RFC 2246

RFC 2246
Title	RFC 2246
Authors	* T. Dierks * C. Allen
Published	April 1999
Type	Standards Track
Pages	77
Id	RFC 2246

RFC 2246

Introduction

RFC 2246 defines the specifications for the Transport Layer Security protocol version 1.0 as an Internet standards-track document published by the Internet Engineering Task Force and authored by T. Dierks and C. Allen. It establishes procedures for secure communications between clients and servers over TCP connections, influencing later work by the Internet Architecture Board, IETF Security Area, and standards bodies like the International Organization for Standardization and the European Telecommunications Standards Institute. The document became a cornerstone for secure web transactions alongside protocols used by Netscape Communications Corporation and implementations in products from vendors such as Microsoft, IBM, Sun Microsystems, and Cisco Systems.

Background and Purpose

RFC 2246 was created to supersede earlier practices for encrypting application data and to provide a unified framework following experiences with proprietary protocols developed by Netscape Communications Corporation and research from the MIT Laboratory for Computer Science. The purpose was to offer interoperable cryptographic protection interoperable with technologies in use at institutions including Bank of America, Visa, and Mastercard for securing financial transactions, as well as to respond to policy work by the Internet Society and recommendations by the National Institute of Standards and Technology. The RFC documents choices about cipher design influenced by analyses from researchers at RSA Laboratories, Bell Labs, and academic groups at Stanford University and Massachusetts Institute of Technology.

Protocol Overview

The protocol described in RFC 2246 specifies a layered architecture comprising a Record Protocol and a Handshake Protocol, designed to secure data for applications such as HTTP, SMTP, POP3, and IMAP. It defines cryptographic primitives drawn from standards like Advanced Encryption Standard, hash functions used in work by Ronald Rivest and Ralph Merkle, and public-key mechanisms that trace to Diffie–Hellman key exchange and RSA. The overview situates TLS 1.0 alongside transport technologies including IPsec and application-layer security mechanisms used in deployments by Oracle Corporation and Adobe Systems. The protocol balances confidentiality, integrity, and authentication goals that are central to recommendations from ISO/IEC JTC 1/SC 27 and the OpenSSL Project.

Message Formats and Handshake

RFC 2246 describes message structures for the TLS Record Protocol, with content types, version fields, and length encodings compatible with established encoding rules used by ITU-T and practices from the W3C. The Handshake Protocol sequences messages like ClientHello, ServerHello, Certificate, ServerKeyExchange, CertificateRequest, ServerHelloDone, ClientKeyExchange, CertificateVerify, ChangeCipherSpec, and Finished; these exchange mechanisms reflect public-key models articulated in literature from Bruce Schneier and from the IACR. The document details format fields for certificates conforming to X.509 standards issued by ITU-T Study Group 17 and procedural interactions with certificate authorities such as Entrust and legacy roots maintained by organizations like VeriSign. Message integrity employs hash constructions indebted to work by Hans Dobbertin and Mihir Bellare, while MAC constructions align with theoretical frameworks advanced at University of California, Berkeley and ETH Zurich.

Security Considerations

RFC 2246 contains extensive security guidance addressing threats analyzed in the cryptanalysis literature from Claude Shannon through contemporary papers by researchers at Carnegie Mellon University, University of Oxford, and Cornell University. It discusses trade-offs among cipher suite choices and offers mitigations for attacks similar to those publicized in incidents involving Netscape Communications Corporation implementations and vulnerability disclosures coordinated by the CERT Coordination Center. The RFC warns about risks from weak key exchange parameters, improper certificate validation highlighted in cases examined by US-CERT, and the need for careful random number generation consistent with findings from NIST. It influenced later protocol revisions and normative guidance from the IETF TLS Working Group and follow-on documents that addressed practical attacks detailed in papers from Microsoft Research and Google.

Implementations and Adoption

Following its publication, RFC 2246 was implemented in major software libraries and products such as OpenSSL Project, GnuTLS, libraries embedded in Mozilla Foundation browsers, server products from Apache Software Foundation and Microsoft IIS, and in networking equipment by Cisco Systems. Adoption was widespread across financial services, ecommerce platforms like those operated by Amazon (company) and eBay, and enterprise services provided by SAP SE. Over time, subsequent standards and advisories from bodies such as the IETF, NIST, and security researchers at Google and Akamai Technologies led to deprecation of older cipher suites and migration paths evident in industry rollouts by PayPal and cloud providers including Amazon Web Services and Microsoft Azure. The protocol specified in RFC 2246 remains a significant milestone in the evolution of Internet security protocols.

Category:Internet Standards