java - 使用 java SecureRandom 类创建随 secret 码

Question

这是我第一次使用 java.security.SecureRandom，我希望有人批评以下代码以确保我正确执行此操作。该代码应该生成任意长度的加密安全随 secret 码。任何意见将不胜感激。

import java.util.*;
import java.security.SecureRandom;

public class PassGen{

    private static final String VALID_PW_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()-_=+{}[]|:;<>?,./";
    private static final int DEFAULT_PASSWORD_LENGTH = 12;
    private static final Random RANDOM = new SecureRandom();


    // main class
    public static void main(String args[]) throws Exception {


        // Set password length
        int pwLength;
        if (args.length < 1)
            pwLength = DEFAULT_PASSWORD_LENGTH;
        else
            pwLength = Integer.parseInt(args[0]);


        // generate password
        String pw = "";
        for (int i=0; i<pwLength; i++) {
            int index = (int)(RANDOM.nextDouble()*VALID_PW_CHARS.length());
            pw += VALID_PW_CHARS.substring(index, index+1);
        }

        System.out.println("pw = " + pw);
  }
}

Answer 1

您可以使用 org.apache.commons.lang.RandomStringUtils ( http://commons.apache.org/proper/commons-lang/javadocs/api-2.6/org/apache/commons/lang/RandomStringUtils.html ) 使用 char 数组和 java.security.SecureRandom 生成密码:

public String generatePassword()
{
    return RandomStringUtils.random(DEFAULT_PASSWORD_LENGTH, 0, VALID_PW_CHARS.length(), false,
            false, VALID_PW_CHARS.toCharArray(), new SecureRandom());
}

在 pom.xml 中

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.4</version>
</dependency>