From eb25f617604ba6df0af8e559f4d78083363dccce Mon Sep 17 00:00:00 2001
From: tuxuser <tuxuser360@gmail.com>
Date: Mon, 5 Feb 2018 15:50:51 +0100
Subject: [PATCH 1/4] More descriptive error msg when laf_crypto fails to
 import, py2 compat, pytest for crypto

---
 laf_crypto.py        | 21 +++++++++++++--------
 lglaf.py             | 17 +++++++++++------
 tests/conftest.py    |  5 +++++
 tests/test_crypto.py | 17 +++++++++++++++++
 4 files changed, 46 insertions(+), 14 deletions(-)
 create mode 100644 tests/conftest.py
 create mode 100644 tests/test_crypto.py

diff --git a/laf_crypto.py b/laf_crypto.py
index 16d87eb..fa7ea19 100644
--- a/laf_crypto.py
+++ b/laf_crypto.py
@@ -1,11 +1,16 @@
-from Crypto.Cipher import AES
+import struct
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+from cryptography.hazmat.backends import default_backend
 from lglaf import int_as_byte
 
 
 def key_transform(old_key):
     new_key = b''
     for x in range(32, 0, -1):
-        new_key += int_as_byte(old_key[x-1] - (x % 0x0C))
+        c = old_key[x-1]
+        if not isinstance(c, int):
+            c = ord(c)
+        new_key += int_as_byte(c - (x % 0x0C))
     return new_key
 
 
@@ -13,11 +18,10 @@ def xor_key(key, kilo_challenge):
     # Reserve key
     key_xor = b''
     pos = 0
+    challenge = struct.unpack('>I', kilo_challenge)[0]
     for i in range(8):
-        key_xor += int_as_byte(key[pos] ^ kilo_challenge[3])
-        key_xor += int_as_byte(key[pos + 1] ^ kilo_challenge[2])
-        key_xor += int_as_byte(key[pos + 2] ^ kilo_challenge[1])
-        key_xor += int_as_byte(key[pos + 3] ^ kilo_challenge[0])
+        k = struct.unpack('<I', key[pos:pos + 4])[0]
+        key_xor += struct.pack('<I', k ^ challenge)
         pos += 4
     return key_xor
 
@@ -29,5 +33,6 @@ def encrypt_kilo_challenge(encryption_key, kilo_challenge):
         plaintext += int_as_byte(k)
     encryption_key = key_transform(encryption_key)
     xored_key = xor_key(encryption_key, kilo_challenge)
-    obj = AES.new(xored_key, AES.MODE_ECB)
-    return obj.encrypt(plaintext)
+    obj = Cipher(algorithms.AES(xored_key), modes.ECB(),
+                 backend=default_backend()).encryptor()
+    return obj.update(plaintext) + obj.finalize()
diff --git a/lglaf.py b/lglaf.py
index 9e9e57f..3bef64d 100755
--- a/lglaf.py
+++ b/lglaf.py
@@ -24,16 +24,21 @@ except ImportError:
 _logger = logging.getLogger("LGLAF.py")
 
 # Python 2/3 compat
-try: input = raw_input
-except: pass
-if '\0' == b'\0': int_as_byte = chr
-else: int_as_byte = lambda x: bytes([x])
+try:
+    input = raw_input
+except:
+    pass
+
+if '\0' == b'\0':
+    int_as_byte = chr
+else:
+    int_as_byte = lambda x: bytes([x])
 
 # laf crypto for KILO challenge/response
 try:
     import laf_crypto
-except ImportError:
-    _logger.warning("LAF Crypto failed to import!")
+except ImportError as e:
+    _logger.warning("LAF Crypto failed to import! Error: %s" % e)
     pass
 
