[unix-history] / usr / src / old / crypt / crypt.c

static char *sccsid = "@(#)crypt.c	4.2 (Berkeley) %G%";

/*
 *	A one-rotor machine designed along the lines of Enigma
 *	but considerably trivialized.
 */

#define ECHO 010
#include <stdio.h>
#define ROTORSZ 256
#define MASK 0377
char	t1[ROTORSZ];
char	t2[ROTORSZ];
char	t3[ROTORSZ];
char	deck[ROTORSZ];
char	*getpass();
char	buf[13];

setup(pw)
char *pw;
{
	int ic, i, k, temp, pf[2];
	unsigned random;
	long seed;

	strncpy(buf, pw, 8);
	while (*pw)
		*pw++ = '\0';
	buf[8] = buf[0];
	buf[9] = buf[1];
	pipe(pf);
	if (fork()==0) {
		close(0);
		close(1);
		dup(pf[0]);
		dup(pf[1]);
		execl("/usr/lib/makekey", "-", 0);
		execl("/lib/makekey", "-", 0);
		exit(1);
	}
	write(pf[1], buf, 10);
	wait((int *)NULL);
	if (read(pf[0], buf, 13) != 13) {
		fprintf(stderr, "crypt: cannot generate key\n");
		exit(1);
	}
	seed = 123;
	for (i=0; i<13; i++)
		seed = seed*buf[i] + i;
	for(i=0;i<ROTORSZ;i++) {
		t1[i] = i;
		deck[i] = i;
	}
	for(i=0;i<ROTORSZ;i++) {
		seed = 5*seed + buf[i%13];
		random = seed % 65521;
		k = ROTORSZ-1 - i;
		ic = (random&MASK)%(k+1);
		random >>= 8;
		temp = t1[k];
		t1[k] = t1[ic];
		t1[ic] = temp;
		if(t3[k]!=0) continue;
		ic = (random&MASK) % k;
		while(t3[ic]!=0) ic = (ic+1) % k;
		t3[k] = ic;
		t3[ic] = k;
	}
	for(i=0;i<ROTORSZ;i++)
		t2[t1[i]&MASK] = i;
}

main(argc, argv)
char *argv[];
{
	register i, n1, n2, nr1, nr2;
	int secureflg = 0;

	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 's') {
		argc--;
		argv++;
		secureflg = 1;
	}
	if (argc != 2){
		setup(getpass("Enter key:"));
	}
	else
		setup(argv[1]);
	n1 = 0;
	n2 = 0;
	nr2 = 0;

	while((i=getchar()) >=0) {
		if (secureflg) {
			nr1 = deck[n1]&MASK;
			nr2 = deck[nr1]&MASK;
		} else {
			nr1 = n1;
		}
		i = t2[(t3[(t1[(i+nr1)&MASK]+nr2)&MASK]-nr2)&MASK]-nr1;
		putchar(i);
		n1++;
		if(n1==ROTORSZ) {
			n1 = 0;
			n2++;
			if(n2==ROTORSZ) n2 = 0;
			if (secureflg) {
				shuffle(deck);
			} else {
				nr2 = n2;
			}
		}
	}
}

shuffle(deck)
	char deck[];
{
	int i, ic, k, temp;
	unsigned random;
	static long seed = 123;

