Review

Uses DSA with defaults which is considered a bad practice.

• missing/condition/value_or_state

org/network/stcp/server/SecureConnectionHandler.java

run()

class SecureConnectionHandler {
	@Override
	public void run() {
		InputStream is;
		OutputStream os;
		try {
			is = socket.getInputStream();
			os = socket.getOutputStream();
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
		Certificate certificate = CertificateManager.getInstance().getCertificate();
		Key privateKey = CertificateManager.getInstance().getPrivateKey();
		byte[] certBytes;
		try {
			certBytes = certificate.getEncoded();
			//send the certificate
			os.write(certBytes);
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			byte[] buffer = new byte[1024];
			while (is.read(buffer) != -1) {
				baos.write(buffer);
			}
			byte[] keyPacketEncrypted = baos.toByteArray();
			Cipher privateCipher = Cipher.getInstance("DSA");
			privateCipher.init(Cipher.DECRYPT_MODE, privateKey);
			byte[] keyPacketDecrypted = privateCipher.doFinal(keyPacketEncrypted);

			SecretKey secretKey = new SecretKeySpec(keyPacketDecrypted, "DSA");
			Cipher communicationCipher = Cipher.getInstance("DSA");
			communicationCipher.init(Cipher.DECRYPT_MODE, secretKey);
			byte[] dataBuffer = new byte[1024 * 4];
			while (is.read(dataBuffer) != -1) {
				byte[] encryptedData = communicationCipher.doFinal(dataBuffer);
				handler.handle(encryptedData);
			}
		} catch (CertificateEncodingException e) {
			throw new RuntimeException(e);
		} catch (IOException e) {
			throw new RuntimeException(e);
		} catch (NoSuchAlgorithmException e) {
			throw new RuntimeException(e);
		} catch (NoSuchPaddingException e) {
			throw new RuntimeException(e);
		} catch (InvalidKeyException e) {
			throw new RuntimeException(e);
		} catch (BadPaddingException e) {
			throw new RuntimeException(e);
		} catch (IllegalBlockSizeException e) {
			throw new RuntimeException(e);
		}
	}

}