move client hello parser to separate package

clienthello/client_hello_parser.go

@@ -7,7 +7,7 @@
 // https://github.com/golang/go/blob/master/src/crypto/tls/handshake_messages.go#L69
 // https://cs.opensource.google/go/go/+/refs/tags/go1.18:src/crypto/tls/handshake_messages.go;l=69
 
-package main
+package clienthello
 
 import (
 	"crypto/md5"
@@ -211,7 +211,7 @@ type highlights struct {
 	JA3MD5    byteSlice `json:"ja3_md5"`
 }
 
-type clientHelloMsg struct {
+type ClientHelloMsg struct {
 	Raw                    byteSlice   `json:"raw"`
 	RecordHeaderTLSVersion uint16      `json:"record_header_tls_version"` // TLSv1.0 (769)
 	TLSVersion             uint16      `json:"client_tls_version"`        // TLSv1.2 (771)
@@ -223,8 +223,8 @@ type clientHelloMsg struct {
 	Highlights             highlights  `json:"highlights"`
 }
 
-func (m *clientHelloMsg) unmarshal(data []byte) bool {
-	*m = clientHelloMsg{Raw: data}
+func (m *ClientHelloMsg) Unmarshal(data []byte) bool {
+	*m = ClientHelloMsg{Raw: data}
 	s := cryptobyte.String(data)
 
 	var random []byte

server.go

@@ -16,6 +16,7 @@ import (
 	"log"
 	"net"
 	"os"
+	"tildegit.org/nervuri/client-hello-mirror/clienthello"
 	"time"
 )
 
@@ -125,8 +126,8 @@ func requestHandler(conn *tls.Conn, rawClientHello []byte) {
 	}
 
 	// Parse Client Hello message.
-	var clientHello clientHelloMsg
-	if !clientHello.unmarshal(rawClientHello) {
+	var clientHelloMsg clienthello.ClientHelloMsg
+	if !clientHelloMsg.Unmarshal(rawClientHello) {
 		log.Println("Failed to parse Client Hello")
 		return
 	}
@@ -158,10 +159,10 @@ func requestHandler(conn *tls.Conn, rawClientHello []byte) {
 			resp.StatusLine = "20 application/json"
 		}
 		output := struct {
-			ClientHello       clientHelloMsg    `json:"client_hello"`
-			TlsConnectionInfo tlsConnectionInfo `json:"connection_info"`
+			ClientHello       clienthello.ClientHelloMsg `json:"client_hello"`
+			TlsConnectionInfo tlsConnectionInfo          `json:"connection_info"`
 		}{
-			clientHello,
+			clientHelloMsg,
 			tlsConnInfo,
 		}
 		outputJSON, err := json.MarshalIndent(output, "", "  ")