John R. Levine wrote: >>> It tells me signing and encryption certificates are valid and even their >>> root certificates are valid... >> >> Well, something's wrong with it. I checked the signature in Alpine, >> Thunderbird, and Evolution, and they all agree it's fine. > > I went back and looked in more detail. The problem appears to be that > this mailing list wraps the signed body in a MIME multipart/mixed > section including both the signed message and the unsigned footer. Some > MUAs look inside the mixed and see the signature, some don't. For the > ones that do, I haven't checked to see how if at all they distinguish > the signed part from the unsigned when they show you the message (shades > of all the l= arguments.) > > So this tells me that existing mail software doesn't try very hard to > recover signatures from modified messages, even for simple changes that > don't need any guessing or heuristics to undo. Why would anyone think > that the situation with DKIM would be any different?
I think you were telling people for a while now to use it for some reason. Anyway, I don't think the problem is as you state. From what I see, I think the issue here is no MIME Application Type association for the application and extension your message was made. Your email provides this MIME info: Content-Type: APPLICATION/pkcs7-signature; name=smime.p7s Content-Transfer-Encoding: BASE64 Content-Description: S/MIME Cryptographic Signature Content-Disposition: attachment; filename=smime.p7s Software that offer auto launching (generally with user permission necessary) using MIME Application association, can either have its own table or depends on the OS to provide it. For example, under Windows, you can use a console window using the ASSOC command to get the file type for the extension: ASSOC .p7s and it returns .p7s=P7SFile then you use the FTYPE command to see what application is responsible to handle this file type. FTYPE P7SFile and it returns: p7sfile=rundll32.exe cryptext.dll,CryptExtOpenPKCS7 %1 So if the email has an attachment file name/extension smime.p7s, then it should allow the user (with permission) to load it by running the above rundll32.exe process passing the rest of the line as parameters and substituting %1 with the local temp storage FQFN for smime.p7s Now, under TBIRD, it apparently is independent of the built-in Windows MIME association table in the registry. So one would think that Outlook would not have a problem and indeed it doesn't; it displays a "seal icon" save button for the SMIME.P7S attachment file when viewing the message under OE. Under TBIRD, you can click TOOLS | OPTIONS and under the Attachments properties tab, you will see the View & Edit Associations button. For me, it is empty list - no MIME associations so shown as a file name "PART 1.2" Now why didn't it atleast show SMIME.P7S as a file attachment? You did have: Content-Disposition: attachment; filename=smime.p7s You should check bugzilla or asks the TBIRD folks why it doesn't at least show the actual file name as the attachment because even if TBIRD doesn't have its own table, when the user tries to save it, Windows will most likely make the shell association. BTW, under OE, while it does show the SMIME.P7S icon attachment, the message display is blank. That may be related to what you are talking about. In any case, its all fubar. -- Hector Santos, CTO http://www.santronics.com http://santronics.blogspot.com _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html