The Point-to-Point Protocol (PPP) [1] provides a standard method for
transporting multi-protocol datagrams over point-to-point links. PPP
defines an extensible Link Control Protocol and a family of Network
Control Protocols (NCPs) for establishing and configuring different
network-layer protocols.

This document describes version two of Microsoft’s PPP CHAP dialect
(MS-CHAP-V2). MS-CHAP-V2 is similar to, but incompatible with, MS-
CHAP version one (MS-CHAP-V1, described in [9]). In particular,
certain protocol fields have been deleted or reused but with
different semantics. In addition, MS-CHAP-V2 features mutual
authentication.

The algorithms used in the generation of various MS-CHAP-V2 protocol
fields are described in section 8. Negotiation and hash generation
examples are provided in section 9.