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Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

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Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#81

Post by deckar01 »

TorKlingberg wrote: post #76
aftbit wrote: post #63

Hi, Eric here, co-creator of evil32. I posted a brief note on our site about this, but here's a little more detail. I found an old (local) backup of the private keys and used it to generate revocation certificates for each key. Fortunately, there is no way for anyone else to access or regenerate the private keys for this particular clone of the strong set, and I have been very careful with my copy - it is only availa…

Sorry, whose private keys did you find a backup of?

It sounds like they have issued revocation certs for the keys associated with the fake accounts to stop people from sending any more messages to the fake accounts. They are also promising not to decrypt any of the messages that were meant for the attack victims, but encrypted for the fake accounts' public keys and sent to the attacker during the attack.

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#82

Post by ktta »

amenghra wrote: post #70

http://pgp.mit.edu/pks/lookup?search=B9E39278

wait, this looks interesting. Can someone comment on this? Are you supposed to know the fingerprint after you input name and stuff or before? Or is this just modification of data like how you can add email IDs?

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#83

Post by lmm »

ktta wrote: post #82
amenghra wrote: post #70

http://pgp.mit.edu/pks/lookup?search=B9E39278

wait, this looks interesting. Can someone comment on this? Are you supposed to know the fingerprint after you input name and stuff or before? Or is this just modification of data like how you can add email IDs?

You're supposed to confirm the fingerprint with the person. At the time the recommendation was a phone call (if you knew their voice) using the PGP word list - it was felt to be computationally implausible to fake that up in realtime. Or people publish fingerprints on their site etc.

Obv. the fingerprint only matters if you want to be sure you are talking to someone specific, in which case you usually have a way to know who they are or why you care. For some use cases trust-on-first-use is adequate.

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#84

Post by derefr »

aftbit wrote: post #63

Hi, Eric here, co-creator of evil32. I posted a brief note on our site about this, but here's a little more detail. I found an old (local) backup of the private keys and used it to generate revocation certificates for each key. Fortunately, there is no way for anyone else to access or regenerate the private keys for this particular clone of the strong set, and I have been very careful with my copy - it is only availa…

> users who want to email someone discover their key by searching the keyserver for that email, then taking the newest key. This is akin to trust-on-first-use, and opts out completely from the web of trust or any kind of external verification

Well, yes? What is the alternative, if I want to email someone who exists only in the form of a pseudonymous online identity?

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#85

Post by startling »

derefr wrote: post #84
aftbit wrote: post #63

Hi, Eric here, co-creator of evil32. I posted a brief note on our site about this, but here's a little more detail. I found an old (local) backup of the private keys and used it to generate revocation certificates for each key. Fortunately, there is no way for anyone else to access or regenerate the private keys for this particular clone of the strong set, and I have been very careful with my copy - it is only availa…

> users who want to email someone discover their key by searching the keyserver for that email, then taking the newest key. This is akin to trust-on-first-use, and opts out completely from the web of trust or any kind of external verification Well, yes? What is the alternative, if I want to email someone who exists only in the form of a pseudonymous online identity?

Find the fingerprint on their website / business card / Twitter / Keybase, download the full key from the keyserver.

Anyone can upload any key to a keyserver with any name.

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#86

Post by ploxiln »

snassar wrote: post #42
d33 wrote: post #35

Earlier quoted context omitted.

At this point this is INSANE that GnuPG still defaults to short IDs...

It doesn't anymore. With GnuPG 2.1 listing of keys shows the fingerprint.

If you use gnupg 2.0.x, you can set "keyid-format long" in your gpg.conf to get 64-bit key IDs (instead of the classic 32-bit ones). Not really good enough, but a reasonably effective short-term stop-gap measure. IMHO.

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#87

Post by tomrod »

ckastner wrote: post #2

This has also been discovered with the Debian project, as I submitted a while ago [1]. The really scary part is the follow-up [2]: > € gpg --search-key samuel.thibault@gnu.org > ... > (1) Samuel Thibault > 4096 bit RSA key 7D069EE6, created: 2014-06-16 And it has 55 signatures from 55 colliding keys... Edit: even the 64-bit fingerprint is probably insufficient, see [3]. [1] https://lists.debian.org/debian-devel/2016/…

Why is this scary?

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#89

Post by vilhelm_s »

TorKlingberg wrote: post #76
aftbit wrote: post #63

Hi, Eric here, co-creator of evil32. I posted a brief note on our site about this, but here's a little more detail. I found an old (local) backup of the private keys and used it to generate revocation certificates for each key. Fortunately, there is no way for anyone else to access or regenerate the private keys for this particular clone of the strong set, and I have been very careful with my copy - it is only availa…

Sorry, whose private keys did you find a backup of?

The ones in the Evil 32 tarball (https://evil32.com/).

Re: Fake Linus Torvalds' Key Found in the Wild, No More Short-IDs

#90

Post by amenghra »

ktta wrote: post #82
amenghra wrote: post #70

http://pgp.mit.edu/pks/lookup?search=B9E39278

wait, this looks interesting. Can someone comment on this? Are you supposed to know the fingerprint after you input name and stuff or before? Or is this just modification of data like how you can add email IDs?

method 1: Keep generating keys until you have a collision.

method 2: What you said, modify the details.

A fun way to play/explore all things GPG is to use a javascript library and Chrome's javascript debugger (e.g. https://openpgpjs.org/)

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