白猫プロジェクトや黒猫のウィズで有名なコロプラさんの暗号技術がゴミだった話 その2

    private static byte[] getByteArray(String s) {
        int len = s.length();
        byte [] data = new byte[len /2];
        for(int i = 0; i <= len ;i+=2) {
            data[i/2] = (byte) (Character.digit(s.charAt(i),16) << 4 + Character.digit(s.charAt(i+1),16));
        }
        return data;
    }

    public static String encrypt(String text) {
        try {
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.ENCRYPT_MODE, (SecretKeySpec)getKeySpec());
            return getHexString(cipher.doFinal(text.getBytes()));
        } catch(Exception e) {
            return "";
        }
    }

    public static String decrypt(String encrypted) {
        try {
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.DECRYPT_MODE, (SecretKeySpec)getKeySpec());
            return new String (cipher.doFinal(getByteArray(encrypted)), "UTF-8");
        } catch(Exception e) {
            return "";
        }
    }

    public static String encryptMD5(String text) {
        try {
            MessageDigest digest = MessageDigest.getInstance("MD5");
            digest.update(text.getBytes());
            return getHexString(digest.digest());
        } catch(Exception e) {
            return "";
        }
    }

    public static String getMD5withSalt(String rawString, String salt) {
        try {
            return encryptMD5(rawString + salt);
        } catch(Exception e) {
            return "";
        }
    }

    public static String getUniqueId() {
        String KEY = "e87e03526ab";
        try {
            String deviceid = Settings.Secure.getString(applicationContext.getContentResolver(), "android_id");
            if (deviceid==null) {
                deviceid="ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff";
            }
            String encrypted = encryptMD5(deviceid + ":" + KEY);
            return encrypt(ver + ":" + encrypted);
        } catch(Exception e) {
            Log.d("test",e.toString());
            return "";
        }
    }

    public static String getDeviceIdFromUUID() {
        String prefKey = "KUMA_API_DEVICE_ID_UUID";
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(applicationContext);
        String deviceid = prefs.getString(prefKey,"");
        if(deviceid.length() == 0 ) {
            String guestSeed = getGuestSeed();
            StringBuilder result = new StringBuilder();
            result.append(randomUUID().toString());
            result.append(guestSeed);
            deviceid = result.toString();
            SharedPreferences.Editor editor = prefs.edit();
            editor.putString(prefKey, deviceid);
            editor.commit();
        }
        return deviceid;
    }