Check API keys for proper format

app.py

@@ -82,7 +82,8 @@ def are_all_inputs_valid(
     if not llm_helper.is_valid_llm_provider_model(selected_provider, selected_model, user_key):
         handle_error(
             'The LLM settings do not look correct. Make sure that an API key/access token'
-            ' is provided if the selected LLM requires it.',
+            ' is provided if the selected LLM requires it. An API key should be 6-64 characters'
+            ' long, only containing alphanumeric characters, hyphens, and underscores.',
             False
         )
         return False

helpers/llm_helper.py

@@ -17,6 +17,8 @@ from global_config import GlobalConfig
 
 
 LLM_PROVIDER_MODEL_REGEX = re.compile(r'\[(.*?)\](.*)')
+# 6-64 characters long, only containing alphanumeric characters, hyphens, and underscores
+API_KEY_REGEX = re.compile(r'^[a-zA-Z0-9\-_]{6,64}$')
 HF_API_HEADERS = {'Authorization': f'Bearer {GlobalConfig.HUGGINGFACEHUB_API_TOKEN}'}
 REQUEST_TIMEOUT = 35
 
@@ -70,9 +72,14 @@ def is_valid_llm_provider_model(provider: str, model: str, api_key: str) -> bool
     if not provider or not model or provider not in GlobalConfig.VALID_PROVIDERS:
         return False
 
-    if provider in [GlobalConfig.PROVIDER_GOOGLE_GEMINI, GlobalConfig.PROVIDER_COHERE,]:
-        if not api_key or len(api_key) < 5:
-            return False
+    if provider in [
+        GlobalConfig.PROVIDER_GOOGLE_GEMINI,
+        GlobalConfig.PROVIDER_COHERE,
+    ] and not api_key:
+        return False
+
+    if api_key:
+        return API_KEY_REGEX.match(api_key) is not None
 
     return True