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package pl.edu.mimuw.cloudatlas.querysigner;
import pl.edu.mimuw.cloudatlas.model.ValueQuery;
import pl.edu.mimuw.cloudatlas.querysignerapi.QuerySignerApi;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import java.rmi.RemoteException;
import java.security.*;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
public class QuerySignerApiImplementation implements QuerySignerApi {
private PublicKey publicKey;
private PrivateKey privateKey;
private final static String ENCRYPTION_ALGORITHM = "RSA";
private final static int NUM_KEY_BITS = 1024;
private Map<String, ValueQuery> queries;
private Set<String> attribsSetByQueries;
QuerySignerApiImplementation() {
this.queries = new HashMap<>();
this.attribsSetByQueries = new HashSet<>();
try {
generateKeys();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
}
private String byteArrayToString(byte[] arr, int offset, int len) {
StringBuffer sb = new StringBuffer();
for (int i = offset, n = Math.min(arr.length, offset + len); i < n; ++i) {
String hex = Integer.toHexString(0xFF & arr[i]);
if (hex.length() < 2) {
sb.append('0');
}
sb.append(hex);
}
return sb.toString();
}
private void generateKeys() throws NoSuchAlgorithmException {
KeyPairGenerator keyGenerator =
KeyPairGenerator.getInstance(ENCRYPTION_ALGORITHM);
keyGenerator.initialize(NUM_KEY_BITS);
KeyPair keyPair = keyGenerator.generateKeyPair();
this.privateKey = keyPair.getPrivate();
this.publicKey = keyPair.getPublic();
}
private byte[] encryptQuery(String query) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
Cipher signCipher = Cipher.getInstance(ENCRYPTION_ALGORITHM);
signCipher.init(Cipher.ENCRYPT_MODE, privateKey);
byte[] encryptedBytes = signCipher.doFinal(query.getBytes());
System.out.println(
"Bytes encrypted with " + ENCRYPTION_ALGORITHM +
": " + byteArrayToString(
encryptedBytes, 0, encryptedBytes.length));
return encryptedBytes;
}
private String decryptQuery(byte[] encryptedQuery) throws NoSuchPaddingException, NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException, InvalidKeyException {
Cipher verifyCipher = Cipher.getInstance(ENCRYPTION_ALGORITHM);
verifyCipher.init(Cipher.DECRYPT_MODE, publicKey);
byte[] decryptedBytes = verifyCipher.doFinal(encryptedQuery);
System.out.println(
"Bytes decrypted with " + ENCRYPTION_ALGORITHM +
": " + byteArrayToString(
decryptedBytes, 0, decryptedBytes.length));
return new String(decryptedBytes);
}
@Override
public byte[] signQuery(String queryName, String queryCode) throws RemoteException {
try {
return encryptQuery(queryName + queryCode);
} catch (NoSuchPaddingException | NoSuchAlgorithmException | InvalidKeyException | BadPaddingException | IllegalBlockSizeException e) {
e.printStackTrace();
throw new RemoteException(e.getLocalizedMessage());
}
}
@Override
public String checkQuery(byte[] encryptedQuery, String queryName, String queryCode) throws RemoteException {
try {
return decryptQuery(encryptedQuery);
} catch (NoSuchPaddingException | NoSuchAlgorithmException | BadPaddingException | IllegalBlockSizeException | InvalidKeyException e) {
e.printStackTrace();
throw new RemoteException(e.getLocalizedMessage());
}
}
@Override
public PublicKey getPublicKey() throws RemoteException {
return publicKey;
}
@Override
public void setPublicKey(PublicKey publicKey) throws RemoteException {
this.publicKey = publicKey;
}
@Override
public byte[] getQuerySignature(String queryName) throws RemoteException {
return queries.get(queryName).getSignature();
}
}
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