#include <des.h>

typedef unsigned int u32;
typedef unsigned long long int u64;

static u64 rotl28(u32, int) __attribute__((__const__));
static u64 rotl28(u32 v, int nbits)
{
 return(((v<<nbits)&0x0fffffff)|((v&0x0fffffff)>>(28-nbits)));
}

void des(void *outarg, const void *inarg, const void *keyarg, int op)
{
 static const unsigned char ip[64]
  = { 58,50,42,34,26,18,10, 2,60,52,44,36,28,20,12, 4,
      62,54,46,38,30,22,14, 6,64,56,48,40,32,24,16, 8,
      57,49,41,33,25,17, 9, 1,59,51,43,35,27,19,11, 3,
      61,53,45,37,29,21,13, 5,63,55,47,39,31,23,15, 7 };
 static const unsigned char fp[64]
  = { 40, 8,48,16,56,24,64,32,39, 7,47,15,55,23,63,31,
      38, 6,46,14,54,22,62,30,37, 5,45,13,53,21,61,29,
      36, 4,44,12,52,20,60,28,35, 3,43,11,51,19,59,27,
      34, 2,42,10,50,18,58,26,33, 1,41, 9,49,17,57,25 };
 static const unsigned char kp[56]
  = { 57,49,41,33,25,17, 9, 1,58,50,42,34,26,18,
      10, 2,59,51,43,35,27,19,11, 3,60,52,44,36,
      63,55,47,39,31,23,15, 7,62,54,46,38,30,22,
      14, 6,61,53,45,37,29,21,13, 5,28,20,12, 4 };
 static const unsigned char krots[16] = { 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 };
 static const unsigned char cp[48]
  = { 14,17,11,24, 1, 5, 3,28,15, 6,21,10,
      23,19,12, 4,26, 8,16, 7,27,20,13, 2,
      41,52,31,37,47,55,30,40,51,45,33,48,
      44,49,39,56,34,53,46,42,50,36,29,32 };
 static const unsigned char ep[48]
  = { 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9,
       8, 9,10,11,12,13,12,13,14,15,16,17,
      16,17,18,19,20,21,20,21,22,23,24,25,
      24,25,26,27,28,29,28,29,30,31,32, 1 };
 static const unsigned char sbox1[64]
  = { 14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
       0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
       4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
      15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13 };
 static const unsigned char sbox2[64]
  = { 15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
       3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
       0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
      13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9 };
 static const unsigned char sbox3[64]
  = { 10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
      13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
      13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
       1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12 };
 static const unsigned char sbox4[64]
  = {  7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
      13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
      10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
       3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14 };
 static const unsigned char sbox5[64]
  = {  2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
      14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
       4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
      11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3 };
 static const unsigned char sbox6[64]
  = { 12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
      10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
       9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
       4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13 };
 static const unsigned char sbox7[64]
  = {  4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
      13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
       1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
       6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12 };
 static const unsigned char sbox8[64]
  = { 13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
       1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
       7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
       2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11 };
 static const unsigned char sboxx[64]
  = {  0,16, 1,17, 2,18, 3,19, 4,20, 5,21, 6,22, 7,23,
       8,24, 9,25,10,26,11,27,12,28,13,29,14,30,15,31,
      32,48,33,49,34,50,35,51,36,52,37,53,38,54,39,55,
      40,56,41,57,42,58,43,59,44,60,45,61,46,62,47,63 };
 static const unsigned char pbox[32]
  = { 16, 7,20,21,29,12,28,17, 1,15,23,26, 5,18,31,10,
       2, 8,24,14,32,27, 3, 9,19,13,30, 6,22,11, 4,25 };
 u32 l;
 u32 r;
 u32 t;
 u32 newr;
 int round;
 u64 tmp;
 u64 tmp2;
 u64 key;
 int i;

