Relax restrictions on which ACLs verify conditions may be used

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 5915a3af339abffa198de442c491851bc4ed3591..8350b4da7b4e2c225b635678876739ad89135807 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -6606,14 +6606,15 @@ cause parts of the string to be replaced by data that is obtained from the
 lookup. Lookups of this type are conditional expansion items. Different results
 can be defined for the cases of lookup success and failure. See chapter
 &<<CHAPexpand>>&, where string expansions are described in detail.
 lookup. Lookups of this type are conditional expansion items. Different results
 can be defined for the cases of lookup success and failure. See chapter
 &<<CHAPexpand>>&, where string expansions are described in detail.

-The key for the lookup is specified as part of the string expansion.
+The key for the lookup is &*specified*& as part of the string expansion.

 .next
 Lists of domains, hosts, and email addresses can contain lookup requests as a
 way of avoiding excessively long linear lists. In this case, the data that is
 returned by the lookup is often (but not always) discarded; whether the lookup
 succeeds or fails is what really counts. These kinds of list are described in
 chapter &<<CHAPdomhosaddlists>>&.
 .next
 Lists of domains, hosts, and email addresses can contain lookup requests as a
 way of avoiding excessively long linear lists. In this case, the data that is
 returned by the lookup is often (but not always) discarded; whether the lookup
 succeeds or fails is what really counts. These kinds of list are described in
 chapter &<<CHAPdomhosaddlists>>&.

-The key for the lookup is given by the context in which the list is expanded.
+The key for the lookup is &*implicit*&,
+given by the context in which the list is expanded.

 .endlist
 
 String expansions, lists, and lookups interact with each other in such a way
 .endlist
 
 String expansions, lists, and lookups interact with each other in such a way


@@ -6648,7 +6649,8 @@ The result of the expansion is not tainted.
 
 In the second example, the lookup is a single item in a domain list. It causes
 Exim to use a lookup to see if the domain that is being processed can be found
 
 In the second example, the lookup is a single item in a domain list. It causes
 Exim to use a lookup to see if the domain that is being processed can be found

-in the file. The file could contains lines like this:
+in the file.
+The file could contains lines like this:

 .code
 domain1:
 domain2:
 .code
 domain1:
 domain2:


@@ -7093,10 +7095,7 @@ passed to a Redis database. See section &<<SECTsql>>&.
 .cindex "sqlite lookup type"
 .cindex "lookup" "sqlite"
 &(sqlite)&: The format of the query is
 .cindex "sqlite lookup type"
 .cindex "lookup" "sqlite"
 &(sqlite)&: The format of the query is

-new
-an optional filename
-followed by an SQL statement
-that is passed to an SQLite database. See section &<<SECTsqlite>>&.
+an SQL statement that is passed to an SQLite database. See section &<<SECTsqlite>>&.

 
 .next
 &(testdb)&: This is a lookup type that is used for testing Exim. It is
 
 .next
 &(testdb)&: This is a lookup type that is used for testing Exim. It is


@@ -8155,18 +8154,28 @@ SQLite is different to the other SQL lookups because a filename is required in
 addition to the SQL query. An SQLite database is a single file, and there is no
 daemon as in the other SQL databases.
 
 addition to the SQL query. An SQLite database is a single file, and there is no
 daemon as in the other SQL databases.
 

+.new

 .oindex &%sqlite_dbfile%&
 .oindex &%sqlite_dbfile%&

-The preferred way of specifying the file is by using the
-&%sqlite_dbfile%& option, set to
-an absolute path.
+There are two ways of
+specifying the file.
+The first is is by using the &%sqlite_dbfile%& main option.
+The second, which allows separate files for each query,
+is to use an option appended, comma-separated, to the &"sqlite"&
+lookup type word.  The option is the word &"file"&, then an equals,
+then the filename.
+The filename in this case cannot contain whitespace or open-brace charachters.
+.wen
+

 A deprecated method is available, prefixing the query with the filename
 separated by white space.
 A deprecated method is available, prefixing the query with the filename
 separated by white space.

-This means that the path name cannot contain white space.
+This means that

 .cindex "tainted data" "sqlite file"
 .cindex "tainted data" "sqlite file"

-It also means that the query cannot use any tainted values, as that taints
+the query cannot use any tainted values, as that taints

 the entire query including the filename - resulting in a refusal to open
 the file.
 
 the entire query including the filename - resulting in a refusal to open
 the file.
 

+In all the above cases the filename must be an absolute path.
+

 Here is a lookup expansion example:
 .code
 sqlite_dbfile = /some/thing/sqlitedb
 Here is a lookup expansion example:
 .code
 sqlite_dbfile = /some/thing/sqlitedb


@@ -9453,10 +9462,22 @@ the data type.  ACL rules always expand strings.  A couple of expansion
 conditions do not expand some of the brace-delimited branches, for security
 reasons,
 .cindex "tainted data" expansion
 conditions do not expand some of the brace-delimited branches, for security
 reasons,
 .cindex "tainted data" expansion

+.cindex "tainted data" definition

 .cindex expansion "tainted data"
 and expansion of data deriving from the sender (&"tainted data"&)
 is not permitted.
 
