A Usable, Secure Communications Protocol: Client-Side TLS - Implementing SSL/TLS Using Cryptography and PKI - page 316

if ( send( connection, ( void * ) send_buffer,
send_buffer_size, 0 ) < send_buffer_size )
{
return -1;
}

free( send_buffer );

return 0;
}

At this point, the actual socket-level send function is called. Now the client
hello message, with its handshake message header, with its TLS header, are sent
to the server for processing. After all of this prepending, the fi nal wire-level
structure is as shown in Figure 6-5.

msg
type

handshake message
body (variable)

type major minor length length major minor current time

client
random

current time random bytes

sess
id
len

random bytes

cipher
suites
length

Comp
meth
len

compression
methods
(variable)

session id
(variable)

cipher suites
(variable)

Figure 6-5: TLS Client Hello with all headers

TLS Server Hello
The server should now select one of the supported cipher suites and respond
with a server hello response. The client is required to block, waiting for an
answer; nothing else can happen on this socket until the server responds.
Expand tls_connect :

// Step 2. Receive the server hello response
if ( receive_tls_msg( connection, parameters ) < 0 )
{
perror( “Unable to receive server hello” );
return 2;
}