--- src/rm.c.orig	Sat Nov 23 23:11:12 1996
+++ src/rm.c	Sun Jan 24 13:37:20 1999
@@ -1,3 +1,10 @@
+/*  patch for rm from fileutils-3.16 to support secure data deletion
+ *  to be activated by -s. -sss gives full erasure security (38 overwrites)
+ *  This patch is from the secure_delete-2.0.tar.gz package available
+ *  at http://www.thehackerschoice.com - get it, and read the documentation!
+ *  (c)1999 by van Hauser / [THC] - The Hacker's Choice, vh@reptile.rug.ac.be
+ */
+
 /* `rm' file deletion utility for GNU.
    Copyright (C) 88, 90, 91, 94, 95, 1996 Free Software Foundation, Inc.
 
@@ -21,6 +28,11 @@
 #include <stdio.h>
 #include <getopt.h>
 #include <sys/types.h>
+/* SRM BEGIN */
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdlib.h>
+/* SRM END */
 
 #include "system.h"
 #include "error.h"
@@ -50,6 +62,14 @@
 int yesno ();
 void strip_trailing_slashes ();
 
+/* SRM BEGIN */
+#define BLOCKSIZE	32769
+#define DIR_SEPERATOR	'/'
+#define FLUSH		sync()
+#define RANDOM_DEVICE	"/dev/urandom"
+/* SRM END */
+
+static int secure_delete ();
 static int clear_directory __P ((struct stat *statp));
 static int duplicate_entry __P ((struct pathstack *stack, ino_t inum));
 static int remove_dir __P ((struct stat *statp));
@@ -68,6 +88,12 @@
 /* Path of file now being processed; extended as necessary.  */
 static char *pathname;
 
+/* SRM BEGIN */
+static int secure;	/* secure overwrite mode */
+static char fillbuf[BLOCKSIZE];
+static FILE *devrandom;
+/* SRM END */
+
 /* Number of bytes currently allocated for `pathname';
    made larger when necessary, but never smaller.  */
 static int pnsize;
@@ -104,6 +130,9 @@
   {"force", no_argument, NULL, 'f'},
   {"interactive", no_argument, NULL, 'i'},
   {"recursive", no_argument, &recursive, 1},
+/* SRM BEGIN */
+  {"secure_delete", no_argument, NULL, 's'},
+/* SRM END */
   {"verbose", no_argument, &verbose, 1},
   {"help", no_argument, &show_help, 1},
   {"version", no_argument, &show_version, 1},
@@ -125,8 +154,8 @@
     = unlink_dirs = 0;
   pnsize = 256;
   pathname = xmalloc (pnsize);
-
-  while ((c = getopt_long (argc, argv, "dfirvR", long_opts, (int *) 0)) != EOF)
+  
+  while ((c = getopt_long (argc, argv, "dfirsvR", long_opts, (int *) 0)) != EOF)
     {
       switch (c)
 	{
@@ -147,6 +176,11 @@
 	case 'R':
 	  recursive = 1;
 	  break;
+/* SRM BEGIN */
+        case 's':
+          secure++;
+          break;
+/* SRM END */
 	case 'v':
 	  verbose = 1;
 	  break;
@@ -198,6 +232,116 @@
   exit (err > 0);
 }
 
