Implemented TLS client auth.

src/app/spreed-speakfreely-server/main.go

@@ -24,6 +24,8 @@ package main
 import (
 	"app/spreed-speakfreely-server/sleepy"
 	"bytes"
+	"crypto/tls"
+	"crypto/x509"
 	"flag"
 	"fmt"
 	"github.com/gorilla/mux"
@@ -394,6 +396,25 @@ func runner(runtime phoenix.Runtime) error {
 	runtime.DefaultHTTPHandler(r)
 	runtime.DefaultHTTPSHandler(r)
 
+	if tlsConfig, err := runtime.TLSConfig(); err == nil {
+		tlsConfig.ClientAuth = tls.VerifyClientCertIfGiven
+		// Create cert pool.
+		pool := x509.NewCertPool()
+		if certificateFn, err := runtime.GetString("users", "certificate_certificate"); err == nil {
+			if certificate, err := loadX509Certificate(certificateFn); err == nil {
+				for _, derCert := range certificate.Certificate {
+					cert, err := x509.ParseCertificate(derCert)
+					if err != nil {
+						continue
+					}
+					pool.AddCert(cert)
+				}
+			}
+			log.Printf("Initialized TLS auth pool with %d certtificates.", len(pool.Subjects()))
+		}
+		tlsConfig.ClientCAs = pool
+	}
+
 	return runtime.Start()
 }
 

src/app/spreed-speakfreely-server/tls.go

@@ -0,0 +1,110 @@
+/*
+ * TLS helpers for Go based on crypto/tls package.
+ *
+ * Copyright (C) 2014 struktur AG. All rights reserved.
+ * Copyright 2011 The Go Authors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following disclaimer
+ *    in the documentation and/or other materials provided with the
+ *    distribution.
+ *  * Neither the name of Google Inc. nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+package main
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"io/ioutil"
+	"strings"
+)
+
+func loadX509PrivateKey(keyFile string) (privateKey crypto.PrivateKey, err error) {
+	keyPEMBlock, err := ioutil.ReadFile(keyFile)
+	if err != nil {
+		return
+	}
+	var keyDERBlock *pem.Block
+	for {
+		keyDERBlock, keyPEMBlock = pem.Decode(keyPEMBlock)
+		if keyDERBlock == nil {
+			err = errors.New("failed to parse key PEM data")
+			return
+		}
+		if keyDERBlock.Type == "PRIVATE KEY" || strings.HasSuffix(keyDERBlock.Type, " PRIVATE KEY") {
+			break
+		}
+	}
+	privateKey, err = parsePrivateKey(keyDERBlock.Bytes)
+	return
+}
+
+func loadX509Certificate(certFile string) (cert tls.Certificate, err error) {
+	certPEMBlock, err := ioutil.ReadFile(certFile)
+	if err != nil {
+		return
+	}
+	var certDERBlock *pem.Block
+	for {
+		certDERBlock, certPEMBlock = pem.Decode(certPEMBlock)
+		if certDERBlock == nil {
+			break
+		}
+		if certDERBlock.Type == "CERTIFICATE" {
+			cert.Certificate = append(cert.Certificate, certDERBlock.Bytes)
+		}
+	}
+
+	if len(cert.Certificate) == 0 {
+		err = errors.New("failed to parse certificate PEM data")
+	}
+	return
+}
+
+// Attempt to parse the given private key DER block. OpenSSL 0.9.8 generates
+// PKCS#1 private keys by default, while OpenSSL 1.0.0 generates PKCS#8 keys.
+// OpenSSL ecparam generates SEC1 EC private keys for ECDSA. We try all three.
+func parsePrivateKey(der []byte) (crypto.PrivateKey, error) {
+	if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
+		return key, nil
+	}
+	if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
+		switch key := key.(type) {
+		case *rsa.PrivateKey, *ecdsa.PrivateKey:
+			return key, nil
+		default:
+			return nil, errors.New("found unknown private key type in PKCS#8 wrapping")
+		}
+	}
+	if key, err := x509.ParseECPrivateKey(der); err == nil {
+		return key, nil
+	}
+	return nil, errors.New("failed to parse private key")
+}

