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新增/未测试 文件加解密操作

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database-mysql
2026-08-12 03:09:26 +08:00
parent c38b8857d5
commit e31384a848
2 changed files with 198 additions and 15 deletions
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15
src/main/java/top/gtb520/java/gnu/java/utils/library/utils/file/Encryption.java
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package top.gtb520.java.gnu.java.utils.library.utils.file;
import java.io.File;
public class Encryption {
/***
* 文件加密
*
* @param file 文件
* @param type 加密类型
*/
public static void EncryptionFile(File file, String type) {
}
}

198
src/main/java/top/gtb520/java/gnu/java/utils/library/utils/file/EncryptionAndDecryption.java Normal file
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package top.gtb520.java.gnu.java.utils.library.utils.file;
import java.io.File;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.StandardOpenOption;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.concurrent.CompletableFuture;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
public class EncryptionAndDecryption {
/***
* 文件加密
* 异步执行加密操作
* 加密后的文件保存为原文件名加 .enc 后缀，位于同目录下
*
* @param file 文件
* @param type 加密类型
* @return 加密后的文件，失败时返回 null
*/
public static File EncryptionFile(File file, EncryptionType type) {
File TargetFile = null;
if (file == null || !file.exists() || !file.isFile()) {
return null;
}
try {
TargetFile = CompletableFuture.supplyAsync(() -> {
try {
// 读取原文件内容
byte[] plainBytes = Files.readAllBytes(file.toPath());
// 根据加密类型生成对称密钥
SecretKey secretKey = generateSecretKey(type);
byte[] encryptedBytes = encryptBytes(plainBytes, secretKey, type);
// 写入加密后的文件，文件格式：[1字节密钥长度][密钥字节][加密数据]
byte[] keyBytes = secretKey.getEncoded();
String encryptedFileName = file.getName() + ".enc";
File encryptedFile = new File(file.getParentFile(), encryptedFileName);
try (OutputStream os = Files.newOutputStream(encryptedFile.toPath(),
StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
os.write(keyBytes.length);
os.write(keyBytes);
os.write(encryptedBytes);
os.flush();
}
return encryptedFile;
} catch (Exception e) {
return null;
}
}).get();
} catch (Exception e) {
TargetFile = null;
}
return TargetFile;
}
/***
* 生成对称密钥
*
* @param type 加密类型
* @return 对称密钥
*/
private static SecretKey generateSecretKey(EncryptionType type) throws NoSuchAlgorithmException {
String algorithm = switch (type) {
case AES -> "AES";
case DES -> "DES";
case RSA -> "AES"; // RSA 为非对称加密，此处用 AES 做对称加密替代
};
KeyGenerator keyGen = KeyGenerator.getInstance(algorithm);
int keySize = switch (type) {
case AES -> 128;
case DES -> 56;
case RSA -> 128;
};
keyGen.init(keySize);
return keyGen.generateKey();
}
/***
* 对字节数据进行加密
*
* @param data 原始数据
* @param key 密钥
* @param type 加密类型
* @return 加密后的数据
*/
private static byte[] encryptBytes(byte[] data, SecretKey key, EncryptionType type)
throws NoSuchAlgorithmException, NoSuchPaddingException,
InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
String algorithm = switch (type) {
case AES -> "AES/ECB/PKCS5Padding";
case DES -> "DES/ECB/PKCS5Padding";
case RSA -> "AES/ECB/PKCS5Padding";
};
Cipher cipher = Cipher.getInstance(algorithm);
cipher.init(Cipher.ENCRYPT_MODE, key);
return cipher.doFinal(data);
}
/***
* 文件解密
* 异步执行解密操作
* 解密后的文件去除 .enc 后缀，保存在同目录下
*
* @param file 加密文件（.enc）
* @param type 加密类型，须与加密时一致
* @return 解密后的文件，失败时返回 null
*/
public static File DecryptionFile(File file, EncryptionType type) {
File TargetFile = null;
if (file == null || !file.exists() || !file.isFile()) {
return null;
}
try {
TargetFile = CompletableFuture.supplyAsync(() -> {
try {
byte[] fileBytes = Files.readAllBytes(file.toPath());
// 读取文件头中的密钥长度和密钥
int keyLength = fileBytes[0] & 0xFF;
byte[] keyBytes = new byte[keyLength];
System.arraycopy(fileBytes, 1, keyBytes, 0, keyLength);
// 还原密钥
String algorithm = switch (type) {
case AES -> "AES";
case DES -> "DES";
case RSA -> "AES";
};
SecretKey secretKey = new javax.crypto.spec.SecretKeySpec(keyBytes, algorithm);
// 提取加密数据部分
byte[] encryptedBytes = new byte[fileBytes.length - 1 - keyLength];
System.arraycopy(fileBytes, 1 + keyLength, encryptedBytes, 0, encryptedBytes.length);
byte[] decryptedBytes = decryptBytes(encryptedBytes, secretKey, type);
// 生成解密后的文件名，去除 .enc 后缀
String fileName = file.getName();
String decryptedFileName = fileName.endsWith(".enc")
? fileName.substring(0, fileName.length() - 4)
: fileName + ".dec";
File decryptedFile = new File(file.getParentFile(), decryptedFileName);
try (OutputStream os = Files.newOutputStream(decryptedFile.toPath(),
StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
os.write(decryptedBytes);
os.flush();
}
return decryptedFile;
} catch (Exception e) {
return null;
}
}).get();
} catch (Exception e) {
TargetFile = null;
}
return TargetFile;
}
/***
* 对字节数据进行解密
*
* @param data 加密数据
* @param key 密钥
* @param type 加密类型
* @return 解密后的数据
*/
private static byte[] decryptBytes(byte[] data, SecretKey key, EncryptionType type)
throws NoSuchAlgorithmException, NoSuchPaddingException,
InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
String algorithm = switch (type) {
case AES -> "AES/ECB/PKCS5Padding";
case DES -> "DES/ECB/PKCS5Padding";
case RSA -> "AES/ECB/PKCS5Padding";
};
Cipher cipher = Cipher.getInstance(algorithm);
cipher.init(Cipher.DECRYPT_MODE, key);
return cipher.doFinal(data);
}
public enum EncryptionType {
AES, DES, RSA;
}
}