| 1 | #include <assert.h> |
| 2 | #include "ssh.h" |
| 3 | |
| 4 | |
| 5 | /* des.c - implementation of DES |
| 6 | */ |
| 7 | |
| 8 | /* |
| 9 | * Description of DES |
| 10 | * ------------------ |
| 11 | * |
| 12 | * Unlike the description in FIPS 46, I'm going to use _sensible_ indices: |
| 13 | * bits in an n-bit word are numbered from 0 at the LSB to n-1 at the MSB. |
| 14 | * And S-boxes are indexed by six consecutive bits, not by the outer two |
| 15 | * followed by the middle four. |
| 16 | * |
| 17 | * The DES encryption routine requires a 64-bit input, and a key schedule K |
| 18 | * containing 16 48-bit elements. |
| 19 | * |
| 20 | * First the input is permuted by the initial permutation IP. |
| 21 | * Then the input is split into 32-bit words L and R. (L is the MSW.) |
| 22 | * Next, 16 rounds. In each round: |
| 23 | * (L, R) <- (R, L xor f(R, K[i])) |
| 24 | * Then the pre-output words L and R are swapped. |
| 25 | * Then L and R are glued back together into a 64-bit word. (L is the MSW, |
| 26 | * again, but since we just swapped them, the MSW is the R that came out |
| 27 | * of the last round.) |
| 28 | * The 64-bit output block is permuted by the inverse of IP and returned. |
| 29 | * |
| 30 | * Decryption is identical except that the elements of K are used in the |
| 31 | * opposite order. (This wouldn't work if that word swap didn't happen.) |
| 32 | * |
| 33 | * The function f, used in each round, accepts a 32-bit word R and a |
| 34 | * 48-bit key block K. It produces a 32-bit output. |
| 35 | * |
| 36 | * First R is expanded to 48 bits using the bit-selection function E. |
| 37 | * The resulting 48-bit block is XORed with the key block K to produce |
| 38 | * a 48-bit block X. |
| 39 | * This block X is split into eight groups of 6 bits. Each group of 6 |
| 40 | * bits is then looked up in one of the eight S-boxes to convert |
| 41 | * it to 4 bits. These eight groups of 4 bits are glued back |
| 42 | * together to produce a 32-bit preoutput block. |
| 43 | * The preoutput block is permuted using the permutation P and returned. |
| 44 | * |
| 45 | * Key setup maps a 64-bit key word into a 16x48-bit key schedule. Although |
| 46 | * the approved input format for the key is a 64-bit word, eight of the |
| 47 | * bits are discarded, so the actual quantity of key used is 56 bits. |
| 48 | * |
| 49 | * First the input key is converted to two 28-bit words C and D using |
| 50 | * the bit-selection function PC1. |
| 51 | * Then 16 rounds of key setup occur. In each round, C and D are each |
| 52 | * rotated left by either 1 or 2 bits (depending on which round), and |
| 53 | * then converted into a key schedule element using the bit-selection |
| 54 | * function PC2. |
| 55 | * |
| 56 | * That's the actual algorithm. Now for the tedious details: all those |
| 57 | * painful permutations and lookup tables. |
| 58 | * |
| 59 | * IP is a 64-to-64 bit permutation. Its output contains the following |
| 60 | * bits of its input (listed in order MSB to LSB of output). |
| 61 | * |
| 62 | * 6 14 22 30 38 46 54 62 4 12 20 28 36 44 52 60 |
| 63 | * 2 10 18 26 34 42 50 58 0 8 16 24 32 40 48 56 |
| 64 | * 7 15 23 31 39 47 55 63 5 13 21 29 37 45 53 61 |
| 65 | * 3 11 19 27 35 43 51 59 1 9 17 25 33 41 49 57 |
| 66 | * |
| 67 | * E is a 32-to-48 bit selection function. Its output contains the following |
| 68 | * bits of its input (listed in order MSB to LSB of output). |
| 69 | * |
| 70 | * 0 31 30 29 28 27 28 27 26 25 24 23 24 23 22 21 20 19 20 19 18 17 16 15 |
| 71 | * 16 15 14 13 12 11 12 11 10 9 8 7 8 7 6 5 4 3 4 3 2 1 0 31 |
| 72 | * |
| 73 | * The S-boxes are arbitrary table-lookups each mapping a 6-bit input to a |
| 74 | * 4-bit output. In other words, each S-box is an array[64] of 4-bit numbers. |
| 75 | * The S-boxes are listed below. The first S-box listed is applied to the |
| 76 | * most significant six bits of the block X; the last one is applied to the |
| 77 | * least significant. |
| 78 | * |
| 79 | * 14 0 4 15 13 7 1 4 2 14 15 2 11 13 8 1 |
| 80 | * 3 10 10 6 6 12 12 11 5 9 9 5 0 3 7 8 |
| 81 | * 4 15 1 12 14 8 8 2 13 4 6 9 2 1 11 7 |
| 82 | * 15 5 12 11 9 3 7 14 3 10 10 0 5 6 0 13 |
| 83 | * |
| 84 | * 15 3 1 13 8 4 14 7 6 15 11 2 3 8 4 14 |
| 85 | * 9 12 7 0 2 1 13 10 12 6 0 9 5 11 10 5 |
| 86 | * 0 13 14 8 7 10 11 1 10 3 4 15 13 4 1 2 |
| 87 | * 5 11 8 6 12 7 6 12 9 0 3 5 2 14 15 9 |
| 88 | * |
| 89 | * 10 13 0 7 9 0 14 9 6 3 3 4 15 6 5 10 |
| 90 | * 1 2 13 8 12 5 7 14 11 12 4 11 2 15 8 1 |
| 91 | * 13 1 6 10 4 13 9 0 8 6 15 9 3 8 0 7 |