src/app/spreed-speakfreely-server/users.go

@@ -22,21 +22,19 @@
 package main
 
 import (
+	"crypto"
 	"crypto/hmac"
 	"crypto/rand"
-	"crypto/rsa"
 	"crypto/sha256"
 	"crypto/x509"
 	"crypto/x509/pkix"
 	"encoding/base64"
 	"encoding/json"
-	"encoding/pem"
 	"errors"
 	"fmt"
 	"github.com/longsleep/pkac"
 	"github.com/satori/go.uuid"
 	"github.com/strukturag/phoenix"
-	"io/ioutil"
 	"log"
 	"math/big"
 	"net/http"
@@ -123,58 +121,12 @@ func (uh *UsersHTTPHeaderHandler) Create(un *UserNonce, request *http.Request) (
 
 }
 
-func loadPEMfromFile(fn string) (block *pem.Block, err error) {
-
-	data, err := ioutil.ReadFile(fn)
-	if err != nil {
-		return
-	}
-
-	block, _ = pem.Decode(data)
-	return block, nil
-
-}
-
 type UsersCertificateHandler struct {
 	validFor    time.Duration
-	privateKey  *rsa.PrivateKey
+	privateKey  crypto.PrivateKey
 	certificate *x509.Certificate
 }
 
-func (uh *UsersCertificateHandler) loadPrivateKey(fn string) error {
-
-	pemBlock, err := loadPEMfromFile(fn)
-	if err != nil {
-		return err
-	}
-	privateKey, err := x509.ParsePKCS1PrivateKey(pemBlock.Bytes)
-	if err != nil {
-		return err
-	}
-
-	uh.privateKey = privateKey
-	log.Printf("Users certificate private key loaded from %s\n", fn)
-	return nil
-
-}
-
-func (uh *UsersCertificateHandler) loadCertificate(fn string) error {
-
-	pemBlock, err := loadPEMfromFile(fn)
-	if err != nil {
-		return err
-	}
-	certificates, err := x509.ParseCertificates(pemBlock.Bytes)
-	if err != nil {
-		return err
-	}
-
-	uh.certificate = certificates[0]
-	log.Printf("Users certificate loaded from %s\n", fn)
-	return nil
-
-}
-
 func (uh *UsersCertificateHandler) makeTemplate(commonName string) (*x509.Certificate, error) {
 
 	notBefore := time.Now()
@@ -183,7 +135,7 @@ func (uh *UsersCertificateHandler) makeTemplate(commonName string) (*x509.Certif
 	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
 	if err != nil {
 		return nil, err
-  	} 
+	}
 
 	return &x509.Certificate{
 		SerialNumber: serialNumber,
@@ -280,6 +232,7 @@ type Users struct {
 func NewUsers(hub *Hub, realm string, runtime phoenix.Runtime) *Users {
 
 	var handler UsersHandler
+	var err error
 
 	mode, _ := runtime.GetString("users", "mode")
 	switch mode {
@@ -300,10 +253,23 @@ func NewUsers(hub *Hub, realm string, runtime phoenix.Runtime) *Users {
 		keyFn, _ := runtime.GetString("users", "certificate_key")
 		certificateFn, _ := runtime.GetString("users", "certificate_certificate")
 		if keyFn != "" && certificateFn != "" {
-			uh.loadPrivateKey(keyFn)
+			if uh.privateKey, err = loadX509PrivateKey(keyFn); err == nil {
+				log.Printf("Users certificate private key loaded from %s\n", keyFn)
+			} else {
+				log.Printf("Failed to load certificat private key: %s\n", err)
+			}
 		}
 		if certificateFn != "" {
-			uh.loadCertificate(certificateFn)
+			if certificate, err := loadX509Certificate(certificateFn); err == nil {
+				if certificates, err := x509.ParseCertificates(certificate.Certificate[0]); err == nil {
+					uh.certificate = certificates[0]
+					log.Printf("Users certificate loaded from %s\n", certificateFn)
+				} else {
+					log.Printf("Failed to parse users certificate: %s\n", err)
+				}
+			} else {
+				log.Printf("Failed to load users certificate: %s\n", err)
+			}
 		}
 		handler = uh
 	default: