Java 如何使用RSA和AES算法对文件进行加密和解密
我想加密test.txt文件,我使用这个java类进行加密和解密。在我的目录中,我有三个文件private.txt用于保存私钥,public.txt用于公钥,test.txt用于加密Java 如何使用RSA和AES算法对文件进行加密和解密,java,jce,Java,Jce,我想加密test.txt文件,我使用这个java类进行加密和解密。在我的目录中,我有三个文件private.txt用于保存私钥,public.txt用于公钥,test.txt用于加密 package EncryptionDecryption; import java.io.BufferedInputStream; public class EncryptionUtil { /** * String to hold name of the e
package EncryptionDecryption;
import java.io.BufferedInputStream;
public class EncryptionUtil {
/**
* String to hold name of the encryption algorithm.
*/
public static final String ALGORITHM = "RSA";
/**
* String to hold the name of the private key file.
*/
public static final String PRIVATE_KEY_FILE = "private.txt";
/**
* String to hold name of the public key file.
*/
public static final String PUBLIC_KEY_FILE = "public.txt";
public static void generateKey() {
try {
final KeyPairGenerator keyGen = KeyPairGenerator.getInstance(ALGORITHM);
keyGen.initialize(1024);
final KeyPair key = keyGen.generateKeyPair();
File privateKeyFile = new File(PRIVATE_KEY_FILE);
File publicKeyFile = new File(PUBLIC_KEY_FILE);
// Create files to store public and private key
if (privateKeyFile.getParentFile() != null) {
privateKeyFile.getParentFile().mkdirs();
}
privateKeyFile.createNewFile();
if (publicKeyFile.getParentFile() != null) {
publicKeyFile.getParentFile().mkdirs();
}
publicKeyFile.createNewFile();
// Saving the Public key in a file
ObjectOutputStream publicKeyOS = new ObjectOutputStream(
new FileOutputStream(publicKeyFile));
publicKeyOS.writeObject(key.getPublic());
System.out.println("public"+key.getPublic().getEncoded());
publicKeyOS.close();
// Saving the Private key in a file
ObjectOutputStream privateKeyOS = new ObjectOutputStream(
new FileOutputStream(privateKeyFile));
privateKeyOS.writeObject(key.getPrivate());
System.out.println("private"+key.getPrivate().getEncoded());
//System.out.println(key.getPrivate());
privateKeyOS.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static boolean areKeysPresent() {
File privateKey = new File(PRIVATE_KEY_FILE);
File publicKey = new File(PUBLIC_KEY_FILE);
if (privateKey.exists() && publicKey.exists()) {
return true;
}
return false;
}
public static byte[] encrypt(byte[]bs, PublicKey key) {
byte[] cipherText = null;
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance(ALGORITHM);
// encrypt the plain text using the public key
cipher.init(Cipher.ENCRYPT_MODE, key);
cipherText = cipher.doFinal(bs);
} catch (Exception e) {
e.printStackTrace();
}
return cipherText;
}
public static String decrypt(byte[] text, PrivateKey key) {
byte[] dectyptedText = null;
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance(ALGORITHM);
// decrypt the text using the private key
cipher.init(Cipher.DECRYPT_MODE, key);
dectyptedText = cipher.doFinal(text);
} catch (Exception ex) {
ex.printStackTrace();
}
return new String(dectyptedText);
}
public static void main(String[] args)throws IOException {
System.out.println("Hai");
try {
// Check if the pair of keys are present else generate those.
generateKey();
File f=new File("test.txt");
byte[] contents = new byte[(int)f.length()];
BufferedInputStream bis = null;
try
{
bis = new BufferedInputStream(new FileInputStream(f));
DataInputStream dis = new DataInputStream(bis);
dis.readFully(contents);
}
finally
{
if(bis != null)
{
bis.close();
}
}
// final String originalText = "Text to be encrypted";
// Encrypt the string using the public key
ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream(PUBLIC_KEY_FILE));
final PublicKey publicKey = (PublicKey) inputStream.readObject();
final byte[] cipherText = encrypt(contents, publicKey);
inputStream.close();
// Decrypt the cipher text using the private key.
ObjectInputStream inputStream1 = new ObjectInputStream(new FileInputStream(PRIVATE_KEY_FILE));
final PrivateKey privateKey = (PrivateKey) inputStream1.readObject();
final String plainText = decrypt(cipherText, privateKey);
// Printing the Original, Encrypted and Decrypted Text
System.out.println("Original Text: " + contents.toString());
System.out.println("Encrypted Text: " +cipherText);
System.out.println("Decrypted Text: " + plainText);
inputStream.close();
inputStream1.close();
} catch (Exception e) {
e.printStackTrace();
}
finally
{
}
}
}
I got this error when debugging
I
public[B@f73c1
private[B@15b9e68
javax.crypto.IllegalBlockSizeException: Data must not be longer than 117 bytes
at com.sun.crypto.provider.RSACipher.a(DashoA13*..)
at com.sun.crypto.provider.RSACipher.engineDoFinal(DashoA13*..)
at javax.crypto.Cipher.doFinal(DashoA13*..)
at EncryptionDecryption.EncryptionUtil.encrypt(EncryptionUtil.java:122)
at EncryptionDecryption.EncryptionUtil.main(EncryptionUtil.java:193)
java.lang.IllegalArgumentException: Null input buffer
at javax.crypto.Cipher.doFinal(DashoA13*..)