| 92 | * 11 4 1 15 2 14 12 3 5 11 10 5 14 2 7 12 |
| 93 | * |
| 94 | * 7 13 13 8 14 11 3 5 0 6 6 15 9 0 10 3 |
| 95 | * 1 4 2 7 8 2 5 12 11 1 12 10 4 14 15 9 |
| 96 | * 10 3 6 15 9 0 0 6 12 10 11 1 7 13 13 8 |
| 97 | * 15 9 1 4 3 5 14 11 5 12 2 7 8 2 4 14 |
| 98 | * |
| 99 | * 2 14 12 11 4 2 1 12 7 4 10 7 11 13 6 1 |
| 100 | * 8 5 5 0 3 15 15 10 13 3 0 9 14 8 9 6 |
| 101 | * 4 11 2 8 1 12 11 7 10 1 13 14 7 2 8 13 |
| 102 | * 15 6 9 15 12 0 5 9 6 10 3 4 0 5 14 3 |
| 103 | * |
| 104 | * 12 10 1 15 10 4 15 2 9 7 2 12 6 9 8 5 |
| 105 | * 0 6 13 1 3 13 4 14 14 0 7 11 5 3 11 8 |
| 106 | * 9 4 14 3 15 2 5 12 2 9 8 5 12 15 3 10 |
| 107 | * 7 11 0 14 4 1 10 7 1 6 13 0 11 8 6 13 |
| 108 | * |
| 109 | * 4 13 11 0 2 11 14 7 15 4 0 9 8 1 13 10 |
| 110 | * 3 14 12 3 9 5 7 12 5 2 10 15 6 8 1 6 |
| 111 | * 1 6 4 11 11 13 13 8 12 1 3 4 7 10 14 7 |
| 112 | * 10 9 15 5 6 0 8 15 0 14 5 2 9 3 2 12 |
| 113 | * |
| 114 | * 13 1 2 15 8 13 4 8 6 10 15 3 11 7 1 4 |
| 115 | * 10 12 9 5 3 6 14 11 5 0 0 14 12 9 7 2 |
| 116 | * 7 2 11 1 4 14 1 7 9 4 12 10 14 8 2 13 |
| 117 | * 0 15 6 12 10 9 13 0 15 3 3 5 5 6 8 11 |
| 118 | * |
| 119 | * P is a 32-to-32 bit permutation. Its output contains the following |
| 120 | * bits of its input (listed in order MSB to LSB of output). |
| 121 | * |
| 122 | * 16 25 12 11 3 20 4 15 31 17 9 6 27 14 1 22 |
| 123 | * 30 24 8 18 0 5 29 23 13 19 2 26 10 21 28 7 |
| 124 | * |
| 125 | * PC1 is a 64-to-56 bit selection function. Its output is in two words, |
| 126 | * C and D. The word C contains the following bits of its input (listed |
| 127 | * in order MSB to LSB of output). |
| 128 | * |
| 129 | * 7 15 23 31 39 47 55 63 6 14 22 30 38 46 |
| 130 | * 54 62 5 13 21 29 37 45 53 61 4 12 20 28 |
| 131 | * |
| 132 | * And the word D contains these bits. |
| 133 | * |
| 134 | * 1 9 17 25 33 41 49 57 2 10 18 26 34 42 |
| 135 | * 50 58 3 11 19 27 35 43 51 59 36 44 52 60 |
| 136 | * |
| 137 | * PC2 is a 56-to-48 bit selection function. Its input is in two words, |
| 138 | * C and D. These are treated as one 56-bit word (with C more significant, |
| 139 | * so that bits 55 to 28 of the word are bits 27 to 0 of C, and bits 27 to |
| 140 | * 0 of the word are bits 27 to 0 of D). The output contains the following |
| 141 | * bits of this 56-bit input word (listed in order MSB to LSB of output). |
| 142 | * |
| 143 | * 42 39 45 32 55 51 53 28 41 50 35 46 33 37 44 52 30 48 40 49 29 36 43 54 |
| 144 | * 15 4 25 19 9 1 26 16 5 11 23 8 12 7 17 0 22 3 10 14 6 20 27 24 |
| 145 | */ |
| 146 | |
| 147 | /* |
| 148 | * Implementation details |
| 149 | * ---------------------- |
| 150 | * |
| 151 | * If you look at the code in this module, you'll find it looks |
| 152 | * nothing _like_ the above algorithm. Here I explain the |
| 153 | * differences... |
| 154 | * |
| 155 | * Key setup has not been heavily optimised here. We are not |
| 156 | * concerned with key agility: we aren't codebreakers. We don't |
| 157 | * mind a little delay (and it really is a little one; it may be a |
| 158 | * factor of five or so slower than it could be but it's still not |
| 159 | * an appreciable length of time) while setting up. The only tweaks |
| 160 | * in the key setup are ones which change the format of the key |
| 161 | * schedule to speed up the actual encryption. I'll describe those |
| 162 | * below. |
| 163 | * |
| 164 | * The first and most obvious optimisation is the S-boxes. Since |
| 165 | * each S-box always targets the same four bits in the final 32-bit |
| 166 | * word, so the output from (for example) S-box 0 must always be |
| 167 | * shifted left 28 bits, we can store the already-shifted outputs |
| 168 | * in the lookup tables. This reduces lookup-and-shift to lookup, |
| 169 | * so the S-box step is now just a question of ORing together eight |
| 170 | * table lookups. |
| 171 | * |
| 172 | * The permutation P is just a bit order change; it's invariant |
| 173 | * with respect to OR, in that P(x)|P(y) = P(x|y). Therefore, we |
| 174 | * can apply P to every entry of the S-box tables and then we don't |
| 175 | * have to do it in the code of f(). This yields a set of tables |
| 176 | * which might be called SP-boxes. |
| 177 | * |
| 178 | * The bit-selection function E is our next target. Note that E is |
| 179 | * immediately followed by the operation of splitting into 6-bit |
| 180 | * chunks. Examining the 6-bit chunks coming out of E we notice |
| 181 | * they're all contiguous within the word (speaking cyclically - |
| 182 | * the end two wrap round); so we can extract those bit strings |
