X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/29f5141e7cb1ee65369d8e49250134edc4e6120a..9eed571fd7c3236326cc6ea74f1455b027df7604:/doc/doc-docbook/spec.xfpt diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 1b024f8f5..e3684ba30 100644 --- 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 &<>&, 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 &<>&. -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 @@ -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 file. The file could contains lines like this: +in the file. +The file could contains lines like this: .code domain1: domain2: @@ -7093,10 +7095,7 @@ passed to a Redis database. See section &<>&. .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 &<>&. +an SQL statement that is passed to an SQLite database. See section &<>&. .next &(testdb)&: This is a lookup type that is used for testing Exim. It is @@ -8061,8 +8060,8 @@ For MySQL, PostgreSQL and Redis lookups (but not currently for Oracle and InterB it is possible to specify a list of servers with an individual query. This is done by appending a comma-separated option to the query type: .display -.endd &`,servers=`&&'server1:server2:server3:...'& +.endd Each item in the list may take one of two forms: .olist If it contains no slashes it is assumed to be just a host name. The appropriate @@ -8096,7 +8095,7 @@ option, you can still update it by a query of this form: ${lookup pgsql,servers=master/db/name/pw {UPDATE ...} } .endd -An older syntax places the servers speciification before the qury, +An older syntax places the servers specification before the query, semicolon separated: .code ${lookup mysql{servers=master; UPDATE ...} } @@ -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. +.new .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. -This means that the path name cannot contain white space. +This means that .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. +In all the above cases the filename must be an absolute path. + 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 +.cindex "tainted data" definition .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" @@ -10169,9 +10190,9 @@ You can use &`fail`& instead of {<&'string3'&>} as in a string extract. .new -.vitem &*${listquote{*&<&'separator'&>&*}{*&<&'string'&>&*}}*" -.citem quoting "for list" -.citem list quoting +.vitem &*${listquote{*&<&'separator'&>&*}{*&<&'string'&>&*}}*& +.cindex quoting "for list" +.cindex list quoting This item doubles any occurrence of the separator character in the given string. An empty string is replaced with a single space. @@ -10180,12 +10201,9 @@ in a list using the given separator. .wen -.vitem "&*${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'&>&*}}*&" &&& + "&*${lookup&~*&<&'search&~type'&>&*&~{*&<&'query'&>&*}&~&&& {*&<&'string1'&>&*}&~{*&<&'string2'&>&*}}*&" .cindex "expansion" "lookup in" .cindex "file" "lookups" @@ -12455,7 +12473,7 @@ the complete argument of the ETRN command (see section &<>&). .cindex "tainted data" If the origin of the data is an incoming message, the result of expanding this variable is tainted. -When un untainted version is needed, one should be obtained from +When in untainted version is needed, one should be obtained from looking up the value in a local (therefore trusted) database. Often &$domain_data$& is usable in this role. @@ -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 -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: