--- name: "Mail::Message::Field::DKIM" section: "3pm" platform: "linux" package: "perl-mail-message" version: "4.05-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/Mail::Message::Field::DKIM" --- # Mail::Message::Field::DKIM(3pm) message header field for dkim signatures ## NAME Mail::Message::Field::DKIM - message header field for dkim signatures ## INHERITANCE ``` Mail::Message::Field::DKIM is a Mail::Message::Field::Structured is a Mail::Message::Field::Full is a Mail::Message::Field is a Mail::Reporter ``` ## SYNOPSIS ``` my $f = Mail::Message::Field->new('DKIM-Signature' => '...'); my $g = Mail::Message::Field->new('DKIM-Signature'); $g->add... ``` ## DESCRIPTION Decode the information contained in a DKIM header. You can also construct DKIM-Signature headers this way. However, verification and signing is not yet implemented. This implementation is based on RFC6376. Extends "DESCRIPTION" in Mail::Message::Field::Structured. ## OVERLOADED Extends "OVERLOADED" in Mail::Message::Field::Structured. - overload: **""** stringification Inherited, see "OVERLOADED" in Mail::Message::Field::Full - overload: **'""'** stringification Inherited, see "OVERLOADED" in Mail::Message::Field - overload: **'0+'** numification Inherited, see "OVERLOADED" in Mail::Message::Field - overload: **'\<=**'\> numeric comparison Inherited, see "OVERLOADED" in Mail::Message::Field - overload: **bool** boolean Inherited, see "OVERLOADED" in Mail::Message::Field - overload: **cmp** string comparison Inherited, see "OVERLOADED" in Mail::Message::Field ## METHODS Extends "METHODS" in Mail::Message::Field::Structured. ### Constructors Extends "Constructors" in Mail::Message::Field::Structured. - $obj-\>**clone**() Inherited, see "Constructors" in Mail::Message::Field - $class-\>**from**($field, %options) Inherited, see "Constructors" in Mail::Message::Field::Full - $class-\>**new**($data) Inherited, see "METHODS" in Mail::Message::Field::Structured ``` -Option --Defined in --Default attributes Mail::Message::Field::Structured charset Mail::Message::Field::Full undef datum Mail::Message::Field::Structured undef encoding Mail::Message::Field::Full 'q' force Mail::Message::Field::Full false language Mail::Message::Field::Full undef ``` - attributes =\> \\@attributes\|\\%attributes - charset =\> $charset - datum =\> $date - encoding =\> 'q'\|'Q'\|'b'\|'B' - force =\> BOOLEAN - language =\> $language ### Attributes Extends "Attributes" in Mail::Message::Field::Structured. - $obj-\>**Name**() Inherited, see "Attributes" in Mail::Message::Field - $obj-\>**body**() Inherited, see "Attributes" in Mail::Message::Field - $obj-\>**folded**() Inherited, see "Attributes" in Mail::Message::Field - $obj-\>**foldedBody**( \[$body\] ) Inherited, see "Attributes" in Mail::Message::Field - $obj-\>**name**() Inherited, see "Attributes" in Mail::Message::Field - $obj-\>**unfoldedBody**( \[$body, \[$wrap\]\] ) Inherited, see "Attributes" in Mail::Message::Field - $obj-\>**wellformedName**( \[STRING\] ) Inherited, see "Attributes" in Mail::Message::Field ### The field Extends "The field" in Mail::Message::Field::Structured. - $any-\>**isStructured**( \[$name\] ) Inherited, see "The field" in Mail::Message::Field - $obj-\>**length**() Inherited, see "The field" in Mail::Message::Field - $obj-\>**nrLines**() Inherited, see "The field" in Mail::Message::Field - $obj-\>**print**( \[$fh\] ) Inherited, see "The field" in Mail::Message::Field - $obj-\>**size**() Inherited, see "The field" in Mail::Message::Field - $obj-\>**string**( \[$wrap\] ) Inherited, see "The field" in Mail::Message::Field - $obj-\>**toDisclose**() Inherited, see "The field" in Mail::Message::Field ### Access to the body Extends "Access to the body" in Mail::Message::Field::Structured. - $obj-\>**decodedBody**(%options) Inherited, see "Access to the body" in Mail::Message::Field::Full ### Access to the content Extends "Access to the content" in Mail::Message::Field::Structured. - $obj-\>**addAttribute**(...) Attributes are not supported here. - $obj-\>**addTag**($name, $value\|@values) Add a tag to the set. When the tag already exists, it is replaced. Names are (converted to) lower-case. When multiple values are given, they will be concatenated with a blank (and may get folded there later) - $obj-\>**addresses**() Inherited, see "Access to the content" in Mail::Message::Field - $obj-\>**attrPairs**() Inherited, see "Access to the content" in Mail::Message::Field::Structured - $obj-\>**attribute**( $object\|\\|\<$name,$value,%options\> ) Inherited, see "Access to the content" in Mail::Message::Field::Structured - $obj-\>**attributes**() Inherited, see "Access to the content" in Mail::Message::Field::Structured - $obj-\>**beautify**() Inherited, see "Access to the content" in Mail::Message::Field::Full - $obj-\>**comment**( \[STRING\] ) Inherited, see "Access to the content" in Mail::Message::Field - $any-\>**createComment**(STRING, %options) Inherited, see "Access to the content" in Mail::Message::Field::Full - $any-\>**createPhrase**(STRING, %options) Inherited, see "Access to the content" in Mail::Message::Field::Full - $any-\>**dateToTimestamp**(STRING) Inherited, see "Access to the content" in Mail::Message::Field - $any-\>**stripCFWS**( \[STRING\] ) Inherited, see "Access to the content" in Mail::Message::Field - $obj-\>**study**() Inherited, see "Access to the content" in Mail::Message::Field - $obj-\>**tag**($name) Returns the value for the named tag. - $any-\>**toDate**( \[$time\] ) Inherited, see "Access to the content" in Mail::Message::Field - $obj-\>**toInt**() Inherited, see "Access to the content" in Mail::Message::Field *DKIM-Signature tags* The tag methods return the tag-value content without any validation or modification. For many situations, the actual content does not need (expensive) validation and interpretation. - $obj-\>**tagAgentID**() The Agent or User Identifier (AUID). Defaults to `@$domain` - $obj-\>**tagAlgorithm**() Signature algorithm. Should be rsa-sha(1\|256): check before use. Required. - $obj-\>**tagBodyLength**() The number of octets which where used to calculate the hash. By default, the whole body was used. - $obj-\>**tagC14N**() The canonicalization method used. Defaults to 'simple/simple'. - $obj-\>**tagDomain**() The sub-domain (SDID) which claims responsibility for this signature. Required. - $obj-\>**tagExpires**() The timestamp when the signature will expire. Recommended. - $obj-\>**tagExtract**() Some headers from the original message packed together. - $obj-\>**tagQueryMethods**() A colon-separated list of method which can be used to retrieve the public key. The default is "dns/txt" (currently the only valid option) - $obj-\>**tagSelector**() The selector subdividing the domain tag. Required. - $obj-\>**tagSignData**() - $obj-\>**tagSignature**() Message signature in base64, with whitespaces removed. Required. - $obj-\>**tagSignedHeaders**() The colon separated list of headers which need to be included in the signature. Required. - $obj-\>**tagTimestamp**() When the signature was created in UNIX-like seconds (since 1970). Recommended. - $obj-\>**tagVersion**() Signature header syntax version (usually 1) ### Internals Extends "Internals" in Mail::Message::Field::Structured. - $any-\>**decode**(STRING, %options) Inherited, see "Internals" in Mail::Message::Field::Full - $obj-\>**encode**(STRING, %options) Inherited, see "Internals" in Mail::Message::Field::Full ### Parsing Extends "Parsing" in Mail::Message::Field::Structured. - $obj-\>**consume**( $line \| \<$name,\<$body\|$objects\>\> ) Inherited, see "Parsing" in Mail::Message::Field - $any-\>**consumeComment**(STRING) Inherited, see "Parsing" in Mail::Message::Field::Full - $obj-\>**consumeDotAtom**(STRING) Inherited, see "Parsing" in Mail::Message::Field::Full - $any-\>**consumePhrase**(STRING) Inherited, see "Parsing" in Mail::Message::Field::Full - $obj-\>**datum**( \[$value\] ) Inherited, see "Parsing" in Mail::Message::Field::Structured - $obj-\>**defaultWrapLength**( \[$length\] ) Inherited, see "Parsing" in Mail::Message::Field - $any-\>**fold**( $name, $body, \[$maxchars\] ) Inherited, see "Parsing" in Mail::Message::Field - $obj-\>**parse**(STRING) Inherited, see "Parsing" in Mail::Message::Field::Full - $obj-\>**produceBody**() Inherited, see "Parsing" in Mail::Message::Field::Full - $obj-\>**setWrapLength**( \[$length\] ) Inherited, see "Parsing" in Mail::Message::Field - $obj-\>**stringifyData**(STRING\|ARRAY\|$objects) Inherited, see "Parsing" in Mail::Message::Field - $obj-\>**unfold**(STRING) Inherited, see "Parsing" in Mail::Message::Field ### Error handling Extends "Error handling" in Mail::Message::Field::Structured. - $obj-\>**AUTOLOAD**() Inherited, see "Error handling" in Mail::Reporter - $obj-\>**notImplemented**() Inherited, see "Error handling" in Mail::Reporter ### Cleanup Extends "Cleanup" in Mail::Message::Field::Structured. - $obj-\>**DESTROY**() Inherited, see "Cleanup" in Mail::Reporter ## DETAILS Extends "DETAILS" in Mail::Message::Field::Structured. ## DIAGNOSTICS - Error: class $package does not implement method $method. Fatal error: the specific `$package` (or one of its superclasses) does not implement this method where it should. This message means that some other related classes do implement this method however the class at hand does not. Probably you should investigate this and probably inform the author of the package. Cast by `notImplemented()` - Warning: field content is not numerical: $content The numeric value of a field is requested (for instance the `"Lines"` or `"Content-Length"` fields should be numerical), however the data contains weird characters. Cast by `toInt()` - Error: field name too long (max $count), in '$name'. It is not specified in the RFCs how long a field name can be, but at least it should be a few characters shorter than the line wrap. Cast by `fold()` - Warning: illegal character in charset '$name'. The field is created with an utf8 string which only contains data from the specified character set. However, that character set can never be a valid name because it contains characters which are not permitted. Cast by `encode()` - Warning: illegal character in field name $name. A new field is being created which does contain characters not permitted by the RFCs. Using this field in messages may break other e-mail clients or transfer agents, and therefore mutulate or extinguish your message. Cast by `consume()` - Warning: illegal character in language '$name'. The field is created with data which is specified to be in a certain language, however, the name of the language cannot be valid: it contains characters which are not permitted by the RFCs. Cast by `encode()` - Warning: illegal encoding '$name', using 'q'. The RFCs only permit base64 (`"b "` or `"B "`) or quoted-printable (`"q"` or `"Q"`) encoding. Other than these four options are illegal. Cast by `encode()` - Error: no attributes for DKIM headers. Is is not possible to add attributes to this field. Cast by `addAttribute()` ## SEE ALSO This module is part of Mail-Message version 4.05, built on April 10, 2026. Website: *http://perl.overmeer.net/mailbox/* ## LICENSE For contributors see file ChangeLog. This software is copyright (c) 2001-2026 by Mark Overmeer. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.