| 183 | * individually rather than explicitly running E. This would yield |
| 184 | * code such as |
| 185 | * |
| 186 | * y |= SPboxes[0][ (rotl(R, 5) ^ top6bitsofK) & 0x3F ]; |
| 187 | * t |= SPboxes[1][ (rotl(R,11) ^ next6bitsofK) & 0x3F ]; |
| 188 | * |
| 189 | * and so on; and the key schedule preparation would have to |
| 190 | * provide each 6-bit chunk separately. |
| 191 | * |
| 192 | * Really we'd like to XOR in the key schedule element before |
| 193 | * looking up bit strings in R. This we can't do, naively, because |
| 194 | * the 6-bit strings we want overlap. But look at the strings: |
| 195 | * |
| 196 | * 3322222222221111111111 |
| 197 | * bit 10987654321098765432109876543210 |
| 198 | * |
| 199 | * box0 XXXXX X |
| 200 | * box1 XXXXXX |
| 201 | * box2 XXXXXX |
| 202 | * box3 XXXXXX |
| 203 | * box4 XXXXXX |
| 204 | * box5 XXXXXX |
| 205 | * box6 XXXXXX |
| 206 | * box7 X XXXXX |
| 207 | * |
| 208 | * The bit strings we need to XOR in for boxes 0, 2, 4 and 6 don't |
| 209 | * overlap with each other. Neither do the ones for boxes 1, 3, 5 |
| 210 | * and 7. So we could provide the key schedule in the form of two |
| 211 | * words that we can separately XOR into R, and then every S-box |
| 212 | * index is available as a (cyclically) contiguous 6-bit substring |
| 213 | * of one or the other of the results. |
| 214 | * |
| 215 | * The comments in Eric Young's libdes implementation point out |
| 216 | * that two of these bit strings require a rotation (rather than a |
| 217 | * simple shift) to extract. It's unavoidable that at least _one_ |
| 218 | * must do; but we can actually run the whole inner algorithm (all |
| 219 | * 16 rounds) rotated one bit to the left, so that what the `real' |
| 220 | * DES description sees as L=0x80000001 we see as L=0x00000003. |
| 221 | * This requires rotating all our SP-box entries one bit to the |
| 222 | * left, and rotating each word of the key schedule elements one to |
| 223 | * the left, and rotating L and R one bit left just after IP and |
| 224 | * one bit right again just before FP. And in each round we convert |
| 225 | * a rotate into a shift, so we've saved a few per cent. |
| 226 | * |
| 227 | * That's about it for the inner loop; the SP-box tables as listed |
| 228 | * below are what I've described here (the original S value, |
| 229 | * shifted to its final place in the input to P, run through P, and |
| 230 | * then rotated one bit left). All that remains is to optimise the |
| 231 | * initial permutation IP. |
| 232 | * |
| 233 | * IP is not an arbitrary permutation. It has the nice property |
| 234 | * that if you take any bit number, write it in binary (6 bits), |
| 235 | * permute those 6 bits and invert some of them, you get the final |
| 236 | * position of that bit. Specifically, the bit whose initial |
| 237 | * position is given (in binary) as fedcba ends up in position |
| 238 | * AcbFED (where a capital letter denotes the inverse of a bit). |
| 239 | * |
| 240 | * We have the 64-bit data in two 32-bit words L and R, where bits |
| 241 | * in L are those with f=1 and bits in R are those with f=0. We |
| 242 | * note that we can do a simple transformation: suppose we exchange |
| 243 | * the bits with f=1,c=0 and the bits with f=0,c=1. This will cause |
| 244 | * the bit fedcba to be in position cedfba - we've `swapped' bits c |
| 245 | * and f in the position of each bit! |
| 246 | * |
| 247 | * Better still, this transformation is easy. In the example above, |
| 248 | * bits in L with c=0 are bits 0x0F0F0F0F, and those in R with c=1 |
| 249 | * are 0xF0F0F0F0. So we can do |
| 250 | * |
| 251 | * difference = ((R >> 4) ^ L) & 0x0F0F0F0F |
| 252 | * R ^= (difference << 4) |
| 253 | * L ^= difference |
| 254 | * |
| 255 | * to perform the swap. Let's denote this by bitswap(4,0x0F0F0F0F). |
| 256 | * Also, we can invert the bit at the top just by exchanging L and |
| 257 | * R. So in a few swaps and a few of these bit operations we can |
| 258 | * do: |
| 259 | * |
| 260 | * Initially the position of bit fedcba is fedcba |
| 261 | * Swap L with R to make it Fedcba |
| 262 | * Perform bitswap( 4,0x0F0F0F0F) to make it cedFba |
| 263 | * Perform bitswap(16,0x0000FFFF) to make it ecdFba |
| 264 | * Swap L with R to make it EcdFba |
| 265 | * Perform bitswap( 2,0x33333333) to make it bcdFEa |
| 266 | * Perform bitswap( 8,0x00FF00FF) to make it dcbFEa |
| 267 | * Swap L with R to make it DcbFEa |
| 268 | * Perform bitswap( 1,0x55555555) to make it acbFED |
| 269 | * Swap L with R to make it AcbFED |
| 270 | * |
