Enigma

C:\Documents and Settings\Administrator\My Documents\DLS\enigma.c

/* * * * * * * * */

Monday, November 30, 2009 5:00 PM

"enigma.c" is in file cbw.tar from anonymous FTP host watmsg.waterloo.edu: pub/crypt/cbw.tar.Z A one-rotor machine designed along the lines of Enigma but considerably trivialized. A public-domain replacement for the UNIX "crypt" command.

#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
C:\Documents and Settings\Administrator\My Documents\DLS\enigma.c

Monday, November 30, 2009 5:00 PM

t1[i] = i; deck[i] = i; } for(i=0;i>= 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 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) { -2-

C:\Documents and Settings\Administrator\My Documents\DLS\enigma.c

Monday, November 30, 2009 5:00 PM

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
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