Java AES文件加解密
之前写了DES加解密，AES几乎与之相同，不同的是底层key的位数而已，不过这些对于我们使用者都是透明的。
AESUtils.java
package demo.security; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.security.Key; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.CipherInputStream; import javax.crypto.CipherOutputStream; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; /** * <p> * AES加密解密工具包 * </p> * * @author IceWee * @date 2012-5-18 * @version 1.0 */ public class AESUtils { private static final String ALGORITHM = "AES"; private static final int KEY_SIZE = 128; private static final int CACHE_SIZE = 1024; /** * <p> * 生成随机密钥 * </p> * * @return * @throws Exception */ public static String getSecretKey() throws Exception { return getSecretKey(null); } /** * <p> * 生成密钥 * </p> * * @param seed 密钥种子 * @return * @throws Exception */ public static String getSecretKey(String seed) throws Exception { KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM); SecureRandom secureRandom; if (seed != null && !"".equals(seed)) { secureRandom = new SecureRandom(seed.getBytes()); } else { secureRandom = new SecureRandom(); } keyGenerator.init(KEY_SIZE, secureRandom); SecretKey secretKey = keyGenerator.generateKey(); return Base64Utils.encode(secretKey.getEncoded()); } /** * <p> * 加密 * </p> * * @param data * @param key * @return * @throws Exception */ public static byte[] encrypt(byte[] data, String key) throws Exception { Key k = toKey(Base64Utils.decode(key)); byte[] raw = k.getEncoded(); SecretKeySpec secretKeySpec = new SecretKeySpec(raw, ALGORITHM); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec); return cipher.doFinal(data); } /** * <p> * 文件加密 * </p> * * @param key * @param sourceFilePath * @param destFilePath * @throws Exception */ public static void encryptFile(String key, String sourceFilePath, String destFilePath) throws Exception { File sourceFile = new File(sourceFilePath); File destFile = new File(destFilePath); if (sourceFile.exists() && sourceFile.isFile()) { if (!destFile.getParentFile().exists()) { destFile.getParentFile().mkdirs(); } destFile.createNewFile(); InputStream in = new FileInputStream(sourceFile); OutputStream out = new FileOutputStream(destFile); Key k = toKey(Base64Utils.decode(key)); byte[] raw = k.getEncoded(); SecretKeySpec secretKeySpec = new SecretKeySpec(raw, ALGORITHM); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec); CipherInputStream cin = new CipherInputStream(in, cipher); byte[] cache = new byte[CACHE_SIZE]; int nRead = 0; while ((nRead = cin.read(cache)) != -1) { out.write(cache, 0, nRead); out.flush(); } out.close(); cin.close(); in.close(); } } /** * <p> * 解密 * </p> * * @param data * @param key * @return * @throws Exception */ public static byte[] decrypt(byte[] data, String key) throws Exception { Key k = toKey(Base64Utils.decode(key)); byte[] raw = k.getEncoded(); SecretKeySpec secretKeySpec = new SecretKeySpec(raw, ALGORITHM); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.DECRYPT_MODE, secretKeySpec); return cipher.doFinal(data); } /** * <p> * 文件解密 * </p> * * @param key * @param sourceFilePath * @param destFilePath * @throws Exception */ public static void decryptFile(String key, String sourceFilePath, String destFilePath) throws Exception { File sourceFile = new File(sourceFilePath); File destFile = new File(destFilePath); if (sourceFile.exists() && sourceFile.isFile()) { if (!destFile.getParentFile().exists()) { destFile.getParentFile().mkdirs(); } destFile.createNewFile(); FileInputStream in = new FileInputStream(sourceFile); FileOutputStream out = new FileOutputStream(destFile); Key k = toKey(Base64Utils.decode(key)); byte[] raw = k.getEncoded(); SecretKeySpec secretKeySpec = new SecretKeySpec(raw, ALGORITHM); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.DECRYPT_MODE, secretKeySpec); CipherOutputStream cout = new CipherOutputStream(out, cipher); byte[] cache = new byte[CACHE_SIZE]; int nRead = 0; while ((nRead = in.read(cache)) != -1) { cout.write(cache, 0, nRead); cout.flush(); } cout.close(); out.close(); in.close(); } } /** * <p> * 转换密钥 * </p> * * @param key * @return * @throws Exception */ private static Key toKey(byte[] key) throws Exception { SecretKey secretKey = new SecretKeySpec(key, ALGORITHM); return secretKey; } }
