/* * Copyright (C) 1995, 1996 Systemics Ltd (http://www.systemics.com/) * All rights reserved. * * This library and applications are FREE FOR COMMERCIAL AND NON-COMMERCIAL USE * as long as the conditions within the COPYRIGHT file are adhered to. * */package java.math;/** * A class implementing arbitrary length integers. * <p>The native code BigNum implementation used by the class was * developed by, and is owned by, Eric Young (eay@mincom.oz.au) * <p>Copyright (C) 1995, 1996 Systemics Ltd (http://www.systemics.com/) * All rights reserved. * * @version     1.00, 11/12/1995 * @author      Systemics (Michael Wynn) */public class BigInteger extends BigNum{		public BigInteger()	{		super();	}	public BigInteger( BigInteger from )	{		super();		copy( this, from );	}	public BigInteger(String hexString)	{		super();		fromString( hexString );	}	public BigInteger( byte buffer[] )	{		super();		fromByteArray( buffer );	}	public Object	clone()	{		return new BigInteger( this );	}		public void	copy( Object src )	{		copy( this, (BigInteger)src );	}		public void 	fromString(String inHex)	{		int len=inHex.length();		if ( len == 0 )		{			zero( this );			return;		}			int pos =0;		byte buffer[] = new byte [( ( len + 1 ) / 2 )];		if ( ( len % 2 ) == 1 )		{			buffer[0]=(byte)asciiToHex(inHex.charAt(0));			pos=1;			len--;		}		for(int ptr = pos; len > 0; len -= 2 )			buffer[pos++] = (byte)( 					( asciiToHex( inHex.charAt( ptr++ ) ) << 4 ) |					( asciiToHex( inHex.charAt( ptr++ ) ) )					);		fromBinary( buffer );	}		public String	toString()	{		byte buffer[] = toByteArray();		StringBuffer returnBuffer = new StringBuffer();				int pos = 0, len = buffer.length;		// remove leading 0`s.		while ( ( pos < len ) && ( buffer[pos] == 0 ) )			pos++;		if ( ( pos < len ) && ( ( ( buffer[pos] >>> 4 ) & 0x0F ) == 0 ) )		{			returnBuffer.append( buffer[0] & 0x0F );			pos++;		} 		for (; pos<len; pos++)			returnBuffer.append( hexToAscii( ( buffer[pos] >>> 4 ) & 0x0F ) )						.append( hexToAscii( buffer[pos] & 0x0F ) );		if ( returnBuffer.length() > 0 )			return returnBuffer.toString();		return "0";	}		protected void	finalize()	{		super.finalize();	}	public BigInteger	modExp(BigInteger power, BigInteger modulo)	{		modExp( this, this, power, modulo );		return this;	}	public BigInteger	mul( BigInteger a, BigInteger b )	{		mul( this, a, b );		return this;	}	public int	cmp( BigInteger a )	{		return cmp( this, a );	}	public BigInteger	inc()	{		inc(this);		return this;	}	public BigInteger	dec()	{		dec(this);		return this;	}	/**	 * An internal function to create a buffer big enough in which	 * to store a number.	 * @param bitLen The number of <b>bits</b> in the number.	 * @return a buffer in which to store a number.	 */	protected static final byte[]	newBuffer( int bitLen )	{		return new byte[( bitLen + 7 ) / 8];	}	/**	 * Convert a number into a byte array	 * @return a byte array	 */	public byte[]	toByteArray()	{		byte buffer[] = newBuffer( bitLength() );		intoBinary( buffer );		return buffer;	}	public void	fromByteArray( byte buf[] )	{		fromBinary( buf );	}	public int	numberOfBits()	{		return bitLength();	}			private static final int	asciiToHex(char c)	{		if ( ( c >= 'a' ) && ( c <= 'f' ) )			return ( c - 'a' + 10 );		if ( ( c >= 'A' ) && ( c <= 'F' ) )			return ( c - 'A' + 10 );		if ( ( c >= '0' ) && ( c <= '9' ) )			return ( c - '0' );		throw new MathError("ascii to hex failed");	}	private static char	hexToAscii(int h)	{		if ( ( h >= 10 ) && ( h <= 15 ) )			return (char)( 'A' + ( h - 10 ) );		if ( ( h >= 0 ) && ( h <= 9 ) )			return (char)( '0' + h );		throw new MathError("hex to ascii failed");	}}