| 374330e2 |
1 | #include <assert.h> |
| 2 | #include "ssh.h" |
| 3 | |
| d1e726bc |
4 | /* des.c - implementation of DES |
| 5 | */ |
| 6 | |
| 374330e2 |
7 | /* |
| d1e726bc |
8 | * Description of DES |
| 9 | * |
| 10 | * Unlike the description in FIPS 46, I'm going to use _sensible_ indices: |
| 11 | * bits in an n-bit word are numbered from 0 at the LSB to n-1 at the MSB. |
| 12 | * And S-boxes are indexed by six consecutive bits, not by the outer two |
| 13 | * followed by the middle four. |
| 14 | * |
| 15 | * The DES encryption routine requires a 64-bit input, and a key schedule K |
| 16 | * containing 16 48-bit elements. |
| 17 | * |
| 18 | * First the input is permuted by the initial permutation IP. |
| 19 | * Then the input is split into 32-bit words L and R. (L is the MSW.) |
| 20 | * Next, 16 rounds. In each round: |
| 21 | * (L, R) <- (R, L xor f(R, K[i])) |
| 22 | * Then the pre-output words L and R are swapped. |
| 23 | * Then L and R are glued back together into a 64-bit word. (L is the MSW, |
| 24 | * again, but since we just swapped them, the MSW is the R that came out |
| 25 | * of the last round.) |
| 26 | * The 64-bit output block is permuted by the inverse of IP and returned. |
| 27 | * |
| 28 | * Decryption is identical except that the elements of K are used in the |
| 29 | * opposite order. (This wouldn't work if that word swap didn't happen.) |
| 30 | * |
| 31 | * The function f, used in each round, accepts a 32-bit word R and a |
| 32 | * 48-bit key block K. It produces a 32-bit output. |
| 33 | * |
| 34 | * First R is expanded to 48 bits using the bit-selection function E. |
| 35 | * The resulting 48-bit block is XORed with the key block K to produce |
| 36 | * a 48-bit block X. |
| 37 | * This block X is split into eight groups of 6 bits. Each group of 6 |
| 38 | * bits is then looked up in one of the eight S-boxes to convert |
| 39 | * it to 4 bits. These eight groups of 4 bits are glued back |
| 40 | * together to produce a 32-bit preoutput block. |
| 41 | * The preoutput block is permuted using the permutation P and returned. |
| 42 | * |
| 43 | * Key setup maps a 64-bit key word into a 16x48-bit key schedule. Although |
| 44 | * the approved input format for the key is a 64-bit word, eight of the |
| 45 | * bits are discarded, so the actual quantity of key used is 56 bits. |
| 46 | * |
| 47 | * First the input key is converted to two 28-bit words C and D using |
| 48 | * the bit-selection function PC1. |
| 49 | * Then 16 rounds of key setup occur. In each round, C and D are each |
| 50 | * rotated left by either 1 or 2 bits (depending on which round), and |
| 51 | * then converted into a key schedule element using the bit-selection |
| 52 | * function PC2. |
| 53 | * |
| 54 | * That's the actual algorithm. Now for the tedious details: all those |
| 55 | * painful permutations and lookup tables. |
| 56 | * |
| 57 | * IP is a 64-to-64 bit permutation. Its output contains the following |
| 58 | * bits of its input (listed in order MSB to LSB of output). |
| 59 | * |
| 60 | * 6 14 22 30 38 46 54 62 4 12 20 28 36 44 52 60 |
| 61 | * 2 10 18 26 34 42 50 58 0 8 16 24 32 40 48 56 |
| 62 | * 7 15 23 31 39 47 55 63 5 13 21 29 37 45 53 61 |
