des.cc

COPE the first practical network coding scheme which is developped on click

/*
 * des.{cc,hh} -- element implements IPsec encryption using DES
 * Alex Snoeren, Benjie Chen
 * contains code from other sources; see below
 *
 * Copyright (c) 1999-2000 Massachusetts Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, subject to the conditions
 * listed in the Click LICENSE file. These conditions include: you must
 * preserve this copyright notice, and you cannot mention the copyright
 * holders in advertising related to the Software without their permission.
 * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
 * notice is a summary of the Click LICENSE file; the license in that file is
 * legally binding.
 */

#include <click/config.h>
#ifndef HAVE_IPSEC
# error "Must #define HAVE_IPSEC in config.h"
#endif
#include "des.hh"
#include "esp.hh"
#include <click/ipaddress.hh>
#include <click/confparse.hh>
#include <click/error.hh>
#include <click/glue.hh>
CLICK_DECLS

Des::Des()
  : Element(1, 1), _op(0)
{
}

Des::~Des()
{
}

Des::Des(int decrypt, unsigned char * key)
{
  add_input();
  add_output();
  _op = decrypt;
  memcpy(_key, key, 8);
}

int
Des::configure(Vector<String> &conf, ErrorHandler *errh)
{
  int dec_int;
  _ignore = 12;

  if (cp_va_parse(conf, this, errh,
		  cpInteger, "Decrypt/Encrypt (0/1)", &dec_int,
		  cpDesCblock, "64-bit DES key", _key,
		  cpOptional,
		  cpInteger, "Bytes to ignore at the end", &_ignore,
		  cpEnd) < 0)
    return -1;
  _op = dec_int;
#ifdef DEBUG
  click_chatter("Key: %x%x%x%x%x%x%x%x",_key[0], _key[1], _key[2], _key[3],
	      _key[4], _key[5], _key[6], _key[7]);
#endif
  return 0;
}

int
Des::initialize(ErrorHandler *)
{
  des_set_key(&_key, _ks);
  return 0;
}


Packet *
Des::simple_action(Packet *p_in)
{
  WritablePacket *p = p_in->uniqueify();
  unsigned char hold[8];
  unsigned char *idat = p->data();
  struct esp_new *esp = (struct esp_new *)p->data();
  des_cblock iv;

  unsigned char *ivp = esp->esp_iv;
  int i, plen = p->length() - sizeof(esp_new) - _ignore;
  idat = p->data() + sizeof(esp_new);
  
  if (_op == DES_DECRYPT)
    memcpy(iv, ivp, 8);

  // de/encrypt the payload
  while (plen > 0) {
    if(_op == DES_DECRYPT) {
      memcpy(hold, idat, 8);
      des_ecb_encrypt((des_cblock *)idat, (des_cblock *)idat,
		      _ks, DES_DECRYPT);
      /* CBC: XOR with the IV */
      for (i = 0; i < 8; i++)
	idat[i] ^= ivp[i];
      memcpy(ivp, hold, 8);
      
    } else {
      /* CBC: XOR with the IV */
      for (i = 0; i < 8; i++)
	idat[i] ^= ivp[i];
      des_ecb_encrypt((des_cblock *)idat, (des_cblock *)idat, 
		      _ks, DES_ENCRYPT);
      ivp = idat;
    }
    idat += 8;
    plen -= 8;
  }

  if (_op == DES_DECRYPT) 
    memcpy(ivp, iv, 8);
  return(p);
}

/* Copyright (C) 1992 Eric Young - see COPYING for more details */
/* Collected and modified by Werner Almesberger */

#define _	ks._

#define ITERATIONS 16

#define c2l(c,l)	(l =((unsigned long)(*((c)++)))    , \
			 l|=((unsigned long)(*((c)++)))<< 8, \
			 l|=((unsigned long)(*((c)++)))<<16, \
			 l|=((unsigned long)(*((c)++)))<<24)


#define l2c(l,c)	(*((c)++)=(unsigned char)(((l)    )&0xff), \
			 *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
			 *((c)++)=(unsigned char)(((l)>>16)&0xff), \
			 *((c)++)=(unsigned char)(((l)>>24)&0xff))

/* from spr.h */

static unsigned long des_SPtrans[8][64]={
/* nibble 0 */
 {0x00820200, 0x00020000, 0x80800000, 0x80820200,
  0x00800000, 0x80020200, 0x80020000, 0x80800000,
  0x80020200, 0x00820200, 0x00820000, 0x80000200,
  0x80800200, 0x00800000, 0x00000000, 0x80020000,
  0x00020000, 0x80000000, 0x00800200, 0x00020200,
  0x80820200, 0x00820000, 0x80000200, 0x00800200,
  0x80000000, 0x00000200, 0x00020200, 0x80820000,
  0x00000200, 0x80800200, 0x80820000, 0x00000000,
  0x00000000, 0x80820200, 0x00800200, 0x80020000,
  0x00820200, 0x00020000, 0x80000200, 0x00800200,
  0x80820000, 0x00000200, 0x00020200, 0x80800000,
  0x80020200, 0x80000000, 0x80800000, 0x00820000,
  0x80820200, 0x00020200, 0x00820000, 0x80800200,
  0x00800000, 0x80000200, 0x80020000, 0x00000000,
  0x00020000, 0x00800000, 0x80800200, 0x00820200,
  0x80000000, 0x80820000, 0x00000200, 0x80020200},

