[OTR-dev] A C# lib

[alex323]

I see. Let me admonish you that the .NET crypto libs are slightly 
different than gcrypt. Before I read the protocol, I never knew what an 
MPI was.

"4 byte unsigned len, big-endian"

I am assuming that that is supposed to be 4 bytes that indicate the 
length of hte public key?
Thanks for your assistance and patience.

Ian Goldberg wrote:

>On Sat, Jan 15, 2005 at 01:19:20PM -0500, alex323 wrote:
>  
>
>>Hmmm.. i'm having some problems. My friend keeps telling me that there 
>>was a malformed key exchange. Maybe one of you can look at what my 
>>program is generating? Thanks
>>
>>To reply to a key exchange (reply=1):
>>?OTR: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.
>>    
>>
>
>You know about otr_parse in the toolkit, right?  Indeed, it says your
>message is malformed.  So let's take it apart.
>
>iang at warren:~$ echo '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' | perl -MMIME::Base64 -pe '$_=&decode_base64($_)' | od -tx1
>0000000 00 01 0a 00 6f 08 5c 76 1a 13 4d 48 05 1d 1b 07
>0000020 7d 60 1e 01 70 33 54 25 5d 48 14 0a 08 77 22 72
>[snip]
>
>You start with:
>  00 01 (Protocol version 1)
>  0a    (Key Exchange Message)
>  00    (reply == 0, unlike what you said)
>  6f 08 5c 76  <- nonsense
>
>An MPI is expected here.  From the Protocol document:
>
>  
>
>>Multi-precision integers (MPI):
>>  4 byte unsigned len, big-endian
>>  len byte unsigned value, big-endian
>>  (MPIs must use the minimum-length encoding; i.e. no leading 0x00
>>  bytes.  This is important when calculating public key fingerprints.)
>>    
>>
>
>You seem to be missing the MPI length field.
>
>   - Ian
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>  
>