Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 19 Jun 2018 16:29:44 +0530
From: Dhiru Kholia <dhiru.kholia@...il.com>
To: john-users@...ts.openwall.com
Subject: Re: CAST5 GPU cracking

On Tue, Jun 19, 2018 at 3:56 PM, Solar Designer <solar@...nwall.com> wrote:
> ./gpg2john newold.asc > newold_out.txt
>
>> Cost 2 (hash algorithm [1:MD5 2:SHA1 3:RIPEMD160 8:SHA256 9:SHA384
>> 10:SHA512 11:SHA224]) is 0 for all loaded hashes
>
> Well, at least this is wrong (cost value not among the listed options)
> and probably indicates we have a bug in there.
>
> So there's probably more for us to fix to support PGP keys this old.

On CentOS 7,

$ gpg --homedir . --s2k-cipher-algo idea --s2k-mode 0 \
    --simple-sk-checksum --gen-key

$ pgpdump secring.gpg
...
Old: Secret Key Packet(tag 5)(931 bytes)
Ver 4 - new
Public key creation time - Tue Jun 19 15:04:57 IST 2018
Pub alg - RSA Encrypt or Sign(pub 1)
RSA n(2048 bits) - ...
RSA e(17 bits) - ...
Sym alg - IDEA(sym 1)
Simple string-to-key(s2k 0): Hash alg - SHA1(hash 2)
...

This is probably the oldest (and possibly weakest) GPG key type we support?

With your key,

$ pgpdump newold.asc
Old: Secret Key Packet(tag 5)(928 bytes)
Ver 3 - old
Public key creation time - Tue Jun 19 00:59:57 IST 2018
Valid days - 0[0 is forever]
Pub alg - RSA Encrypt or Sign(pub 1)
RSA n(2048 bits) - ...
RSA e(5 bits) - ...
Sym alg - IDEA(sym 1)
Simple string-to-key for IDEA
IV - 4c 24 29 7b 7d fe f2 3d
Encrypted RSA d(2046 bits) - ...
Encrypted RSA p(1024 bits) - ...
Encrypted RSA q(1024 bits) - ...
Encrypted RSA u(1022 bits) - ...
Checksum - 52 27

It seems that we don't support this (i.e. Simple string-to-key for
IDEA) S2K yet.

We might also run into a lot of false positives when cracking such
keys due to lack of a strong verifier / checksum.

Dhiru

Powered by blists - more mailing lists

Your e-mail address:

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.