| 271 | * (In the actual code the four swaps are implicit: R and L are |
| 272 | * simply used the other way round in the first, second and last |
| 273 | * bitswap operations.) |
| 274 | * |
| 275 | * The final permutation is just the inverse of IP, so it can be |
| 276 | * performed by a similar set of operations. |
| 277 | */ |
| 278 | |
| 279 | typedef struct { |
| 280 | word32 k0246[16], k1357[16]; |
| 281 | word32 eiv0, eiv1; |
| 282 | word32 div0, div1; |
| 283 | } DESContext; |
| 284 | |
| 285 | #define rotl(x, c) ( (x << c) | (x >> (32-c)) ) |
| 286 | #define rotl28(x, c) ( ( (x << c) | (x >> (28-c)) ) & 0x0FFFFFFF) |
| 287 | |
| 288 | static word32 bitsel(word32 *input, const int *bitnums, int size) { |
| 289 | word32 ret = 0; |
| 290 | while (size--) { |
| 291 | int bitpos = *bitnums++; |
| 292 | ret <<= 1; |
| 293 | if (bitpos >= 0) |
| 294 | ret |= 1 & (input[bitpos / 32] >> (bitpos % 32)); |
| 295 | } |
| 296 | return ret; |
| 297 | } |
| 298 | |
| 299 | void des_key_setup(word32 key_msw, word32 key_lsw, DESContext *sched) { |
| 300 | |
| 301 | static const int PC1_Cbits[] = { |
| 302 | 7, 15, 23, 31, 39, 47, 55, 63, 6, 14, 22, 30, 38, 46, |
| 303 | 54, 62, 5, 13, 21, 29, 37, 45, 53, 61, 4, 12, 20, 28 |
| 304 | }; |
| 305 | static const int PC1_Dbits[] = { |
| 306 | 1, 9, 17, 25, 33, 41, 49, 57, 2, 10, 18, 26, 34, 42, |
| 307 | 50, 58, 3, 11, 19, 27, 35, 43, 51, 59, 36, 44, 52, 60 |
| 308 | }; |
| 309 | /* |
| 310 | * The bit numbers in the two lists below don't correspond to |
| 311 | * the ones in the above description of PC2, because in the |
| 312 | * above description C and D are concatenated so `bit 28' means |
| 313 | * bit 0 of C. In this implementation we're using the standard |
| 314 | * `bitsel' function above and C is in the second word, so bit |
| 315 | * 0 of C is addressed by writing `32' here. |
| 316 | */ |
| 317 | static const int PC2_0246[] = { |
| 318 | 49, 36, 59, 55, -1, -1, 37, 41, 48, 56, 34, 52, -1, -1, 15, 4, |
| 319 | 25, 19, 9, 1, -1, -1, 12, 7, 17, 0, 22, 3, -1, -1, 46, 43 |
| 320 | }; |
| 321 | static const int PC2_1357[] = { |
| 322 | -1, -1, 57, 32, 45, 54, 39, 50, -1, -1, 44, 53, 33, 40, 47, 58, |
| 323 | -1, -1, 26, 16, 5, 11, 23, 8, -1, -1, 10, 14, 6, 20, 27, 24 |
| 324 | }; |
| 325 | static const int leftshifts[] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1}; |
| 326 | |
| 327 | word32 C, D; |
| 328 | word32 buf[2]; |
| 329 | int i; |
| 330 | |
| 331 | buf[0] = key_lsw; |
| 332 | buf[1] = key_msw; |
| 333 | |
| 334 | C = bitsel(buf, PC1_Cbits, 28); |
| 335 | D = bitsel(buf, PC1_Dbits, 28); |
| 336 | |
| 337 | for (i = 0; i < 16; i++) { |
| 338 | C = rotl28(C, leftshifts[i]); |
| 339 | D = rotl28(D, leftshifts[i]); |
| 340 | buf[0] = D; |
| 341 | buf[1] = C; |
| 342 | sched->k0246[i] = bitsel(buf, PC2_0246, 32); |
| 343 | sched->k1357[i] = bitsel(buf, PC2_1357, 32); |
| 344 | } |
| 345 | |
| 346 | sched->eiv0 = sched->eiv1 = 0; |
| 347 | sched->div0 = sched->div1 = 0; /* for good measure */ |
| 348 | } |
| 349 | |
| 350 | static const word32 SPboxes[8][64] = { |
| 351 | {0x01010400, 0x00000000, 0x00010000, 0x01010404, |
| 352 | 0x01010004, 0x00010404, 0x00000004, 0x00010000, |
| 353 | 0x00000400, 0x01010400, 0x01010404, 0x00000400, |
| 354 | 0x01000404, 0x01010004, 0x01000000, 0x00000004, |
| 355 | 0x00000404, 0x01000400, 0x01000400, 0x00010400, |
| 356 | 0x00010400, 0x01010000, 0x01010000, 0x01000404, |
| 357 | 0x00010004, 0x01000004, 0x01000004, 0x00010004, |
| 358 | 0x00000000, 0x00000404, 0x00010404, 0x01000000, |
| 359 | 0x00010000, 0x01010404, 0x00000004, 0x01010000, |
| 360 | 0x01010400, 0x01000000, 0x01000000, 0x00000400, |
| 361 | 0x01010004, 0x00010000, 0x00010400, 0x01000004, |
| 362 | 0x00000400, 0x00000004, 0x01000404, 0x00010404, |
| 363 | 0x01010404, 0x00010004, 0x01010000, 0x01000404, |
| 364 | 0x01000004, 0x00000404, 0x00010404, 0x01010400, |
| 365 | 0x00000404, 0x01000400, 0x01000400, 0x00000000, |
| 366 | 0x00010004, 0x00010400, 0x00000000, 0x01010004L}, |
| 367 | |
| 368 | {0x80108020, 0x80008000, 0x00008000, 0x00108020, |
| 369 | 0x00100000, 0x00000020, 0x80100020, 0x80008020, |
| 370 | 0x80000020, 0x80108020, 0x80108000, 0x80000000, |
| 371 | 0x80008000, 0x00100000, 0x00000020, 0x80100020, |
| 372 | 0x00108000, 0x00100020, 0x80008020, 0x00000000, |
| 373 | 0x80000000, 0x00008000, 0x00108020, 0x80100000, |
| 374 | 0x00100020, 0x80000020, 0x00000000, 0x00108000, |
| 375 | 0x00008020, 0x80108000, 0x80100000, 0x00008020, |
| 376 | 0x00000000, 0x00108020, 0x80100020, 0x00100000, |
| 377 | 0x80008020, 0x80100000, 0x80108000, 0x00008000, |
