2.1 Transport
Messages are transported by using HTTP POST as specified in [RFC2616]. These messages are sent via Hypertext Transfer Protocol over Secure Sockets Layer (HTTPS) by default. The URI uses the virtual directory /KdcProxy unless otherwise configured. The body of the HTTP message contains the KDC_PROXY_MESSAGE (section 2.2.2).
KDC proxy messages are defined using Abstract Syntax Notation One (ASN.1), as specified in [X680], and encoded using Distinguished Encoding Rules (DER), as specified in [X690] section 10.