D:/opendownloadmanager/ODM-1.x/FDMCustomized/FDMCustomized_lib/libdes/set

00001 /* set_key.c */
00002 /* Copyright (C) 1995 Eric Young (eay@mincom.oz.au).
00003  * All rights reserved.
00004  * Copyright remains Eric Young's, and as such any Copyright notices in
00005  * the code are not to be removed.
00006  * See the COPYRIGHT file in the libdes distribution for more details.
00007  */
00008 
00009 /* set_key.c v 1.4 eay 24/9/91
00010  * 1.4 Speed up by 400% :-)
00011  * 1.3 added register declarations.
00012  * 1.2 unrolled make_key_sched a bit more
00013  * 1.1 added norm_expand_bits
00014  * 1.0 First working version
00015  */
00016 
00017 #ifdef _MSC_VER
00018   #include "des_locl.h"
00019   #include "podd.h"
00020   #include "sk.h"
00021 #else
00022   #include "libdes/des_locl.h"
00023   #include "libdes/podd.h"
00024   #include "libdes/sk.h"
00025 #endif /* _MSC_VER */
00026 
00027 static int check_parity(des_cblock *key);
00028 
00029 int des_check_key=0;
00030 
00031 void des_set_odd_parity(key)
00032 des_cblock *key;
00033         {
00034         int i;
00035 
00036         for (i=0; i<DES_KEY_SZ; i++)
00037                 (*key)[i]=odd_parity[(*key)[i]];
00038         }
00039 
00040 static int check_parity(key)
00041 des_cblock *key;
00042         {
00043         int i;
00044 
00045         for (i=0; i<DES_KEY_SZ; i++)
00046                 {
00047                 if ((*key)[i] != odd_parity[(*key)[i]])
00048                         return(0);
00049                 }
00050         return(1);
00051         }
00052 
00053 /* Weak and semi week keys as take from
00054  * %A D.W. Davies
00055  * %A W.L. Price
00056  * %T Security for Computer Networks
00057  * %I John Wiley & Sons
00058  * %D 1984
00059  * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
00060  * (and actual cblock values).
00061  */
00062 #define NUM_WEAK_KEY    16
00063 static des_cblock weak_keys[NUM_WEAK_KEY]={
00064         /* weak keys */
00065         0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
00066         0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,
00067         0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,
00068         0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,
00069         /* semi-weak keys */
00070         0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,
00071         0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,
00072         0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1,
00073         0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E,
00074         0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,
00075         0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01,
00076         0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE,
00077         0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,
00078         0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,
00079         0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01,
00080         0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE,
00081         0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1};
00082 
00083 int des_is_weak_key(key)
00084 des_cblock *key;
00085         {
00086         int i;
00087 
00088         for (i=0; i<NUM_WEAK_KEY; i++)
00089                 /* Added == 0 to comparision, I obviously don't run
00090                  * this section very often :-(, thanks to
00091                  * engineering@MorningStar.Com for the fix
00092                  * eay 93/06/29 */
00093                 if (memcmp(weak_keys[i],key,sizeof(key)) == 0) return(1);
00094         return(0);
00095         }
00096 
00097 /* NOW DEFINED IN des_local.h
00098  * See ecb_encrypt.c for a pseudo description of these macros. 
00099  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
00100  *      (b)^=(t),\
00101  *      (a)=((a)^((t)<<(n))))
00102  */
00103 
00104 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
00105         (a)=(a)^(t)^(t>>(16-(n))))
00106 
00107 static char shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
00108 
00109 /* return 0 if key parity is odd (correct),
00110  * return -1 if key parity error,
00111  * return -2 if illegal weak key.
