[OTR-dev] A C# lib

[alex323]

"(len is the length of the DSA public parameter q)" <-- Sorry, I never 
noticed that before

alex323 wrote:

> 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 
>> 'AAEKAG8IXHYaE01IBR0bB31gHgFwM1QlXUgUCgh3InJIKj5PKQkSLHgiDFwTeBkhbTUWUk0sZ2FJWlAyfnwySjdWIHYjRmxgEAxxU1NbJ1JIX0w2I2guZxFmGCF5R2AQQUgCSi88E2NeWRtcfRMtfVgJVWkbdzJ+GjR5DkkbeGFpfidvBgYPAGl/NARaACNyXz5AOhQxOSM4MwNOGncXCGE9LUM+djx3IR0IdxMaLHFvdCABDT9zJk1IfAMkZT1QYQkhGjMPJEEcegUcG2RKKDpicnMFHlsKVmdAIXk+aFcvTHZrPVV4b28lexFiKUMsJxwgSzdvfWM3IztVbXEiZRM9YA5aCA0PMy1QLFN7aB8TRR5xQGpmJzwRLEE3AggMOn1qcFNuXnkeUxdjQ1FVTWAQNHsPAz8xKkQjRCQYWEhCAzlNU01DJDVXGWMPNhpYFwp0JwlWQDITLwl/BiYCfjc6Fl04Th96eDEkWW1pICYeRUs+JV0ANip3FXJZBQ9DPzsLZBN+YzhUHxplHXlcFi0TTyllPGg0UxYGE0c3bwFrVVUheFNDE2VDOSxKF2gnAgpvCWU5E3BZTAIQWEwEMSp6ey4VBjcpOQ8+QhgFUFNCe0FHFHFkFWJsBVlEPVA1BksdLBc5Kj9pJXltNQ9VeDURPSAvSGY/PE50EE94ZlkPMjxdX1hjFyZaZko/cyUoIWJ6PRFqEjYRQndoNwcwYklGJg12TXlcG11ieBBAEFZQfwlGLGUANgBIG0sZQSs1ZHRhaiJsRFpnSFo/BlIsThl4SQp/FQhvAhAnSng1b3wcfQ40VyQDF1Q3UCkufnUZInVEeVtrWQwgWBQCL3ViaQ==' 
>> | 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
>> _______________________________________________
>> OTR-dev mailing list
>> OTR-dev at lists.cypherpunks.ca
>> http://lists.cypherpunks.ca/mailman/listinfo/otr-dev
>>
>>  
>>
>
>
>
> _______________________________________________
> OTR-dev mailing list
> OTR-dev at lists.cypherpunks.ca
> http://lists.cypherpunks.ca/mailman/listinfo/otr-dev
>