def convert_jwks_uri(jwks_uri):
if not jwks_uri.startswith(_TEXT_CERT_PREFIX):<EOL><INDENT>return jwks_uri<EOL><DEDENT>return jwks_uri.replace(_TEXT_CERT_PREFIX, _JSON_CERT_PREFIX)<EOL>
The PyCrypto library included with Google App Engine is severely limited and
can't read X.509 files, so we change the URI to a special URI that has the
public cert in modulus/exponent form in JSON.