/* * 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); L = rotl(L, 1); R = rotl(R, 1); L ^= f(R, sched->k0246[0], sched->k1357[0]); R ^= f(L, sched->k0246[1], sched->k1357[1]); L ^= f(R, sched->k0246[2], sched->k1357[2]); R ^= f(L, sched->k0246[3], sched->k1357[3]); L ^= f(R, sched->k0246[4], sched->k1357[4]); R ^= f(L, sched->k0246[5], sched->k1357[5]); L ^= f(R, sched->k0246[6], sched->k1357[6]); R ^= f(L, sched->k0246[7], sched->k1357[7]); L ^= f(R, sched->k0246[8], sched->k1357[8]); R ^= f(L, sched->k0246[9], sched->k1357[9]); L ^= f(R, sched->k0246[10], sched->k1357[10]); R ^= f(L, sched->k0246[11], sched->k1357[11]); L ^= f(R, sched->k0246[12], sched->k1357[12]); R ^= f(L, sched->k0246[13], sched->k1357[13]); L ^= f(R, sched->k0246[14], sched->k1357[14]); R ^= f(L, sched->k0246[15], sched->k1357[15]); L = rotl(L, 31); R = rotl(R, 31); swap = L; L = R; R = swap; FP(L, R); output[0] = L; output[1] = R; } #define GET_32BIT_MSB_FIRST(cp) \ (((unsigned long)(unsigned char)(cp)[3]) | \ ((unsigned long)(unsigned char)(cp)[2] << 8) | \ ((unsigned long)(unsigned char)(cp)[1] << 16) | \ ((unsigned long)(unsigned char)(cp)[0] << 24)) #define PUT_32BIT_MSB_FIRST(cp, value) do { \ (cp)[3] = (value); \ (cp)[2] = (value) >> 8; \ (cp)[1] = (value) >> 16; \ (cp)[0] = (value) >> 24; } while (0) static inline void des_cbc_encrypt(unsigned char *dest, const unsigned char *src, struct des_context *sched) { quint32 out[2], L, R; L = GET_32BIT_MSB_FIRST(src); R = GET_32BIT_MSB_FIRST(src + 4); des_encipher(out, L, R, sched); PUT_32BIT_MSB_FIRST(dest, out[0]); PUT_32BIT_MSB_FIRST(dest + 4, out[1]); } static unsigned char * deshash(unsigned char *dst, const unsigned char *key, const unsigned char *src) { struct des_context ctx; des_key_setup(GET_32BIT_MSB_FIRST(key) >> 8, GET_32BIT_MSB_FIRST(key + 3), &ctx); des_cbc_encrypt(dst, src, &ctx); return dst; }