"error" {
	    foreach {chan msg} $args break

	    log 0 "TLS/$chan: error: $msg"
	}
	"info" {
	    # poor man's lassign
	    foreach {chan major minor msg type} $args break

	    if {$msg != ""} {
		append state ": $msg"
	    }
	    # For tracing
	    upvar #0 tls::$chan cb
	    set cb($major) $minor

	    log 2 "TLS/$chan: $major/$minor: $state"
	}
	"message" {
	    # poor man's lassign
	    foreach {chan direction version content_type msg} $args break

	    log 0 "TLS/$chan: info: $direction $msg"
	}
	"session" {
	    foreach {chan session_id ticket lifetime} $args break

	    log 0 "TLS/$chan: session: lifetime $lifetime"
	}
	default	{
	    return -code error "bad option \"$option\":\
		    must be one of error, info, or session"
	}
    }
}

#
# Sample callback when return value is needed
#
proc tls::validate_command {option args} {
    variable debug

    #log 2 [concat $option $args]

    switch -- $option {
	"alpn" {
	    foreach {chan protocol match} $args break

	    log 0 "TLS/$chan: alpn: $protocol $match"
	}
	"hello" {
	    foreach {chan servername} $args break

	    log 0 "TLS/$chan: hello: $servername"
	}
	"sni" {
	    foreach {chan servername} $args break

	    log 0 "TLS/$chan: sni: $servername"
	}
	"verify" {
	    # poor man's lassign
	    foreach {chan depth cert rc err} $args break

	}
	if {$cb(handshake) == "done"} {
	    return 1
	}
    }
}

proc tls::password {rwflag size} {
    log 0 "TLS/Password: did you forget to set your passwd!"
    # Return the worlds best kept secret password.
    return "secret"
}

proc tls::log {level msg} {
    variable debug