| 378 | 0x80100000, 0x80008000, 0x00000020, 0x80108020, |
| 379 | 0x00108020, 0x00000020, 0x00008000, 0x80000000, |
| 380 | 0x00008020, 0x80108000, 0x00100000, 0x80000020, |
| 381 | 0x00100020, 0x80008020, 0x80000020, 0x00100020, |
| 382 | 0x00108000, 0x00000000, 0x80008000, 0x00008020, |
| 383 | 0x80000000, 0x80100020, 0x80108020, 0x00108000L}, |
| 384 | |
| 385 | {0x00000208, 0x08020200, 0x00000000, 0x08020008, |
| 386 | 0x08000200, 0x00000000, 0x00020208, 0x08000200, |
| 387 | 0x00020008, 0x08000008, 0x08000008, 0x00020000, |
| 388 | 0x08020208, 0x00020008, 0x08020000, 0x00000208, |
| 389 | 0x08000000, 0x00000008, 0x08020200, 0x00000200, |
| 390 | 0x00020200, 0x08020000, 0x08020008, 0x00020208, |
| 391 | 0x08000208, 0x00020200, 0x00020000, 0x08000208, |
| 392 | 0x00000008, 0x08020208, 0x00000200, 0x08000000, |
| 393 | 0x08020200, 0x08000000, 0x00020008, 0x00000208, |
| 394 | 0x00020000, 0x08020200, 0x08000200, 0x00000000, |
| 395 | 0x00000200, 0x00020008, 0x08020208, 0x08000200, |
| 396 | 0x08000008, 0x00000200, 0x00000000, 0x08020008, |
| 397 | 0x08000208, 0x00020000, 0x08000000, 0x08020208, |
| 398 | 0x00000008, 0x00020208, 0x00020200, 0x08000008, |
| 399 | 0x08020000, 0x08000208, 0x00000208, 0x08020000, |
| 400 | 0x00020208, 0x00000008, 0x08020008, 0x00020200L}, |
| 401 | |
| 402 | {0x00802001, 0x00002081, 0x00002081, 0x00000080, |
| 403 | 0x00802080, 0x00800081, 0x00800001, 0x00002001, |
| 404 | 0x00000000, 0x00802000, 0x00802000, 0x00802081, |
| 405 | 0x00000081, 0x00000000, 0x00800080, 0x00800001, |
| 406 | 0x00000001, 0x00002000, 0x00800000, 0x00802001, |
| 407 | 0x00000080, 0x00800000, 0x00002001, 0x00002080, |
| 408 | 0x00800081, 0x00000001, 0x00002080, 0x00800080, |
| 409 | 0x00002000, 0x00802080, 0x00802081, 0x00000081, |
| 410 | 0x00800080, 0x00800001, 0x00802000, 0x00802081, |
| 411 | 0x00000081, 0x00000000, 0x00000000, 0x00802000, |
| 412 | 0x00002080, 0x00800080, 0x00800081, 0x00000001, |
| 413 | 0x00802001, 0x00002081, 0x00002081, 0x00000080, |
| 414 | 0x00802081, 0x00000081, 0x00000001, 0x00002000, |
| 415 | 0x00800001, 0x00002001, 0x00802080, 0x00800081, |
| 416 | 0x00002001, 0x00002080, 0x00800000, 0x00802001, |
| 417 | 0x00000080, 0x00800000, 0x00002000, 0x00802080L}, |
| 418 | |
| 419 | {0x00000100, 0x02080100, 0x02080000, 0x42000100, |
| 420 | 0x00080000, 0x00000100, 0x40000000, 0x02080000, |
| 421 | 0x40080100, 0x00080000, 0x02000100, 0x40080100, |
| 422 | 0x42000100, 0x42080000, 0x00080100, 0x40000000, |
| 423 | 0x02000000, 0x40080000, 0x40080000, 0x00000000, |
| 424 | 0x40000100, 0x42080100, 0x42080100, 0x02000100, |
| 425 | 0x42080000, 0x40000100, 0x00000000, 0x42000000, |
| 426 | 0x02080100, 0x02000000, 0x42000000, 0x00080100, |
| 427 | 0x00080000, 0x42000100, 0x00000100, 0x02000000, |
| 428 | 0x40000000, 0x02080000, 0x42000100, 0x40080100, |
| 429 | 0x02000100, 0x40000000, 0x42080000, 0x02080100, |
| 430 | 0x40080100, 0x00000100, 0x02000000, 0x42080000, |
| 431 | 0x42080100, 0x00080100, 0x42000000, 0x42080100, |
| 432 | 0x02080000, 0x00000000, 0x40080000, 0x42000000, |
| 433 | 0x00080100, 0x02000100, 0x40000100, 0x00080000, |
| 434 | 0x00000000, 0x40080000, 0x02080100, 0x40000100L}, |
| 435 | |
| 436 | {0x20000010, 0x20400000, 0x00004000, 0x20404010, |
| 437 | 0x20400000, 0x00000010, 0x20404010, 0x00400000, |
| 438 | 0x20004000, 0x00404010, 0x00400000, 0x20000010, |
| 439 | 0x00400010, 0x20004000, 0x20000000, 0x00004010, |
| 440 | 0x00000000, 0x00400010, 0x20004010, 0x00004000, |
| 441 | 0x00404000, 0x20004010, 0x00000010, 0x20400010, |
| 442 | 0x20400010, 0x00000000, 0x00404010, 0x20404000, |
| 443 | 0x00004010, 0x00404000, 0x20404000, 0x20000000, |
| 444 | 0x20004000, 0x00000010, 0x20400010, 0x00404000, |
| 445 | 0x20404010, 0x00400000, 0x00004010, 0x20000010, |
| 446 | 0x00400000, 0x20004000, 0x20000000, 0x00004010, |
| 447 | 0x20000010, 0x20404010, 0x00404000, 0x20400000, |
| 448 | 0x00404010, 0x20404000, 0x00000000, 0x20400010, |
| 449 | 0x00000010, 0x00004000, 0x20400000, 0x00404010, |
| 450 | 0x00004000, 0x00400010, 0x20004010, 0x00000000, |
| 451 | 0x20404000, 0x20000000, 0x00400010, 0x20004010L}, |
| 452 | |
| 453 | {0x00200000, 0x04200002, 0x04000802, 0x00000000, |
| 454 | 0x00000800, 0x04000802, 0x00200802, 0x04200800, |
| 455 | 0x04200802, 0x00200000, 0x00000000, 0x04000002, |
| 456 | 0x00000002, 0x04000000, 0x04200002, 0x00000802, |
| 457 | 0x04000800, 0x00200802, 0x00200002, 0x04000800, |
| 458 | 0x04000002, 0x04200000, 0x04200800, 0x00200002, |
| 459 | 0x04200000, 0x00000800, 0x00000802, 0x04200802, |
| 460 | 0x00200800, 0x00000002, 0x04000000, 0x00200800, |