at EncryptionDecryption.EncryptionUtil.decrypt(EncryptionUtil.java:147)
at EncryptionDecryption.EncryptionUtil.main(EncryptionUtil.java:198)
java.lang.NullPointerException
at java.lang.String.<init>(String.java:593)
at EncryptionDecryption.EncryptionUtil.decrypt(EncryptionUtil.java:153)
at EncryptionDecryption.EncryptionUtil.main(EncryptionUtil.java:198)
包加密解密;
导入java.io.BufferedInputStream;
公共类EncryptionUtil{
/**
*用于保存加密算法名称的字符串。
*/
公共静态最终字符串算法=“RSA”;
/**
*字符串以保存私钥文件的名称。
*/
公共静态最终字符串PRIVATE\u KEY\u FILE=“PRIVATE.txt”;
/**
*用于保存公钥文件名的字符串。
*/
公共静态最终字符串public\u KEY\u FILE=“public.txt”;
公共静态void generateKey(){
试一试{
final KeyPairGenerator keyGen=KeyPairGenerator.getInstance(算法);
密钥初始化(1024);
final KeyPair key=keyGen.generateKeyPair();
File privateKeyFile=新文件(私钥文件);
文件publicKeyFile=新文件(公钥文件);
//创建文件以存储公钥和私钥
if(privateKeyFile.getParentFile()!=null){
privateKeyFile.getParentFile().mkdirs();
}
privateKeyFile.createNewFile();
如果(publicKeyFile.getParentFile()!=null){
publicKeyFile.getParentFile().mkdirs();
}
publicKeyFile.createNewFile();
//将公钥保存在文件中
ObjectOutputStream publicKeyOS=新的ObjectOutputStream(
新文件输出流(publicKeyFile));
publicKeyOS.writeObject(key.getPublic());
System.out.println(“public”+key.getPublic().getEncoded());
publicKeyOS.close();
//将私钥保存到文件中
ObjectOutputStream privateKeyOS=新的ObjectOutputStream(
新文件输出流(privateKeyFile));
writeObject(key.getPrivate());
System.out.println(“private”+key.getPrivate().getEncoded());
//System.out.println(key.getPrivate());
privateKeyOS.close();
}捕获(例外e){
e、 printStackTrace();
}
}
公共静态布尔值areKeysPresent(){
文件私钥=新文件(私钥文件);
文件公钥=新文件(公钥文件);
if(privateKey.exists()&&publicKey.exists()){
返回true;
}
返回false;
}
公共静态字节[]加密(字节[]bs,公钥){
字节[]密文=空;
试一试{
//获取RSA密码对象并打印提供程序
final Cipher=Cipher.getInstance(算法);
//使用公钥加密纯文本
cipher.init(cipher.ENCRYPT_模式,密钥);
密文=cipher.doFinal(bs);
}捕获(例外e){
e、 printStackTrace();
}
返回密文;
}
公共静态字符串解密(字节[]文本,私钥){
字节[]dectyptedText=null;
试一试{
//获取RSA密码对象并打印提供程序
final Cipher=Cipher.getInstance(算法);
//使用私钥解密文本
cipher.init(cipher.DECRYPT_模式,密钥);
dectyptedText=cipher.doFinal(文本);
}捕获(例外情况除外){
例如printStackTrace();
}
返回新字符串(dectyptedText);
}
公共静态void main(字符串[]args)引发IOException{
系统输出打印号(“Hai”);
试一试{
//检查这对密钥是否存在,否则生成这些密钥。
generateKey();
文件f=新文件(“test.txt”);
字节[]内容=新字节[(int)f.length()];
BufferedInputStream bis=null;
尝试
{
bis=新的BufferedInputStream(新的FileInputStream(f));
DataInputStream dis=新的DataInputStream(bis);
易于阅读(内容);
}
最后
{
如果(bis!=null)
{
二、关闭();
}
}
//最终字符串originalText=“要加密的文本”;
//使用公钥加密字符串
ObjectInputStream inputStream=新ObjectInputStream(新文件inputStream(公共密钥文件));
final PublicKey PublicKey=(PublicKey)inputStream.readObject();
最终字节[]密文=加密(内容,公钥);
inputStream.close();
//使用私钥解密密文。
ObjectInputStream inputStream1=新ObjectInputStream(新文件InputStream(私有密钥文件));
final PrivateKey PrivateKey=(PrivateKey)inputStream1.readObject();
最终字符串明文=解密(密文、私钥);
//打印原始、加密和解密文本
System.out.println(“原始文本:+contents.toString());
System.out.println(“加密文本:“+密文”);
System.out.println(“解密文本:+纯文本”);
inputStream.close();
inputStream1.close();
}捕获(例外e){
e、 printStackTrace();
}
最后
{
}
}
}
我在调试时遇到了这个错误
我
公开的[B@f73c1
私人的[B@15b9e68
javax.crypto.IllegalBlockSizeException:数据长度不得超过117字节
在com.sun.crypto.provider.rsacyper.a(DashoA13*)上
在com.sun.crypto.provider.rsacyper.engineDoFinal(DashoA13*)上
位于javax.crypto.Cipher.doFinal(DashoA13*)
在EncryptionDecryption.EncryptionUtil.encrypt处(EncryptionUtil.java:122)
位于EncryptionDecryption.EncryptionUtil.main(EncryptionUtil.java:193)
java.lang.I