1 /*
   2  * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.security.util;
  27 
  28 import java.io.*;
  29 import java.nio.*;
  30 import java.nio.charset.*;
  31 import java.util.Arrays;
  32 import jdk.internal.access.SharedSecrets;
  33 
  34 /**
  35  * A utility class for reading passwords
  36  *
  37  */
  38 public class Password {
  39     /** Reads user password from given input stream. */
  40     public static char[] readPassword(InputStream in) throws IOException {
  41         return readPassword(in, false);
  42     }
  43 
  44     /** Reads user password from given input stream.
  45      * @param isEchoOn true if the password should be echoed on the screen
  46      */
  47     @SuppressWarnings("fallthrough")
  48     public static char[] readPassword(InputStream in, boolean isEchoOn)
  49             throws IOException {
  50 
  51         char[] consoleEntered = null;
  52         byte[] consoleBytes = null;
  53 
  54         try {
  55             // Use the new java.io.Console class
  56             Console con = null;
  57             if (!isEchoOn && in == System.in && ((con = System.console()) != null)) {
  58                 consoleEntered = con.readPassword();
  59                 // readPassword returns "" if you just print ENTER,
  60                 // to be compatible with old Password class, change to null
  61                 if (consoleEntered != null && consoleEntered.length == 0) {
  62                     return null;
  63                 }
  64                 consoleBytes = convertToBytes(consoleEntered);
  65                 in = new ByteArrayInputStream(consoleBytes);
  66             }
  67 
  68             // Rest of the lines still necessary for KeyStoreLoginModule
  69             // and when there is no console.
  70 
  71             char[] lineBuffer;
  72             char[] buf;
  73             int i;
  74 
  75             buf = lineBuffer = new char[128];
  76 
  77             int room = buf.length;
  78             int offset = 0;
  79             int c;
  80 
  81             boolean done = false;
  82             while (!done) {
  83                 switch (c = in.read()) {
  84                   case -1:
  85                   case '\n':
  86                       done = true;
  87                       break;
  88 
  89                   case '\r':
  90                     int c2 = in.read();
  91                     if ((c2 != '\n') && (c2 != -1)) {
  92                         if (!(in instanceof PushbackInputStream)) {
  93                             in = new PushbackInputStream(in);
  94                         }
  95                         ((PushbackInputStream)in).unread(c2);
  96                     } else {
  97                         done = true;
  98                         break;
  99                     }
 100                     /* fall through */
 101                   default:
 102                     if (--room < 0) {
 103                         buf = new char[offset + 128];
 104                         room = buf.length - offset - 1;
 105                         System.arraycopy(lineBuffer, 0, buf, 0, offset);
 106                         Arrays.fill(lineBuffer, ' ');
 107                         lineBuffer = buf;
 108                     }
 109                     buf[offset++] = (char) c;
 110                     break;
 111                 }
 112             }
 113 
 114             if (offset == 0) {
 115                 return null;
 116             }
 117 
 118             char[] ret = new char[offset];
 119             System.arraycopy(buf, 0, ret, 0, offset);
 120             Arrays.fill(buf, ' ');
 121 
 122             return ret;
 123         } finally {
 124             if (consoleEntered != null) {
 125                 Arrays.fill(consoleEntered, ' ');
 126             }
 127             if (consoleBytes != null) {
 128                 Arrays.fill(consoleBytes, (byte)0);
 129             }
 130         }
 131     }
 132 
 133     /**
 134      * Change a password read from Console.readPassword() into
 135      * its original bytes.
 136      *
 137      * @param pass a char[]
 138      * @return its byte[] format, similar to new String(pass).getBytes()
 139      */
 140     private static byte[] convertToBytes(char[] pass) {
 141         if (enc == null) {
 142             synchronized (Password.class) {
 143                 enc = SharedSecrets.getJavaIOAccess()
 144                         .charset()
 145                         .newEncoder()
 146                         .onMalformedInput(CodingErrorAction.REPLACE)
 147                         .onUnmappableCharacter(CodingErrorAction.REPLACE);
 148             }
 149         }
 150         byte[] ba = new byte[(int)(enc.maxBytesPerChar() * pass.length)];
 151         ByteBuffer bb = ByteBuffer.wrap(ba);
 152         synchronized (enc) {
 153             enc.reset().encode(CharBuffer.wrap(pass), bb, true);
 154         }
 155         if (bb.position() < ba.length) {
 156             ba[bb.position()] = '\n';
 157         }
 158         return ba;
 159     }
 160     private static volatile CharsetEncoder enc;
 161 }