1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251
|
//******************************************************************************
//
// File: FindKeyHyb.java
// Package: edu.rit.hyb.keysearch
// Unit: Class edu.rit.hyb.keysearch.FindKeyHyb
//
// This Java source file is copyright (C) 2012 by Alan Kaminsky. All rights
// reserved. For further information, contact the author, Alan Kaminsky, at
// ark@cs.rit.edu.
//
// This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
// software; you can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// PJ 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.
//
// Linking this library statically or dynamically with other modules is making a
// combined work based on this library. Thus, the terms and conditions of the
// GNU General Public License cover the whole combination.
//
// As a special exception, the copyright holders of this library give you
// permission to link this library with independent modules to produce an
// executable, regardless of the license terms of these independent modules, and
// to copy and distribute the resulting executable under terms of your choice,
// provided that you also meet, for each linked independent module, the terms
// and conditions of the license of that module. An independent module is a
// module which is not derived from or based on this library. If you modify this
// library, you may extend this exception to your version of the library, but
// you are not obligated to do so. If you do not wish to do so, delete this
// exception statement from your version.
//
// A copy of the GNU General Public License is provided in the file gpl.txt. You
// may also obtain a copy of the GNU General Public License on the World Wide
// Web at http://www.gnu.org/licenses/gpl.html.
//
//******************************************************************************
package edu.rit.hyb.keysearch;
import edu.rit.crypto.blockcipher.AES256CipherSmp;
import edu.rit.pj.Comm;
import edu.rit.pj.HybridTeam;
import edu.rit.pj.WorkerIntegerForLoop;
import edu.rit.pj.WorkerRegion;
import edu.rit.util.Hex;
/**
* Class FindKeyHyb is a hybrid SMP cluster parallel program that solves an AES
* partial key search problem. The program's command line arguments are the
* plaintext (128-bit hexadecimal number), the ciphertext (128-bit hexadecimal
* number), the partial key with the <I>n</I> least significant bits set to 0
* (256-bit hexadecimal number), and <I>n</I>, the number of key bits to search
* for. The ciphertext was created by encrypting the plaintext with the key;
* however, not all bits of the key are provided. The problem is to find the
* complete key. The program performs an exhaustive search, trying all possible
* values for the missing key bits until it finds the key that reproduces the
* given ciphertext from the given plaintext.
* <P>
* Usage: java -Dpj.np=<I>Kp</I> -Dpj.nt=<I>Kt</I>
* edu.rit.hyb.keysearch.FindKeyHyb <I>plaintext</I> <I>ciphertext</I>
* <I>partialkey</I> <I>n</I>
* <BR><I>Kp</I> = Number of parallel processes
* <BR><I>Kt</I> = Number of parallel threads per process
* <BR><I>plaintext</I> = Plaintext (128-bit hexadecimal number)
* <BR><I>ciphertext</I> = Ciphertext (128-bit hexadecimal number)
* <BR><I>partialkey</I> = Partial key (256-bit hexadecimal number)
* <BR><I>n</I> = Number of key bits to search for
*
* @author Alan Kaminsky
* @version 14-Mar-2012
*/
public class FindKeyHyb
{
// Prevent construction.
private FindKeyHyb()
{
}
// Shared variables.
// World communicator.
static Comm world;
static int size;
static int rank;
// Command line arguments.
static byte[] plaintext;
static byte[] ciphertext;
static byte[] partialkey;
static int n;
// The least significant 32 bits of the partial key.
static int keylsbs;
// The maximum value for the missing key bits counter.
static int maxcounter;
// The complete key.
static byte[] foundkey;
// Main program.
/**
* AES partial key search main program.
*/
public static void main
(String[] args)
throws Exception
{
// Start timing.
long t1 = System.currentTimeMillis();
// Initialize PJ middleware.
Comm.init (args);
world = Comm.world();
size = world.size();
rank = world.rank();
// Parse command line arguments.
if (args.length != 4) usage();
plaintext = Hex.toByteArray (args[0]);
ciphertext = Hex.toByteArray (args[1]);
partialkey = Hex.toByteArray (args[2]);
n = Integer.parseInt (args[3]);
// Make sure n is not too small or too large.
if (n < 0)
{
System.err.println ("n = " + n + " is too small");
System.exit (1);
}
if (n > 30)
{
System.err.println ("n = " + n + " is too large");
System.exit (1);
}
// Set up program shared variables for doing trial encryptions.
keylsbs =
((partialkey[28] & 0xFF) << 24) |
((partialkey[29] & 0xFF) << 16) |
((partialkey[30] & 0xFF) << 8) |
((partialkey[31] & 0xFF) );
maxcounter = (1 << n) - 1;
// Do trial encryptions in parallel threads.
new HybridTeam().execute (new WorkerRegion()
{
public void run() throws Exception
{
execute (0, maxcounter, new WorkerIntegerForLoop()
{
// Thread local variables.
byte[] trialkey;
byte[] trialciphertext;
AES256CipherSmp cipher;
long p0, p1, p2, p3, p4, p5, p6, p7;
long p8, p9, pa, pb, pc, pd, pe, pf;
// Set up thread local variables. Extra padding to avert
// cache interference.
public void start()
{
trialkey = new byte [32+128];
System.arraycopy (partialkey, 0, trialkey, 0, 32);
trialciphertext = new byte [16+128];
cipher = new AES256CipherSmp (trialkey);
}
// Try every possible combination of low-order key bits.
public void run (int first, int last)
{
for (int counter = first; counter <= last; ++ counter)
{
// Fill in low-order key bits.
int lsbs = keylsbs | counter;
trialkey[28] = (byte) (lsbs >>> 24);
trialkey[29] = (byte) (lsbs >>> 16);
trialkey[30] = (byte) (lsbs >>> 8);
trialkey[31] = (byte) (lsbs );
// Try the key.
cipher.setKey (trialkey);
cipher.encrypt (plaintext, trialciphertext);
// If the result equals the ciphertext, we found the
// key.
if (match (ciphertext, trialciphertext))
{
byte[] key = new byte [32];
System.arraycopy (trialkey, 0, key, 0, 32);
foundkey = key;
}
}
}
});
}
});
// If we found the key, print it.
if (foundkey != null)
{
System.out.println (Hex.toString (foundkey));
}
// Stop timing.
long t2 = System.currentTimeMillis();
System.out.println ((t2-t1) + " msec " + rank);
}
// Hidden operations.
/**
* Returns true if the two byte arrays match.
*/
private static boolean match
(byte[] a,
byte[] b)
{
boolean matchsofar = true;
int n = a.length;
for (int i = 0; i < n; ++ i)
{
matchsofar = matchsofar && a[i] == b[i];
}
return matchsofar;
}
/**
* Print a usage message and exit.
*/
private static void usage()
{
System.err.println ("Usage: java -Dpj.np=<Kp> -Dpj.nt=<Kt> edu.rit.hyb.keysearch.FindKeyHyb <plaintext> <ciphertext> <partialkey> <n>");
System.err.println ("<Kp> = Number of parallel processes");
System.err.println ("<Kt> = Number of parallel threads per process");
System.err.println ("<plaintext> = Plaintext (128-bit hexadecimal number)");
System.err.println ("<ciphertext> = Ciphertext (128-bit hexadecimal number)");
System.err.println ("<partialkey> = Partial key (256-bit hexadecimal number)");
System.err.println ("<n> = Number of key bits to search for");
System.exit (1);
}
}
|