| 63 | * 3 11 19 27 35 43 51 59 1 9 17 25 33 41 49 57 |
| 64 | * |
| 65 | * E is a 32-to-48 bit selection function. Its output contains the following |
| 66 | * bits of its input (listed in order MSB to LSB of output). |
| 67 | * |
| 68 | * 0 31 30 29 28 27 28 27 26 25 24 23 24 23 22 21 20 19 20 19 18 17 16 15 |
| 69 | * 16 15 14 13 12 11 12 11 10 9 8 7 8 7 6 5 4 3 4 3 2 1 0 31 |
| 70 | * |
| 71 | * The S-boxes are arbitrary table-lookups each mapping a 6-bit input to a |
| 72 | * 4-bit output. In other words, each S-box is an array[64] of 4-bit numbers. |
| 73 | * The S-boxes are listed below. The first S-box listed is applied to the |
| 74 | * most significant six bits of the block X; the last one is applied to the |
| 75 | * least significant. |
| 76 | * |
| 77 | * 14 0 4 15 13 7 1 4 2 14 15 2 11 13 8 1 |
| 78 | * 3 10 10 6 6 12 12 11 5 9 9 5 0 3 7 8 |
| 79 | * 4 15 1 12 14 8 8 2 13 4 6 9 2 1 11 7 |
| 80 | * 15 5 12 11 9 3 7 14 3 10 10 0 5 6 0 13 |
| 81 | * |
| 82 | * 15 3 1 13 8 4 14 7 6 15 11 2 3 8 4 14 |
| 83 | * 9 12 7 0 2 1 13 10 12 6 0 9 5 11 10 5 |
| 84 | * 0 13 14 8 7 10 11 1 10 3 4 15 13 4 1 2 |
| 85 | * 5 11 8 6 12 7 6 12 9 0 3 5 2 14 15 9 |
| 86 | * |
| 87 | * 10 13 0 7 9 0 14 9 6 3 3 4 15 6 5 10 |
| 88 | * 1 2 13 8 12 5 7 14 11 12 4 11 2 15 8 1 |
| 89 | * 13 1 6 10 4 13 9 0 8 6 15 9 3 8 0 7 |
| 90 | * 11 4 1 15 2 14 12 3 5 11 10 5 14 2 7 12 |
| 91 | * |
| 92 | * 7 13 13 8 14 11 3 5 0 6 6 15 9 0 10 3 |
| 93 | * 1 4 2 7 8 2 5 12 11 1 12 10 4 14 15 9 |
| 94 | * 10 3 6 15 9 0 0 6 12 10 11 1 7 13 13 8 |
| 95 | * 15 9 1 4 3 5 14 11 5 12 2 7 8 2 4 14 |
| 96 | * |
| 97 | * 2 14 12 11 4 2 1 12 7 4 10 7 11 13 6 1 |
| 98 | * 8 5 5 0 3 15 15 10 13 3 0 9 14 8 9 6 |
| 99 | * 4 11 2 8 1 12 11 7 10 1 13 14 7 2 8 13 |
| 100 | * 15 6 9 15 12 0 5 9 6 10 3 4 0 5 14 3 |
| 101 | * |
| 102 | * 12 10 1 15 10 4 15 2 9 7 2 12 6 9 8 5 |
| 103 | * 0 6 13 1 3 13 4 14 14 0 7 11 5 3 11 8 |
| 104 | * 9 4 14 3 15 2 5 12 2 9 8 5 12 15 3 10 |
| 105 | * 7 11 0 14 4 1 10 7 1 6 13 0 11 8 6 13 |
| 106 | * |
| 107 | * 4 13 11 0 2 11 14 7 15 4 0 9 8 1 13 10 |
| 108 | * 3 14 12 3 9 5 7 12 5 2 10 15 6 8 1 6 |
| 109 | * 1 6 4 11 11 13 13 8 12 1 3 4 7 10 14 7 |
| 110 | * 10 9 15 5 6 0 8 15 0 14 5 2 9 3 2 12 |
| 111 | * |
| 112 | * 13 1 2 15 8 13 4 8 6 10 15 3 11 7 1 4 |
| 113 | * 10 12 9 5 3 6 14 11 5 0 0 14 12 9 7 2 |
| 114 | * 7 2 11 1 4 14 1 7 9 4 12 10 14 8 2 13 |
| 115 | * 0 15 6 12 10 9 13 0 15 3 3 5 5 6 8 11 |
| 116 | * |
| 117 | * P is a 32-to-32 bit permutation. Its output contains the following |
| 118 | * bits of its input (listed in order MSB to LSB of output). |
| 119 | * |
| 120 | * 16 25 12 11 3 20 4 15 31 17 9 6 27 14 1 22 |
| 121 | * 30 24 8 18 0 5 29 23 13 19 2 26 10 21 28 7 |
| 122 | * |
| 123 | * PC1 is a 64-to-56 bit selection function. Its output is in two words, |
| 124 | * C and D. The word C contains the following bits of its input (listed |
| 125 | * in order MSB to LSB of output). |
| 126 | * |
| 127 | * 7 15 23 31 39 47 55 63 6 14 22 30 38 46 |
| 128 | * 54 62 5 13 21 29 37 45 53 61 4 12 20 28 |
| 129 | * |
| 130 | * And the word D contains these bits. |
| 131 | * |
| 132 | * 1 9 17 25 33 41 49 57 2 10 18 26 34 42 |
| 133 | * 50 58 3 11 19 27 35 43 51 59 36 44 52 60 |
