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Re: MD5 To Be Considered Harmful Today

daemon@ATHENA.MIT.EDU (Pavel Machek)
Wed Dec 8 19:51:45 2004

Date: Wed, 8 Dec 2004 23:40:19 +0100
From: Pavel Machek <pavel@ucw.cz>
To: Dan Kaminsky <dan@doxpara.com>
Cc: bugtraq@securityfocus.com
Message-ID: <20041208224019.GB16124@elf.ucw.cz>
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In-Reply-To: <41B77ECF.7030404@doxpara.com>

Hi!

> >:~/misc/md5$ cat msg1
> >I agree to sell you my horse ^Fita^, its saddle and harness for price   
> >14000 dollars. Signed Bara
> >
> > 
> >
> Except you can't do this, since the appended data needs to be identical 
> between the two files.  That's why I used the encrypted payload -- it 
> ties the semantic meaning of the embedded commands to posession of 
> vec1's series of bits, which is of course what a cipher is meant to do.
> 
> Your payloads differ but the above line is incorrect.  Your actual 
> appended files:
> 
> $ cat msg1
> [terminal garbage]I agree to sell you my horse ^Fita^, its saddle and 
> harness for price   1 000 dollars. Signed Bara
> 
> $ cat msg2
> [slightly different terminal garbage]I agree to sell you my horse 
> ^Fita^, its saddle and harness for price   1 000 dollars. Signed Bara

Actually, no, it is not. Try catting it on linux console. It takes
the garbage, overwrites it with ^Hs, then writes ... "its saddle and
harness for price   1", then shifts cursor right (over 4 or `,
depending on first block), then continues with "000 dollars".

My trick does *not* work in Gnome Terminal (I've just verified
it). You need actuall linux console, press ctrl-alt-F1 on most distros
to get to one... but if you tell me what terminal you use, I can
probably create terminal sequence that works there...
								Pavel
-- 
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!

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