/*

 * Implementation of DES encryption for NTLM

 *

 * Copyright 1997-2005 Simon Tatham.

 *

 * This software is released under the MIT license.

 */

/*

 * Description of DES

 * ------------------

 *

 * Unlike the description in FIPS 46, I'm going to use _sensible_ indices:

 * bits in an n-bit word are numbered from 0 at the LSB to n-1 at the MSB.

 * And S-boxes are indexed by six consecutive bits, not by the outer two

 * followed by the middle four.

 *

 * The DES encryption routine requires a 64-bit input, and a key schedule K

 * containing 16 48-bit elements.

 *

 *   First the input is permuted by the initial permutation IP.

 *   Then the input is split into 32-bit words L and R. (L is the MSW.)

 *   Next, 16 rounds. In each round:

 *     (L, R) <- (R, L xor f(R, K[i]))

 *   Then the pre-output words L and R are swapped.

 *   Then L and R are glued back together into a 64-bit word. (L is the MSW,

 *     again, but since we just swapped them, the MSW is the R that came out

 *     of the last round.)

 *   The 64-bit output block is permuted by the inverse of IP and returned.

 *

 * Decryption is identical except that the elements of K are used in the

 * opposite order. (This wouldn't work if that word swap didn't happen.)

 *

 * The function f, used in each round, accepts a 32-bit word R and a

 * 48-bit key block K. It produces a 32-bit output.

 *

 *   First R is expanded to 48 bits using the bit-selection function E.

 *   The resulting 48-bit block is XORed with the key block K to produce

 *     a 48-bit block X.

 *   This block X is split into eight groups of 6 bits. Each group of 6

 *     bits is then looked up in one of the eight S-boxes to convert

 *     it to 4 bits. These eight groups of 4 bits are glued back

 *     together to produce a 32-bit preoutput block.

 *   The preoutput block is permuted using the permutation P and returned.

 *

 * Key setup maps a 64-bit key word into a 16x48-bit key schedule. Although

 * the approved input format for the key is a 64-bit word, eight of the

 * bits are discarded, so the actual quantity of key used is 56 bits.

 *

 *   First the input key is converted to two 28-bit words C and D using

 *     the bit-selection function PC1.

 *   Then 16 rounds of key setup occur. In each round, C and D are each

 *     rotated left by either 1 or 2 bits (depending on which round), and

 *     then converted into a key schedule element using the bit-selection

 *     function PC2.

 *

 * That's the actual algorithm. Now for the tedious details: all those

 * painful permutations and lookup tables.

 *

 * IP is a 64-to-64 bit permutation. Its output contains the following

 * bits of its input (listed in order MSB to LSB of output).

 *

 *    6 14 22 30 38 46 54 62  4 12 20 28 36 44 52 60

 *    2 10 18 26 34 42 50 58  0  8 16 24 32 40 48 56

 *    7 15 23 31 39 47 55 63  5 13 21 29 37 45 53 61

 *    3 11 19 27 35 43 51 59  1  9 17 25 33 41 49 57

 *

 * E is a 32-to-48 bit selection function. Its output contains the following

 * bits of its input (listed in order MSB to LSB of output).

 *

 *    0 31 30 29 28 27 28 27 26 25 24 23 24 23 22 21 20 19 20 19 18 17 16 15

 *   16 15 14 13 12 11 12 11 10  9  8  7  8  7  6  5  4  3  4  3  2  1  0 31

 *

 * The S-boxes are arbitrary table-lookups each mapping a 6-bit input to a

 * 4-bit output. In other words, each S-box is an array[64] of 4-bit numbers.

 * The S-boxes are listed below. The first S-box listed is applied to the

 * most significant six bits of the block X; the last one is applied to the

 * least significant.

