FindMy: Add generate keys script

applications/system/findmy/generate_keys.py

@@ -0,0 +1,84 @@
+import base64
+import os
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import hashes
+
+def advertisement_template():
+    adv = ""
+    adv += "1e"  # length (30)
+    adv += "ff"  # manufacturer specific data
+    adv += "4c00"  # company ID (Apple)
+    adv += "1219"  # offline finding type and length
+    adv += "00"  # state
+    for _ in range(22):
+        adv += "00"
+    adv += "00"  # first two bits of key[0]
+    adv += "00"  # hint
+    return bytearray.fromhex(adv)
+
+def convert_key_to_hex(private_key, public_key):
+    private_key_hex = private_key.private_numbers().private_value.to_bytes(28, byteorder='big').hex()
+    public_key_hex = public_key.public_numbers().x.to_bytes(28, byteorder='big').hex()
+    return private_key_hex, public_key_hex
+
+def generate_mac_and_payload(public_key):
+    public_key_bytes = public_key.public_numbers().x.to_bytes(28, byteorder='big')
+    mac = public_key_bytes[:6].hex()
+    payload = advertisement_template()
+    payload[7:29] = public_key_bytes[6:22]
+    return mac, payload.hex()
+
+def main():
+    nkeys = int(input('Enter the number of keys to generate: '))
+    prefix = input('Enter a name for the keyfiles (optional, press enter to skip): ')
+    print()
+
+    if not os.path.exists('keys'):
+        os.makedirs('keys')
+
+    for i in range(nkeys):
+        while True:
+            private_key = ec.generate_private_key(ec.SECP224R1(), default_backend())
+            public_key = private_key.public_key()
+
+            private_key_bytes = private_key.private_numbers().private_value.to_bytes(28, byteorder='big')
+            public_key_bytes = public_key.public_numbers().x.to_bytes(28, byteorder='big')
+
+            private_key_b64 = base64.b64encode(private_key_bytes).decode("ascii")
+            public_key_b64 = base64.b64encode(public_key_bytes).decode("ascii")
+
+            private_key_hex, public_key_hex = convert_key_to_hex(private_key, public_key)
+            mac, payload = generate_mac_and_payload(public_key)
+
+            public_key_hash = hashes.Hash(hashes.SHA256())
+            public_key_hash.update(public_key_bytes)
+            s256_b64 = base64.b64encode(public_key_hash.finalize()).decode("ascii")
+
+            if '/' not in s256_b64[:7]:
+                fname = f"{prefix}_{s256_b64[:7]}.keys" if prefix else f"{s256_b64[:7]}.keys"
+                    
+                print(f'{i + 1})')
+                print('Private key (Base64):', private_key_b64)
+                print('Public key (Base64):', public_key_b64)
+                print('Hashed adv key (Base64):', s256_b64)
+                print('---------------------------------------------------------------------------------')
+                print('Private key (Hex):', private_key_hex)
+                print('Public key (Hex):', public_key_hex)                    
+                print('---------------------------------------------------------------------------------')
+                print('MAC:', mac)
+                print('Payload:', payload)
+                print()
+                print('Place the .keys file onto your Flipper or input the MAC and Payload manually.')
+
+                with open(f"keys/{fname}", 'w') as f:
+                    f.write(f'Private key: {private_key_b64}\n')
+                    f.write(f'Public key: {public_key_b64}\n')
+                    f.write(f'Hashed adv key: {s256_b64}\n')
+                    f.write(f'Private key (Hex): {private_key_hex}\n')
+                    f.write(f'Public key (Hex): {public_key_hex}\n')
+                    f.write(f'MAC: {mac}\n')
+                    f.write(f'Payload: {payload}\n')
+                break
+
+main()