 # Use Manufacturer key for KILO challenge/response
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..ac1c209
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,5 @@
+import pytest
+
+@pytest.fixture(scope='session')
+def laf_key():
+    return b'qndiakxxuiemdklseqid~a~niq,zjuxl'
diff --git a/tests/test_crypto.py b/tests/test_crypto.py
new file mode 100644
index 0000000..2c82445
--- /dev/null
+++ b/tests/test_crypto.py
@@ -0,0 +1,17 @@
+from binascii import unhexlify
+import laf_crypto
+
+
+def test_transform(laf_key):
+    transformed = laf_crypto.key_transform(laf_key)
+    assert transformed == b'dqoev)ohnsWu\\bk`oiicmZ_lpqe\\ealp'
+
+def test_xor_key(laf_key):
+    transformed_key = b'dqoev)ohnsWu\\bk`oiicmZ_lpqe\\ealp'
+    challenge = unhexlify(b'f29ae130')
+    xored_key = laf_crypto.xor_key(transformed_key, challenge)
+    assert xored_key == b'T\x90\xf5\x97F\xc8\xf5\x9a^\x92\xcd\x87l\x83\xf1\x92_\x88\xf3\x91]\xbb\xc5\x9e@\x90\xff\xaeU\x80\xf6\x82'
+
+def test_challenge(laf_key):
+    resp = laf_crypto.encrypt_kilo_challenge(laf_key, unhexlify(b'f29ae130'))
+    assert resp == unhexlify(b'2f47ca81ebeee6f414263c0542c8d132')

From b5692d385a67654ef8b84b05d3f7f94924700a79 Mon Sep 17 00:00:00 2001
From: tuxuser <tuxuser360@gmail.com>
Date: Mon, 12 Mar 2018 22:38:41 +0100
Subject: [PATCH 2/4] README: Add link to cryptography lib, update Windows LG
 USB driver link

---
 README.md | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 231c589..b0ad961 100644
--- a/README.md
+++ b/README.md
@@ -20,10 +20,11 @@ LGLAF.py depends on:
 
  - Python 2.7 or 3: https://www.python.org/
  - (Windows) LG driver,
-   [LGMobileDriver\_WHQL\_Ver\_4.0.3.exe](http://18d5a.wpc.azureedge.net/8018D5A/tool/dn/downloader.dev?fileKey=UW00120120425)
-   (12986920 bytes,
-   sha256sum: 86e893b7f5da7f7d2656d9ce2563f082271983bb63903d0ed5cb279c560db459)
+   [LGMobileDriver\_WHQL\_Ver\_4.2.0.exe](http://oceanhost.eu/wylc5rg7a8ou/LGMobileDriver_WHQL_Ver_4.2.0.exe.htm)
+   (16691672 bytes,
+   sha256sum: d78ae6dfe7d34b9cabb8c4de5c6e734b6fed20b513d0da0183871bd77abba56c)
  - (Linux) PyUSB: https://walac.github.io/pyusb/
+ - Cryptography library: https://cryptography.io/en/latest/
 
 On Linux, you must also install
 [rules.d/42-usb-lglaf.rules](rules.d/42-usb-lglaf.rules) to `/etc/udev/rules.d/`

From d459dfe7192c200a76897d11f6419c251e9086ed Mon Sep 17 00:00:00 2001
From: tuxuser <tuxuser360@gmail.com>
Date: Sat, 17 Mar 2018 11:31:44 +0100
Subject: [PATCH 3/4] Suggested fix by @Lekensteyn

---
 laf_crypto.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/laf_crypto.py b/laf_crypto.py
index fa7ea19..bb025a2 100644
--- a/laf_crypto.py
+++ b/laf_crypto.py
@@ -6,10 +6,9 @@ from lglaf import int_as_byte
 
 def key_transform(old_key):
     new_key = b''
+    old_key = bytearray(old_key)
     for x in range(32, 0, -1):
         c = old_key[x-1]
-        if not isinstance(c, int):
-            c = ord(c)
         new_key += int_as_byte(c - (x % 0x0C))
     return new_key
 

From a8b4514bbbd4a909df392329328afdda92c0a410 Mon Sep 17 00:00:00 2001
From: tuxuser <tuxuser360@gmail.com>
Date: Sat, 17 Mar 2018 12:06:12 +0100
Subject: [PATCH 4/4] Add note about origin of LG Mobile Windows driver

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index b0ad961..f9ced3f 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,8 @@ LGLAF.py depends on:
  - (Windows) LG driver,
    [LGMobileDriver\_WHQL\_Ver\_4.2.0.exe](http://oceanhost.eu/wylc5rg7a8ou/LGMobileDriver_WHQL_Ver_4.2.0.exe.htm)
    (16691672 bytes,
-   sha256sum: d78ae6dfe7d34b9cabb8c4de5c6e734b6fed20b513d0da0183871bd77abba56c)
+   sha256sum: d78ae6dfe7d34b9cabb8c4de5c6e734b6fed20b513d0da0183871bd77abba56c),
+   **WARNING**: This file was found via google search, it's not downloaded directly from LG servers
  - (Linux) PyUSB: https://walac.github.io/pyusb/
  - Cryptography library: https://cryptography.io/en/latest/