Extended the requirements of the authenticate_client method docu… (#694)

Extended the requirements of the authenticate_client method documentation

1 files changed, 11 insertions, 0 deletions

diff --git a/oauthlib/oauth2/rfc6749/request_validator.py b/oauthlib/oauth2/rfc6749/request_validator.py
index 78d025b..81d9060 100644
--- a/oauthlib/oauth2/rfc6749/request_validator.py
+++ b/oauthlib/oauth2/rfc6749/request_validator.py
@@ -49,6 +49,17 @@ class RequestValidator:
         Headers may be accesses through request.headers and parameters found in
         both body and query can be obtained by direct attribute access, i.e.
         request.client_id for client_id in the URL query.
+		
+        The authentication process is required to contain the identification of
+        the client (i.e. search the database based on the client_id). In case the
+        client doesn't exist based on the received client_id, this method has to
+        return False and the HTTP response created by the library will contain
+        'invalid_client' message. 
+
+        After the client identification succeeds, this method needs to set the
+        client on the request, i.e. request.client = client. A client object's
+        class must contain the 'client_id' attribute and the 'client_id' must have
+        a value.
 
         :param request: OAuthlib request.
         :type request: oauthlib.common.Request