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IAuthenticationModule.Authenticate(String, WebRequest, ICredentials) Método

Definição

Retorna uma instância da classe Authorization em resposta a um desafio de autenticação de um servidor.

public:
 System::Net::Authorization ^ Authenticate(System::String ^ challenge, System::Net::WebRequest ^ request, System::Net::ICredentials ^ credentials);
public System.Net.Authorization? Authenticate(string challenge, System.Net.WebRequest request, System.Net.ICredentials credentials);
public System.Net.Authorization Authenticate(string challenge, System.Net.WebRequest request, System.Net.ICredentials credentials);
abstract member Authenticate : string * System.Net.WebRequest * System.Net.ICredentials -> System.Net.Authorization
Public Function Authenticate (challenge As String, request As WebRequest, credentials As ICredentials) As Authorization

Parâmetros

challenge
String

O desafio de autenticação enviado pelo servidor.

request
WebRequest

A instância de WebRequest associada ao desafio.

credentials
ICredentials

As credenciais associadas ao desafio.

Retornos

Uma instância de Authorization que contém a mensagem de autorização da solicitação, ou null se o desafio não pode ser manipulado.

Exemplos

O exemplo a seguir mostra como usar o método Authenticate. Para obter um exemplo completo, consulte a AuthenticationManager classe .

// Authenticate is the core method for this custom authentication.
// When an Internet resource requests authentication, the WebRequest.GetResponse
// method calls the AuthenticationManager.Authenticate method. This method, in
// turn, calls the Authenticate method on each of the registered authentication
// modules, in the order in which they were registered. When the authentication is
// complete an Authorization object is returned to the WebRequest.
public Authorization Authenticate(String challenge, WebRequest request, ICredentials credentials)
{
  Encoding ASCII = Encoding.ASCII;

  // Get the username and password from the credentials
  NetworkCredential myCreds = credentials.GetCredential(request.RequestUri, "Basic");

  if (PreAuthenticate(request, credentials) == null)
    Console.WriteLine("\n Pre-authentication is not allowed.");
  else
    Console.WriteLine("\n Pre-authentication is allowed.");

  // Verify that the challenge satisfies the authorization requirements.
  bool challengeOk = CheckChallenge(challenge, myCreds.Domain);

  if (!challengeOk)
    return null;

  // Create the encrypted string according to the Basic authentication format as
  // follows:
  // a)Concatenate the username and password separated by colon;
  // b)Apply ASCII encoding to obtain a stream of bytes;
  // c)Apply Base64 encoding to this array of bytes to obtain the encoded
  // authorization.
  string basicEncrypt = myCreds.UserName + ":" + myCreds.Password;

  string basicToken = "Basic " + Convert.ToBase64String(ASCII.GetBytes(basicEncrypt));

  // Create an Authorization object using the encoded authorization above.
  Authorization resourceAuthorization = new Authorization(basicToken);

  // Get the Message property, which contains the authorization string that the
  // client returns to the server when accessing protected resources.
  Console.WriteLine("\n Authorization Message:{0}",resourceAuthorization.Message);

  // Get the Complete property, which is set to true when the authentication process
  // between the client and the server is finished.
  Console.WriteLine("\n Authorization Complete:{0}",resourceAuthorization.Complete);

  Console.WriteLine("\n Authorization ConnectionGroupId:{0}",resourceAuthorization.ConnectionGroupId);

  return resourceAuthorization;
}
  ' Authenticate is the core method for this custom authentication.
  ' When an Internet resource requests authentication, the WebRequest.GetResponse 
  ' method calls the AuthenticationManager.Authenticate method. This method, in 
  ' turn, calls the Authenticate method on each of the registered authentication
  ' modules, in the order in which they were registered. When the authentication is 
  ' complete an Authorization object is returned to the WebRequest.
  Public Function Authenticate(ByVal challenge As String, ByVal request As WebRequest, ByVal credentials As ICredentials) As Authorization _
      Implements IAuthenticationModule.Authenticate


    Dim ASCII As Encoding = Encoding.ASCII

    ' Get the username and password from the credentials
    Dim MyCreds As NetworkCredential = credentials.GetCredential(request.RequestUri, "Basic")

    If PreAuthenticate(request, credentials) Is Nothing Then
      Console.WriteLine(ControlChars.Lf + " Pre-authentication is not allowed.")
    Else
      Console.WriteLine(ControlChars.Lf + " Pre-authentication is allowed.")
    End If
    ' Verify that the challenge satisfies the authorization requirements.
    Dim challengeOk As Boolean = checkChallenge(challenge, MyCreds.Domain)

    If Not challengeOk Then
      Return Nothing
    End If

    ' Create the encrypted string according to the Basic authentication format as
    ' follows:
    ' a)Concatenate the username and password separated by colon;
    ' b)Apply ASCII encoding to obtain a stream of bytes;
    ' c)Apply Base64 encoding to this array of bytes to obtain the encoded 
    ' authorization.
    Dim BasicEncrypt As String = MyCreds.UserName + ":" + MyCreds.Password

    Dim BasicToken As String = "Basic " + Convert.ToBase64String(ASCII.GetBytes(BasicEncrypt))

    ' Create an Authorization object using the encoded authorization above.
    Dim resourceAuthorization As New Authorization(BasicToken)

    ' Get the Message property, which contains the authorization string that the 
    ' client returns to the server when accessing protected resources.
    Console.WriteLine(ControlChars.Lf + " Authorization Message:{0}", resourceAuthorization.Message)

    ' Get the Complete property, which is set to true when the authentication process 
    ' between the client and the server is finished.
    Console.WriteLine(ControlChars.Lf + " Authorization Complete:{0}", resourceAuthorization.Complete)

    Console.WriteLine(ControlChars.Lf + " Authorization ConnectionGroupId:{0}", resourceAuthorization.ConnectionGroupId)


    Return resourceAuthorization
  End Function 'Authenticate
End Class

Comentários

O Authenticate método conduz o processo de autenticação com o servidor e retorna uma Authorization instância para o AuthenticationManager.

Notas aos Implementadores

O AuthenticationManager chama o Authenticate(String, WebRequest, ICredentials) método em módulos de autenticação registrados para determinar qual módulo lida com o desafio. Se o módulo de autenticação não puder lidar com o desafio, o Authenticate(String, WebRequest, ICredentials) método deverá retornar null. Se o módulo de autenticação encontrar um erro ao conduzir o processo de autenticação, Authenticate(String, WebRequest, ICredentials) deverá gerar uma exceção.

Aplica-se a