Thread: sha1

hi, I want to calculate the sha1 hash of some strings... there is an easy way ? can I use a library or I have to find the algo and write it down in C ?

I wrote a C++ class to calculate the SHA1 hash of strings. It shouldn't be too hard to convert to C. There's no code in the header, so you shouldn't need it.

Code:

#include "SHAHash.hpp"

std::string SHAHash::calcSHA( std::string msg )
{

 	DWORD a = 0x67452301;
 	DWORD b = 0xefcdab89;
 	DWORD c = 0x98badcfe;
 	DWORD d = 0x10325476;
 	DWORD e = 0xc3d2e1f0;
 	DWORD w[ 80 ] = { 0 };

	strToBlocks( msg );

	for( DWORD i = 0; i < mNumBlocks; i += 16 )
	{

		DWORD oldA = a;
		DWORD oldB = b;
		DWORD oldC = c;
		DWORD oldD = d;
		DWORD oldE = e;

		for( DWORD j = 0; j < 80; j++ )
		{

			if( j < 16 )
   				w[ j ] = mBlocks[ i + j ];
			else
				w[ j ] = rol( w[ j - 3 ] ^ w[ j - 8 ] ^
                    			w[ j - 14 ] ^ w[ j - 16 ], 1 );

			DWORD t = add( add( rol( a, 5 ), ft( j, b, c, d ) ),
       					add( add( e, w[ j ] ), kt( j ) ) );
			e = d;
			d = c;
			c = rol( b, 30 );
			b = a;
			a = t;

		}

  		a = add( a, oldA );
  		b = add( b, oldB );
  		c = add( c, oldC );
  		d = add( d, oldD );
  		e = add( e, oldE );

	}

	std::ostringstream oss;

	oss<<std::hex<<std::uppercase<<a<<b<<c<<d<<e;

	return oss.str( );

}

void SHAHash::strToBlocks( std::string str )
{

	mNumBlocks = ( ( str.length( ) + 8 ) >> 6 ) + 1;

 	mBlocks.clear( );
 	for( DWORD i = 0; i < mNumBlocks * 16; i++ )
 		mBlocks.push_back( i );

	for( DWORD i = 0; i < mNumBlocks * 16; i++ ) mBlocks[ i ] = 0;

	for( DWORD i = 0; i < str.length( ); i++ )
  		mBlocks[ i >> 2 ] |= str[ i ] << ( 24 - ( i % 4 ) * 8 );

	mBlocks[ str.length( ) >> 2 ] |= 0x80 << ( 24 - ( str.length( ) % 4 ) * 8 );
	mBlocks[ mNumBlocks * 16 - 1 ] = str.length( ) * 8;

}

DWORD SHAHash::add( DWORD x, DWORD y )
{

 	DWORD lsw = ( x & 0xffff ) + ( y & 0xffff );
  	DWORD msw = ( x >> 16 ) + ( y >> 16 ) + ( lsw >> 16 );
  	return ( msw << 16 ) | ( lsw & 0xffff );

}

DWORD SHAHash::rol( DWORD num, int count )
{

	return ( num << count ) | ( num >> ( 32 - count ) );

}

DWORD SHAHash::ft( DWORD i, DWORD b, DWORD c, DWORD d )
{

	if( i < 20 ) return ( b & c ) | ( ( ~b ) & d );
	if( i < 40 ) return ( b ^ c ^ d );
	if( i < 60 ) return ( b & c ) | ( b & d ) | ( c & d );
	return b ^ c ^ d;

}

DWORD SHAHash::kt( DWORD i )
{

 	if( i < 20 ) return 0x5a827999;
  	if( i < 40 ) return 0x6ed9eba1;
  	if( i < 60 ) return 0x8f1bbcdc;
  	return 0xca62c1d6;

}

SHAHash::SHAHash( void )
{

}

SHAHash::~SHAHash( void )
{

}

thank u !!