Base64Utils.java（依赖javabase64-1.3.1.jar）
package demo.security; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import it.sauronsoftware.base64.Base64; /** * <p> * BASE64编码解码工具包 * </p> * <p> * 依赖javabase64-1.3.1.jar * </p> * * @author IceWee * @date 2012-5-19 * @version 1.0 */ public class Base64Utils { /** * 文件读取缓冲区大小 */ private static final int CACHE_SIZE = 1024; /** * <p> * BASE64字符串解码为二进制数据 * </p> * * @param base64 * @return * @throws Exception */ public static byte[] decode(String base64) throws Exception { return Base64.decode(base64.getBytes()); } /** * <p> * 二进制数据编码为BASE64字符串 * </p> * * @param bytes * @return * @throws Exception */ public static String encode(byte[] bytes) throws Exception { return new String(Base64.encode(bytes)); } /** * <p> * 将文件编码为BASE64字符串 * </p> * <p> * 大文件慎用，可能会导致内存溢出 * </p> * * @param filePath 文件绝对路径 * @return * @throws Exception */ public static String encodeFile(String filePath) throws Exception { byte[] bytes = fileToByte(filePath); return encode(bytes); } /** * <p> * BASE64字符串转回文件 * </p> * * @param filePath 文件绝对路径 * @param base64 编码字符串 * @throws Exception */ public static void decodeToFile(String filePath, String base64) throws Exception { byte[] bytes = decode(base64); byteArrayToFile(bytes, filePath); } /** * <p> * 文件转换为二进制数组 * </p> * * @param filePath 文件路径 * @return * @throws Exception */ public static byte[] fileToByte(String filePath) throws Exception { byte[] data = new byte[0]; File file = new File(filePath); if (file.exists()) { FileInputStream in = new FileInputStream(file); ByteArrayOutputStream out = new ByteArrayOutputStream(2048); byte[] cache = new byte[CACHE_SIZE]; int nRead = 0; while ((nRead = in.read(cache)) != -1) { out.write(cache, 0, nRead); out.flush(); } out.close(); in.close(); data = out.toByteArray(); } return data; } /** * <p> * 二进制数据写文件 * </p> * * @param bytes 二进制数据 * @param filePath 文件生成目录 */ public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception { InputStream in = new ByteArrayInputStream(bytes); File destFile = new File(filePath); if (!destFile.getParentFile().exists()) { destFile.getParentFile().mkdirs(); } destFile.createNewFile(); OutputStream out = new FileOutputStream(destFile); byte[] cache = new byte[CACHE_SIZE]; int nRead = 0; while ((nRead = in.read(cache)) != -1) { out.write(cache, 0, nRead); out.flush(); } out.close(); in.close(); } }
AESTester.java
package demo.security; public class AESTester { static String key; static { try { key = AESUtils.getSecretKey(); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) throws Exception { long begin = System.currentTimeMillis(); encryptFile(); decryptFile(); test(); long end = System.currentTimeMillis(); System.err.println("耗时：" + (end-begin)/1000 + "秒"); } static void encryptFile() throws Exception { String sourceFilePath = "D:/demo.mp4"; String destFilePath = "D:/demo_encrypted.mp4"; AESUtils.encryptFile(key, sourceFilePath, destFilePath); } static void decryptFile() throws Exception { String sourceFilePath = "D:/demo_encrypted.mp4"; String destFilePath = "D:/demo_decrypted.mp4"; AESUtils.decryptFile(key, sourceFilePath, destFilePath); } static void test() throws Exception { String source = "这是一行测试DES加密/解密的文字，你看完也等于没看，是不是啊？！"; System.err.println("原文:\t" + source); byte[] inputData = source.getBytes(); inputData = AESUtils.encrypt(inputData, key); System.err.println("加密后:\t" + Base64Utils.encode(inputData)); byte[] outputData = AESUtils.decrypt(inputData, key); String outputStr = new String(outputData); System.err.println("解密后:\t" + outputStr); } }
