文件加解密操作

This commit is contained in:
2026-08-12 03:43:22 +08:00
parent e31384a848
commit 9d452ded62
2 changed files with 245 additions and 35 deletions

View File

@@ -3,6 +3,7 @@ package top.gtb520.java.gnu.java.utils.library.utils.file;
import java.io.File; import java.io.File;
import java.io.OutputStream; import java.io.OutputStream;
import java.nio.file.Files; import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption; import java.nio.file.StandardOpenOption;
import java.security.InvalidKeyException; import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException; import java.security.NoSuchAlgorithmException;
@@ -19,18 +20,23 @@ public class EncryptionAndDecryption {
/*** /***
* 文件加密 * 文件加密
* 异步执行加密操作 * 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 * 加密后覆盖原文件,不添加额外后缀
* 密钥保存到 keyPath 目录下,密钥名为 原文件名.key
* *
* @param file 文件 * @param file 文件
* @param type 加密类型 * @param type 加密类型
* @return 加密后的文件,失败时返回 null * @param keyPath 密钥文件目录路径,密钥名为 文件名.key
* @return 加密后的文件(原文件),失败时返回 null
*/ */
public static File EncryptionFile(File file, EncryptionType type) { public static File EncryptionFile(File file, EncryptionType type, Path keyPath) {
File TargetFile = null; File TargetFile = null;
if (file == null || !file.exists() || !file.isFile()) { if (file == null || !file.exists() || !file.isFile()) {
return null; return null;
} }
if (keyPath == null) {
return null;
}
try { try {
TargetFile = CompletableFuture.supplyAsync(() -> { TargetFile = CompletableFuture.supplyAsync(() -> {
@@ -42,18 +48,23 @@ public class EncryptionAndDecryption {
SecretKey secretKey = generateSecretKey(type); SecretKey secretKey = generateSecretKey(type);
byte[] encryptedBytes = encryptBytes(plainBytes, secretKey, 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] // 将密钥写入 keyPath 目录,密钥名为 文件名.key
byte[] keyBytes = secretKey.getEncoded(); Files.createDirectories(keyPath);
String encryptedFileName = file.getName() + ".enc"; String keyFileName = file.getName() + ".key";
File encryptedFile = new File(file.getParentFile(), encryptedFileName); Path keyFilePath = keyPath.resolve(keyFileName);
try (OutputStream os = Files.newOutputStream(encryptedFile.toPath(), try (OutputStream kos = Files.newOutputStream(keyFilePath,
StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) { StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
os.write(keyBytes.length); kos.write(secretKey.getEncoded());
os.write(keyBytes); kos.flush();
}
// 加密后覆盖写回原文件
try (OutputStream os = Files.newOutputStream(file.toPath(),
StandardOpenOption.TRUNCATE_EXISTING)) {
os.write(encryptedBytes); os.write(encryptedBytes);
os.flush(); os.flush();
} }
return encryptedFile; return file;
} catch (Exception e) { } catch (Exception e) {
return null; return null;
} }
@@ -111,30 +122,28 @@ public class EncryptionAndDecryption {
/*** /***
* 文件解密 * 文件解密
* 异步执行解密操作 * 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 * 解密后覆盖写回原文件,不添加额外后缀
* *
* @param file 加密文件.enc * @param file 加密文件
* @param type 加密类型,须与加密时一致 * @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 * @param keyfile 密钥文件,从中读取解密密钥
* @return 解密后的文件(原文件),失败时返回 null
*/ */
public static File DecryptionFile(File file, EncryptionType type) { public static File DecryptionFile(File file, EncryptionType type, File keyfile) {
File TargetFile = null; File TargetFile = null;
if (file == null || !file.exists() || !file.isFile()) { if (file == null || !file.exists() || !file.isFile()) {
return null; return null;
} }
if (keyfile == null || !keyfile.exists() || !keyfile.isFile()) {
return null;
}
try { try {
TargetFile = CompletableFuture.supplyAsync(() -> { TargetFile = CompletableFuture.supplyAsync(() -> {
try { try {
byte[] fileBytes = Files.readAllBytes(file.toPath()); // 从密钥文件读取密钥
byte[] keyBytes = Files.readAllBytes(keyfile.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) { String algorithm = switch (type) {
case AES -> "AES"; case AES -> "AES";
case DES -> "DES"; case DES -> "DES";
@@ -142,24 +151,19 @@ public class EncryptionAndDecryption {
}; };
SecretKey secretKey = new javax.crypto.spec.SecretKeySpec(keyBytes, algorithm); SecretKey secretKey = new javax.crypto.spec.SecretKeySpec(keyBytes, algorithm);
// 取加密数据部分 // 取加密文件内容
byte[] encryptedBytes = new byte[fileBytes.length - 1 - keyLength]; byte[] encryptedBytes = Files.readAllBytes(file.toPath());
System.arraycopy(fileBytes, 1 + keyLength, encryptedBytes, 0, encryptedBytes.length);
// 解密
byte[] decryptedBytes = decryptBytes(encryptedBytes, secretKey, type); byte[] decryptedBytes = decryptBytes(encryptedBytes, secretKey, type);
// 生成解密后的文件名,去除 .enc 后缀 // 解密后覆盖写回原文件
String fileName = file.getName(); try (OutputStream os = Files.newOutputStream(file.toPath(),
String decryptedFileName = fileName.endsWith(".enc") StandardOpenOption.TRUNCATE_EXISTING)) {
? 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.write(decryptedBytes);
os.flush(); os.flush();
} }
return decryptedFile; return file;
} catch (Exception e) { } catch (Exception e) {
return null; return null;
} }

