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SMTP Service Extension for Secure SMTP over TLS (RFC2487)

IP.com Disclosure Number: IPCOM000003067D
Original Publication Date: 1999-Jan-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 6 page(s) / 14K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

P. Hoffman: AUTHOR

Abstract

This document describes an extension to the SMTP service that allows an SMTP server and client to use transport-layer security to provide private, authenticated communication over the Internet. This gives SMTP agents the ability to protect some or all of their communications from eavesdroppers and attackers.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 20% of the total text.

Network Working Group P. Hoffman

Request for Comments: 2487 Internet Mail Consortium

Category: Standards Track January 1999

SMTP Service Extension for Secure SMTP over TLS

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.

Copyright Notice

Copyright (C) The Internet Society (1999). All Rights Reserved.

1. Abstract

This document describes an extension to the SMTP service that allows

an SMTP server and client to use transport-layer security to provide

private, authenticated communication over the Internet. This gives

SMTP agents the ability to protect some or all of their

communications from eavesdroppers and attackers.

2. Introduction

SMTP [RFC-821] servers and clients normally communicate in the clear

over the Internet. In many cases, this communication goes through one

or more router that is not controlled or trusted by either entity.

Such an untrusted router might allow a third party to monitor or

alter the communications between the server and client.

Further, there is often a desire for two SMTP agents to be able to

authenticate each others' identities. For example, a secure SMTP

server might only allow communications from other SMTP agents it

knows, or it might act differently for messages received from an

agent it knows than from one it doesn't know.

TLS [TLS], more commonly known as SSL, is a popular mechanism for

enhancing TCP communications with privacy and authentication. TLS is

in wide use with the HTTP protocol, and is also being used for adding

security to many other common protocols that run over TCP.

2.1 Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",

"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this

document are to be interpreted as described in [RFC-2119].

3. STARTTLS Extension

The STARTTLS extension to SMTP is laid out as follows:

(1) the name of the SMTP service defined here is STARTTLS;

(2) the EHLO keyword value associated with the extension is STARTTLS;

(3) the STARTTLS keyword has no parameters;

(4) a new SMTP verb, "STARTTLS", is defined;

(5) no additional parameters are added to any SMTP command.

4. The STARTTLS Keyword

The STARTTLS keyword is used to tell the SMTP clie...