Use context.Context in TLS handshake (gorilla#751)

Continued work on gorilla#730.

Author: garyburd

.circleci/config.yml

@@ -67,4 +67,4 @@ workflows:
       - test:
           matrix:
             parameters:
-              version: ["latest", "1.15", "1.14", "1.13", "1.12", "1.11"]
+              version: ["latest", "1.17", "1.16", "1.15", "1.14", "1.13", "1.12", "1.11"]

client.go

@@ -314,11 +314,12 @@ func (d *Dialer) DialContext(ctx context.Context, urlStr string, requestHeader h
 		tlsConn := tls.Client(netConn, cfg)
 		netConn = tlsConn
 
-		var err error
-		if trace != nil {
-			err = doHandshakeWithTrace(trace, tlsConn, cfg)
-		} else {
-			err = doHandshake(tlsConn, cfg)
+		if trace != nil && trace.TLSHandshakeStart != nil {
+			trace.TLSHandshakeStart()
+		}
+		err := doHandshake(ctx, tlsConn, cfg)
+		if trace != nil && trace.TLSHandshakeDone != nil {
+			trace.TLSHandshakeDone(tlsConn.ConnectionState(), err)
 		}
 
 		if err != nil {
@@ -383,15 +384,3 @@ func (d *Dialer) DialContext(ctx context.Context, urlStr string, requestHeader h
 	netConn = nil // to avoid close in defer.
 	return conn, resp, nil
 }
-
-func doHandshake(tlsConn *tls.Conn, cfg *tls.Config) error {
-	if err := tlsConn.Handshake(); err != nil {
-		return err
-	}
-	if !cfg.InsecureSkipVerify {
-		if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
-			return err
-		}
-	}
-	return nil
-}

tls_handshake.go

@@ -0,0 +1,21 @@
+//go:build go1.17
+// +build go1.17
+
+package websocket
+
+import (
+	"context"
+	"crypto/tls"
+)
+
+func doHandshake(ctx context.Context, tlsConn *tls.Conn, cfg *tls.Config) error {
+	if err := tlsConn.HandshakeContext(ctx); err != nil {
+		return err
+	}
+	if !cfg.InsecureSkipVerify {
+		if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
+			return err
+		}
+	}
+	return nil
+}

tls_handshake_116.go

@@ -0,0 +1,21 @@
+//go:build !go1.17
+// +build !go1.17
+
+package websocket
+
+import (
+	"context"
+	"crypto/tls"
+)
+
+func doHandshake(ctx context.Context, tlsConn *tls.Conn, cfg *tls.Config) error {
+	if err := tlsConn.Handshake(); err != nil {
+		return err
+	}
+	if !cfg.InsecureSkipVerify {
+		if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
+			return err
+		}
+	}
+	return nil
+}