RFC 6347, "Datagram Transport Layer Security Version 1.2", January 2012

Note: This RFC has been obsoleted by RFC 9147

Note: This RFC has been updated by RFC 7507, RFC 7905, RFC 8996, RFC 9146

Errata ID: 3917
Status: Reported
Type: Technical
Publication Format(s) : TEXT
Reported By: Martin Thomson
Date Reported: 2014-03-14

Section 4.2.1 says:

   struct {
     ProtocolVersion client_version;
     Random random;
     SessionID session_id;
     opaque cookie<0..2^8-1>;                             // New field
     CipherSuite cipher_suites<2..2^16-1>;
           CompressionMethod compression_methods<1..2^8-1>;
   } ClientHello;

It should say:

   struct {
     ProtocolVersion client_version;
     Random random;
     SessionID session_id;
     opaque cookie<0..2^8-1>;                             // New field
     CipherSuite cipher_suites<2..2^16-1>;
     CompressionMethod compression_methods<1..2^8-1>;
     select (extensions_present) {
       case false:
         struct {};
       case true:
         Extension extensions<0..2^16-1>;
     };
   } ClientHello;

Notes:

This also affects Section 4.3.2 where the same structure is repeated.

Extensions are a part of TLS. They are also part of DTLS in practice, but the RFC omits them. The corrected text includes the relevant part of the ClientHello from RFC 5246.

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