Overview#

ClientHello describes a Step within the TLS Handshake process.

The TLS ClientHello

First message of a TLS handshake is when the Protocol Client initiates a connections to the Protocol Server using a ClientHello.

The message by which the client states its intention to do some SSL/TLS.

Note that "client" is a symbolic role; it means "the party which speaks first". It so happens that in the HTTPS context, which is HTTP-within-SSL-within-TCP, all three layers have a notion of "client" and "server", and they all agree (the TCP client is also the SSL client and the HTTP client), but that's kind of a coincidence.

The ClientHello message contains:

  • the maximum protocol version that the client wishes to support;
  • the ClientHello.random (32 bytes, out of which 28 are suppose to be generated with a cryptographically strong number generator);
  • the "session ID" (in case the client wants to resume a session in an abbreviated handshake, see below);
  • the list of "Cipher Suites" that the client knows of, ordered by client preference;
  • the list of compression algorithms that the client knows of, ordered by client preference;
  • some optional extensions.

More Information#

There might be more information for this subject on one of the following:

Add new attachment

Only authorized users are allowed to upload new attachments.
« This page (revision-3) was last changed on 20-Aug-2016 11:05 by jim