DKIM: support oversigning. Bugs 1309, 1310

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index aa1e677127e23d1e16e19ef45602fdae047954d9..b413791d5b1f16be534d61b0b5cb12a2292d9bc2 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -9677,7 +9677,8 @@ ${readsocket{inet:[::1]:1234}{request string}}
 Only a single host name may be given, but if looking it up yields more than
 one IP address, they are each tried in turn until a connection is made. For
 both kinds of socket, Exim makes a connection, writes the request string
-(unless it is an empty string) and reads from the socket until an end-of-file
+unless it is an empty string; and no terminating NUL is ever sent)
+and reads from the socket until an end-of-file
 is read. A timeout of 5 seconds is applied. Additional, optional arguments
 extend what can be done. Firstly, you can vary the timeout. For example:
 .code
@@ -13786,6 +13787,7 @@ See also the &'Policy controls'& section above.
 .row &%bounce_message_file%&         "content of bounce"
 .row &%bounce_message_text%&         "content of bounce"
 .row &%bounce_return_body%&          "include body if returning message"
+.row &%bounce_return_linesize_limit%& "limit on returned message line length"
 .row &%bounce_return_message%&       "include original message in bounce"
 .row &%bounce_return_size_limit%&    "limit on returned message"
 .row &%bounce_sender_authentication%& "send authenticated sender with bounce"
@@ -14094,6 +14096,24 @@ error that is detected during reception, only those header lines preceding the
 point at which the error was detected are returned.
 .cindex "bounce message" "including original"
 
+.option bounce_return_linesize_limit main integer 998
+.cindex "size" "of bounce lines, limit"
+.cindex "bounce message" "line length limit"
+.cindex "limit" "bounce message line length"
+This option sets a limit in bytes on the line length of messages
+that are returned to senders due to delivery problems,
+when &%bounce_return_message%& is true.
+The default value corresponds to RFC limits.
+If the message being returned has lines longer than this value it is
+treated as if the &%bounce_return_size_limit%& (below) restriction was exceeded.
+
+The option also applies to bounces returned when an error is detected
+during reception of a messsage.
+In this case lines from the original are truncated.
+
+The option does not apply to messages generated by an &(autoreply)& transport.
+
+
 .option bounce_return_message main boolean true
 If this option is set false, none of the original message is included in
 bounce messages generated by Exim. See also &%bounce_return_size_limit%& and
@@ -23398,6 +23418,15 @@ the message. As a result, the overall timeout for a message depends on the size
 of the message. Its value must not be zero. See also &%final_timeout%&.
 
 
+.option dkim_domain smtp string&!! unset
+.option dkim_selector smtp string&!! unset
+.option dkim_private_key smtp string&!! unset
+.option dkim_canon smtp string&!! unset
+.option dkim_strict smtp string&!! unset
+.option dkim_sign_headers smtp string&!! unset
+DKIM signing options.  For details see &<<SECDKIMSIGN>>&.
+
+
 .option delay_after_cutoff smtp boolean true
 This option controls what happens when all remote IP addresses for a given
 domain have been inaccessible for so long that they have passed their retry
@@ -28588,6 +28617,14 @@ Note also that headers cannot be
 modified by any of the post-data ACLs (DATA, MIME and DKIM).
 Headers may be modified by routers (subject to the above) and transports.
 
+.new
+All the usual ACLs are called; if one results in the message being
+rejected, all effort spent in delivery (including the costs on
+the ultimate destination) will be wasted.
+Note that in the case of data-time ACLs this includes the entire
+message body.
+.wen
+
 Cutthrough delivery is not supported via transport-filters or when DKIM signing
 of outgoing messages is done, because it sends data to the ultimate destination
 before the entire message has been received from the source.
@@ -34046,13 +34083,20 @@ specific badly-behaved hosts that you have to live with.
 When Exim receives a VRFY or EXPN command on a TCP/IP connection, it
 runs the ACL specified by &%acl_smtp_vrfy%& or &%acl_smtp_expn%& (as
 appropriate) in order to decide whether the command should be accepted or not.
-If no ACL is defined, the command is rejected.
 
+.new
 .cindex "VRFY" "processing"
+When no ACL is defined for VRFY, or if it rejects without
+setting an explicit response code, the command is accepted
+(with a 252 SMTP response code)
+in order to support awkward clients that do a VRFY before every RCPT.
+.wen
 When VRFY is accepted, it runs exactly the same code as when Exim is
-called with the &%-bv%& option.
+called with the &%-bv%& option, and returns 250/451/550
+SMTP response codes.
 
 .cindex "EXPN" "processing"
+If no ACL for EXPN is defined, the command is rejected.
 When EXPN is accepted, a single-level expansion of the address is done.
 EXPN is treated as an &"address test"& (similar to the &%-bt%& option) rather
 than a verification (the &%-bv%& option). If an unqualified local part is given
@@ -37979,7 +38023,7 @@ where you accept mail from relay sources (internal hosts or authenticated
 senders).
 
 
-.section "Signing outgoing messages" "SECID513"
+.section "Signing outgoing messages" "SECDKIMSIGN"
 .cindex "DKIM" "signing"
 
 Signing is implemented by setting private options on the SMTP transport.
@@ -37994,7 +38038,7 @@ option is put into the &%$dkim_domain%& expansion variable.
 MANDATORY:
 This sets the key selector string. You can use the &%$dkim_domain%& expansion
 variable to look up a matching selector. The result is put in the expansion
-variable &%$dkim_selector%& which should be used in the &%dkim_private_key%&
+variable &%$dkim_selector%& which may be used in the &%dkim_private_key%&
 option along with &%$dkim_domain%&.
 
 .option dkim_private_key smtp string&!! unset