Perform handshake on first read/write

Updates the connection to perform a handshake on first read/write
instead of on accept.

Closes #279.

bench_test.go

@@ -40,7 +40,7 @@ func TestSimpleReadWrite(t *testing.T) {
 			return
 		}
 		buf := make([]byte, 1024)
-		if _, sErr = server.Read(buf); sErr != nil {
+		if _, sErr = server.Read(buf); sErr != nil { //nolint:contextcheck
 			t.Error(sErr)
 		}
 		gotHello <- struct{}{}

config.go

@@ -118,13 +118,10 @@ type Config struct {
 
 	LoggerFactory logging.LoggerFactory
 
-	// ConnectContextMaker is a function to make a context used in Dial(),
-	// Client(), Server(), and Accept(). If nil, the default ConnectContextMaker
-	// is used. It can be implemented as following.
+	// ConnectContextMaker is no longer used. It is kept for compatibility
+	// reasons and will be removed in a future release.
 	//
-	// 	func ConnectContextMaker() (context.Context, func()) {
-	// 		return context.WithTimeout(context.Background(), 30*time.Second)
-	// 	}
+	// Deprecated: Use the context parameter in [HandshakeContext] instead.
 	ConnectContextMaker func() (context.Context, func())
 
 	// MTU is the length at which handshake messages will be fragmented to
@@ -230,17 +227,6 @@ type Config struct {
 	OnConnectionAttempt func(net.Addr) error
 }
 
-func defaultConnectContextMaker() (context.Context, func()) {
-	return context.WithTimeout(context.Background(), 30*time.Second)
-}
-
-func (c *Config) connectContextMaker() (context.Context, func()) {
-	if c.ConnectContextMaker == nil {
-		return defaultConnectContextMaker()
-	}
-	return c.ConnectContextMaker()
-}
-
 func (c *Config) includeCertificateSuites() bool {
 	return c.PSK == nil || len(c.Certificates) > 0 || c.GetCertificate != nil || c.GetClientCertificate != nil
 }