TLS 1.2 - The token supplied to the function is invalid

问题

I have this strange problem, SslStream.AuthenticateAsClient() throws following exception:

System.Security.Authentication.AuthenticationException : A call to SSPI failed, see inner exception.
  ----> System.ComponentModel.Win32Exception : The token supplied to the function is invalid

It happens only when Tls12 is required by the client:

SslStream.AuthenticateAsClient(..., ..., SslProtocols.Tls12);

Code works properly for Ssl3, Tls11 and Tls.

Server certificate is self-signed and 'old'. It uses md5RSA signature and 1024 bits, and innitially I thought that is the problem, as re-generating the certificate makes the exception go away (I tired both SHA1 and SHA512 - both ok).

However, to my surprise FileZilla client is able to connect to this server using this 'old' md5RSA-signed cert and using TLS 1.2:

Here is the certificate:

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

My questions are:

1. Why SslStream.AuthenticateAsClient throws, whereas Filezilla client is able to connect?

2. Are there any .NET/Windows 10/CryptoAPI certificate restrictions when TLS 1.2 is used?

3. If there are restrictions, why FileZilla is not enforcing them?

4. Why so cryptic error message: 'The token supplied to the function is invalid'?

回答1:

I finally figured this out. "The token supplied to the function is invalid" in this context means a "Certificate on the chain is signed with an unsupported or disabled algorithm."

It turns out in practice this almost always means disabled. The list of enabled algorithms is found in HKEY_LOCAL_MACHINE SYSTEM\CurrentControlSet\Control\Cryptography\Configuration\Local\SSL\00010003 Functions. This is a REG_MULTI_SZ with one string per supported algorithm.

I found these values on my Windows 10 machine:

RSA/SHA256
RSA/SHA384
RSA/SHA1
ECDSA/SHA256
ECDSA/SHA384
ECDSA/SHA1
DSA/SHA1

And I added

RSA/SHA512
ECDSA/SHA512

Your key would start working if you added RSA/MD5 however it cannot be emphasized enough this is a bad idea and will open your system up to accepting forged certificates because MD5 has been broken.

Filezilla is working because Mozilla distrusts the host cipher suite.

来源：https://stackoverflow.com/questions/40939031/tls-1-2-the-token-supplied-to-the-function-is-invalid