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fastmail / mail-dkim

Mail::DKIM Perl module, forked from svn://svn.code.sf.net/p/dkimproxy/code/Mail-DKIM/trunk
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incorrect 'unsupported algorithm' when 'v='-tag is missing #5

Closed marcbradshaw closed 4 years ago

marcbradshaw commented 4 years ago

See https://github.com/fastmail/authentication_milter/issues/28

I think I've might stumbled upon a bug when the 'v=' tag is missing in a DKIM record. The DKIM record below does not have a 'v=' tag. This tag is RECOMMENDED but not REQUIRED in the key record but the absence seems to result in a 'temperror' with a human_result blaming an unsupported algorithm.

Example: 

20160525114544pm._domainkey.paddle.com descriptive text "k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCJ6rcSjbkJ/G7dApE4FynJ6jTYI2pKgE9QVDAf0OLpg6WdvtwqyKaayHcqrIljorgs9jZjhQbdF14e1DGcTXPJF8m0tfeQeeNgP5PaHel0plhLJDpT964zfZaUEr5NLeE0fkMZ16CiAyB8ZpH4y4m8FK5O5HGvkAuTgmfF4bVYhwIDAQAB"

DMARC report:

<dkim>
    <domain>paddle.com</domain>
    <selector>20160525114544pm</selector>
    <result>temperror</result>
    <human_result>invalid (unsupported algorithm rsa-sha1)</human_result>
</dkim>