Sans Pareil Technologies, Inc.

/*
 * DigestEngine.h
 *
 * Definition of class DigestEngine.
 *
 * Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
 * and Contributors.
 *
 * Permission is hereby granted, free of charge, to any person or organization
 * obtaining a copy of the software and accompanying documentation covered by
 * this license (the "Software") to use, reproduce, display, distribute,
 * execute, and transmit the Software, and to prepare derivative works of the
 * Software, and to permit third-parties to whom the Software is furnished to
 * do so, all subject to the following:
 *
 * The copyright notices in the Software and this entire statement, including
 * the above license grant, this restriction and the following disclaimer,
 * must be included in all copies of the Software, in whole or in part, and
 * all derivative works of the Software, unless such copies or derivative
 * works are solely in the form of machine-executable object code generated by
 * a source language processor.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#ifndef SPT_DIGEST_DIGESTENGINE
#define SPT_DIGEST_DIGESTENGINE

#if defined( ARDUINO )
#include "../StandardCplusplus/vector"
#include "SPT.h"
#else
#include <vector>
#include <SPT.h>
#endif


namespace spt
{
  /// Provides classes that compute message digests.
  namespace digest
  {
    /**
     * @brief Abstract base class for all classes implementing a message digest algorithm.
     * Digest engines examples are MD5Engine and SHA1Engine. Call
     * {@link update()} repeatedly with data to compute the digest from.
     * When done, call {@link digest()} to obtain the message digest.
     */
    class DigestEngine
    {
    public:
      typedef std::vector<Byte> Digest;

      DigestEngine();
      virtual ~DigestEngine();

      /// Updates the digest with the given data of specified length.
      void update( const void* data, uint32_t length );

      /// Updates the digest with the given character.
      void update( char data );

      /// Updates the digest with the given string data.
      void update( const std::string& data );

      /// Returns the length of the digest in bytes.
      virtual uint32_t digestLength() const = 0;

      /// Resets the engine so that a new digest can be computed.
      virtual void reset() = 0;

      /// Finishes the computation of the digest and
      /// returns the message digest. Resets the engine
      /// and can thus only be called once for every digest.
      /// The returned reference is valid until the next
      /// time digest() is called, or the engine object is destroyed.
      virtual const Digest& digest() = 0;

      /// Converts a message digest into a string of hexadecimal numbers.
      static std::string digestToHex( const Digest& bytes );

    protected:
      /// Updates the digest with the given data. Must be implemented
      /// by subclasses.
      virtual void updateImpl( const void* data, uint32_t length ) = 0;

    private:
      DigestEngine( const DigestEngine& );
      DigestEngine& operator = ( const DigestEngine& );
    };


    inline void DigestEngine::update( const void* data, uint32_t length )
    {
      updateImpl( data, length );
    }


    inline void DigestEngine::update( char data )
    {
      updateImpl( &data, 1 );
    }


    inline void DigestEngine::update( const std::string& data )
    {
      updateImpl( data.data(), static_cast<uint32_t>( data.size() ) );
    }

  } // namespace digest

} // namespace spt


#endif // SPT_DIGEST_DIGESTENGINE

/*
 * DigestEngine.cpp
 *
 * $Id: DigestEngine.cpp 5792 2015-06-13 19:12:19Z rakesh $
 *
 * Library: Foundation
 * Package: Crypt
 * Module:  DigestEngine
 *
 * Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
 * and Contributors.
 *
 * Permission is hereby granted, free of charge, to any person or organization
 * obtaining a copy of the software and accompanying documentation covered by
 * this license (the "Software") to use, reproduce, display, distribute,
 * execute, and transmit the Software, and to prepare derivative works of the
 * Software, and to permit third-parties to whom the Software is furnished to
 * do so, all subject to the following:
 *
 * The copyright notices in the Software and this entire statement, including
 * the above license grant, this restriction and the following disclaimer,
 * must be included in all copies of the Software, in whole or in part, and
 * all derivative works of the Software, unless such copies or derivative
 * works are solely in the form of machine-executable object code generated by
 * a source language processor.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */


#include "DigestEngine.h"

using std::string;
using spt::digest::DigestEngine;


DigestEngine::DigestEngine() {}


DigestEngine::~DigestEngine() {}


string DigestEngine::digestToHex( const Digest& bytes )
{
  static const char digits[] = "0123456789abcdef";
  string result;
  result.reserve( bytes.size() * 2 );

  for ( Digest::const_iterator it = bytes.begin(); it != bytes.end(); ++it )
  {
    spt::Byte c = *it;
    result += digits[(c >> 4) & 0xF];
    result += digits[c & 0xF];
  }

  return result;
}