#15 add whitelist without dkim sig to domains cisco firewall bug


It would be nice to have a list feature in milter
not to sign mails with dkim to domains/ips
which have a buggy cisco firewall which has problems with long dkim headers, cause otherwise mails rest in postfix unless they get bounce cause they couldnt get delivered
this mustn be perfect ( i know it may lead to trouble with multi recipient mails ) but its better than arent able to send to such ips/domains with ignorant admins


  • Anonymous - 2007-07-28
    • assigned_to: nobody --> sm-msk
  • Anonymous - 2007-07-30
    • priority: 5 --> 3
  • Anonymous - 2007-08-03

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    It appears Cisco is already working on a fix for the PIX product. Even if they're not, Cisco is a supporter (in fact, a co-author) of DKIM so they have to fix their stuff regardless of what we do here.

    At the moment we're not sure a fix for this is a good idea. Maintaining a list of sites operating buggy mail filtering firewalls doesn't scale to Internet size, and there's no way to know in advance who's running such a firewall. Any hack we can add to this package will only serve a small percentage of the users out there, making it not a universally useful change to the package.

    Given those facts and the other concerns addressed about this on the discuss list, I don't believe we'll be dealing with this in the filter before Cisco gets a PIX fix out there anyway.

  • Anonymous - 2007-08-03
    • status: open --> closed-rejected
  • Anonymous - 2007-08-03

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    Cisco's rep here says there's a patch to PIX firewalls available.

    The issue is not the size of the DKIM header field. The problem is PIX sees "Content-Type" twice in the message header, determines it must be an attack, and rejects the message.

    You can work around this already by omitting "Content-Type" headers from being signed. See the "-o" command line option or the "OmitHeaders" config file option in the current code to do this.


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