NegotiateStream.BeginAuthenticateAsServer Method (NetworkCredential, ExtendedProtectionPolicy, ProtectionLevel, TokenImpersonationLevel, AsyncCallback, Object)
Called by servers to begin an asynchronous operation to authenticate the client, and optionally the server, in a client-server connection. The authentication process uses the specified server credentials, authentication options, and extended protection policy. This method does not block.
Assembly: System (in System.dll)
[HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)] public virtual IAsyncResult BeginAuthenticateAsServer( NetworkCredential credential, ExtendedProtectionPolicy policy, ProtectionLevel requiredProtectionLevel, TokenImpersonationLevel requiredImpersonationLevel, AsyncCallback asyncCallback, Object asyncState )
Parameters
- credential
- Type: System.Net.NetworkCredential
The NetworkCredential that is used to establish the identity of the client.
- policy
- Type: System.Security.Authentication.ExtendedProtection.ExtendedProtectionPolicy
The ExtendedProtectionPolicy that is used for extended protection.
- requiredProtectionLevel
- Type: System.Net.Security.ProtectionLevel
One of the ProtectionLevel values, indicating the security services for the stream.
- requiredImpersonationLevel
- Type: System.Security.Principal.TokenImpersonationLevel
One of the TokenImpersonationLevel values, indicating how the server can use the client's credentials to access resources.
- asyncCallback
- Type: System.AsyncCallback
An AsyncCallback delegate that references the method to invoke when the authentication is complete.
- asyncState
- Type: System.Object
A user-defined object containing information about the write operation. This object is passed to the asyncCallback delegate when the operation completes.
Return Value
Type: System.IAsyncResultAn IAsyncResult object indicating the status of the asynchronous operation.
Exception | Condition |
---|---|
ArgumentException | The CustomChannelBinding and CustomServiceNames on the extended protection policy passed in the policy parameter are both null. |
ArgumentNullException | credential is null. |
ArgumentOutOfRangeException | requiredImpersonationLevel must be Identification, Impersonation, or Delegation, |
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. |
InvalidOperationException | Authentication has already occurred. - or - This stream was used previously to attempt authentication as the client. You cannot use the stream to retry authentication as the server. |
NotSupportedException | Windows 95 and Windows 98 are not supported. |
ObjectDisposedException | This object has been closed. |
PlatformNotSupportedException | The policy parameter was set to Always on a platform that does not support extended protection. |
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 policy parameter is null, then an extended protection policy is used that has PolicyEnforcement set to Never.
This method is asynchronous and does not block while the operation completes. To block until the operation completes, use one of the AuthenticateAsServer method overloads.
The asynchronous authentication operation must be completed by calling the EndAuthenticateAsServer method. Typically, the method is invoked by the asyncCallback delegate. For detailed information about using the asynchronous programming model, see Calling Synchronous Methods Asynchronously
If the authentication fails, you receive an AuthenticationException or an InvalidCredentialException. In this case, you can retry the authentication with a different credential.
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The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes. |
Windows 7, Windows Vista SP1 or later, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.