From 01a6c9f77fc99fa6f3afa396dc45fc52403195c2 Mon Sep 17 00:00:00 2001
From: Pol Henarejos <pol.henarejos@cttc.es>
Date: Thu, 2 Nov 2023 09:32:19 +0100
Subject: [PATCH] Added Windows & Linux backend for backup/restore.

Fixes #21

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
---
 tools/pico-fido-tool.py     | 32 +++++++++++++++++++--------
 tools/secure_key/windows.py | 44 +++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 9 deletions(-)
 create mode 100644 tools/secure_key/windows.py

diff --git a/tools/pico-fido-tool.py b/tools/pico-fido-tool.py
index 9971387..4123233 100644
--- a/tools/pico-fido-tool.py
+++ b/tools/pico-fido-tool.py
@@ -23,7 +23,6 @@ import sys
 import argparse
 import platform
 from binascii import hexlify
-from words import words
 from threading import Event
 from typing import Mapping, Any, Optional, Callable
 import struct
@@ -58,14 +57,6 @@ except:
 from enum import IntEnum
 from binascii import hexlify
 
-if (platform.system() == 'Windows' or platform.system() == 'Linux'):
-    from secure_key import windows as skey
-elif (platform.system() == 'Darwin'):
-    from secure_key import macos as skey
-else:
-    print('ERROR: platform not supported')
-    sys.exit(-1)
-
 def get_pki_data(url, data=None, method='GET'):
     user_agent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; '
     'rv:1.9.0.7) Gecko/2009021910 Firefox/3.0.7'
@@ -252,6 +243,14 @@ class Vendor:
         return self.ctap.vendor(cmd, sub_cmd, params, pin_uv_protocol, pin_uv_param)
 
     def backup_save(self, filename):
+        if (platform.system() == 'Windows' or platform.system() == 'Linux'):
+            from secure_key import windows as skey
+        elif (platform.system() == 'Darwin'):
+            from secure_key import macos as skey
+        else:
+            print('ERROR: platform not supported')
+            sys.exit(-1)
+        from words import words
         ret = self._call(
             Vendor.CMD.VENDOR_BACKUP,
             Vendor.SUBCMD.ENABLE,
@@ -270,6 +269,14 @@ class Vendor:
             print(f'{(c+1):02d} - {words[coef]}')
 
     def backup_load(self, filename):
+        if (platform.system() == 'Windows' or platform.system() == 'Linux'):
+            from secure_key import windows as skey
+        elif (platform.system() == 'Darwin'):
+            from secure_key import macos as skey
+        else:
+            print('ERROR: platform not supported')
+            sys.exit(-1)
+        from words import words
         d = 0
         if (d == 0):
             for c in range(24):
@@ -349,6 +356,13 @@ class Vendor:
         )
 
     def _get_key_device(self):
+        if (platform.system() == 'Windows' or platform.system() == 'Linux'):
+            from secure_key import windows as skey
+        elif (platform.system() == 'Darwin'):
+            from secure_key import macos as skey
+        else:
+            print('ERROR: platform not supported')
+            sys.exit(-1)
         return skey.get_secure_key()
 
     def get_skey(self):
diff --git a/tools/secure_key/windows.py b/tools/secure_key/windows.py
new file mode 100644
index 0000000..d1c5845
--- /dev/null
+++ b/tools/secure_key/windows.py
@@ -0,0 +1,44 @@
+import sys
+import os
+import base64
+
+DOMAIN = "PicoKeys.com"
+USERNAME = "Pico-Fido"
+
+try:
+    import keyring
+except:
+    print('ERROR: keyring module not found! Install keyring package.\nTry with `pip install keyring`')
+    sys.exit(-1)
+
+try:
+    from cryptography.hazmat.primitives.serialization import Encoding, PrivateFormat, NoEncryption, load_pem_private_key
+    from cryptography.hazmat.primitives.asymmetric import ec
+except:
+    print('ERROR: cryptography module not found! Install cryptography package.\nTry with `pip install cryptography`')
+    sys.exit(-1)
+
+
+
+def generate_secure_key():
+    pkey = ec.generate_private_key(ec.SECP256R1())
+    set_secure_key(pkey)
+    return keyring.get_password(DOMAIN, USERNAME)
+
+def get_d(key):
+    return load_pem_private_key(key, password=None).private_numbers().private_value.to_bytes(32, 'big')
+
+def set_secure_key(pk):
+    try:
+        keyring.delete_password(DOMAIN, USERNAME)
+    except:
+        pass
+    keyring.set_password(DOMAIN, USERNAME, pk.private_bytes(Encoding.PEM, PrivateFormat.PKCS8, NoEncryption()).decode())
+
+def get_secure_key():
+    key = None
+    try:
+        key = keyring.get_password(DOMAIN, USERNAME)
+    except keyring.errors.KeyringError:
+        key = generate_secure_key()
+    return get_d(key.encode())