+
+/*
+ * Encryption routines. These are essentially unmodified from ed.
+ */
+
+#ifdef CRYPT
+/*
+ * crblock: encrypt/decrypt a block of text.
+ * buf is the buffer through which the text is both input and
+ * output. nchar is the size of the buffer. permp is a work
+ * buffer, and startn is the beginning of a sequence.
+ */
+crblock(permp, buf, nchar, startn)
+char *permp;
+char *buf;
+int nchar;
+long startn;
+{
+ register char *p1;
+ int n1;
+ int n2;
+ register char *t1, *t2, *t3;
+
+ t1 = permp;
+ t2 = &permp[256];
+ t3 = &permp[512];
+
+ n1 = startn&0377;
+ n2 = (startn>>8)&0377;
+ p1 = buf;
+ while(nchar--) {
+ *p1 = t2[(t3[(t1[(*p1+n1)&0377]+n2)&0377]-n2)&0377]-n1;
+ n1++;
+ if(n1==256){
+ n1 = 0;
+ n2++;
+ if(n2==256) n2 = 0;
+ }
+ p1++;
+ }
+}
+
+/*
+ * makekey: initialize buffers based on user key a.
+ */
+makekey(a, b)
+char *a, *b;
+{
+ register int i;
+ long t;
+ char temp[KSIZE + 1];
+
+ for(i = 0; i < KSIZE; i++)
+ temp[i] = *a++;
+ time(&t);
+ t += getpid();
+ for(i = 0; i < 4; i++)
+ temp[i] ^= (t>>(8*i))&0377;
+ crinit(temp, b);
+}
+
+/*
+ * crinit: besides initializing the encryption machine, this routine
+ * returns 0 if the key is null, and 1 if it is non-null.
+ */
+crinit(keyp, permp)
+char *keyp, *permp;
+{
+ register char *t1, *t2, *t3;
+ register i;
+ int ic, k, temp;
+ unsigned random;
+ char buf[13];
+ long seed;
+
+ t1 = permp;
+ t2 = &permp[256];
+ t3 = &permp[512];
+ if(*keyp == 0)
+ return(0);
+ strncpy(buf, keyp, 8);
+ while (*keyp)
+ *keyp++ = '\0';
+
+ buf[8] = buf[0];
+ buf[9] = buf[1];
+ domakekey(buf);
+
+ seed = 123;
+ for (i=0; i<13; i++)
+ seed = seed*buf[i] + i;
+ for(i=0;i<256;i++){
+ t1[i] = i;
+ t3[i] = 0;
+ }
+ for(i=0; i<256; i++) {
+ seed = 5*seed + buf[i%13];
+ random = seed % 65521;
+ k = 256-1 - i;
+ ic = (random&0377) % (k+1);
+ random >>= 8;
+ temp = t1[k];
+ t1[k] = t1[ic];
+ t1[ic] = temp;
+ if(t3[k]!=0) continue;
+ ic = (random&0377) % k;
+ while(t3[ic]!=0) ic = (ic+1) % k;
+ t3[k] = ic;
+ t3[ic] = k;
+ }
+ for(i=0; i<256; i++)
+ t2[t1[i]&0377] = i;
+ return(1);
+}
+
+/*
+ * domakekey: the following is the major nonportable part of the encryption
+ * mechanism. A 10 character key is supplied in buffer.
+ * This string is fed to makekey (an external program) which
+ * responds with a 13 character result. This result is placed
+ * in buffer.
+ */
+domakekey(buffer)
+char *buffer;
+{
+ int pf[2];
+
+ if (pipe(pf)<0)
+ pf[0] = pf[1] = -1;
+ 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], buffer, 10);
+ if (wait((int *)NULL)==-1 || read(pf[0], buffer, 13)!=13)
+ error("crypt: cannot generate key");
+ close(pf[0]);
+ close(pf[1]);
+ /* end of nonportable part */
+}
+#endif
projects / unix-history / blobdiff