1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */ 2 /* lib/crypto/builtin/des/key_sched.c */ 3 /* 4 * Copyright 1985, 1986, 1987, 1988, 1990 by the Massachusetts Institute 5 * of Technology. 6 * All Rights Reserved. 7 * 8 * Export of this software from the United States of America may 9 * require a specific license from the United States Government. 10 * It is the responsibility of any person or organization contemplating 11 * export to obtain such a license before exporting. 12 * 13 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 14 * distribute this software and its documentation for any purpose and 15 * without fee is hereby granted, provided that the above copyright 16 * notice appear in all copies and that both that copyright notice and 17 * this permission notice appear in supporting documentation, and that 18 * the name of M.I.T. not be used in advertising or publicity pertaining 19 * to distribution of the software without specific, written prior 20 * permission. Furthermore if you modify this software you must label 21 * your software as modified software and not distribute it in such a 22 * fashion that it might be confused with the original M.I.T. software. 23 * M.I.T. makes no representations about the suitability of 24 * this software for any purpose. It is provided "as is" without express 25 * or implied warranty. 26 */ 27 28 /* 29 * This routine computes the DES key schedule given a key. The 30 * permutations and shifts have been done at compile time, resulting 31 * in a direct one-step mapping from the input key to the key 32 * schedule. 33 * 34 * Also checks parity and weak keys. 35 * 36 * Watch out for the subscripts -- most effectively start at 1 instead 37 * of at zero. Maybe some bugs in that area. 38 * 39 * In case the user wants to cache the computed key schedule, it is 40 * passed as an arg. Also implies that caller has explicit control 41 * over zeroing both the key schedule and the key. 42 * 43 * Originally written 6/85 by Steve Miller, MIT Project Athena. 44 */ 45 46 #include "crypto_int.h" 47 #include "des_int.h" 48 49 #ifdef K5_BUILTIN_DES 50 51 int 52 mit_des_key_sched(mit_des_cblock k, mit_des_key_schedule schedule) 53 { 54 mit_des_make_key_sched(k,schedule); 55 56 if (!mit_des_check_key_parity(k)) /* bad parity --> return -1 */ 57 return(-1); 58 59 if (mit_des_is_weak_key(k)) 60 return(-2); 61 62 /* if key was good, return 0 */ 63 return 0; 64 } 65 66 #endif /* K5_BUILTIN_DES */ 67