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/*
* Copyright (C) 2005-2015 Schlichtherle IT Services.
* All rights reserved. Use is subject to license terms.
*/
package net.java.truecommons.key.console;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import net.java.truecommons.key.spec.KeyStrength;
import net.java.truecommons.key.spec.prompting.KeyPromptingDisabledException;
import net.java.truecommons.key.spec.prompting.PromptingKey;
import net.java.truecommons.key.spec.prompting.PromptingKey.Controller;
import net.java.truecommons.key.spec.prompting.PromptingPbeParameters;
import javax.annotation.concurrent.ThreadSafe;
import java.io.Console;
import java.io.PrintWriter;
import java.net.URI;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.ResourceBundle;
/**
* A console based user interface for prompting for passwords.
*
* @since TrueCommons 2.2
* @author Christian Schlichtherle
*/
@ThreadSafe
abstract class ConsolePromptingPbeParametersView<
P extends PromptingPbeParameters,
S extends KeyStrength>
implements PromptingKey.View {
private static final ResourceBundle resources = ResourceBundle
.getBundle(ConsolePromptingPbeParametersView.class.getName());
/**
* Used to lock out prompting by multiple threads.
*/
private static final Object lock = new Object();
/** The minimum acceptable length of a password. */
private static final int MIN_PASSWD_LEN = 8;
/**
* The last resource ID used when prompting.
* Initialized to the empty string.
*/
@SuppressFBWarnings("ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD")
private static URI lastResource = URI.create(""); // NOI18N
private static final String YES = resources.getString("yes");
private static final String NO = resources.getString("no");
/**
* Returns new parameters for safe password based encryption.
*
* @return New parameters for safe password based encryption.
*/
protected abstract P newPbeParameters();
@Override
public final void promptKeyForWriting(final Controller
controller)
throws KeyPromptingDisabledException {
promptKey(new KeyPrompt() {
@Override
public void promptKey(final Console con) {
final URI resource = controller.getResource();
assert null != resource;
if (!lastResource.equals(resource))
con.format(resources.getString("writeKey.banner"), resource);
lastResource = resource;
P param = controller.getKeyClone();
if (null == param)
param = newPbeParameters();
while (true) {
char[] input1 = con.readPassword(
resources.getString("writeKey.newPasswd1"));
if (null == input1 || 0 >= input1.length)
return;
if (MIN_PASSWD_LEN > input1.length) {
con.format(resources.getString("writeKey.passwd.tooShort"), MIN_PASSWD_LEN);
continue;
}
try {
char[] input2 = con.readPassword(
resources.getString("writeKey.newPasswd2"));
if (input2 == null)
return;
try {
if (!Arrays.equals(input1, input2)) {
con.format(resources.getString("writeKey.passwd.noMatch"));
continue;
}
param.setPassword(input1);
break;
} finally {
Arrays.fill(input2, (char) 0);
}
} finally {
Arrays.fill(input1, (char) 0);
}
}
con.format(resources.getString("keyStrength.banner"));
final String selection;
final Map map;
{
final StringBuilder builder = new StringBuilder();
final S[] array = param.getAllKeyStrengths();
map = new HashMap<>(array.length / 3 * 4 + 1);
final PrintWriter writer = con.writer();
for (final S strength : array) {
if (0 < builder.length())
builder.append('/');
builder.append(strength.getBits());
map.put(strength.getBits(), strength);
writer.println(strength);
}
selection = builder.toString();
}
while (true) {
final S keyStrength = param.getKeyStrength();
String input = con.readLine(
resources.getString("keyStrength.prompt"),
selection,
null == keyStrength ? 0 : keyStrength.getBits());
if (null == input || input.length() <= 0)
break;
try {
final int bits = Integer.parseInt(input);
final S strength = map.get(bits);
if (null != strength) {
assert strength.getBits() == bits;
param.setKeyStrength(strength);
break;
}
} catch (NumberFormatException ignored) {
}
}
controller.setKeyClone(param);
}
});
}
@Override
public void promptKeyForReading(
final Controller controller,
final boolean invalid)
throws KeyPromptingDisabledException {
promptKey(new KeyPrompt() {
@Override
public void promptKey(final Console con) {
if (invalid)
con.format(resources.getString("readKey.invalid"));
final URI resource = controller.getResource();
assert null != resource;
if (!lastResource.equals(resource))
con.format(resources.getString("readKey.banner"), resource);
lastResource = resource;
final char[] passwd = con.readPassword(resources.getString("readKey.passwd"));
if (null == passwd || passwd.length <= 0) {
controller.setKeyClone(null);
return;
}
final P param = newPbeParameters();
param.setPassword(passwd);
Arrays.fill(passwd, (char) 0);
while (true) {
String changeKey = con.readLine(resources.getString("readKey.change"));
param.setChangeRequested(YES.equalsIgnoreCase(changeKey));
if (null == changeKey ||
changeKey.length() <= 0 ||
YES.equalsIgnoreCase(changeKey) ||
NO.equalsIgnoreCase(changeKey)) {
controller.setKeyClone(param);
return;
}
}
}
});
}
private void promptKey(final KeyPrompt keyPrompt)
throws KeyPromptingDisabledException {
final Console con = System.console();
if (null == con)
throw new KeyPromptingDisabledException();
synchronized (lock) {
keyPrompt.promptKey(con);
}
}
private interface KeyPrompt {
void promptKey(Console con);
}
}