text: //----------------------------------------------------------------------------
  //
  // TSDuck - The MPEG Transport Stream Toolkit
  // Copyright (c) 2005-2022, Thierry Lelegard
  // All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are met:
  //
  // 1. Redistributions of source code must retain the above copyright notice,
  //    this list of conditions and the following disclaimer.
  // 2. Redistributions in binary form must reproduce the above copyright
  //    notice, this list of conditions and the following disclaimer in the
  //    documentation and/or other materials provided with the distribution.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  // THE POSSIBILITY OF SUCH DAMAGE.
  //
  //----------------------------------------------------------------------------
  //!
  //!  @file
  //!  ANSI/SCTE 52 DES-based TS packet encryption.
  //!
  //----------------------------------------------------------------------------
  
  #pragma once
  #include "tsDVS042.h"
  #include "tsDES.h"
  
  namespace ts {
      //!
      //! ANSI/SCTE 52 2003 DES-based TS packet encryption.
      //! @ingroup crypto
      //!
      //! DVS 042 has been renamed as "ANSI/SCTE 52 2003". The next iteration of
      //! this standard is "ANSI/SCTE 52 2008". The only difference between the
      //! two versions is the handling of messages shorter than the block size.
      //! In the 2003 (DVS 042) version, the same IV (called "whitener" in the
      //! standard) is used for long and short messages. In the 2008 version, a
      //! different "whitener2" must be used for messages shorter than the block size.
      //!
      class TSDUCKDLL SCTE52_2003 : public DVS042<DES>
      {
          TS_NOCOPY(SCTE52_2003);
      public:
          //!
          //! Constructor.
          //!
          SCTE52_2003() = default;
  
          // Implementation of BlockCipher interface.
          virtual UString name() const override;
  
      private:
          // The IV are identical, there is no specific IV for short blocks.
          virtual bool setShortIV(const void* iv_, size_t iv_length) override;
      };
  
      //!
      //! ANSI/SCTE 52 2008 DES-based TS packet encryption.
      //! @ingroup crypto
      //!
      //! DVS 042 has been renamed as "ANSI/SCTE 52 2003". The next iteration of
      //! this standard is "ANSI/SCTE 52 2008". The only difference between the
      //! two versions is the handling of messages shorter than the block size.
      //! In the 2003 (DVS 042) version, the same IV (called "whitener" in the
      //! standard) is used for long and short messages. In the 2008 version, a
      //! different "whitener2" must be used for messages shorter than the block size.
      //!
      class TSDUCKDLL SCTE52_2008 : public DVS042<DES>
      {
          TS_NOCOPY(SCTE52_2008);
      public:
          //!
          //! Constructor.
          //!
          SCTE52_2008() = default;
  
          // Implementation of BlockCipher interface.
          virtual UString name() const override;
      };
  }
  