Summary

Encrypt a file using hybrid encryption mode

/**
 *  ---------
 * |.##> <##.|  Open Smart Card Development Platform (www.openscdp.org)
 * |#       #|
 * |#       #|  Copyright (c) 1999-2006 CardContact Software & System Consulting
 * |'##> <##'|  Andreas Schwier, 32429 Minden, Germany (www.cardcontact.de)
 *  ---------
 *
 *  This file is part of OpenSCDP.
 *
 *  OpenSCDP is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  OpenSCDP 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 OpenSCDP; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @fileoverview Encrypt a file using hybrid encryption mode
 */

var File = require("scsh/file/File").File;
var FileEncryptor = require("scsh/file/FileEncryptor").FileEncryptor;
var PublicKeyFile = require("scsh/file/PublicKeyFile").PublicKeyFile;


function EncryptFile() {

}



EncryptFile.prototype.loadPublicKey = function(fname) {
	this.pkf = new PublicKeyFile(fname);
}



EncryptFile.prototype.selectPublicKey = function() {
	var fname = typeof(this.pkFileName) != "undefined" ? this.pkFileName : "";
	fname = Dialog.prompt("Select recipient public key", fname, null, "*.pka");
	if (!fname) {
		throw new Error("User abort");
	}
	this.loadPublicKey(fname);
	this.pkFileName = fname;
}



EncryptFile.prototype.selectFileToEncrypt = function() {
	var fname = typeof(this.plainFileName) != "undefined" ? this.plainFileName : "";
	fname = Dialog.prompt("Select file to encrypt", fname, null, "");
	if (!fname) {
		throw new Error("User abort");
	}

	this.plainFileName = fname;

	fname = Dialog.prompt("Save encrypted file as", fname + ".enc", null, "");
	if (!fname) {
		throw new Error("User abort");
	}

	var f = new File(fname);
	if (f.exists()) {
		if (Dialog.prompt("File does already exist. Overwrite ?") == null) {
			throw new Error("User abort");
		}
	}

	this.encFileName = fname;
}



EncryptFile.prototype.encrypt = function() {
	var fenc = new FileEncryptor(undefined, FileEncryptor.HYBRID);
	fenc.deriveKey(this.pkf.getChain()[0]);

	var f = new File(this.plainFileName);
	var bin = f.readAllAsBinary();
	f.close();

	bin = fenc.encrypt(bin);

	var f = new File(this.encFileName);
	f.writeAll(bin);
	f.close();

	print("Encryption complete.");
}


if (typeof(e) == "undefined") {
	var e = new EncryptFile();
}

e.selectPublicKey();
e.selectFileToEncrypt();
e.encrypt();