// Copyright (c) 2020, Oracle and/or its affiliates.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0, as
// published by the Free Software Foundation.
//
// This program is also distributed with certain software (including
// but not limited to OpenSSL) that is licensed under separate terms,
// as designated in a particular file or component or in included license
// documentation.  The authors of MySQL hereby grant you an
// additional permission to link the program and your derivative works
// with the separately licensed software that they have included with
// MySQL.
//
// Without limiting anything contained in the foregoing, this file,
// which is part of MySQL Connector/NET, is also subject to the
// Universal FOSS Exception, version 1.0, a copy of which can be found at
// http://oss.oracle.com/licenses/universal-foss-exception.
//
// This program is distributed in the hope that it will be useful, but
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License, version 2.0, for more details.
//
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using MySql.Data.Authentication.GSSAPI.Native;
using MySql.Data.MySqlClient;
using System.Text;

namespace MySql.Data.Authentication.GSSAPI.Utility
{
  internal static class GssType
  {
    private static readonly Encoding Iso = Encoding.GetEncoding("iso-8859-1");

    internal static Disposable<GssBufferDescStruct> GetBufferFromString(string buffer) =>
        GetBufferFromBytes(Iso.GetBytes(buffer));

    public static Disposable<GssBufferDescStruct> GetBufferFromBytes(byte[] buffer) =>
        Disposable.From(
            Pinned.From(buffer), p => new GssBufferDescStruct
            {
              length = (uint)p.Value.Length,
              value = p.Address
            }, p =>
            {
              var majorStatus = NativeMethods.gss_release_buffer(out var minorStatus, ref p);
              if (majorStatus != Const.GSS_S_COMPLETE)
                throw new MySqlException(ExceptionMessages.FormatGssMessage("GSSAPI: An error occurred releasing a buffer.",
                        majorStatus, minorStatus, Const.GSS_C_NO_OID));
            });
  }
}