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i looked around a lot of similar question but none of this fixing my issue. We are upgrading to TLS 1.2 and am getting the below error which i got from Windows event log

An TLS 1.2 connection request was received from a remote client application, but none of the cipher suites supported by the client application are supported by the server.

lantronix xport pro(Supporting TLS 1.2) Device making a call to the .net service deployed in Windows server 2012.

Client/Server Handshake is failing but am not able to figure out why. issue happens in the below line

stream.AuthenticateAsServer(_serverCertificate, false, SslProtocols.Ssl3| SslProtocols.Tls | SslProtocols.Tls11 | SslProtocols.Tls12, true);

Used Wireshark and Windows server 2012 R2 have only TLs 1.1 and 1.2 enabled using IIS Crypto

Client send TLS 1.2 Request with below Cipher suites

Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f)
Cipher Suite: TLS_RSA_WITH_3DES_EDE_CBC_SHA (0x000a)
Cipher Suite: TLS_RSA_EXPORT1024_WITH_RC4_56_MD5 (0x0060)
Cipher Suite: TLS_RSA_EXPORT1024_WITH_RC4_56_SHA (0x0064)
Cipher Suite: TLS_RSA_EXPORT_WITH_RC4_40_MD5 (0x0003)

But server doesnt respond with Server Hello and finding the error message that none of the cipher supported by server.

I can see in IIS Crypto that AES_128_CBC_SHA in the crypto. But am not sure why it failing and almost stuck for days. Hope to get some clarity on what i can do further to troubleshoot this

Update::

I created a Client from Windows server 2012 and it is connected to the server and it is connecting TLS 1.2 with Cipher Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (0xc028)

But when connecting lantronix xport pro(Supporting TLS 1.2) server says 'The client and server cannot communicate, because they do not possess a common algorithm' on both X86 and x64.

Does it mean 2012 server does not support any of this ciphers sent by client

Cipher Suite: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f) Cipher Suite: TLS_RSA_WITH_3DES_EDE_CBC_SHA (0x000a) Cipher Suite: TLS_RSA_EXPORT1024_WITH_RC4_56_MD5 (0x0060) Cipher Suite: TLS_RSA_EXPORT1024_WITH_RC4_56_SHA (0x0064) Cipher Suite: TLS_RSA_EXPORT_WITH_RC4_40_MD5 (0x0003)

Server creating TCL SSLStream and not using IIS

Any suggestion for this would be great

Thanks

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  • Have you updated the firmware on the Xport Pro? That should be step 1. – Michael Hampton Mar 31 '18 at 16:54
  • A client supporting EXPORT ciphers (which are considered insecure for ages) looks like a severely broken client to me and I doubt that this device has proper support for TLS 1.2. The specification only lists support for SSLv3 which sounds likely given the brokeness of the cipher suite. – Steffen Ullrich Mar 31 '18 at 16:59
  • @MichaelHampton yes i did update to the newest firmware. Is there any thing else i can do to confirm apart from the wireshark where am seeing TLS 1.2 request from client – Peru Mar 31 '18 at 19:44
  • @SteffenUllrich in Wireshark i can see TLS 1.2 and the listed ciphers as per my question from the device . Still this could be wrong and broken ? – Peru Mar 31 '18 at 19:46
  • @Tharun: hard to tell without seeing the actual pcap. Apart from that, are you sure that the windows server is using an RSA and not an ECDSA certificate? – Steffen Ullrich Mar 31 '18 at 20:33
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Get the openssl client http://gnuwin32.sourceforge.net/packages/openssl.htm to see how the cyphres are being called.

The command is openssl s_client -connect website:port

Most likely you might have NTLM pre authentication on your app, I would look into the providers for IIS and disable it. In the HTTP_REQUEST headers you should see something like:

NTLM=

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  • Thanks for the update. am using SSL stream i just updated in the question as well. stream.AuthenticateAsServer is where am getting the exception – Peru Apr 4 '18 at 14:45

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