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Diffstat (limited to 'libdes/f_tables.h')
| -rw-r--r-- | libdes/f_tables.h | 223 |
1 files changed, 0 insertions, 223 deletions
diff --git a/libdes/f_tables.h b/libdes/f_tables.h deleted file mode 100644 index db9cbb9..0000000 --- a/libdes/f_tables.h +++ /dev/null @@ -1,223 +0,0 @@ -/* - * Copyright (c) 1990 Dennis Ferguson. All rights reserved. - * - * Commercial use is permitted only if products which are derived from - * or include this software are made available for purchase and/or use - * in Canada. Otherwise, redistribution and use in source and binary - * forms are permitted. - */ - -/* - * des_tables.h - declarations to import the DES tables, used internally - * by some of the library routines. - */ -#ifndef __DES_TABLES_H__ -#define __DES_TABLES_H__ /* nothing */ - -/* - * These may be declared const if you wish. Be sure to change the - * declarations in des_tables.c as well. - */ -extern unsigned long des_IP_table[256]; -extern unsigned long des_FP_table[256]; -extern unsigned long des_SP_table[8][64]; - -/* - * Use standard shortforms to reference these to save typing - */ -#define IP des_IP_table -#define FP des_FP_table -#define SP des_SP_table - -/* - * Code to do a DES round using the tables. Note that the E expansion - * is easy to compute algorithmically, especially if done out-of-order. - * Take a look at its form and compare it to everything involving temp - * below. Since SP[0-7] don't have any bits in common set it is okay - * to do the successive xor's. - * - * Note too that the SP table has been reordered to match the order of - * the keys (if the original order of SP was 12345678, the reordered - * table is 71354682). This is unnecessary, but was done since some - * compilers seem to like you going through the matrix from beginning - * to end. - * - * There is a difference in the best way to do this depending on whether - * one is encrypting or decrypting. If encrypting we move forward through - * the keys and hence should move forward through the table. If decrypting - * we go back. Part of the need for this comes from trying to emulate - * existing software which generates a single key schedule and uses it - * both for encrypting and decrypting. Generating separate encryption - * and decryption key schedules would allow one to use the same code - * for both. - * - * left, right and temp should be unsigned long values. left and right - * should be the high and low order parts of the cipher block at the - * current stage of processing (this makes sense if you read the spec). - * kp should be an unsigned long pointer which points at the current - * set of subkeys in the key schedule. It is advanced to the next set - * (i.e. by 8 bytes) when this is done. - * - * This occurs in the innermost loop of the DES function. The four - * variables should really be in registers. - * - * When using this, the inner loop of the DES function might look like: - * - * for (i = 0; i < 8; i++) { - * DES_SP_{EN,DE}CRYPT_ROUND(left, right, temp, kp); - * DES_SP_{EN,DE}CRYPT_ROUND(right, left, temp, kp); - * } - * - * Note the trick above. You are supposed to do 16 rounds, swapping - * left and right at the end of each round. By doing two rounds at - * a time and swapping left and right in the code we can avoid the - * swaps altogether. - */ -#define DES_SP_ENCRYPT_ROUND(left, right, temp, kp) \ - (temp) = (((right) >> 11) | ((right) << 21)) ^ *(kp)++; \ - (left) ^= SP[0][((temp) >> 24) & 0x3f] \ - | SP[1][((temp) >> 16) & 0x3f] \ - | SP[2][((temp) >> 8) & 0x3f] \ - | SP[3][((temp) ) & 0x3f]; \ - (temp) = (((right) >> 23) | ((right) << 9)) ^ *(kp)++; \ - (left) ^= SP[4][((temp) >> 24) & 0x3f] \ - | SP[5][((temp) >> 16) & 0x3f] \ - | SP[6][((temp) >> 8) & 0x3f] \ - | SP[7][((temp) ) & 0x3f] - -#define DES_SP_DECRYPT_ROUND(left, right, temp, kp) \ - (temp) = (((right) >> 23) | ((right) << 9)) ^ *(--(kp)); \ - (left) ^= SP[7][((temp) ) & 0x3f] \ - | SP[6][((temp) >> 8) & 0x3f] \ - | SP[5][((temp) >> 16) & 0x3f] \ - | SP[4][((temp) >> 24) & 0x3f]; \ - (temp) = (((right) >> 11) | ((right) << 21)) ^ *(--(kp)); \ - (left) ^= SP[3][((temp) ) & 0x3f] \ - | SP[2][((temp) >> 8) & 0x3f] \ - | SP[1][((temp) >> 16) & 0x3f] \ - | SP[0][((temp) >> 24) & 0x3f] - -/* - * Macros to help deal with the initial permutation table. Note - * the IP table only deals with 32 bits at a time, allowing us to - * collect the bits we need to deal with each half into an unsigned - * long. By