/// <summary>
/// Sends STARTTLS command to SMTP server.
/// </summary>
/// <param name="certCallback">SSL server certificate validation callback. Value null means any certificate is accepted.</param>
/// <exception cref="ObjectDisposedException">Is raised when this object is disposed and this method is accessed.</exception>
/// <exception cref="InvalidOperationException">Is raised when SMTP client is not connected or is already secure connection.</exception>
/// <exception cref="SMTP_ClientException">Is raised when SMTP server returns error.</exception>
/// <remarks>After successful STARTTLS all SMTP session data(EHLO,MAIL FROM, ....) will be reset.
/// If unknwon(not SMTP error) error happens during STARTTLS negotiation, SMTP client should disconnect.</remarks>
public void StartTLS(RemoteCertificateValidationCallback certCallback)
{
if(this.IsDisposed){
throw new ObjectDisposedException(this.GetType().Name);
}
if(!this.IsConnected){
throw new InvalidOperationException("You must connect first.");
}
if(this.IsSecureConnection){
throw new InvalidOperationException("Connection is already secure.");
}
ManualResetEvent wait = new ManualResetEvent(false);
using(StartTlsAsyncOP op = new StartTlsAsyncOP(certCallback)){
op.CompletedAsync += delegate(object s1,EventArgs<StartTlsAsyncOP> e1){
wait.Set();
};
if(!this.StartTlsAsync(op)){
wait.Set();
}
wait.WaitOne();
wait.Close();
if(op.Error != null){
throw op.Error;
}
}
}
/// <summary>
/// Starts sending STARTTLS command to SMTP server.
/// </summary>
/// <param name="op">Asynchronous operation.</param>
/// <returns>Returns true if aynchronous operation is pending (The <see cref="StartTlsAsyncOP.CompletedAsync"/> event is raised upon completion of the operation).
/// Returns false if operation completed synchronously.</returns>
/// <exception cref="ObjectDisposedException">Is raised when this object is disposed and and this method is accessed.</exception>
/// <exception cref="InvalidOperationException">Is raised when SMTP client is not connected or connection is already secure.</exception>
/// <exception cref="ArgumentNullException">Is raised when <b>op</b> is null reference.</exception>
/// <remarks>After successful STARTTLS all SMTP session data(EHLO,MAIL FROM, ....) will be reset.
/// If unknwon(not SMTP error) error happens during STARTTLS negotiation, SMTP client should disconnect.</remarks>
public bool StartTlsAsync(StartTlsAsyncOP op)
{
if(this.IsDisposed){
throw new ObjectDisposedException(this.GetType().Name);
}
if(!this.IsConnected){
throw new InvalidOperationException("You must connect first.");
}
if(this.IsSecureConnection){
throw new InvalidOperationException("Connection is already secure.");
}
if(op == null){
throw new ArgumentNullException("op");
}
if(op.State != AsyncOP_State.WaitingForStart){
throw new ArgumentException("Invalid argument 'op' state, 'op' must be in 'AsyncOP_State.WaitingForStart' state.","op");
}
return op.Start(this);
}
