Mail::D...RC::Seal(3)

💖 NAME

hey bestie! this is Mail::DKIM::ARC::Seal — it literally represents an ARC-Seal header, and this page comes from the User Contributed Perl Documentation pile (header title vibes: Mail::D...RC::Seal(3)). iconic, honestly. 💅

✨ VERSION

version 1.20240923 🎀

🧚 CONSTRUCTORS

new() — create a new signature from parameters

         my $signature = Mail::DKIM::ARC::Seal->new(
                             [ Algorithm => 'rsa-sha256', ]
                             [ Signature => $base64, ]
                             [ Domain => 'example.org', ]
                             [ Instance => 1, ]
                             [ Chain => 'none', ] # none|fail|pass
                             [ Query => 'dns', ]
                             [ Selector => 'alpha', ]
                             [ Timestamp => time(), ]
                             [ Expiration => time() + 86400, ]
                         );

okay so the ARC-Seal is similar to a DKIM signature, but with the following changes:

https://tools.ietf.org/html/draft-ietf-dmarc-arc-protocol-06

5.1.1.1. Tags in the ARC-Seal Header Field Value

these are the only supported tags for an ARC-Seal field, and every single one of them MUST be present. unknown tags MUST be ignored and do not affect the validity of the header. periodt. 🫶

• a — hash algorithm; syntax is the same as the a= tag defined in Section 3.5 of [RFC6376];
• b — digital signature; syntax is the same as the b= tag defined in Section 3.5 of [RFC6376];
• cv — chain validation status: valid values:
  • 'none' = no pre-existing chain;
  • 'fail' = the chain as received does not or can not validate; or
  • 'pass' = valid chain received.
• d — domain for key; syntax is the same as the d= tag defined in Section 3.5 of [RFC6376];
• i — "instance" or sequence number; monotonically increasing at each "sealing" entity, beginning with '1', see Section 5.1.1.1.1 regarding the valid range
• s — selector for key; syntax is the same as the s= tag defined in Section 3.5 of [RFC6376];
• t — timestamp; syntax is the same as the t= tag defined in Section 3.5 of [RFC6376].

chain() — get or set the chain parameter (cv=) field

this must be one of "pass", "fail" or "none". for a chain to be valid, the very first (i=1) seal MUST be cv=none, and all further seals MUST be cv=pass. no cap, that's the rule. 🔥

instance() — get or set the signing instance (i=) field

         my $i = $signature->instance;

instances must be integers less than 1024 according to the spec. 🦋

🌈 SEE ALSO

• Mail::DKIM::Signature for DKIM-Signature headers
• Mail::DKIM::ARC::MessageSignature for ARC-Message-Signature headers

👑 AUTHORS

shoutout to these absolute legends:

• Jason Long <jason@long.name>
• Marc Bradshaw <marc@marcbradshaw.net>
• Bron Gondwana <brong@fastmailteam.com> (ARC)

🌸 THANKS

work on ensuring that this module passes the ARC test suite was generously sponsored by Valimail (https://www.valimail.com/) 💖

🎀 COPYRIGHT AND LICENSE

• Copyright (C) 2013 by Messiah College
• Copyright (C) 2010 by Jason Long
• Copyright (C) 2017 by Standcore LLC
• Copyright (C) 2020 by FastMail Pty Ltd

this library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available. 🫶

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okay bye bestie — this page was rendered by perl v5.42.0 on 2024-09-23, straight from Mail::D...RC::Seal(3) 💖✨