/* * encryption service routines */ #include <stdio.h> /* encryption parameters and tables */ #define ROTORSZ 256 #define MASK 0377 static char t1[ROTORSZ]; static char t2[ROTORSZ]; static char t3[ROTORSZ]; static char t4[ROTORSZ]; /* current rotor settings */ static int N1, N2; resetN12() { N1 = N2 = 0; } setup(pw) char *pw; { int ic, i, k, temp, pf[2]; unsigned random; char buf[13]; long seed; int pid; resetN12(); strncpy(buf, pw, 8); while (*pw) *pw++ = '\0'; buf[8] = buf[0]; buf[9] = buf[1]; pipe(pf); switch (pid = fork()) { case -1: fprintf (stderr, "seal: cannot fork\n"); exit (1); case 0: close(0); close(1); dup(pf[0]); dup(pf[1]); execl("/usr/lib/makekey", "-", 0); execl("/lib/makekey", "-", 0); exit(1); default: write(pf[1], buf, 10); while (wait ((int *) NULL) != pid) ; } if (read(pf[0], buf, 13) != 13) { fprintf(stderr, "seal: 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; 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; t4[i] = (t1[i] + t3[i]) & 0377; } } mangle (buf, limit) char *buf; register char *limit; { register int i; register char *p; register int n1 = N1, n2 = N2; int n3; p = buf; while(p < limit) { i = *p; n3 = t4[n1]; i = t2[(t3[(t1[(i+n3)&MASK]+n2)&MASK]-n2)&MASK]-n3; *p++ = i; n1++; if(n1==ROTORSZ) { n1 = 0; n2++; if(n2==ROTORSZ) n2 = 0; } } N1 = n1; N2 = n2; }