[Cryptography Team] Re: SSL Error

[Ron Teitelbaum]

Chris and Rob,

I just tried it again and it fails consistently.  The problem is definitely
in Cryptography-Core.

(1 to: 10) collect: [:a | 'https://tls.secg.org:40023' asUrl
retrieveContents.]

Works for core 17 and fails for core 18.

Ok I found the problem.

CBC>>initialVector: aByteArray
	"Ferguson and Schneier recommend this on page 72 of 'Practical
Cryptography'."
	cipher encryptBlock: aByteArray.
	super initialVector: aByteArray

Since encrypt and decrypt use initialVector this adds an additional encrypt
into every pass.  Deleting this method fixes the problem.  I understand the
intent here so we should either remove initialVector from encrypt and
decrypt and set vector directly (adding the destroy method from the
superclass initialVector method) or remove this method.  

What do you think?

Ron Teitelbaum

> -----Original Message-----
> From: cryptography-bounces at lists.squeakfoundation.org
> [mailto:cryptography-bounces at lists.squeakfoundation.org] On Behalf Of
> Robert Withers
> Sent: Tuesday, January 02, 2007 10:57 PM
> To: Cryptography Team Development List
> Cc: Ron at USMedRec.com
> Subject: Re: [Cryptography Team] Re: SSL Error
> 
> Ron,
> 
> I just loaded all the latest code versions and your test code seems
> to be working without any issues.  I ran all of the URLs and the test
> server with a SSLTracingConnHandler, all without failure.  I wonder
> what the problem could be on your machine or if anyone else has
> problems with SSL.
> 
> regards,
> Robert
> 
> On Jan 2, 2007, at 7:41 PM, Chris Muller wrote:
> 
> > Happy Holidays Ron!  Looking at the differences between
> > Cryptography-Core-rww.17 and Cryptography-Core-cmm.18, one
> > possibility might be sharing the same vector of a BlockCipher with
> > another place?  Its real easy to do (particularly in test code) but
> > since it's a ByteArray that, for many modes, modified in place, it
> > cannot be shared.
> >
> > Which primitives is your code using; for example if you're not
> > using CTR mode then we could probably eliminate all 23 changes on
> > that class.
> >
> > I reviewed all of the changes once again between those two versions
> > and they all look good.
> >
> > That leaves the differences between Cryptography-RandomAndPrime-rww.
> > 2.mcz and Cryptography-RandomAndPrime-RJT.10.mcz.  That was all the
> > SecureRandom refactoring, do you think it might be the cause?
> >
> >  - Chris
> >
> >
> >
> > ----- Original Message ----
> > From: Ron Teitelbaum <Ron at USMedRec.com>
> > To: Cryptography Team Development List
> > <cryptography at lists.squeakfoundation.org>; chris at funkyobjects.org
> > Sent: Tuesday, January 2, 2007 9:39:04 PM
> > Subject: SSL Error
> >
> > Chris and All,
> >
> > It appears that the changes to
> >
> > Cryptography-RandomAndPrime and Cryptography-Core break the SSL Code.
> >
> > If you load
> >
> > Cryptography-RandomAndPrime-rww.2.mcz
> > Cryptography-Core-rww.17.mcz
> >
> > Then run our SSL example code:
> >
> > 'https://tls.secg.org:40023' asUrl retrieveContents.
> >
> > You will get back the proper contents.
> >
> > Loading
> >
> > Cryptography-RandomAndPrime-RJT.10.mcz
> > Cryptography-Core-cmm.18
> >
> > It breaks with a return message from the server Bad Record Mac.
> >
> > I tried loading each method individually and thought I'd isolated
> > it, but I
> > got inconsistent results.  The RJT version of RandomAndPrime was my
> > change
> > to ensure the initial vector had the proper number of bytes.
> >
> > Test to Mac with the new code appears to still be working.
> >
> > I have not been able to isolate the error yet, but I thought I'd
> > mention it
> > incase anyone has an idea about which change is causing the error.
> >
> > Any help would be appreciated.
> >
> > Thanks,
> >
> > Ron Teitelbaum
> > Cryptography Team Leader
> >
> > Happy New Year to everyone!
> >
> >
> >
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> > cryptography
> 
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