00112  */
00113 int des_set_key(key,schedule)
00114 des_cblock *key;
00115 des_key_schedule schedule;
00116         {
00117         register unsigned long c,d,t,s;
00118         register unsigned char *in;
00119         register unsigned long *k;
00120         register int i;
00121 
00122         if (des_check_key)
00123                 {
00124                 if (!check_parity(key))
00125                         return(-1);
00126 
00127                 if (des_is_weak_key(key))
00128                         return(-2);
00129                 }
00130 
00131         k=(unsigned long *)schedule;
00132         in=(unsigned char *)key;
00133 
00134         c2l(in,c);
00135         c2l(in,d);
00136 
00137         /* do PC1 in 60 simple operations */ 
00138 /*      PERM_OP(d,c,t,4,0x0f0f0f0f);
00139         HPERM_OP(c,t,-2, 0xcccc0000);
00140         HPERM_OP(c,t,-1, 0xaaaa0000);
00141         HPERM_OP(c,t, 8, 0x00ff0000);
00142         HPERM_OP(c,t,-1, 0xaaaa0000);
00143         HPERM_OP(d,t,-8, 0xff000000);
00144         HPERM_OP(d,t, 8, 0x00ff0000);
00145         HPERM_OP(d,t, 2, 0x33330000);
00146         d=((d&0x00aa00aa)<<7)|((d&0x55005500)>>7)|(d&0xaa55aa55);
00147         d=(d>>8)|((c&0xf0000000)>>4);
00148         c&=0x0fffffff; */
00149 
00150         /* I now do it in 47 simple operations :-)
00151          * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
00152          * for the inspiration. :-) */
00153         PERM_OP (d,c,t,4,0x0f0f0f0fL);
00154         HPERM_OP(c,t,-2,0xcccc0000L);
00155         HPERM_OP(d,t,-2,0xcccc0000L);
00156         PERM_OP (d,c,t,1,0x55555555L);
00157         PERM_OP (c,d,t,8,0x00ff00ffL);
00158         PERM_OP (d,c,t,1,0x55555555L);
00159         d=      (((d&0x000000ffL)<<16)| (d&0x0000ff00L)     |
00160                  ((d&0x00ff0000L)>>16)|((c&0xf0000000L)>>4));
00161         c&=0x0fffffffL;
00162 
00163         for (i=0; i<ITERATIONS; i++)
00164                 {
00165                 if (shifts2[i])
00166                         { c=((c>>2)|(c<<26)); d=((d>>2)|(d<<26)); }
00167                 else
00168                         { c=((c>>1)|(c<<27)); d=((d>>1)|(d<<27)); }
00169                 c&=0x0fffffffL;
00170                 d&=0x0fffffffL;
00171                 /* could be a few less shifts but I am to lazy at this
00172                  * point in time to investigate */
00173                 s=      des_skb[0][ (c    )&0x3f                ]|
00174                         des_skb[1][((c>> 6)&0x03)|((c>> 7)&0x3c)]|
00175                         des_skb[2][((c>>13)&0x0f)|((c>>14)&0x30)]|
00176                         des_skb[3][((c>>20)&0x01)|((c>>21)&0x06) |
00177                                                   ((c>>22)&0x38)];
00178                 t=      des_skb[4][ (d    )&0x3f                ]|
00179                         des_skb[5][((d>> 7)&0x03)|((d>> 8)&0x3c)]|
00180                         des_skb[6][ (d>>15)&0x3f                ]|
00181                         des_skb[7][((d>>21)&0x0f)|((d>>22)&0x30)];
00182 
00183                 /* table contained 0213 4657 */
00184                 *(k++)=((t<<16)|(s&0x0000ffffL))&0xffffffffL;
00185                 s=     ((s>>16)|(t&0xffff0000L));
00186 
00187                 s=(s<<4)|(s>>28);
00188                 *(k++)=s&0xffffffffL;
00189                 }
00190         return(0);
00191         }
00192 
00193 int des_key_sched(key,schedule)
00194 des_cblock *key;
00195 des_key_schedule schedule;
00196         {
00197         return(des_set_key(key,schedule));
00198         }
D:/opendownloadmanager/ODM-1.x/FDMCustomized/FDMCustomized_lib/libdes/set_key.c
