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1.1 root 1: /*
2: * $Source: /mit/kerberos/src/lib/des/RCS/random_key.c,v $
3: * $Author: jtkohl $
4: *
5: * Copyright 1988 by the Massachusetts Institute of Technology.
6: *
7: * For copying and distribution information, please see the file
8: * <mit-copyright.h>.
9: *
10: * These routines perform encryption and decryption using the DES
11: * private key algorithm, or else a subset of it-- fewer inner loops.
12: * ( AUTH_DES_ITER defaults to 16, may be less)
13: *
14: * Under U.S. law, this software may not be exported outside the US
15: * without license from the U.S. Commerce department.
16: *
17: * The key schedule is passed as an arg, as well as the cleartext or
18: * ciphertext. The cleartext and ciphertext should be in host order.
19: *
20: * These routines form the library interface to the des facilities.
21: *
22: * spm 8/85 MIT project athena
23: */
24:
25: #ifndef lint
26: static char rcsid_random_key_c[] =
27: "$Header: random_key.c,v 4.8 89/01/21 16:50:39 jtkohl Exp $";
28: #endif lint
29:
30: #include <mit-copyright.h>
31: #include <stdio.h>
32:
33: #include <des.h>
34: #include "des_internal.h"
35:
36: #ifdef BSDUNIX
37: #include <sys/time.h>
38: #endif
39:
40: extern int des_debug;
41: extern int des_debug_print();
42:
43: /* random_key */
44: int
45: des_random_key(key)
46: des_cblock *key;
47: {
48: /*
49: * create a random des key; should force odd parity per byte;
50: * parity is bits 8,16,...64 in des order, implies 0, 8, 16, ...
51: * vax order
52: */
53:
54: register unsigned int temp;
55: register int odd;
56: register unsigned char *c = (unsigned char *) key;
57: unsigned long *k = (unsigned long *) key;
58: static long p = 0;
59: static long n = 0;
60: long gethostid(), random();
61:
62: int i,j;
63:
64: #ifdef BSDUNIX
65: static struct timeval time;
66:
67: if (!p) {
68: p = getpid();
69: p ^= gethostid();
70: }
71:
72: (void) gettimeofday(&time,(struct timezone *)0);
73: /* randomize start */
74: srandom(time.tv_usec ^ time.tv_sec ^ p ^ n++);
75:
76: *k++ = random();
77: *k = random();
78:
79: /* make each byte parity odd */
80: for (i = 0; i <= 7; i++) {
81: odd = 0;
82: temp = (unsigned int) *c;
83: /* ignore bit 0, lsb, it will be parity (on vax) */
84: /* should do this with a table lookup */
85: for (j = 0; j <= 6; j++) {
86: temp = temp >> 1;
87: odd ^= temp & 01;
88: }
89: /* set odd parity in lsb */
90: if (!odd)
91: *c |= 1;
92: else
93: *c &= ~1;
94: c++;
95: }
96:
97: /* **** */
98: #else
99: dont know how to do random numbers for this machine;
100: #endif
101:
102: return 0;
103: }
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