Estoy desesperada con un tema del "FileEncryption", es una tonteria lo que me queda, pero no lo consigo...He encontrado este fichero que encripta/desencripta.
openssl genrsa -out private.pem 2048
To get it into the required (PKCS#8, DER) format:
openssl pkcs8 -topk8 -in private.pem -outform DER -out private.der -nocrypt
To generate a public key from the private key:
openssl rsa -in private.pem -pubout -outform DER -out public.der
An example of how to use the code:
FileEncryption secure = new FileEncryption();
// to encrypt a file
secure.makeKey();
secure.saveKey(encryptedKeyFile, publicKeyFile);
secure.encrypt(fileToEncrypt, encryptedFile);
// to decrypt it again
secure.loadKey(encryptedKeyFile, privateKeyFile);
secure.decrypt(encryptedFile, unencryptedFile);
¿¿¿¿¿¿¿Qué tipo de fichero es "encryptedKeyFile????????¿¿Qué extensión le pongo???? he probado con .key, .pem, sin extensión etc.. y siempre me da el error "invalid key format"...ayudadme plisssssssssss
Código:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
public class FileEncryption {
private static final int AES_Key_Size = 256;
Cipher pkCipher, aesCipher;
byte[] aesKey;
SecretKeySpec aeskeySpec;
/**
* Constructor: creates ciphers
*/
public FileEncryption() throws GeneralSecurityException {
Provider sunjce = new com.sun.crypto.provider.SunJCE();
Security.addProvider(sunjce);
// create RSA public key cipher
pkCipher = Cipher.getInstance("RSA");
// create AES shared key cipher
aesCipher = Cipher.getInstance("AES");
}
/**
* Creates a new AES key
*/
public void makeKey() throws NoSuchAlgorithmException {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(AES_Key_Size);
SecretKey key = kgen.generateKey();
aesKey = key.getEncoded();
aeskeySpec = new SecretKeySpec(aesKey, "AES");
}
/**
* Decrypts an AES key from a file using an RSA private key
*/
public void loadKey(File in, File privateKeyFile) throws GeneralSecurityException, IOException {
// read private key to be used to decrypt the AES key
byte[] encodedKey = new byte[(int)privateKeyFile.length()];
new FileInputStream(privateKeyFile).read(encodedKey);
// create private key
PKCS8EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(encodedKey);
KeyFactory kf = KeyFactory.getInstance("RSA");
PrivateKey pk = kf.generatePrivate(privateKeySpec);
// read AES key
pkCipher.init(Cipher.DECRYPT_MODE, pk);
aesKey = new byte[AES_Key_Size/8];
CipherInputStream is = new CipherInputStream(new FileInputStream(in), pkCipher);
is.read(aesKey);
aeskeySpec = new SecretKeySpec(aesKey, "AES");
System.out.println("Private AES key loaded.");
}
/**
* Encrypts the AES key to a file using an RSA public key
*/
public void saveKey(File out, File publicKeyFile) throws IOException, GeneralSecurityException {
// read public key to be used to encrypt the AES key
byte[] encodedKey = new byte[(int)publicKeyFile.length()];
new FileInputStream(publicKeyFile).read(encodedKey);
// create public key
X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(encodedKey);
KeyFactory kf = KeyFactory.getInstance("RSA");
PublicKey pk = kf.generatePublic(publicKeySpec);
// write AES key
pkCipher.init(Cipher.ENCRYPT_MODE, pk);
CipherOutputStream os = new CipherOutputStream(new FileOutputStream(out), pkCipher);
os.write(aesKey);
System.out.println("Written AES key " + new String(aesKey));
os.close();
}
/**
* Encrypts and then copies the contents of a given file.
*/
public void encrypt(File in, File out) throws IOException,
InvalidKeyException,
NoSuchAlgorithmException,
NoSuchPaddingException {
// aesCipher = Cipher.getInstance("AES");
aesCipher.init(Cipher.ENCRYPT_MODE, aeskeySpec);
FileInputStream is = new FileInputStream(in);
CipherOutputStream os = new CipherOutputStream(new FileOutputStream(out), aesCipher);
Long fileLength = in.length();
System.out.println("File to encrypt: " + in.getName() + "; length: " + fileLength.toString() + " bytes.");
copy(is, os);
os.close();
System.out.println("Encryption performed. Output in " + out.getAbsolutePath());
}
/**
* Decrypts and then copies the contents of a given file.
*/
public void decrypt(File in, File out) throws IOException, InvalidKeyException {
aesCipher.init(Cipher.DECRYPT_MODE, aeskeySpec);
Long fileLength;
CipherInputStream is = new CipherInputStream(new FileInputStream(in), aesCipher);
FileOutputStream os = new FileOutputStream(out);
copy(is, os);
is.close();
os.close();
fileLength = out.length();
System.out.println("New file decrypted: " + out.getAbsolutePath() + "; length: " + fileLength.toString() + " bytes.");
}
/**
* Copies a stream.
*/
private void copy(InputStream is, OutputStream os) throws IOException {
int i;
byte[] b = new byte[1024];
while((i=is.read(b))!=-1) {
os.write(b, 0, i);
}
}
}