| 461 | 0x04000000, 0x00200800, 0x00200000, 0x04000802, |
| 462 | 0x04000802, 0x04200002, 0x04200002, 0x00000002, |
| 463 | 0x00200002, 0x04000000, 0x04000800, 0x00200000, |
| 464 | 0x04200800, 0x00000802, 0x00200802, 0x04200800, |
| 465 | 0x00000802, 0x04000002, 0x04200802, 0x04200000, |
| 466 | 0x00200800, 0x00000000, 0x00000002, 0x04200802, |
| 467 | 0x00000000, 0x00200802, 0x04200000, 0x00000800, |
| 468 | 0x04000002, 0x04000800, 0x00000800, 0x00200002L}, |
| 469 | |
| 470 | {0x10001040, 0x00001000, 0x00040000, 0x10041040, |
| 471 | 0x10000000, 0x10001040, 0x00000040, 0x10000000, |
| 472 | 0x00040040, 0x10040000, 0x10041040, 0x00041000, |
| 473 | 0x10041000, 0x00041040, 0x00001000, 0x00000040, |
| 474 | 0x10040000, 0x10000040, 0x10001000, 0x00001040, |
| 475 | 0x00041000, 0x00040040, 0x10040040, 0x10041000, |
| 476 | 0x00001040, 0x00000000, 0x00000000, 0x10040040, |
| 477 | 0x10000040, 0x10001000, 0x00041040, 0x00040000, |
| 478 | 0x00041040, 0x00040000, 0x10041000, 0x00001000, |
| 479 | 0x00000040, 0x10040040, 0x00001000, 0x00041040, |
| 480 | 0x10001000, 0x00000040, 0x10000040, 0x10040000, |
| 481 | 0x10040040, 0x10000000, 0x00040000, 0x10001040, |
| 482 | 0x00000000, 0x10041040, 0x00040040, 0x10000040, |
| 483 | 0x10040000, 0x10001000, 0x10001040, 0x00000000, |
| 484 | 0x10041040, 0x00041000, 0x00041000, 0x00001040, |
| 485 | 0x00001040, 0x00040040, 0x10000000, 0x10041000L} |
| 486 | }; |
| 487 | |
| 488 | #define f(R, K0246, K1357) (\ |
| 489 | s0246 = R ^ K0246, \ |
| 490 | s1357 = R ^ K1357, \ |
| 491 | s0246 = rotl(s0246, 28), \ |
| 492 | SPboxes[0] [(s0246 >> 24) & 0x3F] | \ |
| 493 | SPboxes[1] [(s1357 >> 24) & 0x3F] | \ |
| 494 | SPboxes[2] [(s0246 >> 16) & 0x3F] | \ |
| 495 | SPboxes[3] [(s1357 >> 16) & 0x3F] | \ |
| 496 | SPboxes[4] [(s0246 >> 8) & 0x3F] | \ |
| 497 | SPboxes[5] [(s1357 >> 8) & 0x3F] | \ |
| 498 | SPboxes[6] [(s0246 ) & 0x3F] | \ |
| 499 | SPboxes[7] [(s1357 ) & 0x3F]) |
| 500 | |
| 501 | #define bitswap(L, R, n, mask) (\ |
| 502 | swap = mask & ( (R >> n) ^ L ), \ |
| 503 | R ^= swap << n, \ |
| 504 | L ^= swap) |
| 505 | |
| 506 | /* Initial permutation */ |
| 507 | #define IP(L, R) (\ |
| 508 | bitswap(R, L, 4, 0x0F0F0F0F), \ |
| 509 | bitswap(R, L, 16, 0x0000FFFF), \ |
| 510 | bitswap(L, R, 2, 0x33333333), \ |
| 511 | bitswap(L, R, 8, 0x00FF00FF), \ |
| 512 | bitswap(R, L, 1, 0x55555555)) |
| 513 | |
| 514 | /* Final permutation */ |
| 515 | #define FP(L, R) (\ |
| 516 | bitswap(R, L, 1, 0x55555555), \ |
| 517 | bitswap(L, R, 8, 0x00FF00FF), \ |
| 518 | bitswap(L, R, 2, 0x33333333), \ |
| 519 | bitswap(R, L, 16, 0x0000FFFF), \ |
| 520 | bitswap(R, L, 4, 0x0F0F0F0F)) |
| 521 | |
| 522 | void des_encipher(word32 *output, word32 L, word32 R, DESContext *sched) { |
| 523 | word32 swap, s0246, s1357; |
| 524 | |
| 525 | IP(L, R); |
| 526 | |
| 527 | L = rotl(L, 1); |
| 528 | R = rotl(R, 1); |
| 529 | |
| 530 | L ^= f(R, sched->k0246[ 0], sched->k1357[ 0]); |
| 531 | R ^= f(L, sched->k0246[ 1], sched->k1357[ 1]); |
| 532 | L ^= f(R, sched->k0246[ 2], sched->k1357[ 2]); |
| 533 | R ^= f(L, sched->k0246[ 3], sched->k1357[ 3]); |
| 534 | L ^= f(R, sched->k0246[ 4], sched->k1357[ 4]); |
| 535 | R ^= f(L, sched->k0246[ 5], sched->k1357[ 5]); |
| 536 | L ^= f(R, sched->k0246[ 6], sched->k1357[ 6]); |
| 537 | R ^= f(L, sched->k0246[ 7], sched->k1357[ 7]); |
| 538 | L ^= f(R, sched->k0246[ 8], sched->k1357[ 8]); |
| 539 | R ^= f(L, sched->k0246[ 9], sched->k1357[ 9]); |
| 540 | L ^= f(R, sched->k0246[10], sched->k1357[10]); |
| 541 | R ^= f(L, sched->k0246[11], sched->k1357[11]); |
| 542 | L ^= f(R, sched->k0246[12], sched->k1357[12]); |
| 543 | R ^= f(L, sched->k0246[13], sched->k1357[13]); |
| 544 | L ^= f(R, sched->k0246[14], sched->k1357[14]); |
| 545 | R ^= f(L, sched->k0246[15], sched->k1357[15]); |
| 546 | |
| 547 | L = rotl(L, 31); |
| 548 | R = rotl(R, 31); |
| 549 | |
| 550 | swap = L; L = R; R = swap; |
| 551 | |
| 552 | FP(L, R); |
| 553 | |
| 554 | output[0] = L; |
| 555 | output[1] = R; |
| 556 | } |
| 557 | |
| 558 | void des_decipher(word32 *output, word32 L, word32 R, DESContext *sched) { |
| 559 | word32 swap, s0246, s1357; |
| 560 | |
| 561 | IP(L, R); |
| 562 | |
| 563 | L = rotl(L, 1); |
| 564 | R = rotl(R, 1); |
| 565 | |
| 566 | L ^= f(R, sched->k0246[15], sched->k1357[15]); |
| 567 | R ^= f(L, sched->k0246[14], sched->k1357[14]); |
| 568 | L ^= f(R, sched->k0246[13], sched->k1357[13]); |
| 569 | R ^= f(L, sched->k0246[12], sched->k1357[12]); |
| 570 | L ^= f(R, sched->k0246[11], sched->k1357[11]); |