 *

 *   14  0  4 15 13  7  1  4  2 14 15  2 11 13  8  1

 *    3 10 10  6  6 12 12 11  5  9  9  5  0  3  7  8

 *    4 15  1 12 14  8  8  2 13  4  6  9  2  1 11  7

 *   15  5 12 11  9  3  7 14  3 10 10  0  5  6  0 13

 *

 *   15  3  1 13  8  4 14  7  6 15 11  2  3  8  4 14

 *    9 12  7  0  2  1 13 10 12  6  0  9  5 11 10  5

 *    0 13 14  8  7 10 11  1 10  3  4 15 13  4  1  2

 *    5 11  8  6 12  7  6 12  9  0  3  5  2 14 15  9

 *

 *   10 13  0  7  9  0 14  9  6  3  3  4 15  6  5 10

 *    1  2 13  8 12  5  7 14 11 12  4 11  2 15  8  1

 *   13  1  6 10  4 13  9  0  8  6 15  9  3  8  0  7

 *   11  4  1 15  2 14 12  3  5 11 10  5 14  2  7 12

 *

 *    7 13 13  8 14 11  3  5  0  6  6 15  9  0 10  3

 *    1  4  2  7  8  2  5 12 11  1 12 10  4 14 15  9

 *   10  3  6 15  9  0  0  6 12 10 11  1  7 13 13  8

 *   15  9  1  4  3  5 14 11  5 12  2  7  8  2  4 14

 *

 *    2 14 12 11  4  2  1 12  7  4 10  7 11 13  6  1

 *    8  5  5  0  3 15 15 10 13  3  0  9 14  8  9  6

 *    4 11  2  8  1 12 11  7 10  1 13 14  7  2  8 13

 *   15  6  9 15 12  0  5  9  6 10  3  4  0  5 14  3

 *

 *   12 10  1 15 10  4 15  2  9  7  2 12  6  9  8  5

 *    0  6 13  1  3 13  4 14 14  0  7 11  5  3 11  8

 *    9  4 14  3 15  2  5 12  2  9  8  5 12 15  3 10

 *    7 11  0 14  4  1 10  7  1  6 13  0 11  8  6 13

 *

 *    4 13 11  0  2 11 14  7 15  4  0  9  8  1 13 10

 *    3 14 12  3  9  5  7 12  5  2 10 15  6  8  1  6

 *    1  6  4 11 11 13 13  8 12  1  3  4  7 10 14  7

 *   10  9 15  5  6  0  8 15  0 14  5  2  9  3  2 12

 *

 *   13  1  2 15  8 13  4  8  6 10 15  3 11  7  1  4

 *   10 12  9  5  3  6 14 11  5  0  0 14 12  9  7  2

 *    7  2 11  1  4 14  1  7  9  4 12 10 14  8  2 13

 *    0 15  6 12 10  9 13  0 15  3  3  5  5  6  8 11

 *

 * P is a 32-to-32 bit permutation. Its output contains the following

 * bits of its input (listed in order MSB to LSB of output).

 *

 *   16 25 12 11  3 20  4 15 31 17  9  6 27 14  1 22

 *   30 24  8 18  0  5 29 23 13 19  2 26 10 21 28  7

 *

 * PC1 is a 64-to-56 bit selection function. Its output is in two words,

 * C and D. The word C contains the following bits of its input (listed

 * in order MSB to LSB of output).

 *

 *    7 15 23 31 39 47 55 63  6 14 22 30 38 46

 *   54 62  5 13 21 29 37 45 53 61  4 12 20 28

 *

 * And the word D contains these bits.

 *

 *    1  9 17 25 33 41 49 57  2 10 18 26 34 42

 *   50 58  3 11 19 27 35 43 51 59 36 44 52 60

 *

 * PC2 is a 56-to-48 bit selection function. Its input is in two words,

 * C and D. These are treated as one 56-bit word (with C more significant,

 * so that bits 55 to 28 of the word are bits 27 to 0 of C, and bits 27 to

 * 0 of the word are bits 27 to 0 of D). The output contains the following

 * bits of this 56-bit input word (listed in order MSB to LSB of output).

 *

 *   42 39 45 32 55 51 53 28 41 50 35 46 33 37 44 52 30 48 40 49 29 36 43 54

 *   15  4 25 19  9  1 26 16  5 11 23  8 12  7 17  0 22  3 10 14  6 20 27 24

 */

/*

 * Implementation details

 * ----------------------

 * 

 * If you look at the code in this module, you'll find it looks

 * nothing _like_ the above algorithm. Here I explain the

 * differences...