| 134 | * |
| 135 | * PC2 is a 56-to-48 bit selection function. Its input is in two words, |
| 136 | * C and D. These are treated as one 56-bit word (with C more significant, |
| 137 | * so that bits 55 to 28 of the word are bits 27 to 0 of C, and bits 27 to |
| 138 | * 0 of the word are bits 27 to 0 of D). The output contains the following |
| 139 | * bits of this 56-bit input word (listed in order MSB to LSB of output). |
| 140 | * |
| 141 | * 42 39 45 32 55 51 53 28 41 50 35 46 33 37 44 52 30 48 40 49 29 36 43 54 |
| 142 | * 15 4 25 19 9 1 26 16 5 11 23 8 12 7 17 0 22 3 10 14 6 20 27 24 |
| 143 | */ |
| 144 | |
| 145 | typedef struct { |
| 146 | word32 k0246[16], k1357[16]; |
| 147 | word32 eiv0, eiv1; |
| 148 | word32 div0, div1; |
| 149 | } DESContext; |
| 374330e2 |
150 | |
| d1e726bc |
151 | #define rotl(x, c) ( (x << c) | (x >> (32-c)) ) |
| 152 | #define rotl28(x, c) ( ( (x << c) | (x >> (28-c)) ) & 0x0FFFFFFF) |
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153 | |
| d1e726bc |
154 | static word32 bitsel(word32 *input, const int *bitnums, int size) { |
| 155 | word32 ret = 0; |
| 156 | while (size--) { |
| 157 | int bitpos = *bitnums++; |
| 158 | ret <<= 1; |
| 159 | if (bitpos >= 0) |
| 160 | ret |= 1 & (input[bitpos / 32] >> (bitpos % 32)); |
| 161 | } |
| 162 | return ret; |
| 163 | } |
| 374330e2 |
164 | |
| d1e726bc |
165 | void des_key_setup(word32 key_msw, word32 key_lsw, DESContext *sched) { |
| 166 | |
| 167 | static const int PC1_Cbits[] = { |
| 168 | 7, 15, 23, 31, 39, 47, 55, 63, 6, 14, 22, 30, 38, 46, |
| 169 | 54, 62, 5, 13, 21, 29, 37, 45, 53, 61, 4, 12, 20, 28 |
| 170 | }; |
| 171 | static const int PC1_Dbits[] = { |
| 172 | 1, 9, 17, 25, 33, 41, 49, 57, 2, 10, 18, 26, 34, 42, |
| 173 | 50, 58, 3, 11, 19, 27, 35, 43, 51, 59, 36, 44, 52, 60 |
| 174 | }; |
| 175 | static const int PC2_0246[] = { |
| 176 | 49, 36, 59, 55, -1, -1, 37, 41, 48, 56, 34, 52, -1, -1, 15, 4, |
| 177 | 25, 19, 9, 1, -1, -1, 12, 7, 17, 0, 22, 3, -1, -1, 46, 43 |
| 178 | }; |
| 179 | static const int PC2_1357[] = { |
| 180 | -1, -1, 57, 32, 45, 54, 39, 50, -1, -1, 44, 53, 33, 40, 47, 58, |
| 181 | -1, -1, 26, 16, 5, 11, 23, 8, -1, -1, 10, 14, 6, 20, 27, 24 |
| 182 | }; |
| 183 | static const int leftshifts[] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1}; |
| 184 | |
| 185 | word32 C, D; |
| 186 | word32 buf[2]; |
| 187 | int i; |
| 188 | |
| 189 | buf[0] = key_lsw; |
| 190 | buf[1] = key_msw; |
| 191 | |
| 192 | C = bitsel(buf, PC1_Cbits, 28); |
| 193 | D = bitsel(buf, PC1_Dbits, 28); |
| 194 | |
| 195 | for (i = 0; i < 16; i++) { |
| 196 | C = rotl28(C, leftshifts[i]); |
| 197 | D = rotl28(D, leftshifts[i]); |
| 198 | buf[0] = D; |
| 199 | buf[1] = C; |
| 200 | sched->k0246[i] = bitsel(buf, PC2_0246, 32); |
| 201 | sched->k1357[i] = bitsel(buf, PC2_1357, 32); |
| 202 | } |
| 374330e2 |
203 | |
| d1e726bc |
204 | sched->eiv0 = sched->eiv1 = 0; |
| 205 | sched->div0 = sched->div1 = 0; /* for good measure */ |
| 206 | } |
| 374330e2 |
207 | |
| d1e726bc |
208 | static const word32 SPboxes[8][64] = { |
| 209 | {0x01010400, 0x00000000, 0x00010000, 0x01010404, |
| 210 | 0x01010004, 0x00010404, 0x00000004, 0x00010000, |