 .cindex expansion "tainted data"
 and expansion of data deriving from the sender (&"tainted data"&)
 is not permitted.
 

+.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 "Literal text in expanded strings" "SECTlittext"
 
 
 .section "Literal text in expanded strings" "SECTlittext"


@@ -10180,12 +10201,9 @@ in a list using the given separator.
 .wen
 
 
 .wen
 
 

-.vitem "&*${lookup{*&<&'key'&>&*}&~*&<&'search&~type'&>&*&~&&&
-        {*&<&'file'&>&*}&~{*&<&'string1'&>&*}&~{*&<&'string2'&>&*}}*&"
-This is the first of one of two different types of lookup item, which are both
-described in the next item.
-
-.vitem "&*${lookup&~*&<&'search&~type'&>&*&~{*&<&'query'&>&*}&~&&&
+.vitem "&*${lookup&~{*&<&'key'&>&*}&~*&<&'search&~type'&>&*&~&&&
+        {*&<&'file'&>&*}&~{*&<&'string1'&>&*}&~{*&<&'string2'&>&*}}*&" &&&
+       "&*${lookup&~*&<&'search&~type'&>&*&~{*&<&'query'&>&*}&~&&&

         {*&<&'string1'&>&*}&~{*&<&'string2'&>&*}}*&"
 .cindex "expansion" "lookup in"
 .cindex "file" "lookups"
         {*&<&'string1'&>&*}&~{*&<&'string2'&>&*}}*&"
 .cindex "expansion" "lookup in"
 .cindex "file" "lookups"


@@ -12455,7 +12473,7 @@ the complete argument of the ETRN command (see section &<<SECTETRN>>&).
 .cindex "tainted data"
 If the origin of the data is an incoming message,
 the result of expanding this variable is tainted.
 .cindex "tainted data"
 If the origin of the data is an incoming message,
 the result of expanding this variable is tainted.

-When un untainted version is needed, one should be obtained from
+When in untainted version is needed, one should be obtained from

 looking up the value in a local (therefore trusted) database.
 Often &$domain_data$& is usable in this role.
 
 looking up the value in a local (therefore trusted) database.
 Often &$domain_data$& is usable in this role.
 


@@ -29224,8 +29242,14 @@ certificate verification to the listed servers.  Verification either must
 or need not succeed respectively.
 
 The &%tls_verify_cert_hostnames%& option lists hosts for which additional
 or need not succeed respectively.
 
 The &%tls_verify_cert_hostnames%& option lists hosts for which additional

-checks are made: that the host name (the one in the DNS A record)
-is valid for the certificate.
+name checks are made on the server certificate.
+.new
+The match against this list is, as per other Exim usage, the
+IP for the host.  That is most closely associated with the
+name on the DNS A (or AAAA) record for the host.
+However, the name that needs to be in the certificate
+is the one at the head of any CNAME chain leading to the A record.
+.wen

 The option defaults to always checking.
 
 The &(smtp)& transport has two OCSP-related options:
 The option defaults to always checking.
 
 The &(smtp)& transport has two OCSP-related options:


@@ -31752,8 +31776,9 @@ send email. Details of how this works are given in section
 .cindex "header lines" "verifying header names only ASCII"
 .cindex "verifying" "header names only ASCII"
 This condition is relevant only in an ACL that is run after a message has been
 .cindex "header lines" "verifying header names only ASCII"
 .cindex "verifying" "header names only ASCII"
 This condition is relevant only in an ACL that is run after a message has been

-received, that is, in an ACL specified by &%acl_smtp_data%& or
-&%acl_not_smtp%&.  It checks all header names (not the content) to make sure
+received.
+This usually means an ACL specified by &%acl_smtp_data%& or &%acl_not_smtp%&.
+It checks all header names (not the content) to make sure

 there are no non-ASCII characters, also excluding control characters.  The
 allowable characters are decimal ASCII values 33 through 126.
 
 there are no non-ASCII characters, also excluding control characters.  The
 allowable characters are decimal ASCII values 33 through 126.
 


@@ -31908,7 +31933,7 @@ Note that '/' is legal in local-parts; if the address may have such
 (eg. is generated from the received message)
 they must be protected from the options parsing by doubling:
 .code
 (eg. is generated from the received message)
 they must be protected from the options parsing by doubling:
 .code

-verify = sender=${sg{${address:$h_sender:}}{/}{//}}
+verify = sender=${listquote{/}{${address:$h_sender:}}}

 .endd
 .endlist
 
 .endd
 .endlist