java - 使用 CBC 的 Java Blowfish 加密
问题描述
我正在尝试使用和生成此站点正在执行的操作https://codebeautify.org/encrypt-decryptBlowfish
CBC
我不确定实际术语是什么,但我想实现的加密方法会产生不一致的加密字符串,尽管使用相同的内容和密钥,
例如,如果我Hello
用 key加密key123
两次,第一个结果可能会显示abcde
,第二个结果应该显示其他内容,例如fghij
. 但是同时解密abcde
和fghij
withkey123
将返回相同的Hello
.
我也可以知道他们用来产生最终结果的编码类型是什么?比如 hex/base64,因为我都试过了,但似乎没有产生类似的结果。
这就是我正在使用的:
加密类:
public static String enc(String content, String key) {
String encCon = "";
try {
String IV = "12345678";
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes("UTF-8"), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
String secret = content;
cipher.init(Cipher.ENCRYPT_MODE, keySpec, new javax.crypto.spec.IvParameterSpec(IV.getBytes("UTF-8")));
byte[] encoding = cipher.doFinal(secret.getBytes("UTF-8"));
System.out.println("-- Encrypted -----------");
encCon = DatatypeConverter.printBase64Binary(encoding);
System.out.println("-- encCon : " + encCon);
} catch (Exception ex) {
logger.error(ex.getMessage(), ex);
}
return encCon;
}
public static String dec(String content, String key) {
String decCon = "";
try {
String IV = "12345678";
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes("UTF-8"), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
// Decode Base64
byte[] ciphertext = DatatypeConverter.parseBase64Binary(content);
// Decrypt
cipher.init(Cipher.DECRYPT_MODE, keySpec, new javax.crypto.spec.IvParameterSpec(IV.getBytes("UTF-8")));
byte[] message = cipher.doFinal(ciphertext);
System.out.println("-- Decrypted -----------");
decCon = new String(message, "UTF-8");
System.out.println("-- decCon : " + decCon);
} catch (Exception ex) {
logger.error(ex.getMessage(), ex);
}
return decCon;
}
调用类(如 Main.java)
// This is what I get from codebeautify site, encrypting Hello with key123
// However, I'm getting javax.crypto.BadPaddingException: Given final block not properly padded
Crypto.dec("08GCpwyZc+qGNuxSvXAD2A==", "key123");
// Below 2 lines works fine, the only problem is the result isn't randomized
String encContent = Crypto.enc("Hello", "key123");
Crypto.dec(encContent, "key123");
解决方案
更新时间 2019 年 4 月 21 日晚上 9:49 UTC
在@MaartenBodewes 和@MarkJeronimus 指出了一些需要考虑的事情之后,我正在更新答案以使其更正确。但是因为这个问题是关于实现的,而不是关于使它更安全的,所以这个和旧版本应该足以至少提供一些洞察力。同样,通过修改以下代码可以实现更安全的解决方案。
变更日志
- 密钥派生
- 处理异常及其详细信息
- 对每个数据使用单个 SecureRandom 实例(iv[8 字节] 和 salt[32 字节])
- 检查要加密的明文和要解密的加密文本的空值和空值
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import java.util.Base64;
import javax.xml.bind.DatatypeConverter;
import java.security.SecureRandom;
import java.security.spec.KeySpec;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
public class Crypto {
private static final char[] tempKey = new char[] {'T', 'E', 'M', 'P', '_', 'G', 'E', 'N', '_', 'K', 'E', 'Y'};
private static final SecureRandom secureRandomForSalt = new SecureRandom();
private static final SecureRandom secureRandomForIV = new SecureRandom();
private static byte[] generateSalt() throws RuntimeException {
try{
byte[] saltBytes = new byte[32];
secureRandomForSalt.nextBytes(saltBytes);
return saltBytes;
}
catch(Exception ex){
ex.printStackTrace();
throw new RuntimeException("An error occurred in salt generation part. Reason: " + ex.getMessage());
}
}
public static String enc(String content) throws RuntimeException {
String encClassMethodNameForLogging = Crypto.class.getName() + ".enc" + " || ";
byte[] salt;
byte[] encodedTmpSecretKey;
SecretKeySpec keySpec;
Cipher cipher;
byte[] iv;
IvParameterSpec ivParameterSpec;
String finalEncResult;
if(content == null || content.trim().length() == 0) {
throw new RuntimeException("To be encrypted text is null or empty");
}
System.out.println("-- Encrypting -----------");
try {
salt = generateSalt();
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in salt generation part. Reason: " + ex.getMessage());
}
try {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(Crypto.tempKey, salt, 65536, 256);
SecretKey tmpSecretKey = factory.generateSecret(spec);
encodedTmpSecretKey = tmpSecretKey.getEncoded();
System.out.println("-- Secret Key Derivation in Encryption: " + Base64.getEncoder().encodeToString(encodedTmpSecretKey));
