<secondary>failure report</secondary>
<see><emphasis>bounce message</emphasis></see>
</indexterm>
+<indexterm role="concept">
+ <primary>de-tainting</primary>
+ <see><emphasis>tainting, de-tainting</emphasis></see>
+</indexterm>
+<indexterm role="concept">
+ <primary>detainting</primary>
+ <see><emphasis>tainting, de-tainting</emphasis></see>
+</indexterm>
<indexterm role="concept">
<primary>dialup</primary>
<see><emphasis>intermittently connected hosts</emphasis></see>
.cindex "tainted data" expansion
.cindex expansion "tainted data"
and expansion of data deriving from the sender (&"tainted data"&)
-is not permitted.
+.new
+is not permitted (including acessing a file using a tainted name).
+The main config option &%allow_insecure_tainted_data%& can be used as
+mitigation during uprades to more secure configurations.
+.wen
+
+.new
+Common ways of obtaining untainted equivalents of variables with
+tainted values
+.cindex "tainted data" "de-tainting"
+come down to using the tainted value as a lookup key in a trusted database.
+This database could be the filesystem structure,
+or the password file,
+or accessed via a DBMS.
+Specific methods are indexed under &"de-tainting"&.
+.wen
.section "Miscellaneous" "SECID96"
.table2
+.row &%add_environment%& "environment variables"
+.row &%allow_insecure_tainted_data%& "turn taint errors into warnings"
.row &%bi_command%& "to run for &%-bi%& command line option"
.row &%debug_store%& "do extra internal checks"
.row &%disable_ipv6%& "do no IPv6 processing"
configuration). This &"magic string"& matches the domain literal form of all
the local host's IP addresses.
+.new
+.option allow_insecure_tainted_data main boolean false
+.cindex "de-tainting"
+.oindex "allow_insecure_tainted_data"
+The handling of tainted data may break older (pre 4.94) configurations.
+Setting this option to "true" turns taint errors (which result in a temporary
+message rejection) into warnings. This option is meant as mitigation only
+and deprecated already today. Future releases of Exim may ignore it.
+The &%taint%& log selector can be used to suppress even the warnings.
+.wen
+
+
.option allow_mx_to_ip main boolean false
.cindex "MX record" "pointing to IP address"
&` smtp_protocol_error `& SMTP protocol errors
&` smtp_syntax_error `& SMTP syntax errors
&` subject `& contents of &'Subject:'& on <= lines
+&`*taint `& taint errors or warnings
&`*tls_certificate_verified `& certificate verification status
&`*tls_cipher `& TLS cipher suite on <= and => lines
&` tls_peerdn `& TLS peer DN on <= and => lines
&`CA=dane`& if using a DNS trust anchor,
and &`CV=no`& if not.
.next
+.cindex "log" "Taint warnings"
+&%taint%&: Log warnings about tainted data. This selector can't be
+turned of if &%allow_insecure_tainted_data%& is false (which is the
+default).
+.next
.cindex "log" "TLS cipher"
.cindex "TLS" "logging cipher"
&%tls_cipher%&: When a message is sent or received over an encrypted
test from the snapshots or the Git before the documentation is updated. Once
the documentation is updated, this file is reduced to a short list.
+Version 4.95
+------------
+
+ 1. The fast-ramp two phase queue run support, previously experimental, is
+ now supported by default.
+
+ 2. The native SRS support, previously experimental, is now supported. It is
+ not built unless specified in the Local/Makefile.
+
+ 3. TLS resumption support, previously experimental, is now supported and
+ included in default builds.
+
+ 4. Single-key LMDB lookups, previously experimental, are now supported.
+ The support is not built unless specified in the Local/Makefile.
+
+ 5. Option "message_linelength_limit" on the smtp transport to enforce (by
+ default) the RFC 998 character limit.
+
+ 6. An option to ignore the cache on a lookup.
+
+ 7. Quota checking during reception (i.e. at SMTP time) for appendfile-
+ transport-managed quotas.
+
+ 8. Sqlite lookups accept a "file=<path>" option to specify a per-operation
+ db file, replacing the previous prefix to the SQL string (which had
+ issues when the SQL used tainted values).
+
+ 9. Lsearch lookups accept a "ret=full" option, to return both the portion
+ of the line matching the key, and the remainder.
+
+10. A command-line option to have a daemon not create a notifier socket.
+
+11. Faster TLS startup. When various configuration options contain no
+ expandable elements, the information can be preloaded and cached rather
+ than the provious behaviour of always loading at startup time for every
+ connection. This helps particularly for the CA bundle.
+
+12. Proxy Protocol Timeout is configurable via "proxy_protocol_timeout"
+ main config option.
+
+13. Option "smtp_accept_msx_per_connection" is now expanded.
+
+13. A main config option "allow_insecure_tainted_data" allows to turn
+ taint errors into warnings.
+
Version 4.94
------------