On Tue 2013-08-20 13:03:27 -0400, Daniel Kahn Gillmor wrote: > I've been meaning to write this up more cleanly, but a summary here will > have to do for now: > > The MIME Content-Type header for an inline-PGP-signed e-mail message is > not signed. This means that an attacker can replay a signed message > while undetectably changing the Content-Type. One example of such an > attack is to leave the base Content-Type as text/plain but to switch > charsets -- the same bytestream can then be interpreted differently.
I've finally written this up, with a demonstration. I'm hosting it here for now: https://dkg.fifthhorseman.net/notes/pgp-inline-harmful/ i hope this is useful for future discussions about inline PGP. Please let me know if you see any problems with the text or if you have any questions. --dkg -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 948 bytes Desc: not available URL: <http://notmuchmail.org/pipermail/notmuch/attachments/20140218/2d90bc0e/attachment.pgp>