th5/tls.go
Adam Langley 93eb884c98 crypto/tls: use pool building for certificate checking
Previously we checked the certificate chain from the leaf
upwards and expected to jump from the last cert in the chain to
a root certificate.

Although technically correct, there are a number of sites with
problems including out-of-order certs, superfluous certs and
missing certs.

The last of these requires AIA chasing, which is a lot of
complexity. However, we can address the more common cases by
using a pool building algorithm, as browsers do.

We build a pool of root certificates and a pool from the
server's chain. We then try to build a path to a root
certificate, using either of these pools.

This differs from the behaviour of, say, Firefox in that Firefox
will accumulate intermedite certificate in a persistent pool in
the hope that it can use them to fill in gaps in future chains.

We don't do that because it leads to confusing errors which only
occur based on the order to sites visited.

This change also enabled SNI for tls.Dial so that sites will return
the correct certificate chain.

R=rsc
CC=golang-dev
https://golang.org/cl/2916041
2010-11-05 09:54:56 -04:00

138 lines
3.3 KiB
Go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This package partially implements the TLS 1.1 protocol, as specified in RFC 4346.
package tls
import (
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"io/ioutil"
"net"
"os"
"strings"
)
func Server(conn net.Conn, config *Config) *Conn {
return &Conn{conn: conn, config: config}
}
func Client(conn net.Conn, config *Config) *Conn {
return &Conn{conn: conn, config: config, isClient: true}
}
type Listener struct {
listener net.Listener
config *Config
}
func (l *Listener) Accept() (c net.Conn, err os.Error) {
c, err = l.listener.Accept()
if err != nil {
return
}
c = Server(c, l.config)
return
}
func (l *Listener) Close() os.Error { return l.listener.Close() }
func (l *Listener) Addr() net.Addr { return l.listener.Addr() }
// NewListener creates a Listener which accepts connections from an inner
// Listener and wraps each connection with Server.
// The configuration config must be non-nil and must have
// at least one certificate.
func NewListener(listener net.Listener, config *Config) (l *Listener) {
l = new(Listener)
l.listener = listener
l.config = config
return
}
func Listen(network, laddr string, config *Config) (net.Listener, os.Error) {
if config == nil || len(config.Certificates) == 0 {
return nil, os.NewError("tls.Listen: no certificates in configuration")
}
l, err := net.Listen(network, laddr)
if err != nil {
return nil, err
}
return NewListener(l, config), nil
}
func Dial(network, laddr, raddr string) (net.Conn, os.Error) {
c, err := net.Dial(network, laddr, raddr)
if err != nil {
return nil, err
}
colonPos := strings.LastIndex(raddr, ":")
if colonPos == -1 {
colonPos = len(raddr)
}
hostname := raddr[:colonPos]
config := defaultConfig()
config.ServerName = hostname
conn := Client(c, config)
err = conn.Handshake()
if err == nil {
return conn, nil
}
c.Close()
return nil, err
}
// LoadX509KeyPair reads and parses a public/private key pair from a pair of
// files. The files must contain PEM encoded data.
func LoadX509KeyPair(certFile string, keyFile string) (cert Certificate, err os.Error) {
certPEMBlock, err := ioutil.ReadFile(certFile)
if err != nil {
return
}
certDERBlock, _ := pem.Decode(certPEMBlock)
if certDERBlock == nil {
err = os.ErrorString("crypto/tls: failed to parse certificate PEM data")
return
}
cert.Certificate = [][]byte{certDERBlock.Bytes}
keyPEMBlock, err := ioutil.ReadFile(keyFile)
if err != nil {
return
}
keyDERBlock, _ := pem.Decode(keyPEMBlock)
if keyDERBlock == nil {
err = os.ErrorString("crypto/tls: failed to parse key PEM data")
return
}
key, err := x509.ParsePKCS1PrivateKey(keyDERBlock.Bytes)
if err != nil {
err = os.ErrorString("crypto/tls: failed to parse key")
return
}
cert.PrivateKey = key
// We don't need to parse the public key for TLS, but we so do anyway
// to check that it looks sane and matches the private key.
x509Cert, err := x509.ParseCertificate(certDERBlock.Bytes)
if err != nil {
return
}
if x509Cert.PublicKeyAlgorithm != x509.RSA || x509Cert.PublicKey.(*rsa.PublicKey).N.Cmp(key.PublicKey.N) != 0 {
err = os.ErrorString("crypto/tls: private key does not match public key")
return
}
return
}