1 files changed, 141 insertions, 0 deletions
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/querysigner/QuerySignerApiImplementation.java b/src/main/java/pl/edu/mimuw/cloudatlas/querysigner/QuerySignerApiImplementation.java
new file mode 100644
index 0000000..a6233d3
--- /dev/null
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/querysigner/QuerySignerApiImplementation.java
@@ -0,0 +1,141 @@
+package pl.edu.mimuw.cloudatlas.querysigner;
+
+import pl.edu.mimuw.cloudatlas.ByteSerializer;
+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 final static String ENCRYPTION_ALGORITHM = "RSA";
+    private final static String DIGEST_ALGORITHM = "SHA-256";
+    private PublicKey publicKey;
+    private PrivateKey privateKey;
+    private Map<String, QueryData> queries;
+    private Set<String> attribsSetByQueries;
+
+    public QuerySignerApiImplementation(PublicKey publicKey, PrivateKey privateKey) {
+        this.publicKey = publicKey;
+        this.privateKey = privateKey;
+        this.queries = new HashMap<>();
+        this.attribsSetByQueries = new HashSet<>();
+    }
+
+    private static 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 byte[] encryptQuery(byte[] query) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
+        Cipher signCipher = Cipher.getInstance(ENCRYPTION_ALGORITHM);
+        signCipher.init(Cipher.ENCRYPT_MODE, privateKey);
+        byte[] encryptedBytes = signCipher.doFinal(query);
+        System.out.println(
+                "Bytes encrypted with " + ENCRYPTION_ALGORITHM +
+                        ": " + byteArrayToString(
+                        encryptedBytes, 0, encryptedBytes.length));
+        return encryptedBytes;
+    }
+
+    private static byte[] decryptQuery(byte[] encryptedQuery, PublicKey publicKey) 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 decryptedBytes;
+    }
+
+    private static byte[] cryptographicHash(byte[] serializedQuery) throws NoSuchAlgorithmException {
+        MessageDigest digestGenerator =
+                MessageDigest.getInstance(DIGEST_ALGORITHM);
+        byte[] digest = digestGenerator.digest(serializedQuery);
+        System.out.println(
+                DIGEST_ALGORITHM + " digest: " +
+                        byteArrayToString(
+                                digest, 0, digest.length));
+        return digest;
+    }
+
+    private static byte[] serializeQuery(String queryName, String queryCode, Boolean install) {
+        ByteSerializer byteSerializer = new ByteSerializer();
+        if (install) {
+            return byteSerializer.serialize(queryName + queryCode + install.toString());
+        } else {
+            return byteSerializer.serialize(queryName + install.toString());
+        }
+    }
+
+    private QueryData signQuery(String queryName, String queryCode, Boolean install) throws RemoteException {
+        QueryUtils.validateQueryName(queryName);
+        try {
+            byte[] serializedQuery = serializeQuery(queryName, queryCode, install);
+            byte[] hashedQuery = cryptographicHash(serializedQuery);
+            byte[] querySignature = encryptQuery(hashedQuery);
+            QueryData newQuery = new QueryData(queryCode, querySignature);
+            newQuery.setInstalled(install);
+            this.queries.put(queryName, newQuery);
+            return newQuery;
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new RemoteException(e.getLocalizedMessage());
+        }
+    }
+
+    @Override
+    public QueryData signInstallQuery(String queryName, String queryCode) throws RemoteException {
+        QueryUtils.validateQueryName(queryName);
+        if (this.queries.containsKey(queryName) && this.queries.get(queryName).isInstalled()) {
+            throw new RemoteException("Query already installed");
+        } else {
+            return signQuery(queryName, queryCode, true);
+        }
+    }
+
+    public static void validateInstallQuery(String queryName, QueryData query, PublicKey publicKey) throws RemoteException,IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException, QuerySigner.InvalidQueryException {
+        validateQuery(queryName, query, publicKey, true);
+    }
+
+    public static void validateQuery(String queryName, QueryData query, PublicKey publicKey, boolean install) throws RemoteException,IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException, QuerySigner.InvalidQueryException {
+        QueryUtils.validateQueryName(queryName);
+        byte[] decryptedQuery = decryptQuery(query.getSignature(), publicKey);
+        byte[] serializedQuery = serializeQuery(queryName, query.getCode(), install);
+        byte[] hashedSerializedQuery = cryptographicHash(serializedQuery);
+        String decryptedQueryString = byteArrayToString(decryptedQuery, 0, decryptedQuery.length);
+        String hashedSerializedQueryString = byteArrayToString(hashedSerializedQuery, 0, hashedSerializedQuery.length);
+        if (!decryptedQueryString.equals(hashedSerializedQueryString)) {
+            throw new QuerySigner.InvalidQueryException();
+        }
+    }
+
+    @Override
+    public QueryData signUninstallQuery(String queryName) throws RemoteException {
+        QueryUtils.validateQueryName(queryName);
+        if (this.queries.containsKey(queryName) && this.queries.get(queryName).isInstalled()) {
+            return signQuery(queryName, "", false);
+        } else {
+            throw new RemoteException("Query is not installed");
+        }
+    }
+
+    public static void validateUninstallQuery(String queryName, QueryData query, PublicKey publicKey) throws RemoteException, NoSuchAlgorithmException, IllegalBlockSizeException, BadPaddingException, QuerySigner.InvalidQueryException, NoSuchPaddingException, InvalidKeyException {
+        validateQuery(queryName, query, publicKey, false);
+    }
+}