--- begin forwarded text From: Pablo Calamera <pablo@microsoft.com> To: "'Robert Hettinga'" <rah@shipwright.com>, "'mac-crypto@vmeng.com'" <mac-crypto@vmeng.com> Subject: RE: Hidden WebTV signatures Date: Mon, 12 Oct 1998 11:46:37 -0700 Yes. Well, the crypto part anyways ;-)
-----Original Message----- From: mac-crypto@vmeng.com [mailto:mac-crypto@vmeng.com]On Behalf Of Robert Hettinga Sent: Sunday, October 11, 1998 8:08 AM To: mac-crypto@vmeng.com Subject: Hidden WebTV signatures
Pablo?
Did *you* do this???
:-)
Cheers, Bob Hettinga
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From: pgut001@cs.auckland.ac.nz (Peter Gutmann) To: cypherpunks@cyberpass.net Subject: Hidden WebTV signatures X-Authenticated: relaymail v0.9 on cs26.cs.auckland.ac.nz Date: Mon, 12 Oct 1998 03:29:04 (NZDT) Sender: owner-cypherpunks@cyberpass.net Precedence: first-class Reply-To: pgut001@cs.auckland.ac.nz (Peter Gutmann) X-Loop: cypherpunks@cyberpass.net
For those of you who don't read sci.crypt, Robert Ames <gnome@istar.ca> has posted an article in which he observes that all WebTV posts contain an X-WebTV-Signature: line containing base64-encoded data. For samples of WebTV-generated posts, try the alt.weemba newsgroup, which is filled with WebTV-user drool (caution: remember to employ protection when exposting your mind to the content of the messages). Some samples:
X-WebTV-Signature: 1
ETAsAhQDqtur/jfleJ2CDOnNrVoeyALEQAIUOQyCBbzjx5HHfxeMERDgCjztXOU= X-WebTV-Signature: 1
ETAtAhUAmCCzQt+Tqt6fNX+L9+gDCECaqQkCFA0YCPz5tk85mUgq7iX/u4vWvOgG
These decode into ASN.1-encoded DSA signatures, eg:
1 30 45: SEQUENCE { 3 02 21: INTEGER : 00 98 20 B3 42 DF 93 AA DE 9F 35 7F 8B F7 E8 03 : 08 40 9A A9 09 26 02 20: INTEGER : 0D 18 08 FC F9 B6 4F 39 99 48 2A EE 25 FF BB 8B : D6 BC E8 06 : }
for the second one. The key isn't included in the header, presumably the @webtv.net address can be tied to the hardware which contains some hardcoded DSA key. I wonder if WebTV users know they're signing each message they send?
Peter.
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----------------- Robert A. Hettinga <mailto: rah@philodox.com> Philodox Financial Technology Evangelism <http://www.philodox.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'
--- end forwarded text ----------------- Robert A. Hettinga <mailto: rah@philodox.com> Philodox Financial Technology Evangelism <http://www.philodox.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'