	for(i=0;i<ROTORSZ;i++) {
		seed = 5*seed + buf[i%13];
		random = seed % 65521;
		k = ROTORSZ-1 - i;
		ic = (random&MASK)%(k+1);
		temp = deck[k];
		deck[k] = deck[ic];
		deck[ic] = temp;
	}
}
Commit	Line	Data
154b09ca KM	1	static char *sccsid = "@(#)crypt.c 4.2 (Berkeley) %G%";
154b09ca KM	2
eadbf085 BJ	3	/*
	4	* A one-rotor machine designed along the lines of Enigma
	5	* but considerably trivialized.
	6	*/
	7
	8	#define ECHO 010
	9	#include <stdio.h>
	10	#define ROTORSZ 256
	11	#define MASK 0377
	12	char t1[ROTORSZ];
	13	char t2[ROTORSZ];
	14	char t3[ROTORSZ];
154b09ca	15	char deck[ROTORSZ];
eadbf085	16	char *getpass();
154b09ca	17	char buf[13];
eadbf085 BJ	18
	19	setup(pw)
	20	char *pw;
	21	{
	22	int ic, i, k, temp, pf[2];
	23	unsigned random;
eadbf085 BJ	24	long seed;
	25
	26	strncpy(buf, pw, 8);
	27	while (*pw)
	28	*pw++ = '\0';
	29	buf[8] = buf[0];
	30	buf[9] = buf[1];
	31	pipe(pf);
	32	if (fork()==0) {
	33	close(0);
	34	close(1);
	35	dup(pf[0]);
	36	dup(pf[1]);
	37	execl("/usr/lib/makekey", "-", 0);
	38	execl("/lib/makekey", "-", 0);
	39	exit(1);
	40	}
	41	write(pf[1], buf, 10);
	42	wait((int *)NULL);
	43	if (read(pf[0], buf, 13) != 13) {
	44	fprintf(stderr, "crypt: cannot generate key\n");
	45	exit(1);
	46	}
	47	seed = 123;
	48	for (i=0; i<13; i++)
	49	seed = seed*buf[i] + i;
154b09ca	50	for(i=0;i<ROTORSZ;i++) {
eadbf085	51	t1[i] = i;
154b09ca KM	52	deck[i] = i;
154b09ca KM	53	}
eadbf085 BJ	54	for(i=0;i<ROTORSZ;i++) {
	55	seed = 5*seed + buf[i%13];
	56	random = seed % 65521;
	57	k = ROTORSZ-1 - i;
	58	ic = (random&MASK)%(k+1);
	59	random >>= 8;
	60	temp = t1[k];
	61	t1[k] = t1[ic];
	62	t1[ic] = temp;
	63	if(t3[k]!=0) continue;
	64	ic = (random&MASK) % k;
	65	while(t3[ic]!=0) ic = (ic+1) % k;
	66	t3[k] = ic;
	67	t3[ic] = k;
	68	}
	69	for(i=0;i<ROTORSZ;i++)
	70	t2[t1[i]&MASK] = i;
	71	}
	72
	73	main(argc, argv)
	74	char *argv[];
	75	{
154b09ca KM	76	register i, n1, n2, nr1, nr2;
154b09ca KM	77	int secureflg = 0;
eadbf085	78
154b09ca KM	79	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 's') {
	80	argc--;
	81	argv++;
	82	secureflg = 1;
	83	}
eadbf085 BJ	84	if (argc != 2){
	85	setup(getpass("Enter key:"));
	86	}
	87	else
	88	setup(argv[1]);
	89	n1 = 0;
	90	n2 = 0;
154b09ca	91	nr2 = 0;
eadbf085 BJ	92
eadbf085 BJ	93	while((i=getchar()) >=0) {
154b09ca KM	94	if (secureflg) {
	95	nr1 = deck[n1]&MASK;
	96	nr2 = deck[nr1]&MASK;
	97	} else {
	98	nr1 = n1;
	99	}
	100	i = t2[(t3[(t1[(i+nr1)&MASK]+nr2)&MASK]-nr2)&MASK]-nr1;
eadbf085 BJ	101	putchar(i);
	102	n1++;
	103	if(n1==ROTORSZ) {
	104	n1 = 0;
	105	n2++;
	106	if(n2==ROTORSZ) n2 = 0;
154b09ca KM	107	if (secureflg) {
	108	shuffle(deck);
	109	} else {
	110	nr2 = n2;
	111	}
eadbf085 BJ	112	}
	113	}
	114	}
154b09ca KM	115
	116	shuffle(deck)
	117	char deck[];
	118	{
	119	int i, ic, k, temp;
	120	unsigned random;
	121	static long seed = 123;
	122
	123	for(i=0;i<ROTORSZ;i++) {
	124	seed = 5*seed + buf[i%13];
	125	random = seed % 65521;
	126	k = ROTORSZ-1 - i;
	127	ic = (random&MASK)%(k+1);
	128	temp = deck[k];
	129	deck[k] = deck[ic];
	130	deck[ic] = temp;
	131	}
	132	}