Commit | Line | Data |
---|---|---|
9c79dca0 BJ |
1 | /* |
2 | * A one-rotor machine designed along the lines of Enigma | |
3 | * but considerably trivialized. | |
4 | */ | |
5 | ||
6 | #define ECHO 010 | |
7 | #include <stdio.h> | |
8 | #define ROTORSZ 256 | |
9 | #define MASK 0377 | |
10 | char t1[ROTORSZ]; | |
11 | char t2[ROTORSZ]; | |
12 | char t3[ROTORSZ]; | |
13 | char *getpass(); | |
14 | ||
15 | setup(pw) | |
16 | char *pw; | |
17 | { | |
18 | int ic, i, k, temp, pf[2]; | |
19 | unsigned random; | |
20 | char buf[13]; | |
21 | long seed; | |
22 | ||
23 | strncpy(buf, pw, 8); | |
24 | while (*pw) | |
25 | *pw++ = '\0'; | |
26 | buf[8] = buf[0]; | |
27 | buf[9] = buf[1]; | |
28 | pipe(pf); | |
29 | if (fork()==0) { | |
30 | close(0); | |
31 | close(1); | |
32 | dup(pf[0]); | |
33 | dup(pf[1]); | |
34 | execl("/usr/lib/makekey", "-", 0); | |
35 | execl("/lib/makekey", "-", 0); | |
36 | exit(1); | |
37 | } | |
38 | write(pf[1], buf, 10); | |
39 | wait((int *)NULL); | |
40 | if (read(pf[0], buf, 13) != 13) { | |
41 | fprintf(stderr, "crypt: cannot generate key\n"); | |
42 | exit(1); | |
43 | } | |
44 | seed = 123; | |
45 | for (i=0; i<13; i++) | |
46 | seed = seed*buf[i] + i; | |
47 | for(i=0;i<ROTORSZ;i++) | |
48 | t1[i] = i; | |
49 | for(i=0;i<ROTORSZ;i++) { | |
50 | seed = 5*seed + buf[i%13]; | |
51 | random = seed % 65521; | |
52 | k = ROTORSZ-1 - i; | |
53 | ic = (random&MASK)%(k+1); | |
54 | random >>= 8; | |
55 | temp = t1[k]; | |
56 | t1[k] = t1[ic]; | |
57 | t1[ic] = temp; | |
58 | if(t3[k]!=0) continue; | |
59 | ic = (random&MASK) % k; | |
60 | while(t3[ic]!=0) ic = (ic+1) % k; | |
61 | t3[k] = ic; | |
62 | t3[ic] = k; | |
63 | } | |
64 | for(i=0;i<ROTORSZ;i++) | |
65 | t2[t1[i]&MASK] = i; | |
66 | } | |
67 | ||
68 | main(argc, argv) | |
69 | char *argv[]; | |
70 | { | |
71 | register i, n1, n2; | |
72 | ||
73 | if (argc != 2){ | |
74 | setup(getpass("Enter key:")); | |
75 | } | |
76 | else | |
77 | setup(argv[1]); | |
78 | n1 = 0; | |
79 | n2 = 0; | |
80 | ||
81 | while((i=getchar()) >=0) { | |
82 | i = t2[(t3[(t1[(i+n1)&MASK]+n2)&MASK]-n2)&MASK]-n1; | |
83 | putchar(i); | |
84 | n1++; | |
85 | if(n1==ROTORSZ) { | |
86 | n1 = 0; | |
87 | n2++; | |
88 | if(n2==ROTORSZ) n2 = 0; | |
89 | } | |
90 | } | |
91 | } |