I’m interested if Google App Engine provides a way to use a X.509 Certificate to create a HTTPS connection (the server where I have to connect provides the public certificate – to encrypt data that I send and the private key to decrypt the data received from that server).
According to this post https://groups.google.com/forum/?fromgroups#!topic/google-appengine-python/C9RSDGeIraE it’s not possible but 3 years passed since this answer was posted.
SSL client certificates are not currently supported. The feature request is here.