YubiKey improvements and PIV reset

src/gam/__init__.py

@@ -7912,6 +7912,10 @@ def doCreateOrRotateServiceAccountKeys(iam=None,
         new_data['yubikey_key_type'] = f'RSA{local_key_size}'
         new_data.pop('private_key', None)
         yk = yubikey.YubiKey(new_data)
+        if 'yubikey_serial_number' not in new_data:
+            new_data['yubikey_serial_number'] = yk.get_serial_number()
+        if 'yubikey_slot' not in new_data:
+            new_data['yubikey_slot'] = 'AUTHENTICATION'
         publicKeyData = yk.get_certificate()
     elif local_key_size:
         # Generate private key locally, store in file
@@ -11847,6 +11851,12 @@ def ProcessGAMCommand(args):
                 elif command == 'getcommand':
                     gapi_directory_cros.get_command()
             sys.exit(0)
+        elif command in ['yubikey']:
+            action = sys.argv[2].lower().replace('_', '')
+            if action == 'resetpiv':
+                yk = yubikey.YubiKey()
+                yk.reset_piv()
+            sys.exit(0)
         users = getUsersToModify()
         command = sys.argv[3].lower()
         if command == 'print' and len(sys.argv) == 4:

src/gam/auth/yubikey.py

@@ -1,34 +1,57 @@
 from base64 import b64encode
+import datetime
+from secrets import SystemRandom
+import string
 import sys
 from threading import Timer
 
 from cryptography.hazmat.primitives import hashes, serialization
 from cryptography.hazmat.primitives.asymmetric import padding
 from ykman.device import connect_to_device
-from yubikit.piv import KEY_TYPE, SLOT, InvalidPinError, PivSession
+from ykman.piv import generate_self_signed_certificate, \
+                      generate_chuid
+from yubikit.piv import DEFAULT_MANAGEMENT_KEY, \
+                        InvalidPinError, \
+                        KEY_TYPE, \
+                        MANAGEMENT_KEY_TYPE, \
+                        PIN_POLICY, \
+                        PivSession, \
+                        OBJECT_ID, \
+                        SLOT, \
+                        TOUCH_POLICY
 from yubikit.core.smartcard import ApduError
 from gam import controlflow
 
 class YubiKey():
 
-    def __init__(self, service_account_info):
+    def __init__(self, service_account_info=None):
-        key_type = service_account_info.get('yubikey_key_type', 'RSA2048')
+        self.key_type = None
-        try:
+        self.slot = None
-            self.key_type = getattr(KEY_TYPE, key_type.upper())
+        self.serial_number = None
-        except AttributeError:
+        self.pin = None
-            controlflow.system_error_exit(6, f'{key_type} is not a valid value for yubikey_key_type')
+        self.key_id = None
-        slot = service_account_info.get('yubikey_slot', 'AUTHENTICATION')
+        if service_account_info:
-        try:
+            key_type = service_account_info.get('yubikey_key_type', 'RSA2048')
-            self.slot = getattr(SLOT, slot.upper())
+            try:
-        except AttributeError:
+                self.key_type = getattr(KEY_TYPE, key_type.upper())
-            controlflow.system_error_exit(6, f'{slot} is not a valid value for yubikey_slot')
+            except AttributeError:
-        self.serial_number = service_account_info.get('yubikey_serial_number')
+                controlflow.system_error_exit(6, f'{key_type} is not a valid value for yubikey_key_type')
-        self.pin = service_account_info.get('yubikey_pin')
+            slot = service_account_info.get('yubikey_slot', 'AUTHENTICATION')
-        self.key_id = service_account_info.get('private_key_id')
+            try:
+                self.slot = getattr(SLOT, slot.upper())
+            except AttributeError:
+                controlflow.system_error_exit(6, f'{slot} is not a valid value for yubikey_slot')
+            self.serial_number = service_account_info.get('yubikey_serial_number')
+            self.pin = service_account_info.get('yubikey_pin')
+            self.key_id = service_account_info.get('private_key_id')
+
+    def _connect(self):
+        conn, _, _ = connect_to_device(self.serial_number)
+        return conn
 
     def get_certificate(self):
         try:
-            conn, _, _ = connect_to_device(self.serial_number)
+            conn = self._connect()
             with conn:
                 session = PivSession(conn)
                 if self.pin:
@@ -49,11 +72,65 @@ class YubiKey():
         except ValueError as err:
             controlflow.system_error_exit(9, f'YubiKey - {err}')
 
+
+    def get_serial_number(self):
+        try:
+            _, _, info = connect_to_device(self.serial_number)
+            return info.serial
+        except ValueError as err:
+            controlflow.system_error_exit(9, f'YubikKey = {err}')
+
+    def reset_piv(self):
+        '''Resets YubiKey PIV app and generates new key for GAM to use.'''
+        reply = str(input('This will wipe all PIV keys and configuration from your YubiKey. Are you sure? (y/N) ').lower().strip())
+        if reply != 'y':
+            sys.exit(1)
+        try:
+            conn = self._connect()
+            with conn:
+                piv = PivSession(conn)
+                piv.reset()
+                rnd = SystemRandom()
+                pin_puk_chars = string.ascii_letters + string.digits + string.punctuation
+                new_puk = ''.join(rnd.choice(pin_puk_chars) for _ in range(8))
+                new_pin = ''.join(rnd.choice(pin_puk_chars) for _ in range(8))
+                piv.change_puk('12345678', new_puk)
+                piv.change_pin('123456', new_pin)
+                print(f'PIN set to:  {new_pin}')
+                piv.authenticate(MANAGEMENT_KEY_TYPE.TDES,
+                                 DEFAULT_MANAGEMENT_KEY)
+
+                piv.verify_pin(new_pin)
+                print('Yubikey is generating a non-exportable private key...')
+                pubkey = piv.generate_key(SLOT.AUTHENTICATION,
+                                          KEY_TYPE.RSA2048,
+                                          PIN_POLICY.ALWAYS,
+                                          TOUCH_POLICY.NEVER)
+                now = datetime.datetime.utcnow()
+                valid_to = now + datetime.timedelta(days=36500)
+                subject = 'CN=GAM Created Key'
+                piv.authenticate(MANAGEMENT_KEY_TYPE.TDES,
+                                 DEFAULT_MANAGEMENT_KEY)
+                piv.verify_pin(new_pin)
+                cert = generate_self_signed_certificate(piv,
+                                                        SLOT.AUTHENTICATION,
+                                                        pubkey,
+                                                        subject,
+                                                        now,
+                                                        valid_to)
+                piv.put_certificate(SLOT.AUTHENTICATION,
+                                    cert)
+                piv.put_object(OBJECT_ID.CHUID,
+                               generate_chuid())
+        except ValueError as err:
+            controlflow.system_error_exit(8, f'Yubikey - {err}')
+
+
     def sign(self, message):
         if 'mplock' in globals():
             mplock.acquire()
         try:
-            conn, _, _ = connect_to_device(self.serial_number)
+            conn = self._connect()
             with conn:
                 session = PivSession(conn)
                 if self.pin: