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hash - 汉克雷斯特。如何检查字节数组等于

问题描述

需要在不涉及数据库的情况下为创建管理员创建应用程序密码。管理员密码在创建后将保存在数据库中。根据以下测试方法，将 byte[] 写入/从文件中读取相同的值存在问题。

这是很好的方法吗？处理二进制数据有什么问题？

import org.apache.commons.io.FileUtils;
import org.junit.BeforeClass;
import org.junit.Test;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import java.io.*;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import java.util.Arrays;
import java.util.Random;
import static org.junit.Assert.assertEquals;

public class Passwords {
static byte[] salt;
static byte[] password_hash;

private static final Random RANDOM = new SecureRandom();
private static final int ITERATIONS = 10000;
private static final int KEY_LENGTH = 256;

static String password_file ="C:\\Users\\hp\\IdeaProjects\\pp20_hotel_v1\\src\\main\\resources\\app_password_hash";
static String salt_file = "C:\\Users\\hp\\IdeaProjects\\pp20_hotel_v1\\src\\main\\resources\\salt_hash";

public static byte[] getNextSalt() {
    byte[] salt = new byte[16];
    RANDOM.nextBytes(salt);
    return salt;
}

private static void writeBinary(String path, byte[] arr){
    File file = new File(path);
    FileOutputStream fos = null;
    try {
        fos = new FileOutputStream(file);
        FileUtils.writeByteArrayToFile(file, arr);
        fos.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

private static byte[] hash(char[] password, byte[] salt) {
    PBEKeySpec spec = new PBEKeySpec(password, salt, ITERATIONS, KEY_LENGTH);
    Arrays.fill(password, Character.MIN_VALUE);
    try {
        SecretKeyFactory skf = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
        return skf.generateSecret(spec).getEncoded();
    } catch (NoSuchAlgorithmException | InvalidKeySpecException e) {
        throw new AssertionError("Error while hashing a password: " + e.getMessage(), e);
    } finally {
        spec.clearPassword();
    }
}

private static byte[] readBinary(String path){
    File file = new File(path);
    byte fileContent[] = null;
    try {
        fileContent = FileUtils.readFileToByteArray(file);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return fileContent;
}

@BeforeClass
public static void writeSaltAndPassword(){
    String password = "12345678";
    salt = getNextSalt();
    password_hash = hash(password.toCharArray(), salt);
    System.out.println("salt : "+salt);
    System.out.println("password_hash : "+password_hash);
    writeBinary(password_file, password_hash);
    writeBinary(salt_file, salt);
}

@Test
public void checkPassword(){
    byte[] actual_password_hash=readBinary(password_file);
    assertEquals(password_hash, actual_password_hash);
}

}

标签： hashinputstreamoutputstreamfileutils

解决方案

问题就在于此。Hamcrest 不会逐个检查 byte[] 元素。需要写：

for(int i=0; i<password_hash.length;i++){
        if(password_hash[i]!=actual_password_hash[i]){
            System.out.println(password_hash[i]!=actual_password_hash[i]);
            return;
        }
    }

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