src/org/ibex/crypto/CheckPassword.java

   1 // Copyright 2000-2005 the Contributors, as shown in the revision logs.
   2 // Licensed under the Apache Public Source License 2.0 ("the License").
   3 // You may not use this file except in compliance with the License.
   4
   5 package org.ibex.crypto;
   6 import org.ibex.util.*;
   7 import java.util.*;
   8 import java.io.*;
   9
  10 /**
  11  *  Implementation of the "checkpassword" protocol; requires bash and
  12  *  /bin/true.
  13  *
  14  *  Documented here:
  15  *
  16  *    http://cr.yp.to/checkpwd/interface.html
  17  *
  18  *  A debian implementation can be found in the "fgetty" package, and
  19  *  gets installed in /bin/checkpassword.
  20  */
  21 public class CheckPassword {
  22     public static boolean verify(String user, String pass) {
  23         try {
  24             Process p =
  25                 Runtime.getRuntime().exec(new String[] {
  26                     "bash",
  27                     "-c",
  28                     "checkpassword /bin/true 3<&0"
  29                 });
  30             PrintWriter pw = new PrintWriter(p.getOutputStream());
  31             pw.print(user);
  32             pw.print('\0');
  33             pw.print(pass);
  34             pw.print('\0');
  35             // timestamp (ignored)
  36             pw.print('\0');
  37             pw.flush();
  38             pw.close();
  39             int exitcode = p.waitFor();
  40             // FEATURE: grab errors off of stderr?
  41             if (exitcode!=0)
  42                 Log.error(CheckPassword.class, "exitcode " + exitcode);
  43             return exitcode==0;
  44         } catch (Exception e) { Log.warn(CheckPassword.class, e); }
  45         return false;
  46     }
  47 }