[Netmail-cvs] netmail hashcash.java,NONE,1.1

[Pascal <pas...@us...>]

Update of /cvsroot/netmail/netmail
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv26721

Added Files:
	hashcash.java 
Log Message:
First working version of my hashcash agent for Novell NetMail

--- NEW FILE: hashcash.java ---
/* Copyright (C) 2004  Pascal
 * Originally written for http://netmail.sourceforge.net
 * Licensed under the terms of the GNU GPL, the text
 * of which is included as the file named "gpl.txt".
 */
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Calendar;
import java.util.EmptyStackException;
import java.util.Enumeration;
import java.util.Random;
import java.util.Stack;
import java.util.TimeZone;
import java.util.Vector;
import java.security.MessageDigest;
public class hashcash {
    public static void main(String[] args) throws Throwable {
        BufferedReader in = new BufferedReader(new FileReader("hashcash.conf"));
        String s;
        String host = "127.0.0.1";
        int port = 689;
        int bits = 22;
        Vector from = new Vector();
        while (in.ready()) {
            s = in.readLine().trim();
            if (s.length() > 0) switch(Character.toLowerCase(s.charAt(0))) {
                case 'i':
                    host = s.split("=")[1];
                    break;
                case 'p':
                    port = new Integer(s.split("=")[1]).intValue();
                    break;
                case 'b':
                    bits = new Integer(s.split("=")[1]).intValue();
                    break;
                case 'f':
                    from.add(s.split("=")[1].toLowerCase() + " - ");
                    break;
                case '#':
                    break;
                default:
                    throw new Exception("Error in config file");
            }
        }
        ServerSocket ss = register(host, port, "HashCash");
        Stack freeThreads = HThread.freeThreads = new Stack();
        HThread.host = host;
        HThread.bits = bits;
        HThread.from = from;
        while (!ss.isClosed()) {
            Socket sock = ss.accept();
            try {
                HThread thread = (HThread) freeThreads.pop();
                thread.sock = sock;
                thread.start();
            } catch (EmptyStackException e) {
                new HThread(sock);
            }
        }
    }

    private static final ServerSocket register(String host, int port, String agent) {
        Socket nmap = null;
        ServerSocket ss = null;
        try {
            nmap = new Socket(host, port);
            BufferedReader in = new BufferedReader(new InputStreamReader(nmap.getInputStream()));
            String s = in.readLine();
            ss = new ServerSocket(0,0,nmap.getLocalAddress());
            if (s.startsWith("4242 "))
                throw new Exception("Please add " + nmap.getLocalAddress().getHostAddress() + " to NMAP trusted hosts via NWAdmin.");
            if (!s.startsWith("1000 "))
                throw new Exception("NMAP protocol error 1: " + s);
            PrintStream out = new PrintStream(nmap.getOutputStream());
            out.println("QWAIT 4 " + ss.getLocalPort() + " " + agent);
            s = in.readLine();
            if (!s.startsWith("1000 "))
                throw new Exception("Failed to register with queue: " + s);
        } catch (Throwable t) {
            System.out.println(t.getMessage());
            System.exit(1);
        }
        try {
            nmap.close();
        } catch (Throwable t) {}
        return ss;
    }

    private static final class HThread extends Thread {
        private static Stack freeThreads;
        private static String host;
        private static int bits;
        private static Vector from;
        private final Random r = new Random();
        private final Calendar cal = Calendar.getInstance();
        private final MessageDigest md;
        public Socket sock;
        HThread(Socket s) throws Throwable {
            super();
            md = MessageDigest.getInstance("SHA");
            sock = s;
            super.start();
        }

        public final synchronized void start() {
            this.notify();
        }

        private final synchronized void waitForJob() {
            while (sock == null) {
                try {
                    this.wait(1000);
                } catch (InterruptedException e) {}
            }
        }

        public final void run() {
            while (true) {
                try {
                    if (!sock.getLocalAddress().getHostAddress().equals(host))
                        throw new Exception("unauthorized connection from " + sock.getLocalAddress().getHostAddress());
                    BufferedReader in = new BufferedReader(new InputStreamReader(sock.getInputStream()));
                    String s = in.readLine();
                    if (!s.startsWith("6020 "))
                        throw new Exception("NMAP protocol error 2: " + s);
                    String id = s.split(" ")[1];
                    int size = new Integer(s.split(" ")[3]).intValue();
                    Vector env = new Vector();
                    for (int x = new Integer(s.split(" ")[2]).intValue() - (in.readLine().length() + 2); x > 0; x -= (s.length() + 2)) {
                        env.add(s = in.readLine());
                    }
                    s = in.readLine();
                    if (!s.startsWith("6021 "))
                        throw new Exception("NMAP protocol error 3: " + s);
                    boolean process = false;
                    Stack to = new Stack();
                    for (Enumeration e = env.elements(); e.hasMoreElements();) {
                        s = (String)e.nextElement();
                        switch(s.charAt(0)) {
                            case 'F':
                                for (Enumeration n = from.elements(); n.hasMoreElements();) {
                                    if (s.toLowerCase().endsWith((String)n.nextElement())) process = true;
                                }
                                break;
                            case 'R':
                                to.push(s.split(" ")[1]);
                        }
                    }