 tmp = (((u64)(((const unsigned char *)keyarg)[0])) << 56) |
       (((u64)(((const unsigned char *)keyarg)[1])) << 48) |
       (((u64)(((const unsigned char *)keyarg)[2])) << 40) |
       (((u64)(((const unsigned char *)keyarg)[3])) << 32) |
       (((u64)(((const unsigned char *)keyarg)[4])) << 24) |
       (((u64)(((const unsigned char *)keyarg)[5])) << 16) |
       (((u64)(((const unsigned char *)keyarg)[6])) <<  8) |
       (((u64)(((const unsigned char *)keyarg)[7]))      );
 key = 0;
 for (i=0;i<56;i++) key = (key << 1) | ((tmp >> (64-kp[i])) & 1);
 tmp = (((u64)(((const unsigned char *)inarg)[0])) << 56) |
       (((u64)(((const unsigned char *)inarg)[1])) << 48) |
       (((u64)(((const unsigned char *)inarg)[2])) << 40) |
       (((u64)(((const unsigned char *)inarg)[3])) << 32) |
       (((u64)(((const unsigned char *)inarg)[4])) << 24) |
       (((u64)(((const unsigned char *)inarg)[5])) << 16) |
       (((u64)(((const unsigned char *)inarg)[6])) <<  8) |
       (((u64)(((const unsigned char *)inarg)[7]))      );
 /* tmp2 is uninitialized; this is OK because all uninitialized bits
    get shifted above bit 64, so they are dropped when tmp2 is split
    into l and r, below. */
 for (i=0;i<64;i++) tmp2 = (tmp2 << 1) | ((tmp >> (64-ip[i])) & 1);
 l = (tmp2 >> 32) & 0xffffffff;
 r = tmp2 & 0xffffffff;
 for (round=0;round<16;round++)
  { switch (op)
     { case ENCRYPT:
	  key = (rotl28(key>>28,krots[round]) << 28) | rotl28(key,krots[round]);
	  break;
       case DECRYPT:
	  if (round) key = (rotl28(key>>28,28-krots[16-round]) << 28) | rotl28(key,28-krots[16-round]);
	  break;
       default:
	  key = 0;
	  break;
     }
    /* tmp is uninitialized; this is OK because all uninitialized bits are
       shifted up above bit 48, and only the low 48 bits are used. */
    for (i=0;i<48;i++) tmp = (tmp << 1) | (1 & ( (r >> (32-ep[i])) ^
						 (u32)(key >> (56-cp[i])) ));
    t = (sbox1[sboxx[(tmp>>42)&0x3f]] << 28) |
	(sbox2[sboxx[(tmp>>36)&0x3f]] << 24) |
	(sbox3[sboxx[(tmp>>30)&0x3f]] << 20) |
	(sbox4[sboxx[(tmp>>24)&0x3f]] << 16) |
	(sbox5[sboxx[(tmp>>18)&0x3f]] << 12) |
	(sbox6[sboxx[(tmp>>12)&0x3f]] <<  8) |
	(sbox7[sboxx[(tmp>> 6)&0x3f]] <<  4) |
	(sbox8[sboxx[(tmp    )&0x3f]]      );
    newr = 0;
    for (i=0;i<32;i++) newr = (newr << 1) | ((t >> (32-pbox[i])) & 1);
    newr ^= l;
    l = r;
    r = newr;
  }
 tmp = (((u64)r) << 32) | l;
 for (i=0;i<64;i++) tmp2 = (tmp2 << 1) | ((tmp >> (64-fp[i])) & 1);
 ((unsigned char *)outarg)[0] = tmp2 >> 56;
 ((unsigned char *)outarg)[1] = tmp2 >> 48;
 ((unsigned char *)outarg)[2] = tmp2 >> 40;
 ((unsigned char *)outarg)[3] = tmp2 >> 32;
 ((unsigned char *)outarg)[4] = tmp2 >> 24;
 ((unsigned char *)outarg)[5] = tmp2 >> 16;
 ((unsigned char *)outarg)[6] = tmp2 >>  8;
 ((unsigned char *)outarg)[7] = tmp2;
}

void des3(void *outarg, const void *inarg, const void *keyarg, int op)
{
 char tmp[8];

 switch (op)
  { case ENCRYPT:
       des(&tmp[0],inarg,keyarg,ENCRYPT);
       des(&tmp[0],&tmp[0],8+(const char *)keyarg,DECRYPT);
       des(outarg,&tmp[0],16+(const char *)keyarg,ENCRYPT);
       break;
    case DECRYPT:
       des(&tmp[0],inarg,16+(const char *)keyarg,DECRYPT);
       des(&tmp[0],&tmp[0],8+(const char *)keyarg,ENCRYPT);
       des(outarg,&tmp[0],keyarg,DECRYPT);
       break;
  }
}