 *

 * Key setup has not been heavily optimised here. We are not

 * concerned with key agility: we aren't codebreakers. We don't

 * mind a little delay (and it really is a little one; it may be a

 * factor of five or so slower than it could be but it's still not

 * an appreciable length of time) while setting up. The only tweaks

 * in the key setup are ones which change the format of the key

 * schedule to speed up the actual encryption. I'll describe those

 * below.

 *

 * The first and most obvious optimisation is the S-boxes. Since

 * each S-box always targets the same four bits in the final 32-bit

 * word, so the output from (for example) S-box 0 must always be

 * shifted left 28 bits, we can store the already-shifted outputs

 * in the lookup tables. This reduces lookup-and-shift to lookup,

 * so the S-box step is now just a question of ORing together eight

 * table lookups.

 *

 * The permutation P is just a bit order change; it's invariant

 * with respect to OR, in that P(x)|P(y) = P(x|y). Therefore, we

 * can apply P to every entry of the S-box tables and then we don't

 * have to do it in the code of f(). This yields a set of tables

 * which might be called SP-boxes.

 *

 * The bit-selection function E is our next target. Note that E is

 * immediately followed by the operation of splitting into 6-bit

 * chunks. Examining the 6-bit chunks coming out of E we notice

 * they're all contiguous within the word (speaking cyclically -

 * the end two wrap round); so we can extract those bit strings

 * individually rather than explicitly running E. This would yield

 * code such as

 *

 *     y |= SPboxes[0][ (rotl(R, 5) ^  top6bitsofK) & 0x3F ];

 *     t |= SPboxes[1][ (rotl(R,11) ^ next6bitsofK) & 0x3F ];

 *

 * and so on; and the key schedule preparation would have to

 * provide each 6-bit chunk separately.

 *

 * Really we'd like to XOR in the key schedule element before

 * looking up bit strings in R. This we can't do, naively, because

 * the 6-bit strings we want overlap. But look at the strings:

 *

 *       3322222222221111111111

 * bit   10987654321098765432109876543210

 * 

 * box0  XXXXX                          X

 * box1     XXXXXX

 * box2         XXXXXX

 * box3             XXXXXX

 * box4                 XXXXXX

 * box5                     XXXXXX

 * box6                         XXXXXX

 * box7  X                          XXXXX

 *

 * The bit strings we need to XOR in for boxes 0, 2, 4 and 6 don't

 * overlap with each other. Neither do the ones for boxes 1, 3, 5

 * and 7. So we could provide the key schedule in the form of two

 * words that we can separately XOR into R, and then every S-box

 * index is available as a (cyclically) contiguous 6-bit substring

 * of one or the other of the results.

 *

 * The comments in Eric Young's libdes implementation point out

 * that two of these bit strings require a rotation (rather than a

 * simple shift) to extract. It's unavoidable that at least _one_

 * must do; but we can actually run the whole inner algorithm (all

 * 16 rounds) rotated one bit to the left, so that what the `real'

 * DES description sees as L=0x80000001 we see as L=0x00000003.

 * This requires rotating all our SP-box entries one bit to the

 * left, and rotating each word of the key schedule elements one to

 * the left, and rotating L and R one bit left just after IP and

 * one bit right again just before FP. And in each round we convert

 * a rotate into a shift, so we've saved a few per cent.

 *

 * That's about it for the inner loop; the SP-box tables as listed

 * below are what I've described here (the original S value,

 * shifted to its final place in the input to P, run through P, and

 * then rotated one bit left). All that remains is to optimise the

 * initial permutation IP.

 *

 * IP is not an arbitrary permutation. It has the nice property

 * that if you take any bit number, write it in binary (6 bits),

 * permute those 6 bits and invert some of them, you get the final

 * position of that bit. Specifically, the bit whose initial

 * position is given (in binary) as fedcba ends up in position

 * AcbFED (where a capital letter denotes the inverse of a bit).

