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PPP Challenge Handshake Authentication Protocol (CHAP) (RFC1994)

IP.com Disclosure Number: IPCOM000004204D
Original Publication Date: 1996-Aug-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 10 page(s) / 22K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

W. Simpson: AUTHOR

Abstract

The Point-to-Point Protocol (PPP) [1] provides a standard method for transporting multi-protocol datagrams over point-to-point links.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 13% of the total text.

Network Working Group W. Simpson

Request for Comments: 1994 DayDreamer

Obsoletes: 1334 August 1996

Category: Standards Track

PPP Challenge Handshake Authentication Protocol (CHAP)

Status of this Memo

This document specifies an Internet standards track protocol for the

Internet community, and requests discussion and suggestions for

improvements. Please refer to the current edition of the "Internet

Official Protocol Standards" (STD 1) for the standardization state

and status of this protocol. Distribution of this memo is unlimited.

Abstract

The Point-to-Point Protocol (PPP) [1] provides a standard method for

transporting multi-protocol datagrams over point-to-point links.

PPP also defines an extensible Link Control Protocol, which allows

negotiation of an Authentication Protocol for authenticating its peer

before allowing Network Layer protocols to transmit over the link.

This document defines a method for Authentication using PPP, which

uses a random Challenge, with a cryptographically hashed Response

which depends upon the Challenge and a secret key.

Table of Contents

1. Introduction .......................................... 1

1.1 Specification of Requirements ................... 1

1.2 Terminology ..................................... 2

2. Challenge-Handshake Authentication Protocol ........... 2

2.1 Advantages ...................................... 3

2.2 Disadvantages ................................... 3

2.3 Design Requirements ............................. 4

3. Configuration Option Format ........................... 5

4. Packet Format ......................................... 6

4.1 Challenge and Response .......................... 7

4.2 Success and Failure ............................. 9

SECURITY CONSIDERATIONS ...................................... 10

ACKNOWLEDGEMENTS ............................................. 11

REFERENCES ................................................... 12

CONTACTS ..................................................... 12

Simpson [Page i]

RFC 1994 PPP CHAP August 1996

1. Introduction

In order to establish communications over a point-to-point link, each

end of the PPP link must first send LCP packets to configure the data

link during Link Establishment phase. After the link has been

established, PPP provides for an optional Authentication phase before

proceeding to the Network-Layer Protocol phase.

By default, authentication is not mandatory. If authentication of

the link is desired, an implementation MUST specify the

Authentication-Protocol Configuration Option during Link

Establ...