NegotiateStream.AuthenticateAsClientAsync Method (NetworkCredential, String, ProtectionLevel, TokenImpersonationLevel)

.NET Framework (current version)
 
System_CAPS_noteNote

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Called by clients to authenticate the client, and optionally the server, in a client-server connection as an asynchronous operation. The authentication process uses the specified credentials and authentication options.

Namespace:   System.Net.Security
Assembly:  System (in System.dll)

[HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)]
public virtual Task AuthenticateAsClientAsync(
	NetworkCredential credential,
	string targetName,
	ProtectionLevel requiredProtectionLevel,
	TokenImpersonationLevel allowedImpersonationLevel
)

Parameters

credential
Type: System.Net.NetworkCredential

The NetworkCredential that is used to establish the identity of the client.

targetName
Type: System.String

The Service Principal Name (SPN) that uniquely identifies the server to authenticate.

requiredProtectionLevel
Type: System.Net.Security.ProtectionLevel

One of the ProtectionLevel values, indicating the security services for the stream.

allowedImpersonationLevel
Type: System.Security.Principal.TokenImpersonationLevel

One of the TokenImpersonationLevel values, indicating how the server can use the client's credentials to access resources.

Return Value

Type: System.Threading.Tasks.Task

Returns Task

The task object representing the asynchronous operation.

Exception Condition
ArgumentOutOfRangeException

allowedImpersonationLevel is not a valid value.

ArgumentNullException

targetName is null.

AuthenticationException

The authentication failed. You can use this object to retry the authentication.

InvalidCredentialException

The authentication failed. You can use this object to retry the authentication.

ObjectDisposedException

This object has been closed.

InvalidOperationException

Authentication has already occurred.

- or -

This stream was used previously to attempt authentication as the server. You cannot use the stream to retry authentication as the client.

Use the requiredProtectionLevel parameter to request security services for data transmitted using the authenticated stream. For example, to have the data encrypted and signed, specify the EncryptAndSign value. Successful authentication does not guarantee that the requested ProtectionLevel has been granted. You must check the IsEncrypted and IsSigned properties to determine what security services are used by the NegotiateStream.

If the authentication fails, you receive an AuthenticationException or an InvalidCredentialException. In this case, you can retry the authentication with a different credential.

.NET Framework
Available since 4.5
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