16

我想将加密密码存储在 Java 文件中。我看到了一个使用javax.crypto的解决方案,但问题是密钥是动态生成的,而且是随机的。

然后在运行时在 Java 程序中获取并解密此密码。鉴于我要将已经加密的密码存储在文件中 - 我想在解密时获得正确的文本。

有没有办法告诉 javax.crypto 方法:

key = KeyGenerator.getInstance(algorithm).generateKey()

这可以用我自己基于某个私钥生成的密钥替换吗?

谁能指出一些有关如何执行此操作的资源?

4

7 回答 7

27

这是我正在寻找的使用javax.crypto库和 apache commons 编解码器库在 Base64 中进行编码和解码的解决方案:

import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import org.apache.commons.codec.binary.Base64;

public class TrippleDes {

    private static final String UNICODE_FORMAT = "UTF8";
    public static final String DESEDE_ENCRYPTION_SCHEME = "DESede";
    private KeySpec ks;
    private SecretKeyFactory skf;
    private Cipher cipher;
    byte[] arrayBytes;
    private String myEncryptionKey;
    private String myEncryptionScheme;
    SecretKey key;

    public TrippleDes() throws Exception {
        myEncryptionKey = "ThisIsSpartaThisIsSparta";
        myEncryptionScheme = DESEDE_ENCRYPTION_SCHEME;
        arrayBytes = myEncryptionKey.getBytes(UNICODE_FORMAT);
        ks = new DESedeKeySpec(arrayBytes);
        skf = SecretKeyFactory.getInstance(myEncryptionScheme);
        cipher = Cipher.getInstance(myEncryptionScheme);
        key = skf.generateSecret(ks);
    }


    public String encrypt(String unencryptedString) {
        String encryptedString = null;
        try {
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] plainText = unencryptedString.getBytes(UNICODE_FORMAT);
            byte[] encryptedText = cipher.doFinal(plainText);
            encryptedString = new String(Base64.encodeBase64(encryptedText));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return encryptedString;
    }


    public String decrypt(String encryptedString) {
        String decryptedText=null;
        try {
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] encryptedText = Base64.decodeBase64(encryptedString);
            byte[] plainText = cipher.doFinal(encryptedText);
            decryptedText= new String(plainText);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return decryptedText;
    }


    public static void main(String args []) throws Exception
    {
        TrippleDes td= new TrippleDes();

        String target="imparator";
        String encrypted=td.encrypt(target);
        String decrypted=td.decrypt(encrypted);

        System.out.println("String To Encrypt: "+ target);
        System.out.println("Encrypted String:" + encrypted);
        System.out.println("Decrypted String:" + decrypted);

    }

}

运行上述程序会产生以下输出:

String To Encrypt: imparator
Encrypted String:FdBNaYWfjpWN9eYghMpbRA==
Decrypted String:imparator
于 2012-04-25T13:17:31.020 回答
27

对称密钥加密:对称密钥使用相同的密钥进行加密和解密。这种类型的密码学的主要挑战是在发送者和接收者两方之间交换密钥。

示例: 以下示例使用对称密钥进行加密和解密算法,该算法可作为 Sun 的 JCE(J ava Cryptography Extension)的一部分。Sun JCE 有两层,加密 API 层和提供者层。

DES数据加密标准)是一种流行的对称密钥算法。目前 DES 已经过时并且被认为是不安全的。三重 DES和更强的DES变体。它是一种对称密钥分组密码。还有其他算法BlowfishTwofishAES(高级加密标准)。AES 是 DES 上的最新加密标准。

脚步 :

  1. 添加安全提供程序:我们使用 JDK 提供的 SunJCE 提供程序。
  2. 生成密钥:使用KeyGenerator和算法生成密钥。我们正在使用DESedeDESede是 3DES 实现的描述性名称:DESede = DES-Encrypt-Decrypt-Encrypt = Triple DES)。
  3. 编码文本:为了跨平台的一致性,使用 . 将纯文本编码为字节UTF-8 encoding
  4. 加密文本:用实例化CipherENCRYPT_MODE使用密钥并加密字节。
  5. 解密文本:用实例化CipherDECRYPT_MODE使用相同的密钥并解密字节。

