Optimize capture verification method in China region

bimmer_connected/api/authentication.py

@@ -19,6 +19,7 @@
     create_s256_code_challenge,
     generate_cn_nonce,
     generate_token,
+    get_capture_position,
     get_correlation_id,
     handle_httpstatuserror,
 )
@@ -284,16 +285,8 @@ async def _login_china(self):
             )
             verify_id = captcha_res.json()["data"]["verifyId"]
 
-            for i in range(1, 13):
-                try:
-                    captcha_check_res = await client.post(
-                        AUTH_CHINA_CAPTCHA_CHECK_URL,
-                        json={"position": 0.74 + i / 100, "verifyId": verify_id},
-                    )
-                    if captcha_check_res.status_code == 201:
-                        break
-                except MyBMWAPIError:
-                    continue
+            position = get_capture_position(captcha_res.json()["data"]["backGroundImg"])
+            await client.post(AUTH_CHINA_CAPTCHA_CHECK_URL, json={"position": position, "verifyId": verify_id})
 
             # Get token
             response = await client.post(

bimmer_connected/api/utils.py

@@ -3,6 +3,7 @@
 import base64
 import datetime
 import hashlib
+import io
 import json
 import logging
 import mimetypes
@@ -17,6 +18,7 @@
 from Crypto.Hash import SHA256
 from Crypto.Random import get_random_bytes
 from Crypto.Util.Padding import pad
+from PIL import Image
 
 from bimmer_connected.models import AnonymizedResponse, MyBMWAPIError, MyBMWAuthError, MyBMWQuotaError
 
@@ -185,3 +187,41 @@ def generate_cn_nonce(username: str) -> str:
     aes_hex = cipher_aes.encrypt(pad(phone_text.encode(), AES.block_size)).hex()
 
     return k2 + i1 + sha256_a + aes_hex + k1 + i2 + sha256_b
+
+
+def get_capture_position(base64_background_img: str) -> str:
+    """Get the position of the capture in the background image."""
+    target_color = [220, 230, 221]
+    tolerance = 15
+    block = {"width": 15, "height": 75}
+
+    img_bytes = io.BytesIO(base64.b64decode(base64_background_img))
+    img = Image.open(img_bytes)
+    pixels = list(img.getdata())
+
+    position = ""
+    found_block = False
+
+    for y in range(0, img.height - block["height"]):
+        for x in range(0, img.width - block["width"]):
+            found_block = True
+            for i in range(block["height"]):
+                for j in range(block["width"]):
+                    pixel_index = (y + i) * img.width + (x + j)
+                    pr = pixels[pixel_index][:3]
+                    dr = abs(pr[0] - target_color[0])
+                    dg = abs(pr[1] - target_color[1])
+                    db = abs(pr[2] - target_color[2])
+
+                    if dr > tolerance or dg > tolerance or db > tolerance:
+                        found_block = False
+                        break
+                if not found_block:
+                    break
+            if found_block:
+                position = str(round((x - 26) / img.width, 2))
+                break
+        if found_block:
+            break
+
+    return position

bimmer_connected/tests/common.py

@@ -96,11 +96,8 @@ def add_login_routes(self) -> None:
             200, json=load_response(RESPONSE_DIR / "auth" / "auth_slider_captcha.json")
         )
 
-        self.post("/eadrax-coas/v1/cop/check-captcha").mock(
-            side_effect=[
-                httpx.Response(422),
-                httpx.Response(201, json=load_response(RESPONSE_DIR / "auth" / "auth_slider_captcha_check.json")),
-            ]
+        self.post("/eadrax-coas/v1/cop/check-captcha").respond(
+            200, json=load_response(RESPONSE_DIR / "auth" / "auth_slider_captcha_check.json")
         )
 
         self.post("/eadrax-coas/v2/login/pwd").respond(

bimmer_connected/tests/test_utils.py

@@ -11,10 +11,11 @@
 import respx
 import time_machine
 
+from bimmer_connected.api.utils import get_capture_position
 from bimmer_connected.models import ChargingSettings, ValueWithUnit
 from bimmer_connected.utils import MyBMWJSONEncoder, get_class_property_names, parse_datetime
 
-from . import VIN_G26
+from . import RESPONSE_DIR, VIN_G26, load_response
 from .conftest import prepare_account_with_vehicles
 
 
@@ -112,3 +113,10 @@ def test_charging_settings():
     assert cs.chargingTarget == 90
     assert cs.dcLoudness is None
     assert cs.isUnlockCableActive is None
+
+
+def test_get_capture_position():
+    """Test the auto get slider captcha position."""
+    base64_background_img = load_response(RESPONSE_DIR / "auth" / "auth_slider_captcha.json")["data"]["backGroundImg"]
+    position = get_capture_position(base64_background_img)
+    assert position == "0.81"

requirements.txt

@@ -1,3 +1,4 @@
 httpx
 pycryptodome>=3.4
 pyjwt>=2.1.0
+Pillow>=6.2.0