Is there a way to change the Packet Info Field based on criteria?

edit

There can be more than one ssl.handshake.type field within a single packet, so you need to account for this. The following is a simple Lua post-dissector that appends the SSL handshake type(s) to the Info column. It ought to serve as a basic starting point for any further work:

sslpost = Proto("SSLpost", "SSL post-dissector")
ssl_handshake_type_f = Field.new("ssl.handshake.type")

function sslpost.dissector(tvb, pinfo, tree)

    local ssl_hst = {ssl_handshake_type_f()}
    if ssl_hst then
        pinfo.cols.info:append(": Handshake Type" .. ((#ssl_hst > 1) and "s: " or ": "))
        for i in pairs(ssl_hst) do
            pinfo.cols.info:append(ssl_hst[i]() .. " ")
        end

    end
end

register_postdissector(sslpost)

Testing this against the ssl.pcap file in the Wireshark menagerie produces this tshark result:

$ tshark -r ssl.pcap -Y "ssl.handshake.type"
  2009-02-13 11:55:59.814985   0.045490 0.000000 9.155.133.167 → unlabelled-50-61-58-81.versatel.net SSLv2 196 Client Hello: Handshake Type: 1
  2009-02-13 11:55:59.910024   0.140529 0.095039 unlabelled-50-61-58-81.versatel.net → 9.155.133.167 SSLv3 989 Server Hello, Certificate, Server Hello Done: Handshake Types: 2 11 14
  2009-02-13 11:55:59.912738   0.143243 0.002714 9.155.133.167 → unlabelled-50-61-58-81.versatel.net SSLv3 258 Client Key Exchange, Change Cipher Spec, Encrypted Handshake Message: Handshake Type: 16