From 0d1bdc501cb932c9d270fb0e01bead2d6d04b3ab Mon Sep 17 00:00:00 2001 From: SoniEx2 Date: Tue, 26 Jul 2022 16:33:32 -0300 Subject: Finish world codes --- .../java/ganarchy/friendcode/util/ConfigUtil.java | 5 +- .../java/ganarchy/friendcode/util/KeyUtil.java | 109 ++++++++++++++++++++- 2 files changed, 107 insertions(+), 7 deletions(-) diff --git a/src/main/java/ganarchy/friendcode/util/ConfigUtil.java b/src/main/java/ganarchy/friendcode/util/ConfigUtil.java index b2d6af2..66d497f 100644 --- a/src/main/java/ganarchy/friendcode/util/ConfigUtil.java +++ b/src/main/java/ganarchy/friendcode/util/ConfigUtil.java @@ -22,8 +22,9 @@ public class ConfigUtil { * The message stored in the config. Could probably use some improvement. */ private static final String CONFIG_MESSAGE = - "This is the friendcode config file." - + " It's created when you open your world to a friend code."; + "THIS FILE CONTAINS SECRETS! This is the friendcode config file." + + " It's created when you open your world to a friend code." + + " Keep it private. And make a backup."; /** * The (cached) global friendcode config dir. */ diff --git a/src/main/java/ganarchy/friendcode/util/KeyUtil.java b/src/main/java/ganarchy/friendcode/util/KeyUtil.java index ab5d614..79a6a45 100644 --- a/src/main/java/ganarchy/friendcode/util/KeyUtil.java +++ b/src/main/java/ganarchy/friendcode/util/KeyUtil.java @@ -1,11 +1,27 @@ package ganarchy.friendcode.util; +import org.apache.commons.codec.binary.Base64; + +import javax.crypto.*; +import javax.crypto.spec.GCMParameterSpec; +import javax.crypto.spec.SecretKeySpec; +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; import java.nio.file.Path; +import java.security.*; +import java.util.Properties; /** * Helper to deal with private keys. */ public class KeyUtil { + // it is important to use encryption, as you don't want random users + // hosting the world code. by encrypting the world code to an user, it + // prevents that. + // then you can freely share the world files and nothing bad happens. + /** * Reads and decrypts a private key file. * @@ -13,18 +29,101 @@ public class KeyUtil { * @return The decrypted private key, or null if it doesn't exist. */ public static String readKeyFile(Path keyFile) { - return null; + byte[] file; + byte[] out; + try { + file = Files.readAllBytes(keyFile); + } catch (IOException e) { + return null; + } + if (file.length < 12 + 16 + 884) { // 12 (IV) + 16 (tag) + 884 (key) + return null; + } + try { + var c = Cipher.getInstance("AES/GCM/NoPadding"); + Key key = getGlobalKey(); + byte[] iv = new byte[12]; + System.arraycopy(file, 0, iv, 0, 12); + c.init(Cipher.DECRYPT_MODE, key, new GCMParameterSpec(128, iv)); + out = c.doFinal(file, 12, file.length - 12); + } catch (AEADBadTagException e) { + return null; + } catch ( + NoSuchAlgorithmException | NoSuchPaddingException + | InvalidAlgorithmParameterException | InvalidKeyException + | IllegalBlockSizeException | BadPaddingException e + ) { + throw new RuntimeException(e); + } + return StandardCharsets.UTF_8.decode(ByteBuffer.wrap(out)).toString(); } /** * Encrypts and writes a private key file. * - * @param keyFile The path to the key file. - * @param key The private key. + * @param keyFile The path to the key file. + * @param privateKey The private key. * @return Whether writing the key succeeded. */ - public static boolean writeKeyFile(Path keyFile, String key) { - return false; + public static boolean writeKeyFile(Path keyFile, String privateKey) { + byte[] in = privateKey.getBytes(StandardCharsets.UTF_8); + byte[] iv = new byte[12]; + byte[] out; + try { + var c = Cipher.getInstance("AES/GCM/NoPadding"); + Key key = getGlobalKey(); + var rand = new SecureRandom(); + rand.nextBytes(iv); + c.init(Cipher.ENCRYPT_MODE, key, new GCMParameterSpec(128, iv)); + out = c.doFinal(in, 0, in.length); + } catch ( + NoSuchAlgorithmException | NoSuchPaddingException + | InvalidAlgorithmParameterException | InvalidKeyException + | IllegalBlockSizeException | BadPaddingException e + ) { + throw new RuntimeException(e); + } + try (var file = Files.newOutputStream(keyFile)) { + file.write(iv); + file.write(out); + file.flush(); + return true; + } catch (IOException e) { + return false; + } + } + + /** + * Returns the global key used for the encryption/decryption of world keys. + */ + private static Key getGlobalKey() { + Properties prop = new Properties(); + if (ConfigUtil.getSettings(prop)) { + var key = prop.getProperty("key.aes"); + if (key != null) { + byte[] bytes = null; + try { + bytes = Base64.decodeBase64(key); + } catch (IllegalArgumentException ignored) { + } + if (bytes != null && bytes.length == 16) { + return new SecretKeySpec(bytes, "AES"); + } + } + } + prop.clear(); + try { + var gen = KeyGenerator.getInstance("AES"); + gen.init(128); + Key key = gen.generateKey(); + var encoded = Base64.encodeBase64String(key.getEncoded()); + prop.setProperty("key.aes", encoded); + // if the key didn't save we'll just regen world codes. + ConfigUtil.updateSettings(prop); + return key; + } catch (NoSuchAlgorithmException e) { + throw new RuntimeException(e); + } } } -- cgit 1.4.1