Add documentation for X509StoreContextError

I'm not sure if it is customary to provide documentation for exceptions
or not, but because this exception provides an additional meaningful
attribute on the exception base class, I figured it would be helpful to
document.

1 files changed, 12 insertions, 0 deletions

diff --git a/doc/api/crypto.rst b/doc/api/crypto.rst
index 5528870..3955802 100644
--- a/doc/api/crypto.rst
+++ b/doc/api/crypto.rst
@@ -536,6 +536,18 @@ The X509Store object has currently just one method:
     Add the certificate *cert* to the certificate store.
 
 
+X509StoreContextError objects
+-----------------------------
+
+The X509StoreContextError is an exception raised from
+`X509StoreContext.verify_certificate` in circumstances where a certificate
+cannot be verified in a provided context.
+
+The exception objects have a :py:class:`basestring` ``message`` attribute which
+contains error messages and :py:class:`X509` ``certificate`` attribute by which
+they indicate where the verification error was detected.
+
+
 X509StoreContext objects
 ------------------------