| 211 | 0x00000400, 0x01010400, 0x01010404, 0x00000400, |
| 212 | 0x01000404, 0x01010004, 0x01000000, 0x00000004, |
| 213 | 0x00000404, 0x01000400, 0x01000400, 0x00010400, |
| 214 | 0x00010400, 0x01010000, 0x01010000, 0x01000404, |
| 215 | 0x00010004, 0x01000004, 0x01000004, 0x00010004, |
| 216 | 0x00000000, 0x00000404, 0x00010404, 0x01000000, |
| 217 | 0x00010000, 0x01010404, 0x00000004, 0x01010000, |
| 218 | 0x01010400, 0x01000000, 0x01000000, 0x00000400, |
| 219 | 0x01010004, 0x00010000, 0x00010400, 0x01000004, |
| 220 | 0x00000400, 0x00000004, 0x01000404, 0x00010404, |
| 221 | 0x01010404, 0x00010004, 0x01010000, 0x01000404, |
| 222 | 0x01000004, 0x00000404, 0x00010404, 0x01010400, |
| 223 | 0x00000404, 0x01000400, 0x01000400, 0x00000000, |
| 224 | 0x00010004, 0x00010400, 0x00000000, 0x01010004L}, |
| 225 | |
| 226 | {0x80108020, 0x80008000, 0x00008000, 0x00108020, |
| 227 | 0x00100000, 0x00000020, 0x80100020, 0x80008020, |
| 228 | 0x80000020, 0x80108020, 0x80108000, 0x80000000, |
| 229 | 0x80008000, 0x00100000, 0x00000020, 0x80100020, |
| 230 | 0x00108000, 0x00100020, 0x80008020, 0x00000000, |
| 231 | 0x80000000, 0x00008000, 0x00108020, 0x80100000, |
| 232 | 0x00100020, 0x80000020, 0x00000000, 0x00108000, |
| 233 | 0x00008020, 0x80108000, 0x80100000, 0x00008020, |
| 234 | 0x00000000, 0x00108020, 0x80100020, 0x00100000, |
| 235 | 0x80008020, 0x80100000, 0x80108000, 0x00008000, |
| 236 | 0x80100000, 0x80008000, 0x00000020, 0x80108020, |
| 237 | 0x00108020, 0x00000020, 0x00008000, 0x80000000, |
| 238 | 0x00008020, 0x80108000, 0x00100000, 0x80000020, |
| 239 | 0x00100020, 0x80008020, 0x80000020, 0x00100020, |
| 240 | 0x00108000, 0x00000000, 0x80008000, 0x00008020, |
| 241 | 0x80000000, 0x80100020, 0x80108020, 0x00108000L}, |
| 242 | |
| 243 | {0x00000208, 0x08020200, 0x00000000, 0x08020008, |
| 244 | 0x08000200, 0x00000000, 0x00020208, 0x08000200, |
| 245 | 0x00020008, 0x08000008, 0x08000008, 0x00020000, |
| 246 | 0x08020208, 0x00020008, 0x08020000, 0x00000208, |
| 247 | 0x08000000, 0x00000008, 0x08020200, 0x00000200, |
| 248 | 0x00020200, 0x08020000, 0x08020008, 0x00020208, |
| 249 | 0x08000208, 0x00020200, 0x00020000, 0x08000208, |
| 250 | 0x00000008, 0x08020208, 0x00000200, 0x08000000, |
| 251 | 0x08020200, 0x08000000, 0x00020008, 0x00000208, |
| 252 | 0x00020000, 0x08020200, 0x08000200, 0x00000000, |
| 253 | 0x00000200, 0x00020008, 0x08020208, 0x08000200, |
| 254 | 0x08000008, 0x00000200, 0x00000000, 0x08020008, |
| 255 | 0x08000208, 0x00020000, 0x08000000, 0x08020208, |
| 256 | 0x00000008, 0x00020208, 0x00020200, 0x08000008, |
| 257 | 0x08020000, 0x08000208, 0x00000208, 0x08020000, |
| 258 | 0x00020208, 0x00000008, 0x08020008, 0x00020200L}, |
| 259 | |
| 260 | {0x00802001, 0x00002081, 0x00002081, 0x00000080, |
| 261 | 0x00802080, 0x00800081, 0x00800001, 0x00002001, |
| 262 | 0x00000000, 0x00802000, 0x00802000, 0x00802081, |
| 263 | 0x00000081, 0x00000000, 0x00800080, 0x00800001, |
| 264 | 0x00000001, 0x00002000, 0x00800000, 0x00802001, |
| 265 | 0x00000080, 0x00800000, 0x00002001, 0x00002080, |
| 266 | 0x00800081, 0x00000001, 0x00002080, 0x00800080, |
| 267 | 0x00002000, 0x00802080, 0x00802081, 0x00000081, |
| 268 | 0x00800080, 0x00800001, 0x00802000, 0x00802081, |