| 571 | R ^= f(L, sched->k0246[10], sched->k1357[10]); |
| 572 | L ^= f(R, sched->k0246[ 9], sched->k1357[ 9]); |
| 573 | R ^= f(L, sched->k0246[ 8], sched->k1357[ 8]); |
| 574 | L ^= f(R, sched->k0246[ 7], sched->k1357[ 7]); |
| 575 | R ^= f(L, sched->k0246[ 6], sched->k1357[ 6]); |
| 576 | L ^= f(R, sched->k0246[ 5], sched->k1357[ 5]); |
| 577 | R ^= f(L, sched->k0246[ 4], sched->k1357[ 4]); |
| 578 | L ^= f(R, sched->k0246[ 3], sched->k1357[ 3]); |
| 579 | R ^= f(L, sched->k0246[ 2], sched->k1357[ 2]); |
| 580 | L ^= f(R, sched->k0246[ 1], sched->k1357[ 1]); |
| 581 | R ^= f(L, sched->k0246[ 0], sched->k1357[ 0]); |
| 582 | |
| 583 | L = rotl(L, 31); |
| 584 | R = rotl(R, 31); |
| 585 | |
| 586 | swap = L; L = R; R = swap; |
| 587 | |
| 588 | FP(L, R); |
| 589 | |
| 590 | output[0] = L; |
| 591 | output[1] = R; |
| 592 | } |
| 593 | |
| 594 | #define GET_32BIT_MSB_FIRST(cp) \ |
| 595 | (((unsigned long)(unsigned char)(cp)[3]) | \ |
| 596 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 597 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 598 | ((unsigned long)(unsigned char)(cp)[0] << 24)) |
| 599 | |
| 600 | #define PUT_32BIT_MSB_FIRST(cp, value) do { \ |
| 601 | (cp)[3] = (value); \ |
| 602 | (cp)[2] = (value) >> 8; \ |
| 603 | (cp)[1] = (value) >> 16; \ |
| 604 | (cp)[0] = (value) >> 24; } while (0) |
| 605 | |
| 606 | static void des_cbc_encrypt(unsigned char *dest, const unsigned char *src, |
| 607 | unsigned int len, DESContext *sched) { |
| 608 | word32 out[2], iv0, iv1; |
| 609 | unsigned int i; |
| 610 | |
| 611 | assert((len & 7) == 0); |
| 612 | |
| 613 | iv0 = sched->eiv0; |
| 614 | iv1 = sched->eiv1; |
| 615 | for (i = 0; i < len; i += 8) { |
| 616 | iv0 ^= GET_32BIT_MSB_FIRST(src); src += 4; |
| 617 | iv1 ^= GET_32BIT_MSB_FIRST(src); src += 4; |
| 618 | des_encipher(out, iv0, iv1, sched); |
| 619 | iv0 = out[0]; |
| 620 | iv1 = out[1]; |
| 621 | PUT_32BIT_MSB_FIRST(dest, iv0); dest += 4; |
| 622 | PUT_32BIT_MSB_FIRST(dest, iv1); dest += 4; |
| 623 | } |
| 624 | sched->eiv0 = iv0; |
| 625 | sched->eiv1 = iv1; |
| 626 | } |
| 627 | |
| 628 | static void des_cbc_decrypt(unsigned char *dest, const unsigned char *src, |
| 629 | unsigned int len, DESContext *sched) { |
| 630 | word32 out[2], iv0, iv1, xL, xR; |
| 631 | unsigned int i; |
| 632 | |
| 633 | assert((len & 7) == 0); |
| 634 | |
| 635 | iv0 = sched->div0; |
| 636 | iv1 = sched->div1; |
| 637 | for (i = 0; i < len; i += 8) { |
| 638 | xL = GET_32BIT_MSB_FIRST(src); src += 4; |
| 639 | xR = GET_32BIT_MSB_FIRST(src); src += 4; |
| 640 | des_decipher(out, xL, xR, sched); |
| 641 | iv0 ^= out[0]; |
| 642 | iv1 ^= out[1]; |
| 643 | PUT_32BIT_MSB_FIRST(dest, iv0); dest += 4; |
| 644 | PUT_32BIT_MSB_FIRST(dest, iv1); dest += 4; |
| 645 | iv0 = xL; |
| 646 | iv1 = xR; |
| 647 | } |
| 648 | sched->div0 = iv0; |
| 649 | sched->div1 = iv1; |
| 650 | } |
| 651 | |
| 652 | static void des_3cbc_encrypt(unsigned char *dest, const unsigned char *src, |
| 653 | unsigned int len, DESContext *scheds) { |
| 654 | des_cbc_encrypt(dest, src, len, &scheds[0]); |
| 655 | des_cbc_decrypt(dest, src, len, &scheds[1]); |
| 656 | des_cbc_encrypt(dest, src, len, &scheds[2]); |
| 657 | } |
| 658 | |
| 659 | static void des_cbc3_encrypt(unsigned char *dest, const unsigned char *src, |
| 660 | unsigned int len, DESContext *scheds) { |
| 661 | word32 out[2], iv0, iv1; |
| 662 | unsigned int i; |
| 663 | |
| 664 | assert((len & 7) == 0); |
| 665 | |
| 666 | iv0 = scheds->eiv0; |
| 667 | iv1 = scheds->eiv1; |
| 668 | for (i = 0; i < len; i += 8) { |
| 669 | iv0 ^= GET_32BIT_MSB_FIRST(src); src += 4; |
| 670 | iv1 ^= GET_32BIT_MSB_FIRST(src); src += 4; |
| 671 | des_encipher(out, iv0, iv1, &scheds[0]); |
| 672 | des_decipher(out, out[0], out[1], &scheds[1]); |
| 673 | des_encipher(out, out[0], out[1], &scheds[2]); |
| 674 | iv0 = out[0]; |
| 675 | iv1 = out[1]; |
| 676 | PUT_32BIT_MSB_FIRST(dest, iv0); dest += 4; |
| 677 | PUT_32BIT_MSB_FIRST(dest, iv1); dest += 4; |
| 678 | } |
| 679 | scheds->eiv0 = iv0; |
| 680 | scheds->eiv1 = iv1; |
| 681 | } |
| 682 | |
| 683 | static void des_3cbc_decrypt(unsigned char *dest, const unsigned char *src, |
| 684 | unsigned int len, DESContext *scheds) { |
| 685 | des_cbc_decrypt(dest, src, len, &scheds[2]); |
| 686 | des_cbc_encrypt(dest, src, len, &scheds[1]); |
| 687 | des_cbc_decrypt(dest, src, len, &scheds[0]); |
| 688 | } |
| 689 | |
| 690 | static void des_cbc3_decrypt(unsigned char *dest, const unsigned char *src, |
| 691 | unsigned int len, DESContext *scheds) { |
| 692 | word32 out[2], iv0, iv1, xL, xR; |
