind the authentication to that context, and fail the
 authentication process if that context differs.  Specifically, some TLS
 Some authentication mechanisms are able to use external context at both ends
 of the session to bind the authentication to that context, and fail the
 authentication process if that context differs.  Specifically, some TLS


@@ -28197,9 +28249,16 @@ This defaults off to ensure smooth upgrade across Exim releases, in case
 this option causes some clients to start failing.  Some future release
 of Exim might have switched the default to be true.
 
 this option causes some clients to start failing.  Some future release
 of Exim might have switched the default to be true.
 

-However, Channel Binding in TLS has proven to be vulnerable in current versions.
-Do not plan to rely upon this feature for security, ever, without consulting
-with a subject matter expert (a cryptographic engineer).
+. However, Channel Binding in TLS has proven to be vulnerable in current versions.
+. Do not plan to rely upon this feature for security, ever, without consulting
+. with a subject matter expert (a cryptographic engineer).
+
+.new
+This option was deprecated in previous releases due to doubts over
+the "Triple Handshake" vulnerability.
+Exim takes suitable precausions (requiring Extended Master Secret if TLS
+Session Resumption was used) for safety.
+.wen

 
 
 .option server_hostname gsasl string&!! "see below"
 
 
 .option server_hostname gsasl string&!! "see below"


@@ -36015,8 +36074,7 @@ incoming SMTP message from a source that is not permitted to send them.
 
 
 .section "Resent- header lines" "SECID220"
 
 
 .section "Resent- header lines" "SECID220"

-.cindex "&%Resent-%& header lines"
-.cindex "header lines" "Resent-"
+.chindex Resent-

 RFC 2822 makes provision for sets of header lines starting with the string
 &`Resent-`& to be added to a message when it is resent by the original
 recipient to somebody else. These headers are &'Resent-Date:'&,
 RFC 2822 makes provision for sets of header lines starting with the string
 &`Resent-`& to be added to a message when it is resent by the original
 recipient to somebody else. These headers are &'Resent-Date:'&,


@@ -36072,8 +36130,7 @@ existing &'Bcc:'& is not removed.
 
 
 .section "The Date: header line" "SECID223"
 
 
 .section "The Date: header line" "SECID223"

-.cindex "&'Date:'& header line"
-.cindex "header lines" "Date:"
+.cindex Date:

 If a locally-generated or submission-mode message has no &'Date:'& header line,
 Exim adds one, using the current date and time, unless the
 &%suppress_local_fixups%& control has been specified.
 If a locally-generated or submission-mode message has no &'Date:'& header line,
 Exim adds one, using the current date and time, unless the
 &%suppress_local_fixups%& control has been specified.


@@ -36090,8 +36147,7 @@ messages.
 
 
 .section "The Envelope-to: header line" "SECID225"
 
 
 .section "The Envelope-to: header line" "SECID225"

-.cindex "&'Envelope-to:'& header line"
-.cindex "header lines" "Envelope-to:"
+.chindex Envelope-to:

 .oindex "&%envelope_to_remove%&"
 &'Envelope-to:'& header lines are not part of the standard RFC 2822 header set.
 Exim can be configured to add them to the final delivery of messages. (See the
 .oindex "&%envelope_to_remove%&"
 &'Envelope-to:'& header lines are not part of the standard RFC 2822 header set.
 Exim can be configured to add them to the final delivery of messages. (See the


@@ -36102,8 +36158,7 @@ messages.
 
 
 .section "The From: header line" "SECTthefrohea"
 
 
 .section "The From: header line" "SECTthefrohea"

-.cindex "&'From:'& header line"
-.cindex "header lines" "From:"
+.chindex From:

 .cindex "Sendmail compatibility" "&""From""& line"
 .cindex "message" "submission"
 .cindex "submission mode"
 .cindex "Sendmail compatibility" "&""From""& line"
 .cindex "message" "submission"
 .cindex "submission mode"


@@ -36146,8 +36201,7 @@ name as described in section &<<SECTconstr>>&.
 
