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Re: [reSIProcate] reSIProcate and LCS?


Hi Scott, Sandeep,

FYI: I sort of answered my own question later this afternoon. The reason why TLS wasn't working when resip was the server was because the sipStack->addTransport() function is defaulting TlsTransport to SecurityTypes::TLSv1. When LCS sends the SSLv2 compatible client hello message, it sent a RST because my TLS layer didn't recognize a v2 message. So, I changed my application (limpc) and added SecurityTypes::SSLv23 and that worked (at least it got me further). Now, the LCS server is sending a RST after the ServerHelloDone message from resip.

Chris

Chris Rigg wrote:

Hi Scott,

Thanks for your quick response.

Yes, you are right -- to talk to LCS in Federation mode you MUST use TLS transport. And in fact, I have tried this out. I am able to establish a TLS session underneath me when the resip stack is a client and the LCS's access proxy is the server. To do this, I had to do a bunch of cert/pem stuff (as you might imagine). Essentially, I copied the root_cert that I used on the LCS to sign the AP's to my linux machine into $HOME/.sipCerts/. Then, of course, I had to also copy the root_cert that I created on my Linux machine (that was used to sign my domain_key for my resip stack) over to the AP's list of trusted certificate authorities. And this worked! I was able to establish a TLS session with LCS's AP w/out code modifications to the stack (although as I stated in my previous mail, this inital excitement quickly wore off once I started trying to reverse engineer the MSFT SIP message extensions).

However, in the reverse direction (where resip is the server and LCS's AP is the client) resip doesn't like something in the TLS "compatible client hello" message and resip immediately sends a TCP RST.

So, any idea why resip would respond w/ a TCP RST? Is it just simply that resip doesn't support any of their cipher suites?? The resip logs seem to indicate a "version error" (I've included those below too). Here is the ssldump of the messaging:

New TCP connection #1: lcs-im.com(1127) <-> bldr-ccm51.resip.com(5061)
1 1  0.0005 (0.0005)  C>S SSLv2 compatible client hello
 Version 3.1
 cipher suites
 TLS_RSA_WITH_RC4_128_MD5
 TLS_RSA_WITH_RC4_128_SHA
 TLS_RSA_WITH_3DES_EDE_CBC_SHA
 SSL2_CK_RC4
 SSL2_CK_3DES
 SSL2_CK_RC2
 TLS_RSA_WITH_DES_CBC_SHA
 SSL2_CK_DES
 TLS_RSA_EXPORT1024_WITH_RC4_56_SHA
 TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA
 TLS_RSA_EXPORT_WITH_RC4_40_MD5
 TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5
 SSL2_CK_RC4_EXPORT40
 SSL2_CK_RC2_EXPORT40
 TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
 TLS_DHE_DSS_WITH_DES_CBC_SHA
 TLS_DHE_DSS_EXPORT1024_WITH_DES_CBC_SHA
1    0.0088 (0.0083)  S>C  TCP RST

And here is the verbose level tracing that I have enabled on the resip stack: DEBUG | 20050816-152420.407 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TcpBaseTransport.cxx:109 | Received TCP connection from: [ V4 10.94.150.117:1127 TLS received on: Transport: [ V4 0.0.0.0:5061 TLS connectionId=0 ] connectionId=0 ] as fd=9 DEBUG | 20050816-152420.408 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | ConnectionBase.cxx:42 | ConnectionBase::ConnectionBase, who: [ V4 10.94.150.117:1127 TLS received on: Transport: [ V4 0.0.0.0:5061 TLS connectionId=0 ] connectionId=0 ] 0x8074d38 DEBUG | 20050816-152420.409 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:35 | Creating TLS connection [ V4 10.94.150.117:1127 TLS received on: Transport: [ V4 0.0.0.0:5061 TLS connectionId=0 ] connectionId=0 ] on 9 DEBUG | 20050816-152420.409 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:43 | Trying to form TLS connection - acting as server DEBUG | 20050816-152420.410 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:161 | TLS error in accept ok=-1 err=1 error:00000001:lib(0):func(0):reason(1) ERR | 20050816-152420.410 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:182 | TLS connection failed ok=-1 err=1 error:00000001:lib(0):func(0):reason(1) ERR | 20050816-152420.411 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:190 | (SSL Error ssl) ERR | 20050816-152420.411 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:227 | error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number INFO | 20050816-152420.412 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:229 | Error code = 336130315 file=s3_pkt.c line=297 ERR | 20050816-152420.412 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TlsConnection.cxx:234 | Couldn't TLS connect DEBUG | 20050816-152420.412 | bldr-ccm51 | limpc | RESIP | 32375 | 3069674144 | os/BaseException.cxx:17 | BaseException at TlsConnection.cxx:108 TLS setup failed INFO | 20050816-152420.413 | bldr-ccm51 | limpc | RESIP:TRANSPORT | 32375 | 3069674144 | TransportSelector.cxx:187 | Exception thrown from Transport::process: TransportException TLS setup failed @ TlsConnection.cxx:108

Thanks,
Chris

Scott Godin wrote:

Apparently to use "Federation Mode" you must use the TLS transport.  As
far as I know - no one has tried this with resip yet.  Although it is on
my list of things to try out.  : )

On the other hand - I have used resip to communicate with LCS by setting
up the resip endpoint as a trusted node.  Note:  LCS does not support
UDP - so you must use a TCP transport.  Don't expect to be able to
register with LCS though - since you need to implement those Microsoft
extensions that you mentioned (ie. Kerberos/NTLM Authentication instead
of Digest).

Scott

-----Original Message-----
From: resiprocate-devel-bounces@xxxxxxxxxxxxxxxxxxx
[mailto:resiprocate-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of
Chris Rigg
Sent: Tuesday, August 16, 2005 5:21 PM
To: resiprocate-devel@xxxxxxxxxxxxxxxxxxx
Subject: [reSIProcate] reSIProcate and LCS?

Hello,

I am trying to connect reSIProcate to Microsoft's LCS (Live Communications Server) in Federation mode (i.e. Public IM). In this mode, instant messenger users (i.e. MOC clients) can communicate OUTSIDE

of their domain. For example, with Federation mode a user named john@xxxxxxx (that uses LCS as their enterprise IM server) can IM with sam@xxxxxxxx The inter-domain protocol that is used to make this happen is called "Federation". The protocol is basically just some MSFT extensions onto standard SIP/SIMPLE messages. However, I'm running into plenty of problems when trying to interoperate between reSIProcate and
LCS.

Has anyone tried to do something similar?? If so, was there a detailed Microsoft Federation mode interface spec that you followed or something?

Thanks,
Chris
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