HUB setup (#108)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

ultralytics/hub/auth.py

@@ -0,0 +1,69 @@
+import requests
+
+from ultralytics.hub.config import HUB_API_ROOT
+from ultralytics.hub.utils import request_with_credentials
+from ultralytics.yolo.utils import is_colab
+
+API_KEY_PATH = "https://hub.ultralytics.com/settings?tab=api+keys"
+
+
+class Auth:
+    id_token = api_key = model_key = False
+
+    def __init__(self, api_key=None):
+        self.api_key = self._clean_api_key(api_key)
+        self.authenticate() if self.api_key else self.auth_with_cookies()
+
+    @staticmethod
+    def _clean_api_key(key: str) -> str:
+        """Strip model from key if present"""
+        separator = "_"
+        return key.split(separator)[0] if separator in key else key
+
+    def authenticate(self) -> bool:
+        """Attempt to authenticate with server"""
+        try:
+            header = self.get_auth_header()
+            if header:
+                r = requests.post(f"{HUB_API_ROOT}/v1/auth", headers=header)
+                if not r.json().get('success', False):
+                    raise ConnectionError("Unable to authenticate.")
+                return True
+            raise ConnectionError("User has not authenticated locally.")
+        except ConnectionError:
+            self.id_token = self.api_key = False  # reset invalid
+            return False
+
+    def auth_with_cookies(self) -> bool:
+        """
+        Attempt to fetch authentication via cookies and set id_token.
+        User must be logged in to HUB and running in a supported browser.
+        """
+        if not is_colab():
+            return False  # Currently only works with Colab
+        try:
+            authn = request_with_credentials(f"{HUB_API_ROOT}/v1/auth/auto")
+            if authn.get("success", False):
+                self.id_token = authn.get("data", {}).get("idToken", None)
+                self.authenticate()
+                return True
+            raise ConnectionError("Unable to fetch browser authentication details.")
+        except ConnectionError:
+            self.id_token = False  # reset invalid
+            return False
+
+    def get_auth_header(self):
+        if self.id_token:
+            return {"authorization": f"Bearer {self.id_token}"}
+        elif self.api_key:
+            return {"x-api-key": self.api_key}
+        else:
+            return None
+
+    def get_state(self) -> bool:
+        """Get the authentication state"""
+        return self.id_token or self.api_key
+
+    def set_api_key(self, key: str):
+        """Get the authentication state"""
+        self.api_key = key