View File

@@ -0,0 +1,206 @@
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Path;
import top.gtb520.java.gnu.java.utils.library.utils.file.EncryptionAndDecryption;
import top.gtb520.java.gnu.java.utils.library.utils.file.EncryptionAndDecryption.EncryptionType;
public class EncryptionAndDecryptionTest {
static int passCount = 0;
static int failCount = 0;
public static void main(String[] args) throws Exception {
System.out.println("========== EncryptionAndDecryption 测试开始 ==========");
// 正常场景AES 加密/解密
testEncryptDecryptAES();
// 正常场景DES 加密/解密
testEncryptDecryptDES();
// 正常场景RSA 加密/解密
testEncryptDecryptRSA();
// 正常场景:验证密钥文件生成
testKeyFileGenerated();
// 正常场景:加密后文件内容发生变化
testFileContentChangedAfterEncrypt();
// 异常场景file 为 null
testNullFile();
// 异常场景keyPath 为 null
testNullKeyPath();
// 异常场景keyfile 为 null解密
testNullKeyFile();
// 异常场景:文件不存在
testFileNotExist();
// 异常场景:密钥文件不存在(解密)
testKeyFileNotExist();
System.out.println("========== 测试结果 ==========");
System.out.println("通过: " + passCount);
System.out.println("失败: " + failCount);
System.out.println("总计: " + (passCount + failCount));
if (failCount > 0) {
System.out.println("存在失败的测试用例!");
System.exit(1);
} else {
System.out.println("全部测试通过!");
}
}
/**
* 创建临时测试文件并写入测试内容
*/
static File createTempFile(String prefix) throws Exception {
Path tempDir = Files.createTempDirectory("enc_test_");
File tempFile = tempDir.resolve(prefix + ".txt").toFile();
Files.writeString(tempFile.toPath(), "Hello, EncryptionAndDecryption Test! 测试内容123");
return tempFile;
}
/**
* 创建临时密钥目录
*/
static Path createTempKeyPath() throws Exception {
return Files.createTempDirectory("enc_key_");
}
static void assertEquals(Object expected, Object actual, String testName) {
if (expected == null && actual == null) {
passCount++;
System.out.println("[PASS] " + testName);
} else if (expected != null && expected.equals(actual)) {
passCount++;
System.out.println("[PASS] " + testName);
} else {
failCount++;
System.out.println("[FAIL] " + testName + " | 期望: " + expected + ", 实际: " + actual);
}
}
static void assertTrue(boolean condition, String testName) {
if (condition) {
passCount++;
System.out.println("[PASS] " + testName);
} else {
failCount++;
System.out.println("[FAIL] " + testName);
}
}
// ==================== 正常场景 ====================
static void testEncryptDecryptAES() throws Exception {
String testName = "AES 加密后解密,内容还原";
File file = createTempFile("aes_test");
Path keyPath = createTempKeyPath();
String originalContent = Files.readString(file.toPath());
File encrypted = EncryptionAndDecryption.EncryptionFile(file, EncryptionType.AES, keyPath);
assertTrue(encrypted != null, testName + " - 加密返回非null");
File keyFile = keyPath.resolve(file.getName() + ".key").toFile();
File decrypted = EncryptionAndDecryption.DecryptionFile(file, EncryptionType.AES, keyFile);
assertTrue(decrypted != null, testName + " - 解密返回非null");
String decryptedContent = Files.readString(file.toPath());
assertEquals(originalContent, decryptedContent, testName);
}
static void testEncryptDecryptDES() throws Exception {
String testName = "DES 加密后解密,内容还原";
File file = createTempFile("des_test");
Path keyPath = createTempKeyPath();
String originalContent = Files.readString(file.toPath());
File encrypted = EncryptionAndDecryption.EncryptionFile(file, EncryptionType.DES, keyPath);
assertTrue(encrypted != null, testName + " - 加密返回非null");
File keyFile = keyPath.resolve(file.getName() + ".key").toFile();
File decrypted = EncryptionAndDecryption.DecryptionFile(file, EncryptionType.DES, keyFile);
assertTrue(decrypted != null, testName + " - 解密返回非null");
String decryptedContent = Files.readString(file.toPath());
assertEquals(originalContent, decryptedContent, testName);
}
static void testEncryptDecryptRSA() throws Exception {
String testName = "RSA 加密后解密,内容还原";
File file = createTempFile("rsa_test");
Path keyPath = createTempKeyPath();
String originalContent = Files.readString(file.toPath());
File encrypted = EncryptionAndDecryption.EncryptionFile(file, EncryptionType.RSA, keyPath);
assertTrue(encrypted != null, testName + " - 加密返回非null");
File keyFile = keyPath.resolve(file.getName() + ".key").toFile();
File decrypted = EncryptionAndDecryption.DecryptionFile(file, EncryptionType.RSA, keyFile);
assertTrue(decrypted != null, testName + " - 解密返回非null");
String decryptedContent = Files.readString(file.toPath());
assertEquals(originalContent, decryptedContent, testName);
}
static void testKeyFileGenerated() throws Exception {
String testName = "加密后密钥文件正确生成";
File file = createTempFile("key_test");
Path keyPath = createTempKeyPath();
EncryptionAndDecryption.EncryptionFile(file, EncryptionType.AES, keyPath);
File keyFile = keyPath.resolve(file.getName() + ".key").toFile();
assertTrue(keyFile.exists(), testName + " - 密钥文件存在");
assertTrue(keyFile.length() > 0, testName + " - 密钥文件非空");
}
static void testFileContentChangedAfterEncrypt() throws Exception {
String testName = "加密后文件内容与原文不同";
File file = createTempFile("content_test");
Path keyPath = createTempKeyPath();
byte[] originalBytes = Files.readAllBytes(file.toPath());
EncryptionAndDecryption.EncryptionFile(file, EncryptionType.AES, keyPath);
byte[] encryptedBytes = Files.readAllBytes(file.toPath());
assertTrue(!java.util.Arrays.equals(originalBytes, encryptedBytes), testName);
}
// ==================== 异常场景 ====================
static void testNullFile() throws Exception {
String testName = "file 为 null 时加密返回 null";
Path keyPath = createTempKeyPath();
File result = EncryptionAndDecryption.EncryptionFile(null, EncryptionType.AES, keyPath);
assertEquals(null, result, testName);
}
static void testNullKeyPath() throws Exception {
String testName = "keyPath 为 null 时加密返回 null";
File file = createTempFile("null_keypath");
File result = EncryptionAndDecryption.EncryptionFile(file, EncryptionType.AES, null);
assertEquals(null, result, testName);
}
static void testNullKeyFile() throws Exception {
String testName = "keyfile 为 null 时解密返回 null";
File file = createTempFile("null_keyfile");
File result = EncryptionAndDecryption.DecryptionFile(file, EncryptionType.AES, null);
assertEquals(null, result, testName);
}
static void testFileNotExist() throws Exception {
String testName = "文件不存在时加密返回 null";
Path keyPath = createTempKeyPath();
File notExist = new File("non_existent_file_12345.txt");
File result = EncryptionAndDecryption.EncryptionFile(notExist, EncryptionType.AES, keyPath);
assertEquals(null, result, testName);
}
static void testKeyFileNotExist() throws Exception {
String testName = "密钥文件不存在时解密返回 null";
File file = createTempFile("no_keyfile");
File notExistKey = new File("non_existent_key_12345.key");
File result = EncryptionAndDecryption.DecryptionFile(file, EncryptionType.AES, notExistKey);
assertEquals(null, result, testName);
}
}