以上给出的所有步骤和概念都是相同的,我们只是替换算法。

import java.util.Base64;    
import javax.crypto.Cipher;  
import javax.crypto.KeyGenerator;   
import javax.crypto.SecretKey;  
public class EncryptionDecryptionAES {  
    static Cipher cipher;  

    public static void main(String[] args) throws Exception {
        /* 
         create key 
         If we need to generate a new key use a KeyGenerator
         If we have existing plaintext key use a SecretKeyFactory
        */ 
        KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
        keyGenerator.init(128); // block size is 128bits
        SecretKey secretKey = keyGenerator.generateKey();
        
        /*
          Cipher Info
          Algorithm : for the encryption of electronic data
          mode of operation : to avoid repeated blocks encrypt to the same values.
          padding: ensuring messages are the proper length necessary for certain ciphers 
          mode/padding are not used with stream cyphers.  
         */
        cipher = Cipher.getInstance("AES"); //SunJCE provider AES algorithm, mode(optional) and padding schema(optional)  

        String plainText = "AES Symmetric Encryption Decryption";
        System.out.println("Plain Text Before Encryption: " + plainText);

        String encryptedText = encrypt(plainText, secretKey);
        System.out.println("Encrypted Text After Encryption: " + encryptedText);

        String decryptedText = decrypt(encryptedText, secretKey);
        System.out.println("Decrypted Text After Decryption: " + decryptedText);
    }

    public static String encrypt(String plainText, SecretKey secretKey)
            throws Exception {
        byte[] plainTextByte = plainText.getBytes();
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte[] encryptedByte = cipher.doFinal(plainTextByte);
        Base64.Encoder encoder = Base64.getEncoder();
        String encryptedText = encoder.encodeToString(encryptedByte);
        return encryptedText;
    }

    public static String decrypt(String encryptedText, SecretKey secretKey)
            throws Exception {
        Base64.Decoder decoder = Base64.getDecoder();
        byte[] encryptedTextByte = decoder.decode(encryptedText);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedByte = cipher.doFinal(encryptedTextByte);
        String decryptedText = new String(decryptedByte);
        return decryptedText;
    }
}

输出:

Plain Text Before Encryption: AES Symmetric Encryption Decryption
Encrypted Text After Encryption: sY6vkQrWRg0fvRzbqSAYxepeBIXg4AySj7Xh3x4vDv8TBTkNiTfca7wW/dxiMMJl
Decrypted Text After Decryption: AES Symmetric Encryption Decryption

来源

示例:密码有两种模式,它们是加密和解密。我们必须在设置模式后每次开始加密或解密文本。 在此处输入图像描述

于 2015-12-04T22:32:25.113 回答
5

KeyGenerator用于生成密钥

你可能想检查KeySpec,SecretKeySecretKeyFactory

http://docs.oracle.com/javase/1.5.0/docs/api/javax/crypto/spec/package-summary.html

于 2012-04-24T18:30:37.320 回答
2

这是我几个月前制作的示例 课程加密和解密数据

import java.security.*;
import java.security.spec.*;

import java.io.*;
import javax.crypto.*;
import javax.crypto.spec.*;

public class TestEncryptDecrypt {

private final String ALGO = "DES";
private final String MODE = "ECB";
private final String PADDING = "PKCS5Padding";
private static int mode = 0;

public static void main(String args[]) {
    TestEncryptDecrypt me = new TestEncryptDecrypt();
    if(args.length == 0) mode = 2;
    else mode = Integer.parseInt(args[0]);
    switch (mode) {
    case 0:
        me.encrypt();
        break;
    case 1:
        me.decrypt();
        break;
    default:
        me.encrypt();
        me.decrypt();
    }
}

public void encrypt() {
try {
    System.out.println("Start encryption ...");

    /* Get Input Data */
    String input = getInputData();
    System.out.println("Input data : "+input);

    /* Create Secret Key */
    KeyGenerator keyGen = KeyGenerator.getInstance(ALGO);
    SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");
    keyGen.init(56,random);
      Key sharedKey = keyGen.generateKey();

    /* Create the Cipher and init it with the secret key */
    Cipher c = Cipher.getInstance(ALGO+"/"+MODE+"/"+PADDING);
    //System.out.println("\n" + c.getProvider().getInfo());
    c.init(Cipher.ENCRYPT_MODE,sharedKey);
    byte[] ciphertext = c.doFinal(input.getBytes());
    System.out.println("Input Encrypted : "+new String(ciphertext,"UTF8"));