| 269 | 0x00000081, 0x00000000, 0x00000000, 0x00802000, |
| 270 | 0x00002080, 0x00800080, 0x00800081, 0x00000001, |
| 271 | 0x00802001, 0x00002081, 0x00002081, 0x00000080, |
| 272 | 0x00802081, 0x00000081, 0x00000001, 0x00002000, |
| 273 | 0x00800001, 0x00002001, 0x00802080, 0x00800081, |
| 274 | 0x00002001, 0x00002080, 0x00800000, 0x00802001, |
| 275 | 0x00000080, 0x00800000, 0x00002000, 0x00802080L}, |
| 276 | |
| 277 | {0x00000100, 0x02080100, 0x02080000, 0x42000100, |
| 278 | 0x00080000, 0x00000100, 0x40000000, 0x02080000, |
| 279 | 0x40080100, 0x00080000, 0x02000100, 0x40080100, |
| 280 | 0x42000100, 0x42080000, 0x00080100, 0x40000000, |
| 281 | 0x02000000, 0x40080000, 0x40080000, 0x00000000, |
| 282 | 0x40000100, 0x42080100, 0x42080100, 0x02000100, |
| 283 | 0x42080000, 0x40000100, 0x00000000, 0x42000000, |
| 284 | 0x02080100, 0x02000000, 0x42000000, 0x00080100, |
| 285 | 0x00080000, 0x42000100, 0x00000100, 0x02000000, |
| 286 | 0x40000000, 0x02080000, 0x42000100, 0x40080100, |
| 287 | 0x02000100, 0x40000000, 0x42080000, 0x02080100, |
| 288 | 0x40080100, 0x00000100, 0x02000000, 0x42080000, |
| 289 | 0x42080100, 0x00080100, 0x42000000, 0x42080100, |
| 290 | 0x02080000, 0x00000000, 0x40080000, 0x42000000, |
| 291 | 0x00080100, 0x02000100, 0x40000100, 0x00080000, |
| 292 | 0x00000000, 0x40080000, 0x02080100, 0x40000100L}, |
| 293 | |
| 294 | {0x20000010, 0x20400000, 0x00004000, 0x20404010, |
| 295 | 0x20400000, 0x00000010, 0x20404010, 0x00400000, |
| 296 | 0x20004000, 0x00404010, 0x00400000, 0x20000010, |
| 297 | 0x00400010, 0x20004000, 0x20000000, 0x00004010, |
| 298 | 0x00000000, 0x00400010, 0x20004010, 0x00004000, |
| 299 | 0x00404000, 0x20004010, 0x00000010, 0x20400010, |
| 300 | 0x20400010, 0x00000000, 0x00404010, 0x20404000, |
| 301 | 0x00004010, 0x00404000, 0x20404000, 0x20000000, |
| 302 | 0x20004000, 0x00000010, 0x20400010, 0x00404000, |
| 303 | 0x20404010, 0x00400000, 0x00004010, 0x20000010, |
| 304 | 0x00400000, 0x20004000, 0x20000000, 0x00004010, |
| 305 | 0x20000010, 0x20404010, 0x00404000, 0x20400000, |
| 306 | 0x00404010, 0x20404000, 0x00000000, 0x20400010, |
| 307 | 0x00000010, 0x00004000, 0x20400000, 0x00404010, |
| 308 | 0x00004000, 0x00400010, 0x20004010, 0x00000000, |
| 309 | 0x20404000, 0x20000000, 0x00400010, 0x20004010L}, |
| 310 | |
| 311 | {0x00200000, 0x04200002, 0x04000802, 0x00000000, |
| 312 | 0x00000800, 0x04000802, 0x00200802, 0x04200800, |
| 313 | 0x04200802, 0x00200000, 0x00000000, 0x04000002, |
| 314 | 0x00000002, 0x04000000, 0x04200002, 0x00000802, |
| 315 | 0x04000800, 0x00200802, 0x00200002, 0x04000800, |
| 316 | 0x04000002, 0x04200000, 0x04200800, 0x00200002, |
| 317 | 0x04200000, 0x00000800, 0x00000802, 0x04200802, |
| 318 | 0x00200800, 0x00000002, 0x04000000, 0x00200800, |
| 319 | 0x04000000, 0x00200800, 0x00200000, 0x04000802, |
| 320 | 0x04000802, 0x04200002, 0x04200002, 0x00000002, |
| 321 | 0x00200002, 0x04000000, 0x04000800, 0x00200000, |
| 322 | 0x04200800, 0x00000802, 0x00200802, 0x04200800, |
| 323 | 0x00000802, 0x04000002, 0x04200802, 0x04200000, |
| 324 | 0x00200800, 0x00000000, 0x00000002, 0x04200802, |
| 325 | 0x00000000, 0x00200802, 0x04200000, 0x00000800, |
| 326 | 0x04000002, 0x04000800, 0x00000800, 0x00200002L}, |