/* nibble 1 */
 {0x10042004, 0x00000000, 0x00042000, 0x10040000,
  0x10000004, 0x00002004, 0x10002000, 0x00042000,
  0x00002000, 0x10040004, 0x00000004, 0x10002000,
  0x00040004, 0x10042000, 0x10040000, 0x00000004,
  0x00040000, 0x10002004, 0x10040004, 0x00002000,
  0x00042004, 0x10000000, 0x00000000, 0x00040004,
  0x10002004, 0x00042004, 0x10042000, 0x10000004,
  0x10000000, 0x00040000, 0x00002004, 0x10042004,
  0x00040004, 0x10042000, 0x10002000, 0x00042004,
  0x10042004, 0x00040004, 0x10000004, 0x00000000,
  0x10000000, 0x00002004, 0x00040000, 0x10040004,
  0x00002000, 0x10000000, 0x00042004, 0x10002004,
  0x10042000, 0x00002000, 0x00000000, 0x10000004,
  0x00000004, 0x10042004, 0x00042000, 0x10040000,
  0x10040004, 0x00040000, 0x00002004, 0x10002000,
  0x10002004, 0x00000004, 0x10040000, 0x00042000},

/* nibble 2 */
 {0x41000000, 0x01010040, 0x00000040, 0x41000040,
  0x40010000, 0x01000000, 0x41000040, 0x00010040,
  0x01000040, 0x00010000, 0x01010000, 0x40000000,
  0x41010040, 0x40000040, 0x40000000, 0x41010000,
  0x00000000, 0x40010000, 0x01010040, 0x00000040,
  0x40000040, 0x41010040, 0x00010000, 0x41000000,
  0x41010000, 0x01000040, 0x40010040, 0x01010000,
  0x00010040, 0x00000000, 0x01000000, 0x40010040,
  0x01010040, 0x00000040, 0x40000000, 0x00010000,
  0x40000040, 0x40010000, 0x01010000, 0x41000040,
  0x00000000, 0x01010040, 0x00010040, 0x41010000,
  0x40010000, 0x01000000, 0x41010040, 0x40000000,
  0x40010040, 0x41000000, 0x01000000, 0x41010040,
  0x00010000, 0x01000040, 0x41000040, 0x00010040,
  0x01000040, 0x00000000, 0x41010000, 0x40000040,
  0x41000000, 0x40010040, 0x00000040, 0x01010000},

/* nibble 3 */
 {0x00100402, 0x04000400, 0x00000002, 0x04100402,
  0x00000000, 0x04100000, 0x04000402, 0x00100002,
  0x04100400, 0x04000002, 0x04000000, 0x00000402,
  0x04000002, 0x00100402, 0x00100000, 0x04000000,
  0x04100002, 0x00100400, 0x00000400, 0x00000002,
  0x00100400, 0x04000402, 0x04100000, 0x00000400,
  0x00000402, 0x00000000, 0x00100002, 0x04100400,
  0x04000400, 0x04100002, 0x04100402, 0x00100000,
  0x04100002, 0x00000402, 0x00100000, 0x04000002,
  0x00100400, 0x04000400, 0x00000002, 0x04100000,
  0x04000402, 0x00000000, 0x00000400, 0x00100002,
  0x00000000, 0x04100002, 0x04100400, 0x00000400,
  0x04000000, 0x04100402, 0x00100402, 0x00100000,
  0x04100402, 0x00000002, 0x04000400, 0x00100402,
  0x00100002, 0x00100400, 0x04100000, 0x04000402,
  0x00000402, 0x04000000, 0x04000002, 0x04100400},

/* nibble 4 */
 {0x02000000, 0x00004000, 0x00000100, 0x02004108,
  0x02004008, 0x02000100, 0x00004108, 0x02004000,
  0x00004000, 0x00000008, 0x02000008, 0x00004100,
  0x02000108, 0x02004008, 0x02004100, 0x00000000,
  0x00004100, 0x02000000, 0x00004008, 0x00000108,
  0x02000100, 0x00004108, 0x00000000, 0x02000008,
  0x00000008, 0x02000108, 0x02004108, 0x00004008,
  0x02004000, 0x00000100, 0x00000108, 0x02004100,
  0x02004100, 0x02000108, 0x00004008, 0x02004000,
  0x00004000, 0x00000008, 0x02000008, 0x02000100,
  0x02000000, 0x00004100, 0x02004108, 0x00000000,
  0x00004108, 0x02000000, 0x00000100, 0x00004008,
  0x02000108, 0x00000100, 0x00000000, 0x02004108,
  0x02004008, 0x02004100, 0x00000108, 0x00004000,
  0x00004100, 0x02004008, 0x02000100, 0x00000108,
  0x00000008, 0x00004108, 0x02004000, 0x02000008},