    /* Save key to a file */
    save(sharedKey.getEncoded(),"shared.key");

    /* Save encrypted data to a file */
    save(ciphertext,"encrypted.txt");
} catch (Exception e) {
    e.printStackTrace();
}   
}

public void decrypt() {
try {
    System.out.println("Start decryption ...");

    /* Get encoded shared key from file*/
    byte[] encoded = load("shared.key");
      SecretKeyFactory kf = SecretKeyFactory.getInstance(ALGO);
    KeySpec ks = new DESKeySpec(encoded);
    SecretKey ky = kf.generateSecret(ks);

    /* Get encoded data */
    byte[] ciphertext = load("encrypted.txt");
    System.out.println("Encoded data = " + new String(ciphertext,"UTF8"));

    /* Create a Cipher object and initialize it with the secret key */
    Cipher c = Cipher.getInstance(ALGO+"/"+MODE+"/"+PADDING);
    c.init(Cipher.DECRYPT_MODE,ky);

    /* Update and decrypt */
    byte[] plainText = c.doFinal(ciphertext);
    System.out.println("Plain Text : "+new String(plainText,"UTF8"));
} catch (Exception e) {
    e.printStackTrace();
}   
}

private String getInputData() {
    String id = "owner.id=...";
    String name = "owner.name=...";
    String contact = "owner.contact=...";
    String tel = "owner.tel=...";
    final String rc = System.getProperty("line.separator");
    StringBuffer buf = new StringBuffer();
    buf.append(id);
    buf.append(rc);
    buf.append(name);
    buf.append(rc);
    buf.append(contact);
    buf.append(rc);
    buf.append(tel);
    return buf.toString();
}


private void save(byte[] buf, String file) throws IOException {
      FileOutputStream fos = new FileOutputStream(file);
      fos.write(buf);
      fos.close();
}

private byte[] load(String file) throws FileNotFoundException, IOException {
    FileInputStream fis = new FileInputStream(file);
    byte[] buf = new byte[fis.available()];
    fis.read(buf);
    fis.close();
    return buf;
}
}
于 2012-04-24T18:33:45.900 回答
2

您可能想要使用非常容易使用的jasypt库(Java 简化加密)。(另外,建议检查加密密码而不是解密加密密码)

要使用 jasypt,如果您使用的是 maven,您可以将 jasypt 包含到您的 pom.xml 文件中,如下所示:

<dependency>
    <groupId>org.jasypt</groupId>
    <artifactId>jasypt</artifactId>
    <version>1.9.3</version>
    <scope>compile</scope>
</dependency>

然后加密密码,你可以使用 StrongPasswordEncryptor

public static String encryptPassword(String inputPassword) {
    StrongPasswordEncryptor encryptor = new StrongPasswordEncryptor();
    return encryptor.encryptPassword(inputPassword);
}

注意: 每次调用 encryptPassword 时加密的密码都不一样,但是 checkPassword 方法仍然可以检查未加密的密码是否仍然与每个加密的密码匹配。

要检查未加密的密码和加密的密码,可以使用 checkPassword 方法:

public static boolean checkPassword(String inputPassword, String encryptedStoredPassword) {
    StrongPasswordEncryptor encryptor = new StrongPasswordEncryptor();
    return encryptor.checkPassword(inputPassword, encryptedStoredPassword);
}

下面的页面提供了有关创建安全加密密码所涉及的复杂性的详细信息。

http://www.jasypt.org/howtoencryptuserpasswords.html

于 2020-08-16T05:26:45.437 回答
0
public class GenerateEncryptedPassword {

    public static void main(String[] args){

        Scanner sc= new Scanner(System.in);    
        System.out.println("Please enter the password that needs to be encrypted :");
        String input = sc.next();

        try {
            String encryptedPassword= AESencrp.encrypt(input);
            System.out.println("Encrypted password generated is :"+encryptedPassword);
        } catch (Exception ex) {
            Logger.getLogger(GenerateEncryptedPassword.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}
于 2017-12-01T04:43:04.090 回答
0

如果您使用静态密钥,加密和解密总是给出相同的结果;

public static final String CRYPTOR_KEY = "your static key here";
byte[] keyByte = Base64.getDecoder().decode(CRYPTOR_KEY);
key = new SecretKeySpec(keyByte, "AES");
于 2019-07-10T07:55:41.197 回答