                    PrintStream out = new PrintStream(sock.getOutputStream());
                    int header = 0;
                    if (process) {
                        out.println("QHEAD " + id);
                        s = in.readLine();
                        if (!s.startsWith("2023 "))
                            throw new Exception("NMAP protocol error 4: " + s);
                        header = new Integer(s.split(" ")[1]).intValue();
                        for (int x = header; x > 0; x -= (s.length() + 2)) {
                            s = in.readLine();
                            if (s.startsWith("X-Hashcash: "))
                                process = false;
                        }
                        s = in.readLine();
                        if (!s.startsWith("1000 "))
                            throw new Exception("NMAP protocol error 5: " + s);
                    }
                    if (process) {
                        out.println("QCREA");
                        s = in.readLine();
                        if (!s.startsWith("1000 "))
                            throw new Exception("NMAP protocol error 6: " + s);
                        out.println("QADDQ " + id + " 0 " + header);
                        s = in.readLine();
                        if (!s.startsWith("1000 "))
                            throw new Exception("NMAP protocol error 7: " + s);
                        do {
                            s = "0:" + timeToYYMMDD(cal) + ":" + (String)to.pop() + ":";
                            byte[] c = new byte[s.length() + Math.max(11,6+bits*100/595)];
                            System.arraycopy(s.getBytes(),0,c,0,s.length());
                            for (int x = s.length(); x < c.length; x++)
                                c[x] = getRandomChar(r);
                            byte[] h = new byte[20];
                            h = md.digest(c);
                            while (!zeroBits(h,bits)) {
                                for (int x = c.length; x-- > s.length() && (c[x] = incChar(c[x])) == 48;);
                                h = md.digest(c);
                            }
                            out.println("QSTOR MESSAGE " + (c.length + 14));
                            out.println("X-Hashcash: " + new String(c));
                            s = in.readLine();
                            if (!s.startsWith("1000 "))
                                throw new Exception("NMAP protocol error 8: " + s);
                        } while (!to.empty());
                        out.println("QADDQ " + id + " " + header + " " + (size - header));
                        s = in.readLine();
                        if (!s.startsWith("1000 "))
                            throw new Exception("NMAP protocol error 9: " + s);
                        for (Enumeration e = env.elements(); e.hasMoreElements();) {
                            out.println("QSTOR RAW " + e.nextElement());
                            s = in.readLine();
                            if (!s.startsWith("1000 "))
                                throw new Exception("NMAP protocol error 10: " + s);
                        }
                        out.println("QRUN");
                        s = in.readLine();
                        if (!s.startsWith("1000 "))
                            throw new Exception("NMAP protocol error 11: " + s);
                        out.println("QDELE " + id);
                        s = in.readLine();
                        if (!s.startsWith("1000 "))
                            throw new Exception("NMAP protocol error 12: " + s);
                    }
                    out.println("QDONE");
                    s = in.readLine();
                    if (!s.startsWith("1000 "))
                        throw new Exception("NMAP protocol error 13: " + s);
                } catch (Throwable t) {
                    System.out.println(t.getMessage());
                } finally {
                    try {
                        sock.close();
                    } catch (Throwable t) {}
                }
                sock = null;
                freeThreads.push(this);
                waitForJob();
            }
        }

/*
 * All methods below this line are from Yet Another Hash Cash Tool 1.0
 * Created on 05.12.2003 by Sebastian Gesemann (sgeseman \at upb \dot de)
 */

	/**
	 * @return one random character out of 62 ('A'..'Z','a'..'z','0'..'9')
	 */
	private static final byte getRandomChar(Random rnd) {
		int x = rnd.nextInt(62);
		if (x<10) return (byte)(48+x); // ASCII code for '0'..'9'
		x-=10;
		if (x<26) return (byte)(65+x); // ASCII code for 'A'..'Z'
		x-=26;
		return (byte)(97+x); // ASCII code for 'a'..'z'
	}

	/**
	 * @param c
	 * @return c+1 (within '0'..'9','A'..'Z','a'..'z')
	 */
	private static final byte incChar(byte c) {
		c++;
		if (c==48+10) return (byte)65;
		if (c==65+26) return (byte)97;
		if (c==97+26) return (byte)48;
		return c;
	}

	/**
	 * @param ba
	 * @param minimum
	 * @return checks whether a bitstring (MSB first) starts at least with [minimum] zeros
	 */
	private static final boolean zeroBits(byte[] ba, int minimum) {
		int o=0;
		while (minimum>=8) {
			if (ba[o++]!=(byte)0) return false;
			minimum-=8;
		}
		if (minimum>0) {
			int m = (0xFF << (8-minimum)) & 0xFF;
			if ((ba[o] & m) != 0) return false;
		}
		return true;
	}

	/**
	 * @param i
	 * @return returns a two-digit string (leading zero for i<10)
	 */
    private static final String twoDigits(int i) {
		return i<10 ? "0"+i : Integer.toString(i);
	}

	/**
	 * @param c
	 * @return returns a 6 character string (YYMMDD) for a given Calendar
	 */
    private static final String timeToYYMMDD(Calendar c) {
		return twoDigits(c.get(Calendar.YEAR) % 100)
		+twoDigits((c.get(Calendar.MONTH)+1) % 100)
		+twoDigits(c.get(Calendar.DAY_OF_MONTH) % 100);
	}
    }
}