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (InvalidKeySpecException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: Key length may not be correct");
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage());
}
try {
keySpec = new SecretKeySpec(encodedTmpSecretKey, "Blowfish");
cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (NoSuchPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation: The particular padding mechanism is requested but is not available in the environment");
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage());
}
try {
iv = new byte[cipher.getBlockSize()];
secureRandomForIV.nextBytes(iv);
ivParameterSpec = new IvParameterSpec(iv);
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in iv creation part. Reason: " + ex.getMessage());
}
try {
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
byte[] encoding = cipher.doFinal(content.getBytes("UTF-8"));
String encCon = DatatypeConverter.printBase64Binary(encoding);
String ivStr = DatatypeConverter.printBase64Binary(iv);
String saltStr = DatatypeConverter.printBase64Binary(salt);
System.out.println("-- encCon : " + encCon);
System.out.println("-- iv : " + ivStr);
System.out.println("-- salt : " + saltStr);
finalEncResult = encCon + ":" + ivStr + ":" + saltStr;
System.out.println("-- finalEncRes : " + finalEncResult + "\n");
}
catch (InvalidKeyException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: Most probably you didn't download and copy 'Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files'");
}
catch (InvalidAlgorithmParameterException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: IV length may not be correct");
}
catch (IllegalBlockSizeException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: The length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher");
}
catch (BadPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: A particular padding mechanism is expected for the input data but the data is not padded properly (Most probably wrong/corrupt key caused this)");
}
catch (UnsupportedEncodingException ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: The Character Encoding is not supported");
}
catch (Exception ex){
ex.printStackTrace();
throw new RuntimeException(encClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage());
}
return finalEncResult;
}
public static String dec(String encContent) throws RuntimeException {
String decClassMethodNameForLogging = Crypto.class.getName() + ".dec" + " || ";
String decCon;
byte[] salt;
byte[] encodedTmpSecretKey;
SecretKeySpec keySpec;
Cipher cipher;
byte[] iv;
if(encContent == null || encContent.trim().length() == 0) {
throw new RuntimeException("To be decrypted text is null or empty");
}
System.out.println("-- Decrypting -----------");
try {
salt = DatatypeConverter.parseBase64Binary(encContent.substring(encContent.lastIndexOf(":") + 1));
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in salt retrieving part. Reason: " + ex.getMessage());
}
try {
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(Crypto.tempKey, salt, 65536, 256);
SecretKey tmpSecretKey = factory.generateSecret(spec);
encodedTmpSecretKey = tmpSecretKey.getEncoded();
System.out.println("-- Secret Key Gathering in Decryption: " + Base64.getEncoder().encodeToString(encodedTmpSecretKey));
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (InvalidKeySpecException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage() + " - Explanation: Key length may not be correct");
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in key derivation part. Reason: " + ex.getMessage());
}
try {
keySpec = new SecretKeySpec(encodedTmpSecretKey, "Blowfish");
cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
}
catch (NoSuchAlgorithmException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation: The particular cryptographic algorithm requested is not available in the environment");
}
catch (NoSuchPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage() + " - Explanation : The particular padding mechanism requested is not available in the environment");
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in cipher instantiation part. Reason: " + ex.getMessage());
}
try {
