我想加密test.txt文件我正在使用这个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 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)