| 327 | |
| 328 | {0x10001040, 0x00001000, 0x00040000, 0x10041040, |
| 329 | 0x10000000, 0x10001040, 0x00000040, 0x10000000, |
| 330 | 0x00040040, 0x10040000, 0x10041040, 0x00041000, |
| 331 | 0x10041000, 0x00041040, 0x00001000, 0x00000040, |
| 332 | 0x10040000, 0x10000040, 0x10001000, 0x00001040, |
| 333 | 0x00041000, 0x00040040, 0x10040040, 0x10041000, |
| 334 | 0x00001040, 0x00000000, 0x00000000, 0x10040040, |
| 335 | 0x10000040, 0x10001000, 0x00041040, 0x00040000, |
| 336 | 0x00041040, 0x00040000, 0x10041000, 0x00001000, |
| 337 | 0x00000040, 0x10040040, 0x00001000, 0x00041040, |
| 338 | 0x10001000, 0x00000040, 0x10000040, 0x10040000, |
| 339 | 0x10040040, 0x10000000, 0x00040000, 0x10001040, |
| 340 | 0x00000000, 0x10041040, 0x00040040, 0x10000040, |
| 341 | 0x10040000, 0x10001000, 0x10001040, 0x00000000, |
| 342 | 0x10041040, 0x00041000, 0x00041000, 0x00001040, |
| 343 | 0x00001040, 0x00040040, 0x10000000, 0x10041000L} |
| 344 | }; |
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345 | |
| d1e726bc |
346 | #define f(R, K0246, K1357) (\ |
| 347 | s0246 = R ^ K0246, \ |
| 348 | s1357 = R ^ K1357, \ |
| 349 | s0246 = rotl(s0246, 28), \ |
| 350 | SPboxes[0] [(s0246 >> 24) & 0x3F] | \ |
| 351 | SPboxes[1] [(s1357 >> 24) & 0x3F] | \ |
| 352 | SPboxes[2] [(s0246 >> 16) & 0x3F] | \ |
| 353 | SPboxes[3] [(s1357 >> 16) & 0x3F] | \ |
| 354 | SPboxes[4] [(s0246 >> 8) & 0x3F] | \ |
| 355 | SPboxes[5] [(s1357 >> 8) & 0x3F] | \ |
| 356 | SPboxes[6] [(s0246 ) & 0x3F] | \ |
| 357 | SPboxes[7] [(s1357 ) & 0x3F]) |
| 358 | |
| 359 | #define bitswap(L, R, n, mask) (\ |
| 360 | swap = mask & ( (R >> n) ^ L ), \ |
| 361 | R ^= swap << n, \ |
| 362 | L ^= swap) |
| 363 | |
| 364 | /* Initial permutation */ |
| 365 | #define IP(L, R) (\ |
| 366 | bitswap(R, L, 4, 0x0F0F0F0F), \ |
| 367 | bitswap(R, L, 16, 0x0000FFFF), \ |
| 368 | bitswap(L, R, 2, 0x33333333), \ |
| 369 | bitswap(L, R, 8, 0x00FF00FF), \ |
| 370 | bitswap(R, L, 1, 0x55555555)) |
| 371 | |
| 372 | /* Final permutation */ |
| 373 | #define FP(L, R) (\ |
| 374 | bitswap(R, L, 1, 0x55555555), \ |
| 375 | bitswap(L, R, 8, 0x00FF00FF), \ |
| 376 | bitswap(L, R, 2, 0x33333333), \ |
| 377 | bitswap(R, L, 16, 0x0000FFFF), \ |
| 378 | bitswap(R, L, 4, 0x0F0F0F0F)) |
| 379 | |
| 380 | void des_encipher(word32 *output, word32 L, word32 R, DESContext *sched) { |
| 381 | word32 swap, s0246, s1357; |
| 382 | |
| 383 | IP(L, R); |
| 384 | |
| 385 | L = rotl(L, 1); |
| 386 | R = rotl(R, 1); |
| 387 | |
| 388 | L ^= f(R, sched->k0246[ 0], sched->k1357[ 0]); |
| 389 | R ^= f(L, sched->k0246[ 1], sched->k1357[ 1]); |
| 390 | L ^= f(R, sched->k0246[ 2], sched->k1357[ 2]); |
| 391 | R ^= f(L, sched->k0246[ 3], sched->k1357[ 3]); |
| 392 | L ^= f(R, sched->k0246[ 4], sched->k1357[ 4]); |
| 393 | R ^= f(L, sched->k0246[ 5], sched->k1357[ 5]); |
| 394 | L ^= f(R, sched->k0246[ 6], sched->k1357[ 6]); |
| 395 | R ^= f(L, sched->k0246[ 7], sched->k1357[ 7]); |
| 396 | L ^= f(R, sched->k0246[ 8], sched->k1357[ 8]); |
| 397 | R ^= f(L, sched->k0246[ 9], sched->k1357[ 9]); |
| 398 | L ^= f(R, sched->k0246[10], sched->k1357[10]); |
| 399 | R ^= f(L, sched->k0246[11], sched->k1357[11]); |
| 400 | L ^= f(R, sched->k0246[12], sched->k1357[12]); |
