/* 
 *  Copyright (C) 2000 - 2014 TagServlet Ltd
 *
 *  This file is part of Open BlueDragon (OpenBD) CFML Server Engine.
 *  
 *  OpenBD is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  Free Software Foundation,version 3.
 *  
 *  OpenBD is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with OpenBD.  If not, see http://www.gnu.org/licenses/
 *  
 *  Additional permission under GNU GPL version 3 section 7
 *  
 *  If you modify this Program, or any covered work, by linking or combining 
 *  it with any of the JARS listed in the README.txt (or a modified version of 
 *  (that library), containing parts covered by the terms of that JAR, the 
 *  licensors of this Program grant you additional permission to convey the 
 *  resulting work. 
 *  README.txt @ http://www.openbluedragon.org/license/README.txt
 *  
 *  http://www.openbd.org/
 *  $Id: encrypt.java 2461 2014-12-17 11:48:57Z alan $
 */

package com.naryx.tagfusion.expression.function;

import java.util.List;

import com.nary.security.Cryptography;
import com.naryx.tagfusion.cfm.engine.cfBinaryData;
import com.naryx.tagfusion.cfm.engine.cfData;
import com.naryx.tagfusion.cfm.engine.cfSession;
import com.naryx.tagfusion.cfm.engine.cfStringData;
import com.naryx.tagfusion.cfm.engine.cfmRunTimeException;


public class encrypt extends functionBase {

	private static final long serialVersionUID = 1L;


	public encrypt() {
		min = 2;
		max = 6;
	}


	public String[] getParamInfo() {
		return new String[] {
				"string to encrypt",
				"encryption key",
				"encryption algorithm to be applied. If not specified, a default of BD_DEFAULT will be used. The CFMX_COMPAT algorithm option is not supported.",
				"the encoding - uu (default), hex or base64 are valid options",
				"the salt to be applied in encryption",
				"the number of iterations"
		};
	}


	public java.util.Map<String,String> getInfo() {
		return makeInfo(
				"security",
				"Encrypts the given string with the optional parameters",
				ReturnType.STRING );
	}


	public cfData execute( cfSession _session, List<cfData> parameters ) throws cfmRunTimeException {
		// parameters - string, key[, algorithm[, encoding[, IVorSalt[,
		// iterations]]]]
		String data = parameters.get( parameters.size() - 1 ).getString();
		String key = parameters.get( parameters.size() - 2 ).getString();

		String fullAlgorithm = getAlgorithm( _session, parameters );
		String encoding = getEncoding( _session, parameters );
		byte[] ivOrSalt = getIvOrSalt( _session, parameters, 4 );

		if ( fullAlgorithm.equalsIgnoreCase( "bd_default" ) ) {
			String result = com.nary.security.encrypter.encrypt( data, key );
			return new cfStringData( result );
		} else if ( fullAlgorithm.equalsIgnoreCase( "bdnet62_compat" ) ) {
			String result = com.nary.security.encrypter.encrypt( data, key );
			return new cfStringData( result );
		} else {
			int iterations = getIterations( _session, parameters, 5 );

			byte[] dataBytes = data.getBytes();
			byte[] encrypted;
			try {
				encrypted = Cryptography.doCipher( Cryptography.ENCRYPT_MODE, dataBytes, fullAlgorithm, key.getBytes(), ivOrSalt, iterations );
				return new cfStringData( BinaryEncode.encode( _session, encoding, encrypted ) );

			} catch ( Exception e ) {
				throwException( _session, e.getMessage() );
				return null; // keep compiler happy
			}

		}
	}


	protected String getAlgorithm( cfSession _session, List<cfData> parameters ) throws cfmRunTimeException {
		if ( parameters.size() > 2 ) {
			return parameters.get( parameters.size() - 3 ).getString();
		} else {
			return "bd_default";
		}
	}


	protected String getEncoding( cfSession _session, List<cfData> parameters ) throws cfmRunTimeException {
		if ( parameters.size() > 3 ) {
			return parameters.get( parameters.size() - 4 ).getString();
		} else {
			return "uu";
		}
	}


	protected byte[] getIvOrSalt( cfSession _session, List<cfData> parameters, int _i ) throws cfmRunTimeException {
		if ( parameters.size() > _i ) {
			cfData ivOrSalt = parameters.get( parameters.size() - ( _i + 1 ) );
			if ( ivOrSalt.getDataType() != cfData.CFBINARYDATA ) {
				throwException( _session, "Invalid IVorSalt type. A value of type binary is required." );
			} else {
				return ( (cfBinaryData) ivOrSalt ).getByteArray();
			}
		}

		return null;
	}


	protected int getIterations( cfSession _session, List<cfData> parameters, int _i ) throws cfmRunTimeException {
		if ( parameters.size() > _i ) {
			return parameters.get( parameters.size() - ( _i + 1 ) ).getInt();
		}

		return 1;
	}

}