iv = DatatypeConverter.parseBase64Binary(encContent.substring(encContent.indexOf(":") + 1, encContent.lastIndexOf(":")));
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in iv creation part. Reason: " + ex.getMessage());
}
try {
cipher.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(iv));
byte[] decoding = cipher.doFinal(Base64.getDecoder().decode(encContent.substring(0, encContent.indexOf(":"))));
decCon = new String(decoding, "UTF-8");
System.out.println("-- decCon : " + decCon + "\n");
}
catch (InvalidKeyException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: Most probably you didn't download and copy 'Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files'");
}
catch (InvalidAlgorithmParameterException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: IV length may not be correct");
}
catch (IllegalBlockSizeException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage() + " - Explanation: The length of data provided to a block cipher is incorrect, i.e., does not match the block size of the cipher");
}
catch (BadPaddingException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: A particular padding mechanism is expected for the input data but the data is not padded properly (Most probably wrong/corrupt key caused this)");
}
catch (UnsupportedEncodingException ex){
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in encryption part. Reason: " + ex.getMessage() + " - Explanation: The Character Encoding is not supported");
}
catch (Exception ex) {
ex.printStackTrace();
throw new RuntimeException(decClassMethodNameForLogging + "An error occurred in decryption part. Reason: " + ex.getMessage());
}
return decCon;
}
public static void main(String args[]) {
System.out.println("-- Original -------------");
String plainText = "hello world";
System.out.println("-- origWord : " + plainText + "\n");
String e = Crypto.enc(plainText);
String d = Crypto.dec(e);
System.out.println("-- Results --------------");
System.out.println("-- PlainText: " + plainText);
System.out.println("-- EncryptedText: " + e);
System.out.println("-- DecryptedText: " + d);
}
}
此外,可执行版本在下面;
https://www.jdoodle.com/a/19HT
原始答案
我看到书面评论满足您的需求,但我想分享以下解决方案,以满足您作为代码示例的需求并供将来参考;
** 使用随机 IV(密码块大小针对 IV 大小给出,但静态字节大小也可以定义为例如“16 字节”)
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
import javax.xml.bind.DatatypeConverter;
import java.security.SecureRandom;
import javax.crypto.spec.IvParameterSpec;
public class Crypto {
public static String enc(String content, String key) {
String encCon = "";
String ivStr = "";
try {
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes("UTF-8"), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
byte[] iv = new byte[cipher.getBlockSize()];
SecureRandom secureRandom = new SecureRandom();
secureRandom.nextBytes(iv);
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
String secret = content;
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
byte[] encoding = cipher.doFinal(secret.getBytes("UTF-8"));
System.out.println("-- Encrypted -----------");
encCon = DatatypeConverter.printBase64Binary(encoding);
ivStr = DatatypeConverter.printBase64Binary(iv);
System.out.println("-- encCon : " + encCon);
System.out.println("-- iv : " + ivStr);
} catch (Exception ex) {
ex.printStackTrace();
}
return encCon + ":" + ivStr;
}
public static String dec(String encContent, String key) {
String decCon = "";
try {
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes("UTF-8"), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
byte[] iv = DatatypeConverter.parseBase64Binary(encContent.substring(encContent.indexOf(":") + 1));
String secret = encContent.substring(0, encContent.indexOf(":"));
cipher.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(iv));
byte[] decoding = cipher.doFinal(Base64.getDecoder().decode(secret));
System.out.println("-- Decrypted -----------");
decCon = new String(decoding, "UTF-8");
System.out.println("-- decCon : " + decCon);
} catch (Exception ex) {
ex.printStackTrace();
}
return decCon;
}
public static void main(String args[]) {
String e = Crypto.enc("hello world", "key123");
String d = Crypto.dec(e, "key123");
}
}
注意:当然可以实现更安全的解决方案。提供上述解决方案只是为了提供一点见解。
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