SourceCrypter.java

package sourcecrypter;

import javax.crypto.*;
import java.security.*;
import java.io.*;
import java.util.*;
import javax.tools.*;

public class SourceCrypter {

    private SecretKey key;
    private DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();
    private String inputClassName = "";
    private String crypterClassName;
    //Decrypt Method
    private List<String> dm = new ArrayList<String>();
    //Main Method
    private List<String> mm = new ArrayList<String>();
    //JavaSourceFromString Class
    private List<String> jsfs = new ArrayList<String>();
    //Header
    private List<String> imports = new ArrayList<String>();
    //Everything else
    private String byteKey = "private static byte[] byteKey = {";
    private String encCode = "private static byte[] encSource = {";
    private String keyString = "private static SecretKey key = new SecretKeySpec(byteKey, \"AES\");";

    //fileName must be different than sourceFile!!!!
    public SourceCrypter(String sourceFile, String fileName, boolean compile) {
        try {
            crypterClassName = fileName;

            if (!sourceFile.toLowerCase().endsWith(".java")) {
                System.out.println("Crypter only works with *.java files!");
                return;
            }

            System.out.println("Read " + sourceFile);
            FileReader fr = new FileReader(sourceFile);
            BufferedReader br = new BufferedReader(fr);

            //Read File
            String fileString = "";
            String line = "";
            while ((line = br.readLine()) != null) {
                if (line.isEmpty()) {
                    continue;
                } else if (inputClassName.isEmpty() && line.contains(" class ")) {
                    int start_index = line.indexOf(" class ") + 7;
                    int end_index = start_index + 1;
                    while (end_index < line.length() - 1 && Character.isLetter(line.charAt(end_index))) {
                        end_index++;
                    }
                    inputClassName = line.substring(start_index, end_index);//get classname as subString!
                } else if (line.contains(" ")) {
                    line = line.replace(" ", "");
                }
                fileString = fileString + line;
            }
            //Close Streams
            br.close();
            fr.close();

            System.out.println("Generate AES Key...");
            generateKey();
            System.out.println("Add AES Key to SourceString...");
            byte[] tmpKey = key.getEncoded();
            for (int i = 0; i < tmpKey.length; i++) {
                byteKey = byteKey + tmpKey[i] + ",";
            }
            byteKey = byteKey + "};";

            System.out.println("Encrypt SourceCode...");
            byte[] encryptedSource = encryptString(fileString);
            System.out.println("Add encrypted SourceCode...");
            for (int i = 0; i < encryptedSource.length; i++) {
                encCode = encCode + encryptedSource[i] + ",";
            }
            encCode = encCode + "};";

            System.out.println("Init Crypter SourceCode...");
            init();

            System.out.println("Write CrypterClass File....");
            FileWriter fw = new FileWriter(crypterClassName + ".java");
            BufferedWriter bw = new BufferedWriter(fw);
            for (String tmp : imports) {
                bw.write(tmp);
            }
            bw.write("public class " + crypterClassName + "{");
            bw.write(byteKey);
            bw.write(encCode);
            bw.write(keyString);
            for (String tmp : mm) {
                bw.write(tmp);
            }
            for (String tmp : dm) {
                bw.write(tmp);
            }
            bw.write("}");
            for (String tmp : jsfs) {
                bw.write(tmp);
            }
            bw.close();
            fw.close();

            if (compile) {
                System.out.println("Compiling " + crypterClassName + ".java...");
                compileFile(new File(crypterClassName + ".java"));
                for (Diagnostic diagnostic : diagnostics.getDiagnostics()) {
                    System.out.println("Error on Line " + diagnostic.getLineNumber());
                }
            }
            System.out.println("Done!");
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }

    private void init() {
        //Init imports
        imports.add("import java.util.*;");
        imports.add("import java.net.*;");
        imports.add("import java.io.*;");
        imports.add("import javax.tools.*;");
        imports.add("import javax.tools.JavaCompiler.*;");
        imports.add("import javax.crypto.*;");
        imports.add("import javax.crypto.spec.*;");

        //Init Main Method
        mm.add("public static void main(String[] argv){");
        mm.add("try{");
        mm.add("JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();");
        mm.add("DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<javafileobject>();");
        mm.add("String sourceCode = decryptSource(encSource);");
        mm.add("StringWriter writer = new StringWriter();");
        mm.add("PrintWriter out = new PrintWriter(writer);");
        mm.add("out.println(sourceCode);");
        mm.add("out.close();");
        mm.add("JavaFileObject file = new JavaSourceFromString(\"" + inputClassName + "\", writer.toString());");
        mm.add("Iterable<? extends JavaFileObject> compilationUnits = Arrays.asList(file);");
        mm.add("CompilationTask task = compiler.getTask(null, null, diagnostics, null, null, compilationUnits);");
        mm.add("boolean success = task.call();");
        mm.add("for(Diagnostic diagnostic : diagnostics.getDiagnostics()){");
        mm.add("System.out.println(\"Error on Line \"+diagnostic.getLineNumber());}");
        mm.add("if(success){");
        mm.add("Class.forName(\"" + inputClassName + "\").getD eclaredMethod(\"main\", new Class[]{String[].class}).invoke(null,new Object[]{null});}");
        mm.add("}catch(Throwable e){e.printStackTrace();}}");

        //Init Decryption Method
        dm.add("private static String decryptSource(byte[] input){");
        dm.add("try{");
        dm.add("Cipher cipher = Cipher.getInstance(\"AES\");");
        dm.add("cipher.init(Cipher.DECRYPT_MODE, key);");
        dm.add("byte[] output = cipher.doFinal(input);");
        dm.add("return new String(output);");
        dm.add("}catch(Throwable e){");
        dm.add("e.printStackTrace();");
        dm.add("return null;}}");

        //Init JavaSourceFromString Class
        jsfs.add("class JavaSourceFromString extends SimpleJavaFileObject{");
        jsfs.add("final String code;");
        jsfs.add("JavaSourceFromString(String name, String code){");
        jsfs.add("super(URI.create(\"String:///\"+name.replace('.','/')+Kind.SOURCE.extension),Kind.SOURCE);");
        jsfs.add("this.code = code;}");
        jsfs.add("@Override ");
        jsfs.add("public CharSequence getCharContent(boolean ignoreEncodingErrors){");
        jsfs.add("return code;}}");
    }

    private void generateKey() {
        try {
            KeyGenerator keygen = KeyGenerator.getInstance("AES");
            SecureRandom random = new SecureRandom();
            keygen.init(random);
            key = keygen.generateKey();
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }

    private byte[] encryptString(String words) {
        try {
            byte[] input = words.getBytes();

            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.ENCRYPT_MODE, key);

            byte[] output = cipher.doFinal(input);
            return output;
        } catch (Throwable e) {
            e.printStackTrace();
            return null;
        }
    }

    private void compileFile(File file) {
        try {
            JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
            StandardJavaFileManager fileManager = compiler.getStandardFileManager(diagnostics, null, null);
            Iterable<? extends JavaFileObject> compilationUnit = fileManager.getJavaFileObjects(file);
            compiler.getTask(null, fileManager, diagnostics, null, null, compilationUnit).call();
            fileManager.close();
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }
}