| 693 | unsigned int i; |
| 694 | |
| 695 | assert((len & 7) == 0); |
| 696 | |
| 697 | iv0 = scheds->div0; |
| 698 | iv1 = scheds->div1; |
| 699 | for (i = 0; i < len; i += 8) { |
| 700 | xL = GET_32BIT_MSB_FIRST(src); src += 4; |
| 701 | xR = GET_32BIT_MSB_FIRST(src); src += 4; |
| 702 | des_decipher(out, xL, xR, &scheds[2]); |
| 703 | des_encipher(out, out[0], out[1], &scheds[1]); |
| 704 | des_decipher(out, out[0], out[1], &scheds[0]); |
| 705 | iv0 ^= out[0]; |
| 706 | iv1 ^= out[1]; |
| 707 | PUT_32BIT_MSB_FIRST(dest, iv0); dest += 4; |
| 708 | PUT_32BIT_MSB_FIRST(dest, iv1); dest += 4; |
| 709 | iv0 = xL; |
| 710 | iv1 = xR; |
| 711 | } |
| 712 | scheds->div0 = iv0; |
| 713 | scheds->div1 = iv1; |
| 714 | } |
| 715 | |
| 716 | static DESContext cskeys[3], sckeys[3]; |
| 717 | |
| 718 | static void des3_cskey(unsigned char *key) { |
| 719 | des_key_setup(GET_32BIT_MSB_FIRST(key), |
| 720 | GET_32BIT_MSB_FIRST(key+4), &cskeys[0]); |
| 721 | des_key_setup(GET_32BIT_MSB_FIRST(key+8), |
| 722 | GET_32BIT_MSB_FIRST(key+12), &cskeys[1]); |
| 723 | des_key_setup(GET_32BIT_MSB_FIRST(key+16), |
| 724 | GET_32BIT_MSB_FIRST(key+20), &cskeys[2]); |
| 725 | logevent("Initialised triple-DES client->server encryption"); |
| 726 | } |
| 727 | |
| 728 | static void des3_csiv(unsigned char *key) { |
| 729 | cskeys[0].eiv0 = GET_32BIT_MSB_FIRST(key); |
| 730 | cskeys[0].eiv1 = GET_32BIT_MSB_FIRST(key+4); |
| 731 | } |
| 732 | |
| 733 | static void des3_sciv(unsigned char *key) { |
| 734 | sckeys[0].div0 = GET_32BIT_MSB_FIRST(key); |
| 735 | sckeys[0].div1 = GET_32BIT_MSB_FIRST(key+4); |
| 736 | } |
| 737 | |
| 738 | static void des3_sckey(unsigned char *key) { |
| 739 | des_key_setup(GET_32BIT_MSB_FIRST(key), |
| 740 | GET_32BIT_MSB_FIRST(key+4), &sckeys[0]); |
| 741 | des_key_setup(GET_32BIT_MSB_FIRST(key+8), |
| 742 | GET_32BIT_MSB_FIRST(key+12), &sckeys[1]); |
| 743 | des_key_setup(GET_32BIT_MSB_FIRST(key+16), |
| 744 | GET_32BIT_MSB_FIRST(key+20), &sckeys[2]); |
| 745 | logevent("Initialised triple-DES server->client encryption"); |
| 746 | } |
| 747 | |
| 748 | static void des3_sesskey(unsigned char *key) { |
| 749 | des3_cskey(key); |
| 750 | des3_sckey(key); |
| 751 | } |
| 752 | |
| 753 | static void des3_encrypt_blk(unsigned char *blk, int len) { |
| 754 | des_3cbc_encrypt(blk, blk, len, cskeys); |
| 755 | } |
| 756 | |
| 757 | static void des3_decrypt_blk(unsigned char *blk, int len) { |
| 758 | des_3cbc_decrypt(blk, blk, len, sckeys); |
| 759 | } |
| 760 | |
| 761 | static void des3_ssh2_encrypt_blk(unsigned char *blk, int len) { |
| 762 | des_cbc3_encrypt(blk, blk, len, cskeys); |
| 763 | } |
| 764 | |
| 765 | static void des3_ssh2_decrypt_blk(unsigned char *blk, int len) { |
| 766 | des_cbc3_decrypt(blk, blk, len, sckeys); |
| 767 | } |
| 768 | |
| 769 | void des3_decrypt_pubkey(unsigned char *key, |
| 770 | unsigned char *blk, int len) { |
| 771 | DESContext ourkeys[3]; |
| 772 | des_key_setup(GET_32BIT_MSB_FIRST(key), |
| 773 | GET_32BIT_MSB_FIRST(key+4), &ourkeys[0]); |
| 774 | des_key_setup(GET_32BIT_MSB_FIRST(key+8), |
| 775 | GET_32BIT_MSB_FIRST(key+12), &ourkeys[1]); |
| 776 | des_key_setup(GET_32BIT_MSB_FIRST(key), |
| 777 | GET_32BIT_MSB_FIRST(key+4), &ourkeys[2]); |
| 778 | des_3cbc_decrypt(blk, blk, len, ourkeys); |
| 779 | } |
| 780 | |
| 781 | struct ssh_cipher ssh_3des_ssh2 = { |
| 782 | NULL, |
| 783 | des3_csiv, des3_cskey, |
| 784 | des3_sciv, des3_sckey, |
| 785 | des3_ssh2_encrypt_blk, |
| 786 | des3_ssh2_decrypt_blk, |
| 787 | "3des-cbc", |
| 788 | 8 |
| 789 | }; |
| 790 | |
| 791 | struct ssh_cipher ssh_3des = { |
| 792 | des3_sesskey, |
| 793 | NULL, NULL, NULL, NULL, |
| 794 | des3_encrypt_blk, |
| 795 | des3_decrypt_blk, |
| 796 | "3des-cbc", |
| 797 | 8 |
| 798 | }; |
| 799 | |
| 800 | static void des_sesskey(unsigned char *key) { |
| 801 | des_key_setup(GET_32BIT_MSB_FIRST(key), |
| 802 | GET_32BIT_MSB_FIRST(key+4), &cskeys[0]); |
| 803 | logevent("Initialised single-DES encryption"); |
| 804 | } |
| 805 | |
| 806 | static void des_encrypt_blk(unsigned char *blk, int len) { |
| 807 | des_cbc_encrypt(blk, blk, len, cskeys); |
| 808 | } |
| 809 | |
| 810 | static void des_decrypt_blk(unsigned char *blk, int len) { |
| 811 | des_cbc_decrypt(blk, blk, len, cskeys); |
| 812 | } |
| 813 | |
| 814 | struct ssh_cipher ssh_des = { |
| 815 | des_sesskey, |
| 816 | NULL, NULL, NULL, NULL, /* SSH 2 bits - unused */ |
| 817 | des_encrypt_blk, |
| 818 | des_decrypt_blk, |
| 819 | "des-cbc", /* should never be used - not a valid cipher in ssh2 */ |
| 820 | 8 |
| 821 | }; |