//

// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements. See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership. The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License. You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied. See the License for the

// specific language governing permissions and limitations

// under the License.

//

package com.cloud.utils;

import java.security.SecureRandom;

import java.util.Random;

/**

* Generate random passwords

*

*/

public class PasswordGenerator {

//Leave out visually confusing l,L,1,o,O,0

static private char[] lowerCase = new char[] {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};

static private char[] upperCase = new char[] {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};

static private char[] numeric = new char[] {'2', '3', '4', '5', '6', '7', '8', '9'};

static private char[] alphaNumeric = new char[] {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y',

'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '2', '3', '4', '5', '6', '7', '8', '9'};

static private int minLength = 3;

public static String generateRandomPassword(int num) {

Random r = new SecureRandom();

StringBuilder password = new StringBuilder();

//Guard for num < minLength

if (num < minLength) {

//Add alphanumeric chars at random

for (int i = 0; i < minLength; i++) {

password.append(generateAlphaNumeric(r));

}

} else {

// Generate random 3-character string with a lowercase character,

// uppercase character, and a digit

password.append(generateLowercaseChar(r)).append(generateUppercaseChar(r)).append(generateDigit(r));

// Generate a random n-character string with only lowercase

// characters

for (int i = 0; i < num - 3; i++) {

password.append(generateLowercaseChar(r));

}

}

return password.toString();

}

private static char generateLowercaseChar(Random r) {

return lowerCase[r.nextInt(lowerCase.length)];

}

private static char generateDigit(Random r) {

return numeric[r.nextInt(numeric.length)];

}

private static char generateUppercaseChar(Random r) {

return upperCase[r.nextInt(upperCase.length)];

}

private static char generateAlphaNumeric(Random r) {

return alphaNumeric[r.nextInt(alphaNumeric.length)];

}

public static String generatePresharedKey(int numChars) {

Random r = new SecureRandom();

StringBuilder psk = new StringBuilder();

for (int i = 0; i < numChars; i++) {

psk.append(generateAlphaNumeric(r));

}

return psk.toString();

}

}