add -s flag for increased security

SCCS-vsn: old/crypt/crypt.c 4.2

diff --git a/usr/src/old/crypt/crypt.c b/usr/src/old/crypt/crypt.c
index b2656b5..ff65632 100644 (file)
--- a/usr/src/old/crypt/crypt.c
+++ b/usr/src/old/crypt/crypt.c
@@ -1,4 +1,5 @@
-static char *sccsid = "@(#)crypt.c     4.1 (Berkeley) %G%";
+static char *sccsid = "@(#)crypt.c     4.2 (Berkeley) %G%";
+

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


@@ -11,14 +12,15 @@ static char *sccsid = "@(#)crypt.c  4.1 (Berkeley) %G%";
 char   t1[ROTORSZ];
 char   t2[ROTORSZ];
 char   t3[ROTORSZ];
 char   t1[ROTORSZ];
 char   t2[ROTORSZ];
 char   t3[ROTORSZ];

+char   deck[ROTORSZ];

 char   *getpass();
 char   *getpass();

+char   buf[13];

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

-       char buf[13];

        long seed;
 
        strncpy(buf, pw, 8);
        long seed;
 
        strncpy(buf, pw, 8);


@@ -45,8 +47,10 @@ char *pw;
        seed = 123;
        for (i=0; i<13; i++)
                seed = seed*buf[i] + i;
        seed = 123;
        for (i=0; i<13; i++)
                seed = seed*buf[i] + i;

-       for(i=0;i<ROTORSZ;i++)
+       for(i=0;i<ROTORSZ;i++) {

                t1[i] = i;
                t1[i] = i;

+               deck[i] = i;
+       }

        for(i=0;i<ROTORSZ;i++) {
                seed = 5*seed + buf[i%13];
                random = seed % 65521;
        for(i=0;i<ROTORSZ;i++) {
                seed = 5*seed + buf[i%13];
                random = seed % 65521;


@@ -69,8 +73,14 @@ char *pw;
 main(argc, argv)
 char *argv[];
 {
 main(argc, argv)
 char *argv[];
 {

-       register i, n1, n2;
+       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:"));
        }
        if (argc != 2){
                setup(getpass("Enter key:"));
        }


@@ -78,15 +88,45 @@ char *argv[];
                setup(argv[1]);
        n1 = 0;
        n2 = 0;
                setup(argv[1]);
        n1 = 0;
        n2 = 0;

+       nr2 = 0;

 
        while((i=getchar()) >=0) {
 
        while((i=getchar()) >=0) {

-               i = t2[(t3[(t1[(i+n1)&MASK]+n2)&MASK]-n2)&MASK]-n1;
+               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;
                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;
+       }
+}