 *

 * We have the 64-bit data in two 32-bit words L and R, where bits

 * in L are those with f=1 and bits in R are those with f=0. We

 * note that we can do a simple transformation: suppose we exchange

 * the bits with f=1,c=0 and the bits with f=0,c=1. This will cause

 * the bit fedcba to be in position cedfba - we've `swapped' bits c

 * and f in the position of each bit!

 * 

 * Better still, this transformation is easy. In the example above,

 * bits in L with c=0 are bits 0x0F0F0F0F, and those in R with c=1

 * are 0xF0F0F0F0. So we can do

 *

 *     difference = ((R >> 4) ^ L) & 0x0F0F0F0F

 *     R ^= (difference << 4)

 *     L ^= difference

 *

 * to perform the swap. Let's denote this by bitswap(4,0x0F0F0F0F).

 * Also, we can invert the bit at the top just by exchanging L and

 * R. So in a few swaps and a few of these bit operations we can

 * do:

 * 

 * Initially the position of bit fedcba is     fedcba

 * Swap L with R to make it                    Fedcba

 * Perform bitswap( 4,0x0F0F0F0F) to make it   cedFba

 * Perform bitswap(16,0x0000FFFF) to make it   ecdFba

 * Swap L with R to make it                    EcdFba

 * Perform bitswap( 2,0x33333333) to make it   bcdFEa

 * Perform bitswap( 8,0x00FF00FF) to make it   dcbFEa

 * Swap L with R to make it                    DcbFEa

 * Perform bitswap( 1,0x55555555) to make it   acbFED

 * Swap L with R to make it                    AcbFED

 *

 * (In the actual code the four swaps are implicit: R and L are

 * simply used the other way round in the first, second and last

 * bitswap operations.)

 *

 * The final permutation is just the inverse of IP, so it can be

 * performed by a similar set of operations.

 */

struct des_context {

	quint32 k0246[16], k1357[16];

};

#define rotl(x, c) ( (x << c) | (x >> (32-c)) )

#define rotl28(x, c) ( ( (x << c) | (x >> (28-c)) ) & 0x0FFFFFFF)

static quint32 bitsel(quint32 * input, const int *bitnums, int size)

{

	quint32 ret = 0;

	while (size--) {

		int bitpos = *bitnums++;

		ret <<= 1;

		if (bitpos >= 0)

			ret |= 1 & (input[bitpos / 32] >> (bitpos % 32));

	}

	return ret;

}

static inline void des_key_setup(quint32 key_msw, quint32 key_lsw,

				 struct des_context *sched)

{

	/* Tables are modified to work with 56-bit key */

	static const int PC1_Cbits[] = {

		6, 13, 20, 27, 34, 41, 48, 55, 5, 12, 19, 26, 33, 40,

		47, 54, 4, 11, 18, 25, 32, 39, 46, 53, 3, 10, 17, 24

	};

	static const int PC1_Dbits[] = {

		0, 7, 14, 21, 28, 35, 42, 49, 1, 8, 15, 22, 29, 36,

		43, 50, 2, 9, 16, 23, 30, 37, 44, 51, 31, 38, 45, 52

	};

	/*

	 * The bit numbers in the two lists below don't correspond to

	 * the ones in the above description of PC2, because in the

	 * above description C and D are concatenated so `bit 28' means

	 * bit 0 of C. In this implementation we're using the standard

	 * `bitsel' function above and C is in the second word, so bit

	 * 0 of C is addressed by writing `32' here.

