IIS 7.5应用程序中托管的WCF客户端在连接时不使用TLS 1.2

Question

Problem:

I have a generated WCF client which consumes a third party WebService. This client is part of a WeAPI Controler hosted in IIS 7.5. The third party Service requires TLS 1.2 for connections.

When the WCF client tries to connect to the third party WebService I can see in Fiddler that the handshake fails and that the client request indicates that it is using TLS 1.0 instead of 1.2 (see Fiddler output below).

I already tried KB245030 and activated TLS 1.2 for SChannel both client and server but with no avail (Also using the NARTAC Tool)
http://support2.microsoft.com/kb/245030

If I use Fiddler and modify the Fiddler Script to always use TLS 1.2 the Service call works fine.

Question:

Is it possible to configure the system so that the WCF client call uses TLS 1.2 when hosted in IIS 7.5?

Fiddler capture:

A SSLv3-compatible ClientHello handshake was found. Fiddler extracted the parameters below.

Version: 3.1 (TLS/1.0)<br/>
Random: ...<br/>
SessionID: empty

Extensions:<br/>
    renegotiation_info  00<br/>
    server_name ...<br/>
    elliptic_curves secp256r1 [0x17], secp384r1 [0x18]<br/>
    ec_point_formats    uncompressed [0x0]

Ciphers:<br/>
    [002F]  TLS_RSA_AES_128_SHA<br/>
    [0035]  TLS_RSA_AES_256_SHA<br/>
    [0005]  SSL_RSA_WITH_RC4_128_SHA<br/>
    [000A]  SSL_RSA_WITH_3DES_EDE_SHA<br/>
    [C013]  TLS1_CK_ECDHE_RSA_WITH_AES_128_CBC_SHA<br/>
    [C014]  TLS1_CK_ECDHE_RSA_WITH_AES_256_CBC_SHA<br/>
    [C009]  TLS1_CK_ECDHE_ECDSA_WITH_AES_128_CBC_SHA<br/>
    [C00A]  TLS1_CK_ECDHE_ECDSA_WITH_AES_256_CBC_SHA<br/>
    [0032]  TLS_DHE_DSS_WITH_AES_128_SHA<br/>
    [0038]  TLS_DHE_DSS_WITH_AES_256_SHA<br/>
    [0013]  SSL_DHE_DSS_WITH_3DES_EDE_SHA<br/>
    [0004]  SSL_RSA_WITH_RC4_128_MD5<br/>

Compression:<br/>
    [00]    NO_COMPRESSION<br/>

Answer 1

I received an answer to this question from Microsoft support, there is an Windows Update für .Net which fixes this problem:
http://support.microsoft.com/kb/2960358