+/* SRM BEGIN */
+
+void fill_buf(char pattern[3]) {
+    int loop;
+    int where;
+    for (loop = 0; loop < (BLOCKSIZE / 3); loop++) {
+        where = loop * 3;
+        fillbuf[where] = pattern[0];
+        fillbuf[where+1] = pattern[1];
+        fillbuf[where+2] = pattern[2];
+    }
+}
+void random_buf() {
+    int loop;
+    if (devrandom != NULL)
+        for (loop = 0; loop < BLOCKSIZE; loop++)
+            fillbuf[loop] = (unsigned char) (256.0*rand()/(RAND_MAX+1.0));
+    else
+        fread(&fillbuf, BLOCKSIZE, 1, devrandom);
+}
+
+/* overwriting the file several times */
+
+ static int
+ secure_delete (delfile)
+       char *delfile;
+ {
+    unsigned char write_modes[27][3] = {
+	{"\x55\x55\x55"}, {"\xaa\xaa\xaa"}, {"\x92\x49\x24"}, {"\x49\x24\x92"},
+	{"\x24\x92\x49"}, {"\x00\x00\x00"}, {"\x11\x11\x11"}, {"\x22\x22\x22"},
+	{"\x33\x33\x33"}, {"\x44\x44\x44"}, {"\x55\x55\x55"}, {"\x66\x66\x66"},
+	{"\x77\x77\x77"}, {"\x88\x88\x88"}, {"\x99\x99\x99"}, {"\xaa\xaa\xaa"},
+	{"\xbb\xbb\xbb"}, {"\xcc\xcc\xcc"}, {"\xdd\xdd\xdd"}, {"\xee\xee\xee"},
+	{"\xff\xff\xff"}, {"\x92\x49\x24"}, {"\x49\x24\x92"}, {"\x24\x92\x49"},
+	{"\x6d\xb6\xdb"}, {"\xb6\xdb\x6d"}, {"\xdb\x6d\xb6"}
+    };
+     unsigned char std_array[3] = "\xff\xff\xff";
+     FILE *f;
+     int file;
+     unsigned long writes;
+     unsigned long counter;
+     unsigned long filesize;
+     struct stat filestat;
+     int turn;
+     int result;
+     unsigned char ch;
+     char newname[512];
+
+/* open the file, get the filesize, calculate the numbers of needed writings */
+    if (lstat(delfile, &filestat))
+        return 1;
+    if (! S_ISREG(filestat.st_mode))
+        return 1;
+    if ((f = fopen(delfile, "r+b")) == NULL)
+        return 1;
+    filesize = filestat.st_size;
+    writes = (1 + (filesize / BLOCKSIZE));
+    file=fileno(f);
+    (void) setvbuf(stdout, NULL, _IONBF, 0);
+    devrandom = fopen(RANDOM_DEVICE, "r");
+
+    if (verbose)
+        printf(" ");
+
+
+    if (secure > 1) {
+        fill_buf(std_array);
+        for (counter=1; counter<=writes; counter++)
+            fwrite(&fillbuf, 1, BLOCKSIZE, f);
+        if (verbose)
+            printf("*");
+        fflush(f);
+        fsync(file);
+    }
+
+/* do the overwriting stuff */
+        for (turn=0; turn<=36; turn++) {
+            rewind(f);
+            if ((secure < 3) && (turn > 0)) break;
+            if ((turn>=5) && (turn<=31)) {
+	       fill_buf(write_modes[turn-5]);
+               for (counter=1; counter<=writes; counter++)
+                   fwrite(&fillbuf, 1, BLOCKSIZE, f);
+            } else {
+               for (counter=1; counter<=writes; counter++) {
+                  random_buf();
+                  fwrite(&fillbuf, 1, BLOCKSIZE, f);
+               }
+            }
+            fflush(f);
+            if (fsync(file) < 0)
+		FLUSH;
+            if (verbose)
+                printf("*");
+        }
+    (void) fclose(f);
+    (void) fclose(devrandom);
+/* Hard Flush -> Force cached data to be written to disk */
+    FLUSH;
+/* open + truncating the file, so an attacker doesn't know the diskblocks */
+   if ((file = open(delfile, O_WRONLY | O_TRUNC)) >= 0)
+       close(file);
+   if (verbose)
+       printf(" wiped\n");
+   return 0;
+}
+
+/* SRM END */
+
 /* Remove file or directory `pathname' after checking appropriate things.
    Return 0 if `pathname' is removed, 1 if not.  */
 
@@ -264,8 +408,16 @@
 	return 1;
     }
 
-  if (verbose)
-    printf ("%s\n", pathname);
+  if (verbose) {
+    printf ("%s", pathname);
+    if (secure == 0)
+        printf ("\n");
+  }
+      
+/* SRM BEGIN */
+  if (secure)
+    secure_delete(pathname);
+/* SRM END */
 
   if (unlink (pathname) && (errno != ENOENT || !ignore_missing_files))
     {
@@ -536,11 +688,13 @@
   -f, --force           ignore nonexistent files, never prompt\n\
   -i, --interactive     prompt before any removal\n\
   -r, -R, --recursive   remove the contents of directories recursively\n\
+  -s, --secure_delete   secure overwrite (-sss for full security)\n\
   -v, --verbose         explain what is being done\n\
       --help            display this help and exit\n\
       --version         output version information and exit\n\
 "));
       puts (_("\nReport bugs to fileutils-bugs@gnu.ai.mit.edu"));
+      puts (_("\nWith secure_delete patch by van Hauser <vh@reptile.rug.ac.be>"));
     }
   exit (status);
 }