| 401 | R ^= f(L, sched->k0246[13], sched->k1357[13]); |
| 402 | L ^= f(R, sched->k0246[14], sched->k1357[14]); |
| 403 | R ^= f(L, sched->k0246[15], sched->k1357[15]); |
| 404 | |
| 405 | L = rotl(L, 31); |
| 406 | R = rotl(R, 31); |
| 407 | |
| 408 | swap = L; L = R; R = swap; |
| 409 | |
| 410 | FP(L, R); |
| 411 | |
| 412 | output[0] = L; |
| 413 | output[1] = R; |
| 414 | } |
| 374330e2 |
415 | |
| d1e726bc |
416 | void des_decipher(word32 *output, word32 L, word32 R, DESContext *sched) { |
| 417 | word32 swap, s0246, s1357; |
| 374330e2 |
418 | |
| d1e726bc |
419 | IP(L, R); |
| 374330e2 |
420 | |
| d1e726bc |
421 | L = rotl(L, 1); |
| 422 | R = rotl(R, 1); |
| 374330e2 |
423 | |
| d1e726bc |
424 | L ^= f(R, sched->k0246[15], sched->k1357[15]); |
| 425 | R ^= f(L, sched->k0246[14], sched->k1357[14]); |
| 426 | L ^= f(R, sched->k0246[13], sched->k1357[13]); |
| 427 | R ^= f(L, sched->k0246[12], sched->k1357[12]); |
| 428 | L ^= f(R, sched->k0246[11], sched->k1357[11]); |
| 429 | R ^= f(L, sched->k0246[10], sched->k1357[10]); |
| 430 | L ^= f(R, sched->k0246[ 9], sched->k1357[ 9]); |
| 431 | R ^= f(L, sched->k0246[ 8], sched->k1357[ 8]); |
| 432 | L ^= f(R, sched->k0246[ 7], sched->k1357[ 7]); |
| 433 | R ^= f(L, sched->k0246[ 6], sched->k1357[ 6]); |
| 434 | L ^= f(R, sched->k0246[ 5], sched->k1357[ 5]); |
| 435 | R ^= f(L, sched->k0246[ 4], sched->k1357[ 4]); |
| 436 | L ^= f(R, sched->k0246[ 3], sched->k1357[ 3]); |
| 437 | R ^= f(L, sched->k0246[ 2], sched->k1357[ 2]); |
| 438 | L ^= f(R, sched->k0246[ 1], sched->k1357[ 1]); |
| 439 | R ^= f(L, sched->k0246[ 0], sched->k1357[ 0]); |
| 440 | |
| 441 | L = rotl(L, 31); |
| 442 | R = rotl(R, 31); |
| 443 | |
| 444 | swap = L; L = R; R = swap; |
| 445 | |
| 446 | FP(L, R); |
| 447 | |
| 448 | output[0] = L; |
| 449 | output[1] = R; |
| 374330e2 |
450 | } |
| 451 | |
| d1e726bc |
452 | #define GET_32BIT_MSB_FIRST(cp) \ |
| 453 | (((unsigned long)(unsigned char)(cp)[3]) | \ |
| 454 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 455 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 456 | ((unsigned long)(unsigned char)(cp)[0] << 24)) |
| 457 | |
| 458 | #define PUT_32BIT_MSB_FIRST(cp, value) do { \ |
| 459 | (cp)[3] = (value); \ |
| 460 | (cp)[2] = (value) >> 8; \ |
| 461 | (cp)[1] = (value) >> 16; \ |
| 462 | (cp)[0] = (value) >> 24; } while (0) |
| 463 | |
| 464 | static void des_cbc_encrypt(unsigned char *dest, const unsigned char *src, |
| 465 | unsigned int len, DESContext *sched) { |
| 466 | word32 out[2], iv0, iv1; |
| 467 | unsigned int i; |
| 468 | |
| 469 | assert((len & 7) == 0); |
| 470 | |
| 471 | iv0 = sched->eiv0; |
| 472 | iv1 = sched->eiv1; |
| 473 | for (i = 0; i < len; i += 8) { |
| 474 | iv0 ^= GET_32BIT_MSB_FIRST(src); src += 4; |
| 475 | iv1 ^= GET_32BIT_MSB_FIRST(src); src += 4; |
| 476 | des_encipher(out, iv0, iv1, sched); |
| 477 | iv0 = out[0]; |
| 478 | iv1 = out[1]; |
| 479 | PUT_32BIT_MSB_FIRST(dest, iv0); dest += 4; |
| 480 | PUT_32BIT_MSB_FIRST(dest, iv1); dest += 4; |
| 374330e2 |
481 | } |
| d1e726bc |
482 | sched->eiv0 = iv0; |
| 483 | sched->eiv1 = iv1; |
| 374330e2 |
484 | } |
| 485 | |
| d1e726bc |
486 | static void des_cbc_decrypt(unsigned char *dest, const unsigned char *src, |