	 */

	static const int PC2_0246[] = {

		49, 36, 59, 55, -1, -1, 37, 41, 48, 56, 34, 52, -1, -1, 15, 4,

		25, 19, 9, 1, -1, -1, 12, 7, 17, 0, 22, 3, -1, -1, 46, 43

	};

	static const int PC2_1357[] = {

		-1, -1, 57, 32, 45, 54, 39, 50, -1, -1, 44, 53, 33, 40, 47, 58,

		-1, -1, 26, 16, 5, 11, 23, 8, -1, -1, 10, 14, 6, 20, 27, 24

	};

	static const int leftshifts[] =	{

		1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1

	};

	quint32 C, D;

	quint32 buf[2];

	int i;

	buf[0] = key_lsw;

	buf[1] = key_msw;

	C = bitsel(buf, PC1_Cbits, 28);

	D = bitsel(buf, PC1_Dbits, 28);

	for (i = 0; i < 16; i++) {

		C = rotl28(C, leftshifts[i]);

		D = rotl28(D, leftshifts[i]);

		buf[0] = D;

		buf[1] = C;

		sched->k0246[i] = bitsel(buf, PC2_0246, 32);

		sched->k1357[i] = bitsel(buf, PC2_1357, 32);

	}

}

static const quint32 SPboxes[8][64] = {

	{0x01010400, 0x00000000, 0x00010000, 0x01010404,

	 0x01010004, 0x00010404, 0x00000004, 0x00010000,

	 0x00000400, 0x01010400, 0x01010404, 0x00000400,

	 0x01000404, 0x01010004, 0x01000000, 0x00000004,

	 0x00000404, 0x01000400, 0x01000400, 0x00010400,

	 0x00010400, 0x01010000, 0x01010000, 0x01000404,

	 0x00010004, 0x01000004, 0x01000004, 0x00010004,

	 0x00000000, 0x00000404, 0x00010404, 0x01000000,

	 0x00010000, 0x01010404, 0x00000004, 0x01010000,

	 0x01010400, 0x01000000, 0x01000000, 0x00000400,

	 0x01010004, 0x00010000, 0x00010400, 0x01000004,

	 0x00000400, 0x00000004, 0x01000404, 0x00010404,

	 0x01010404, 0x00010004, 0x01010000, 0x01000404,

	 0x01000004, 0x00000404, 0x00010404, 0x01010400,

	 0x00000404, 0x01000400, 0x01000400, 0x00000000,

	 0x00010004, 0x00010400, 0x00000000, 0x01010004},

	{0x80108020, 0x80008000, 0x00008000, 0x00108020,

	 0x00100000, 0x00000020, 0x80100020, 0x80008020,

	 0x80000020, 0x80108020, 0x80108000, 0x80000000,

	 0x80008000, 0x00100000, 0x00000020, 0x80100020,

	 0x00108000, 0x00100020, 0x80008020, 0x00000000,

	 0x80000000, 0x00008000, 0x00108020, 0x80100000,

	 0x00100020, 0x80000020, 0x00000000, 0x00108000,

	 0x00008020, 0x80108000, 0x80100000, 0x00008020,

	 0x00000000, 0x00108020, 0x80100020, 0x00100000,

	 0x80008020, 0x80100000, 0x80108000, 0x00008000,

	 0x80100000, 0x80008000, 0x00000020, 0x80108020,

	 0x00108020, 0x00000020, 0x00008000, 0x80000000,

	 0x00008020, 0x80108000, 0x00100000, 0x80000020,

	 0x00100020, 0x80008020, 0x80000020, 0x00100020,

	 0x00108000, 0x00000000, 0x80008000, 0x00008020,

	 0x80000000, 0x80100020, 0x80108020, 0x00108000},

	{0x00000208, 0x08020200, 0x00000000, 0x08020008,

	 0x08000200, 0x00000000, 0x00020208, 0x08000200,

	 0x00020008, 0x08000008, 0x08000008, 0x00020000,

	 0x08020208, 0x00020008, 0x08020000, 0x00000208,

	 0x08000000, 0x00000008, 0x08020200, 0x00000200,

	 0x00020200, 0x08020000, 0x08020008, 0x00020208,

	 0x08000208, 0x00020200, 0x00020000, 0x08000208,

