CheckSum.cc

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/*---------------------------------------------------------------------\
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\---------------------------------------------------------------------*/
#include <iostream>
#include <sstream>

#include "zypp/base/Logger.h"
#include "zypp/base/Gettext.h"
#include "zypp/base/String.h"

#include "zypp/CheckSum.h"
#include "zypp/Digest.h"

using std::endl;

namespace zypp
{ 

  const std::string & CheckSum::md5Type()
  { static std::string _type( "md5" ); return _type; }

  const std::string & CheckSum::shaType()
  { static std::string _type( "sha" ); return _type; }

  const std::string & CheckSum::sha1Type()
  { static std::string _type( "sha1" ); return _type; }

  const std::string & CheckSum::sha256Type()
  { static std::string _type( "sha256" ); return _type; }


  CheckSum::CheckSum()
  {}

  CheckSum::CheckSum( const std::string & type, const std::string & checksum )
  : _type( str::toLower( type ) )
  , _checksum( checksum )
  {
    switch ( checksum.size() )
    {
      case 64:
        if ( _type == sha256Type() )
          return;
        if ( _type.empty() || _type == shaType() )
        {
          _type = sha256Type();
          return;
        }
        // else: dubious
        break;

      case 40:
        if ( _type == sha1Type() )
          return;
        if ( _type.empty() || _type == shaType() )
        {
          _type = sha1Type();
          return;
        }
        // else: dubious
        break;

      case 32:
        if (  _type == md5Type() )
          return;
        if ( _type.empty() )
        {
          _type = md5Type();
          return;
        }
        // else: dubious
        break;

      case 0:
        return; // empty checksum is ok
        break;

      default:
        if ( _type.empty() )
        {
          WAR << "Can't determine type of " << checksum.size() << " byte checksum '" << _checksum << "'" << endl;
          return;
        }
        // else: dubious
        break;
    }

    // dubious: Throw on malformed known types, otherwise log a warning.
    std::string msg = str::form ( _("Dubious type '%s' for %u byte checksum '%s'"),
                                  _type.c_str(), checksum.size(), _checksum.c_str() );
    if (    _type == md5Type()
         || _type == shaType()
         || _type == sha1Type()
         || _type == sha256Type() )
    {
      ZYPP_THROW( CheckSumException( msg ) );
    }
    else
    {
      WAR << msg << endl;
    }
  }

  CheckSum::CheckSum( const std::string & type_r, std::istream & input_r )
  {
    if ( input_r.good() && ! type_r.empty() )
      {
        _type = str::toLower( type_r );
        _checksum = Digest::digest( _type, input_r );
        if ( ! input_r.eof() || _checksum.empty() )
          {
            _type = _checksum = std::string();
          }
      }
  }

  std::string CheckSum::type() const
  { return _type; }

  std::string CheckSum::checksum() const
  { return _checksum; }

  bool CheckSum::empty() const
  { return (checksum().empty() || type().empty()); }

  std::string CheckSum::asString() const
  {
    std::ostringstream str;
    str << *this;
    return str.str();
  }

  std::ostream & operator<<( std::ostream & str, const CheckSum & obj )
  {
    if ( obj.checksum().empty() )
      {
        return str << std::string("NoCheckSum");
      }

    return str << ( obj.type().empty() ? std::string("UNKNOWN") : obj.type() ) << '-' << obj.checksum();
  }

  bool operator==( const CheckSum & lhs, const CheckSum & rhs )
  { return lhs.checksum() == rhs.checksum() && lhs.type() == rhs.type(); }

  bool operator!=( const CheckSum & lhs, const CheckSum & rhs )
  { return ! ( lhs == rhs ); }

} // namespace zypp