| 487 | unsigned int len, DESContext *sched) { |
| 488 | word32 out[2], iv0, iv1, xL, xR; |
| 489 | unsigned int i; |
| 490 | |
| 491 | assert((len & 7) == 0); |
| 492 | |
| 493 | iv0 = sched->div0; |
| 494 | iv1 = sched->div1; |
| 495 | for (i = 0; i < len; i += 8) { |
| 496 | xL = GET_32BIT_MSB_FIRST(src); src += 4; |
| 497 | xR = GET_32BIT_MSB_FIRST(src); src += 4; |
| 498 | des_decipher(out, xL, xR, sched); |
| 499 | iv0 ^= out[0]; |
| 500 | iv1 ^= out[1]; |
| 501 | PUT_32BIT_MSB_FIRST(dest, iv0); dest += 4; |
| 502 | PUT_32BIT_MSB_FIRST(dest, iv1); dest += 4; |
| 503 | iv0 = xL; |
| 504 | iv1 = xR; |
| 374330e2 |
505 | } |
| d1e726bc |
506 | sched->div0 = iv0; |
| 507 | sched->div1 = iv1; |
| 374330e2 |
508 | } |
| 509 | |
| d1e726bc |
510 | static void des_3cbc_encrypt(unsigned char *dest, const unsigned char *src, |
| 511 | unsigned int len, DESContext *scheds) { |
| 512 | des_cbc_encrypt(dest, src, len, &scheds[0]); |
| 513 | des_cbc_decrypt(dest, src, len, &scheds[1]); |
| 514 | des_cbc_encrypt(dest, src, len, &scheds[2]); |
| 374330e2 |
515 | } |
| 516 | |
| d1e726bc |
517 | static void des_3cbc_decrypt(unsigned char *dest, const unsigned char *src, |
| 518 | unsigned int len, DESContext *scheds) { |
| 519 | des_cbc_decrypt(dest, src, len, &scheds[2]); |
| 520 | des_cbc_encrypt(dest, src, len, &scheds[1]); |
| 521 | des_cbc_decrypt(dest, src, len, &scheds[0]); |
| 374330e2 |
522 | } |
| 523 | |
| d1e726bc |
524 | DESContext keys[3]; |
| 374330e2 |
525 | |
| 526 | static void des3_sesskey(unsigned char *key) { |
| d1e726bc |
527 | des_key_setup(GET_32BIT_MSB_FIRST(key), |
| 528 | GET_32BIT_MSB_FIRST(key+4), &keys[0]); |
| 529 | des_key_setup(GET_32BIT_MSB_FIRST(key+8), |
| 530 | GET_32BIT_MSB_FIRST(key+12), &keys[1]); |
| 531 | des_key_setup(GET_32BIT_MSB_FIRST(key+16), |
| 532 | GET_32BIT_MSB_FIRST(key+20), &keys[2]); |
| c5e9c988 |
533 | logevent("Initialised triple-DES encryption"); |
| 374330e2 |
534 | } |
| 535 | |
| 536 | static void des3_encrypt_blk(unsigned char *blk, int len) { |
| d1e726bc |
537 | des_3cbc_encrypt(blk, blk, len, keys); |
| 374330e2 |
538 | } |
| 539 | |
| 540 | static void des3_decrypt_blk(unsigned char *blk, int len) { |
| d1e726bc |
541 | des_3cbc_decrypt(blk, blk, len, keys); |
| 374330e2 |
542 | } |
| 543 | |
| 544 | struct ssh_cipher ssh_3des = { |
| 545 | des3_sesskey, |
| 546 | des3_encrypt_blk, |
| 547 | des3_decrypt_blk |
| 548 | }; |
| 549 | |
| 9697bfd2 |
550 | static void des_sesskey(unsigned char *key) { |
| d1e726bc |
551 | des_key_setup(GET_32BIT_MSB_FIRST(key), |
| 552 | GET_32BIT_MSB_FIRST(key+4), &keys[0]); |
| c5e9c988 |
553 | logevent("Initialised single-DES encryption"); |
| 9697bfd2 |
554 | } |
| 555 | |
| 556 | static void des_encrypt_blk(unsigned char *blk, int len) { |
| d1e726bc |
557 | des_cbc_encrypt(blk, blk, len, keys); |
| 9697bfd2 |
558 | } |
| 559 | |
| 560 | static void des_decrypt_blk(unsigned char *blk, int len) { |
| d1e726bc |
561 | des_cbc_decrypt(blk, blk, len, keys); |
| 9697bfd2 |
562 | } |
| 563 | |
| 564 | struct ssh_cipher ssh_des = { |
| 565 | des_sesskey, |
| 566 | des_encrypt_blk, |
| 567 | des_decrypt_blk |
| 568 | }; |
projects / u / mdw / putty / blame