	 0x00000008, 0x08020208, 0x00000200, 0x08000000,

	 0x08020200, 0x08000000, 0x00020008, 0x00000208,

	 0x00020000, 0x08020200, 0x08000200, 0x00000000,

	 0x00000200, 0x00020008, 0x08020208, 0x08000200,

	 0x08000008, 0x00000200, 0x00000000, 0x08020008,

	 0x08000208, 0x00020000, 0x08000000, 0x08020208,

	 0x00000008, 0x00020208, 0x00020200, 0x08000008,

	 0x08020000, 0x08000208, 0x00000208, 0x08020000,

	 0x00020208, 0x00000008, 0x08020008, 0x00020200},

	{0x00802001, 0x00002081, 0x00002081, 0x00000080,

	 0x00802080, 0x00800081, 0x00800001, 0x00002001,

	 0x00000000, 0x00802000, 0x00802000, 0x00802081,

	 0x00000081, 0x00000000, 0x00800080, 0x00800001,

	 0x00000001, 0x00002000, 0x00800000, 0x00802001,

	 0x00000080, 0x00800000, 0x00002001, 0x00002080,

	 0x00800081, 0x00000001, 0x00002080, 0x00800080,

	 0x00002000, 0x00802080, 0x00802081, 0x00000081,

	 0x00800080, 0x00800001, 0x00802000, 0x00802081,

	 0x00000081, 0x00000000, 0x00000000, 0x00802000,

	 0x00002080, 0x00800080, 0x00800081, 0x00000001,

	 0x00802001, 0x00002081, 0x00002081, 0x00000080,

	 0x00802081, 0x00000081, 0x00000001, 0x00002000,

	 0x00800001, 0x00002001, 0x00802080, 0x00800081,

	 0x00002001, 0x00002080, 0x00800000, 0x00802001,

	 0x00000080, 0x00800000, 0x00002000, 0x00802080},

	{0x00000100, 0x02080100, 0x02080000, 0x42000100,

	 0x00080000, 0x00000100, 0x40000000, 0x02080000,

	 0x40080100, 0x00080000, 0x02000100, 0x40080100,

	 0x42000100, 0x42080000, 0x00080100, 0x40000000,

	 0x02000000, 0x40080000, 0x40080000, 0x00000000,

	 0x40000100, 0x42080100, 0x42080100, 0x02000100,

	 0x42080000, 0x40000100, 0x00000000, 0x42000000,

	 0x02080100, 0x02000000, 0x42000000, 0x00080100,

	 0x00080000, 0x42000100, 0x00000100, 0x02000000,

	 0x40000000, 0x02080000, 0x42000100, 0x40080100,

	 0x02000100, 0x40000000, 0x42080000, 0x02080100,

	 0x40080100, 0x00000100, 0x02000000, 0x42080000,

	 0x42080100, 0x00080100, 0x42000000, 0x42080100,

	 0x02080000, 0x00000000, 0x40080000, 0x42000000,

	 0x00080100, 0x02000100, 0x40000100, 0x00080000,

	 0x00000000, 0x40080000, 0x02080100, 0x40000100},

	{0x20000010, 0x20400000, 0x00004000, 0x20404010,

	 0x20400000, 0x00000010, 0x20404010, 0x00400000,

	 0x20004000, 0x00404010, 0x00400000, 0x20000010,

	 0x00400010, 0x20004000, 0x20000000, 0x00004010,

	 0x00000000, 0x00400010, 0x20004010, 0x00004000,

	 0x00404000, 0x20004010, 0x00000010, 0x20400010,

	 0x20400010, 0x00000000, 0x00404010, 0x20404000,

	 0x00004010, 0x00404000, 0x20404000, 0x20000000,

	 0x20004000, 0x00000010, 0x20400010, 0x00404000,

	 0x20404010, 0x00400000, 0x00004010, 0x20000010,

	 0x00400000, 0x20004000, 0x20000000, 0x00004010,

	 0x20000010, 0x20404010, 0x00404000, 0x20400000,

	 0x00404010, 0x20404000, 0x00000000, 0x20400010,

	 0x00000010, 0x00004000, 0x20400000, 0x00404010,

