// Copyright 2014 go-dockerclient authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//
// The content is borrowed from Docker's own source code to provide a simple
// tls based dialer
package docker
import (
"crypto/tls"
"errors"
"net"
"strings"
"time"
)
type tlsClientCon struct {
*tls.Conn
rawConn net.Conn
}
func (c *tlsClientCon) CloseWrite() error {
// Go standard tls.Conn doesn't provide the CloseWrite() method so we do it
// on its underlying connection.
if cwc, ok := c.rawConn.(interface {
CloseWrite() error
}); ok {
return cwc.CloseWrite()
}
return nil
}
func tlsDialWithDialer(dialer *net.Dialer, network, addr string, config *tls.Config) (net.Conn, error) {
// We want the Timeout and Deadline values from dialer to cover the
// whole process: TCP connection and TLS handshake. This means that we
// also need to start our own timers now.
timeout := dialer.Timeout
if !dialer.Deadline.IsZero() {
deadlineTimeout := dialer.Deadline.Sub(time.Now())
if timeout == 0 || deadlineTimeout < timeout {
timeout = deadlineTimeout
}
}
var errChannel chan error
if timeout != 0 {
errChannel = make(chan error, 2)
time.AfterFunc(timeout, func() {
errChannel <- errors.New("")
})
}
rawConn, err := dialer.Dial(network, addr)
if err != nil {
return nil, err
}
colonPos := strings.LastIndex(addr, ":")
if colonPos == -1 {
colonPos = len(addr)
}
hostname := addr[:colonPos]
// If no ServerName is set, infer the ServerName
// from the hostname we're connecting to.
if config.ServerName == "" {
// Make a copy to avoid polluting argument or default.
config = copyTLSConfig(config)
config.ServerName = hostname
}
conn := tls.Client(rawConn, config)
if timeout == 0 {
err = conn.Handshake()
} else {
go func() {
errChannel <- conn.Handshake()
}()
err = <-errChannel
}
if err != nil {
rawConn.Close()
return nil, err
}
// This is Docker difference with standard's crypto/tls package: returned a
// wrapper which holds both the TLS and raw connections.
return &tlsClientCon{conn, rawConn}, nil
}
// this exists to silent an error message in go vet
func copyTLSConfig(cfg *tls.Config) *tls.Config {
return &tls.Config{
Certificates: cfg.Certificates,
CipherSuites: cfg.CipherSuites,
ClientAuth: cfg.ClientAuth,
ClientCAs: cfg.ClientCAs,
ClientSessionCache: cfg.ClientSessionCache,
CurvePreferences: cfg.CurvePreferences,
InsecureSkipVerify: cfg.InsecureSkipVerify,
MaxVersion: cfg.MaxVersion,
MinVersion: cfg.MinVersion,
NameToCertificate: cfg.NameToCertificate,
NextProtos: cfg.NextProtos,
PreferServerCipherSuites: cfg.PreferServerCipherSuites,
Rand: cfg.Rand,
RootCAs: cfg.RootCAs,
ServerName: cfg.ServerName,
SessionTicketKey: cfg.SessionTicketKey,
SessionTicketsDisabled: cfg.SessionTicketsDisabled,
}
}