 
 .section "The Message-ID: header line" "SECID226"
 
 
 .section "The Message-ID: header line" "SECID226"

-.cindex "&'Message-ID:'& header line"
-.cindex "header lines" "Message-ID:"
+.chindex Message-ID:

 .cindex "message" "submission"
 .oindex "&%message_id_header_text%&"
 If a locally-generated or submission-mode incoming message does not contain a
 .cindex "message" "submission"
 .oindex "&%message_id_header_text%&"
 If a locally-generated or submission-mode incoming message does not contain a


@@ -36162,8 +36216,7 @@ in this header line by setting the &%message_id_header_text%& and/or
 
 
 .section "The Received: header line" "SECID227"
 
 
 .section "The Received: header line" "SECID227"

-.cindex "&'Received:'& header line"
-.cindex "header lines" "Received:"
+.chindex Received:

 A &'Received:'& header line is added at the start of every message. The
 contents are defined by the &%received_header_text%& configuration option, and
 Exim automatically adds a semicolon and a timestamp to the configured string.
 A &'Received:'& header line is added at the start of every message. The
 contents are defined by the &%received_header_text%& configuration option, and
 Exim automatically adds a semicolon and a timestamp to the configured string.


@@ -36179,8 +36232,7 @@ changed to the time of acceptance, which is (apart from a small delay while the
 
 
 .section "The References: header line" "SECID228"
 
 
 .section "The References: header line" "SECID228"

-.cindex "&'References:'& header line"
-.cindex "header lines" "References:"
+.chindex References:

 Messages created by the &(autoreply)& transport include a &'References:'&
 header line. This is constructed according to the rules that are described in
 section 3.64 of RFC 2822 (which states that replies should contain such a
 Messages created by the &(autoreply)& transport include a &'References:'&
 header line. This is constructed according to the rules that are described in
 section 3.64 of RFC 2822 (which states that replies should contain such a


@@ -36194,8 +36246,7 @@ incoming message. If there are more than 12, the first one and then the final
 
 
 .section "The Return-path: header line" "SECID229"
 
 
 .section "The Return-path: header line" "SECID229"

-.cindex "&'Return-path:'& header line"
-.cindex "header lines" "Return-path:"
+.chindex Return-path:

 .oindex "&%return_path_remove%&"
 &'Return-path:'& header lines are defined as something an MTA may insert when
 it does the final delivery of messages. (See the generic &%return_path_add%&
 .oindex "&%return_path_remove%&"
 &'Return-path:'& header lines are defined as something an MTA may insert when
 it does the final delivery of messages. (See the generic &%return_path_add%&


@@ -36208,7 +36259,7 @@ default), Exim removes &'Return-path:'& header lines from incoming messages.
 .section "The Sender: header line" "SECTthesenhea"
 .cindex "&'Sender:'& header line"
 .cindex "message" "submission"
 .section "The Sender: header line" "SECTthesenhea"
 .cindex "&'Sender:'& header line"
 .cindex "message" "submission"

-.cindex "header lines" "Sender:"
+.chindex Sender:

 For a locally-originated message from an untrusted user, Exim may remove an
 existing &'Sender:'& header line, and it may add a new one. You can modify
 these actions by setting the &%local_sender_retain%& option true, the
 For a locally-originated message from an untrusted user, Exim may remove an
 existing &'Sender:'& header line, and it may add a new one. You can modify
 these actions by setting the &%local_sender_retain%& option true, the


@@ -38308,8 +38359,11 @@ parentheses afterwards.
 When more than one address is included in a single delivery (for example, two
 SMTP RCPT commands in one transaction) the second and subsequent addresses are
 flagged with &`->`& instead of &`=>`&. When two or more messages are delivered
 When more than one address is included in a single delivery (for example, two
 SMTP RCPT commands in one transaction) the second and subsequent addresses are
 flagged with &`->`& instead of &`=>`&. When two or more messages are delivered

-down a single SMTP connection, an asterisk follows the IP address in the log
-lines for the second and subsequent messages.
+down a single SMTP connection, an asterisk follows the
+.new
+remote IP address (and port if enabled)
+.wen
+in the log lines for the second and subsequent messages.

 When two or more messages are delivered down a single TLS connection, the
 DNS and some TLS-related information logged for the first message delivered
 will not be present in the log lines for the second and subsequent messages.
 When two or more messages are delivered down a single TLS connection, the
 DNS and some TLS-related information logged for the first message delivered
 will not be present in the log lines for the second and subsequent messages.