	 0x00004000, 0x00400010, 0x20004010, 0x00000000,

	 0x20404000, 0x20000000, 0x00400010, 0x20004010},

	{0x00200000, 0x04200002, 0x04000802, 0x00000000,

	 0x00000800, 0x04000802, 0x00200802, 0x04200800,

	 0x04200802, 0x00200000, 0x00000000, 0x04000002,

	 0x00000002, 0x04000000, 0x04200002, 0x00000802,

	 0x04000800, 0x00200802, 0x00200002, 0x04000800,

	 0x04000002, 0x04200000, 0x04200800, 0x00200002,

	 0x04200000, 0x00000800, 0x00000802, 0x04200802,

	 0x00200800, 0x00000002, 0x04000000, 0x00200800,

	 0x04000000, 0x00200800, 0x00200000, 0x04000802,

	 0x04000802, 0x04200002, 0x04200002, 0x00000002,

	 0x00200002, 0x04000000, 0x04000800, 0x00200000,

	 0x04200800, 0x00000802, 0x00200802, 0x04200800,

	 0x00000802, 0x04000002, 0x04200802, 0x04200000,

	 0x00200800, 0x00000000, 0x00000002, 0x04200802,

	 0x00000000, 0x00200802, 0x04200000, 0x00000800,

	 0x04000002, 0x04000800, 0x00000800, 0x00200002},

	{0x10001040, 0x00001000, 0x00040000, 0x10041040,

	 0x10000000, 0x10001040, 0x00000040, 0x10000000,

	 0x00040040, 0x10040000, 0x10041040, 0x00041000,

	 0x10041000, 0x00041040, 0x00001000, 0x00000040,

	 0x10040000, 0x10000040, 0x10001000, 0x00001040,

	 0x00041000, 0x00040040, 0x10040040, 0x10041000,

	 0x00001040, 0x00000000, 0x00000000, 0x10040040,

	 0x10000040, 0x10001000, 0x00041040, 0x00040000,

	 0x00041040, 0x00040000, 0x10041000, 0x00001000,

	 0x00000040, 0x10040040, 0x00001000, 0x00041040,

	 0x10001000, 0x00000040, 0x10000040, 0x10040000,

	 0x10040040, 0x10000000, 0x00040000, 0x10001040,

	 0x00000000, 0x10041040, 0x00040040, 0x10000040,

	 0x10040000, 0x10001000, 0x10001040, 0x00000000,

	 0x10041040, 0x00041000, 0x00041000, 0x00001040,

	 0x00001040, 0x00040040, 0x10000000, 0x10041000}

};

#define f(R, K0246, K1357) (\

	s0246 = R ^ K0246, \

	s1357 = R ^ K1357, \

	s0246 = rotl(s0246, 28), \

	SPboxes[0] [(s0246 >> 24) & 0x3F] | \

	SPboxes[1] [(s1357 >> 24) & 0x3F] | \

	SPboxes[2] [(s0246 >> 16) & 0x3F] | \

	SPboxes[3] [(s1357 >> 16) & 0x3F] | \

	SPboxes[4] [(s0246 >>  8) & 0x3F] | \

	SPboxes[5] [(s1357 >>  8) & 0x3F] | \

	SPboxes[6] [(s0246      ) & 0x3F] | \

	SPboxes[7] [(s1357      ) & 0x3F])

#define bitswap(L, R, n, mask) (\

	swap = mask & ( (R >> n) ^ L ), \

	R ^= swap << n, \

	L ^= swap)

/* Initial permutation */

#define IP(L, R) (\

	bitswap(R, L,  4, 0x0F0F0F0F), \

	bitswap(R, L, 16, 0x0000FFFF), \

	bitswap(L, R,  2, 0x33333333), \

	bitswap(L, R,  8, 0x00FF00FF), \

	bitswap(R, L,  1, 0x55555555))

/* Final permutation */

#define FP(L, R) (\

	bitswap(R, L,  1, 0x55555555), \

	bitswap(L, R,  8, 0x00FF00FF), \

	bitswap(L, R,  2, 0x33333333), \

	bitswap(R, L, 16, 0x0000FFFF), \

	bitswap(R, L,  4, 0x0F0F0F0F))

static void

des_encipher(quint32 *output, quint32 L, quint32 R,

	     struct des_context *sched)

{

	quint32 swap, s0246, s1357;

	IP(L, R);