Subject: [TLS] why TLS 1.2 uses length prefixed messages

From: "Andris Berzins" <[email-masked]>
Date: Wed, 14 Nov 2012 00:36:34 +0200

I have noticed that TLS 1.2 introduces additional length field for messages.
For example CertificateVerify:

Structure of this message (TLS 1.1):
      struct {
           Signature signature;
      } CertificateVerify;

Structure of this message (TLS 1.2):
      struct {
           digitally-signed struct {
               opaque handshake_messages[handshake_messages_length];
           }
      } CertificateVerify;

Is there reason why TLS 1.2 uses additional length field?