tls.DialContext

tlscontext.go

package main

import (
	"context"
	"crypto/tls"
	"net"
	"time"
)

func dialContextWithDialer(ctx context.Context, dialer *net.Dialer, network, addr string, config *tls.Config) (*tls.Conn, error) {
	timeout := dialer.Timeout

	if !dialer.Deadline.IsZero() {
		deadlineTimeout := dialer.Deadline.Sub(time.Now())
		if timeout == 0 || deadlineTimeout < timeout {
			timeout = deadlineTimeout
		}
	}

	if timeout != 0 {
		var cancel context.CancelFunc

		ctx, cancel = context.WithTimeout(ctx, timeout)
		defer cancel()
	}

	rawConn, err := dialer.DialContext(ctx, network, addr)
	if err != nil {
		return nil, err
	}

	conn := tls.Client(rawConn, config)

	errChannel := make(chan error, 1)

	go func() {
		errChannel <- conn.Handshake()
	}()

	select {
	case err := <-errChannel:
		if err != nil {
			rawConn.Close()
			return nil, err
		}

		return conn, nil

	case <-ctx.Done():
		return nil, ctx.Err()
	}
}

func dialContext(ctx context.Context, network, addr string, config *tls.Config) (*tls.Conn, error) {
	return dialContextWithDialer(ctx, new(net.Dialer), network, addr, config)
}