/* nibble 5 */
 {0x20000010, 0x00080010, 0x00000000, 0x20080800,
  0x00080010, 0x00000800, 0x20000810, 0x00080000,
  0x00000810, 0x20080810, 0x00080800, 0x20000000,
  0x20000800, 0x20000010, 0x20080000, 0x00080810,
  0x00080000, 0x20000810, 0x20080010, 0x00000000,
  0x00000800, 0x00000010, 0x20080800, 0x20080010,
  0x20080810, 0x20080000, 0x20000000, 0x00000810,
  0x00000010, 0x00080800, 0x00080810, 0x20000800,
  0x00000810, 0x20000000, 0x20000800, 0x00080810,
  0x20080800, 0x00080010, 0x00000000, 0x20000800,
  0x20000000, 0x00000800, 0x20080010, 0x00080000,
  0x00080010, 0x20080810, 0x00080800, 0x00000010,
  0x20080810, 0x00080800, 0x00080000, 0x20000810,
  0x20000010, 0x20080000, 0x00080810, 0x00000000,
  0x00000800, 0x20000010, 0x20000810, 0x20080800,
  0x20080000, 0x00000810, 0x00000010, 0x20080010},

/* nibble 6 */
 {0x00001000, 0x00000080, 0x00400080, 0x00400001,
  0x00401081, 0x00001001, 0x00001080, 0x00000000,
  0x00400000, 0x00400081, 0x00000081, 0x00401000,
  0x00000001, 0x00401080, 0x00401000, 0x00000081,
  0x00400081, 0x00001000, 0x00001001, 0x00401081,
  0x00000000, 0x00400080, 0x00400001, 0x00001080,
  0x00401001, 0x00001081, 0x00401080, 0x00000001,
  0x00001081, 0x00401001, 0x00000080, 0x00400000,
  0x00001081, 0x00401000, 0x00401001, 0x00000081,
  0x00001000, 0x00000080, 0x00400000, 0x00401001,
  0x00400081, 0x00001081, 0x00001080, 0x00000000,
  0x00000080, 0x00400001, 0x00000001, 0x00400080,
  0x00000000, 0x00400081, 0x00400080, 0x00001080,
  0x00000081, 0x00001000, 0x00401081, 0x00400000,
  0x00401080, 0x00000001, 0x00001001, 0x00401081,
  0x00400001, 0x00401080, 0x00401000, 0x00001001},

/* nibble 7 */
 {0x08200020, 0x08208000, 0x00008020, 0x00000000,
  0x08008000, 0x00200020, 0x08200000, 0x08208020,
  0x00000020, 0x08000000, 0x00208000, 0x00008020,
  0x00208020, 0x08008020, 0x08000020, 0x08200000,
  0x00008000, 0x00208020, 0x00200020, 0x08008000,
  0x08208020, 0x08000020, 0x00000000, 0x00208000,
  0x08000000, 0x00200000, 0x08008020, 0x08200020,
  0x00200000, 0x00008000, 0x08208000, 0x00000020,
  0x00200000, 0x00008000, 0x08000020, 0x08208020,
  0x00008020, 0x08000000, 0x00000000, 0x00208000,
  0x08200020, 0x08008020, 0x08008000, 0x00200020,
  0x08208000, 0x00000020, 0x00200020, 0x08008000,
  0x08208020, 0x00200000, 0x08200000, 0x08000020,
  0x00208000, 0x00008020, 0x08008020, 0x08200000,
  0x00000020, 0x08208000, 0x00208020, 0x00000000,
  0x08000000, 0x08200020, 0x00008000, 0x00208020}};

/* from sk.h */

static unsigned long des_skb[8][64]={
/* for C bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
 {0x00000000,0x00000010,0x20000000,0x20000010,
  0x00010000,0x00010010,0x20010000,0x20010010,
  0x00000800,0x00000810,0x20000800,0x20000810,
  0x00010800,0x00010810,0x20010800,0x20010810,
  0x00000020,0x00000030,0x20000020,0x20000030,
  0x00010020,0x00010030,0x20010020,0x20010030,
  0x00000820,0x00000830,0x20000820,0x20000830,
  0x00010820,0x00010830,0x20010820,0x20010830,
  0x00080000,0x00080010,0x20080000,0x20080010,
  0x00090000,0x00090010,0x20090000,0x20090010,
  0x00080800,0x00080810,0x20080800,0x20080810,
  0x00090800,0x00090810,0x20090800,0x20090810,
  0x00080020,0x00080030,0x20080020,0x20080030,
  0x00090020,0x00090030,0x20090020,0x20090030,
  0x00080820,0x00080830,0x20080820,0x20080830,
  0x00090820,0x00090830,0x20090820,0x20090830},