X-Git-Url: https://projects.mako.cc/source/twitter-api-cdsw/blobdiff_plain/b5d973d7a0a14eca21b2981ffacf4fb9ea77ba41..HEAD:/oauthlib/oauth1/rfc5849/signature.py

diff --git a/oauthlib/oauth1/rfc5849/signature.py b/oauthlib/oauth1/rfc5849/signature.py
index f57d80a..8fa22ba 100644
--- a/oauthlib/oauth1/rfc5849/signature.py
+++ b/oauthlib/oauth1/rfc5849/signature.py
@@ -500,6 +500,8 @@ def sign_rsa_sha1(base_string, rsa_private_key):
 
 
 def sign_rsa_sha1_with_client(base_string, client):
+    if not client.rsa_key:
+        raise ValueError('rsa_key is required when using RSA signature method.')
     return sign_rsa_sha1(base_string, client.rsa_key)