carefully selecting how the bits are ordered we also - * take advantages of symmetries in the table so that we can use a - * single table to compute the permutation of all bytes. This sounds - * complicated, but if you go through the process of designing the - * table you'll find the symmetries fall right out. - * - * The follow macros compute the set of bits used to index the - * table for produce the left and right permuted result. - */ -#define DES_IP_LEFT_BITS(left, right) \ - ((((left) & 0x55555555) << 1) | ((right) & 0x55555555)) -#define DES_IP_RIGHT_BITS(left, right) \ - (((left) & 0xaaaaaaaa) | (((right) & 0xaaaaaaaa) >> 1)) - -/* - * The following macro does an in-place initial permutation given - * the current left and right parts of the block and a single - * temporary. Use this more as a guide for rolling your own, though. - * The best way to do the IP depends on the form of the data you - * are dealing with. If you use this, though, try to make left, - * right and temp register unsigned longs. - */ -#define DES_INITIAL_PERM(left, right, temp) \ - (temp) = DES_IP_RIGHT_BITS((left), (right)); \ - (right) = DES_IP_LEFT_BITS((left), (right)); \ - (left) = IP[((right) >> 24) & 0xff] \ - | (IP[((right) >> 16) & 0xff] << 1) \ - | (IP[((right) >> 8) & 0xff] << 2) \ - | (IP[(right) & 0xff] << 3); \ - (right) = IP[((temp) >> 24) & 0xff] \ - | (IP[((temp) >> 16) & 0xff] << 1) \ - | (IP[((temp) >> 8) & 0xff] << 2) \ - | (IP[(temp) & 0xff] << 3) - - -/* - * Now the final permutation stuff. The same comments apply to - * this as to the initial permutation, except that we use different - * bits and shifts. - */ -#define DES_FP_LEFT_BITS(left, right) \ - ((((left) & 0x0f0f0f0f) << 4) | ((right) & 0x0f0f0f0f)) -#define DES_FP_RIGHT_BITS(left, right) \ - (((left) & 0xf0f0f0f0) | (((right) & 0xf0f0f0f0) >> 4)) - - -/* - * Here is a sample final permutation. Note that there is a trick - * here. DES requires swapping the left and right parts after the - * last cipher round but before the final permutation. We do this - * swapping internally, which is why left and right are confused - * at the beginning. - */ -#define DES_FINAL_PERM(left, right, temp) \ - (temp) = DES_FP_RIGHT_BITS((right), (left)); \ - (right) = DES_FP_LEFT_BITS((right), (left)); \ - (left) = (FP[((right) >> 24) & 0xff] << 6) \ - | (FP[((right) >> 16) & 0xff] << 4) \ - | (FP[((right) >> 8) & 0xff] << 2) \ - | FP[(right) & 0xff]; \ - (right) = (FP[((temp) >> 24) & 0xff] << 6) \ - | (FP[((temp) >> 16) & 0xff] << 4) \ - | (FP[((temp) >> 8) & 0xff] << 2) \ - | FP[temp & 0xff] - - -/* - * Finally, as a sample of how all this might be held together, the - * following two macros do in-place encryptions and decryptions. left - * and right are two unsigned long variables which at the beginning - * are expected to hold the clear (encrypted) block in host byte order - * (left the high order four bytes, right the low order). At the end - * they will contain the encrypted (clear) block. temp is an unsigned long - * used as a temporary. kp is an unsigned long pointer pointing at - * the start of the key schedule. All these should be in registers. - * - * You can probably do better than these by rewriting for particular - * situations. These aren't bad, though. - */ -#define DES_DO_ENCRYPT(left, right, temp, kp) \ - do { \ - register int i; \ - DES_INITIAL_PERM((left), (right), (temp)); \ - for (i = 0; i < 8; i++) { \ - DES_SP_ENCRYPT_ROUND((left), (right), (temp), (kp)); \ - DES_SP_ENCRYPT_ROUND((right), (left), (temp), (kp)); \ - } \ - DES_FINAL_PERM((left), (right), (temp)); \ - (kp) -= (2 * 16); \ - } while (0) - -#define DES_DO_DECRYPT(left, right, temp, kp) \ - do { \ - register int i; \ - DES_INITIAL_PERM((left), (right), (temp)); \ - (kp) += (2 * 16); \ - for (i = 0; i < 8; i++) { \ - DES_SP_DECRYPT_ROUND((left), (right), (temp), (kp)); \ - DES_SP_DECRYPT_ROUND((right), (left), (temp), (kp)); \ - } \ - DES_FINAL_PERM((left), (right), (temp)); \ - } while (0) - -/* - * These are handy dandy utility thingies for straightening out bytes. - * Included here because they're used a couple of places. - */ -#define GET_HALF_BLOCK(lr, ip) \ - (lr) = ((u_int32)(*(ip)++)) << 24; \ - (lr) |= ((u_int32)(*(ip)++)) << 16; \ - (lr) |= ((u_int32)(*(ip)++)) << 8; \ - (lr) |= (u_int32)(*(ip)++) - -#define PUT_HALF_BLOCK(lr, op) \ - *(op)++ = ((lr) >> 24) & 0xff; \ - *(op)++ = ((lr) >> 16) & 0xff; \ - *(op)++ = ((lr) >> 8) & 0xff; \ - *(op)++ = (lr) & 0xff - -#endif /* __DES_TABLES_H__ */ |