Set Token-Binding HTTP header

net/socket/ssl_client_socket_openssl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // OpenSSL binding for SSLClientSocket. The class layout and general principle
 // of operation is derived from SSLClientSocketNSS.
 
 #include "net/socket/ssl_client_socket_openssl.h"
 
 #include <errno.h>
 #include <openssl/bio.h>
 #include <openssl/bytestring.h>
 #include <openssl/err.h>
 #include <openssl/evp.h>
 #include <openssl/mem.h>
 #include <openssl/ssl.h>
 #include <string.h>
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/profiler/scoped_tracker.h"
+#include "base/stl_util.h"

[davidben, 2016/01/22 00:19:21]

Unused?

[nharper, 2016/01/22 19:36:52]

Removed.

 #include "base/strings/string_piece.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_local.h"
 #include "base/values.h"
 #include "crypto/ec_private_key.h"
 #include "crypto/openssl_util.h"
 #include "crypto/scoped_openssl_types.h"
 #include "net/base/ip_address_number.h"
 #include "net/base/net_errors.h"
 #include "net/cert/cert_verifier.h"
@@ skipping 480 matching lines @@
       transport_read_error_(OK),
       transport_write_error_(OK),
       server_cert_chain_(new PeerCertificateChain(NULL)),
       completed_connect_(false),
       was_ever_used_(false),
       cert_verifier_(context.cert_verifier),
       cert_transparency_verifier_(context.cert_transparency_verifier),
       channel_id_service_(context.channel_id_service),
       tb_was_negotiated_(false),
       tb_negotiated_param_(TB_PARAM_ECDSAP256),
+      tb_signed_ekm_map_(10),
       ssl_(NULL),
       transport_bio_(NULL),
       transport_(std::move(transport_socket)),
       host_and_port_(host_and_port),
       ssl_config_(ssl_config),
       ssl_session_cache_shard_(context.ssl_session_cache_shard),
       next_handshake_state_(STATE_NONE),
       disconnected_(false),
       npn_status_(kNextProtoUnsupported),
       channel_id_sent_(false),
@@ skipping 31 matching lines @@
     std::string* proto) const {
   *proto = npn_proto_;
   return npn_status_;
 }
 
 ChannelIDService*
 SSLClientSocketOpenSSL::GetChannelIDService() const {
   return channel_id_service_;
 }
 
+int SSLClientSocketOpenSSL::GetSignedEKMForTokenBinding(
+    crypto::ECPrivateKey* key,
+    std::vector<uint8_t>* out) {
+  // The same key will be used across multiple requests to sign the same value,
+  // so the signature is cached.
+  std::string raw_public_key;
+  if (!key->ExportRawPublicKey(&raw_public_key))
+    return ERR_FAILED;
+  SignedEkmMap::iterator it = tb_signed_ekm_map_.Get(raw_public_key);
+  if (it != tb_signed_ekm_map_.end()) {
+    *out = it->second;
+    return OK;
+  }
+
+  size_t tb_ekm_size = 32;

[davidben, 2016/01/22 00:19:21]

Nit: Could just use sizeof(tb_ekm_buf) everywhere I think.

[nharper, 2016/01/22 19:36:52]

Done.

+  uint8_t tb_ekm_buf[32];
+  static const char kTokenBindingExporterLabel[] = "EXPORTER-Token-Binding";
+  size_t ekm_label_length = strlen(kTokenBindingExporterLabel);

[davidben, 2016/01/22 00:19:21]

Nit: Could just use strlen(kTokenBindingExporterLabel) at the call site I think.

[nharper, 2016/01/22 19:36:52]

Done.

+  if (!SSL_export_keying_material(ssl_, tb_ekm_buf, tb_ekm_size,
+                                  kTokenBindingExporterLabel, ekm_label_length,
+                                  nullptr, 0, false)) {

[davidben, 2016/01/22 00:19:21]

Nit: false /* no context */

[nharper, 2016/01/22 19:36:52]

I've made this change, but I'm not sure it's any clearer.

+    return ERR_FAILED;
+  }
+
+  size_t sig_len;
+  crypto::ScopedEVP_PKEY_CTX pctx(EVP_PKEY_CTX_new(key->key(), nullptr));
+  if (!EVP_PKEY_sign_init(pctx.get()) ||
+      !EVP_PKEY_sign(pctx.get(), nullptr, &sig_len, tb_ekm_buf, tb_ekm_size)) {
+    return ERR_FAILED;
+  }
+  out->resize(sig_len);
+  if (!EVP_PKEY_sign(pctx.get(), out->data(), &sig_len, tb_ekm_buf,
+                     tb_ekm_size)) {
+    return ERR_FAILED;
+  }
+  out->resize(sig_len);
+
+  tb_signed_ekm_map_.Put(raw_public_key, *out);
+  return OK;
+}
+
 SSLFailureState SSLClientSocketOpenSSL::GetSSLFailureState() const {
   return ssl_failure_state_;
 }
 
 int SSLClientSocketOpenSSL::ExportKeyingMaterial(
     const base::StringPiece& label,
     bool has_context, const base::StringPiece& context,
     unsigned char* out, unsigned int outlen) {
   if (!IsConnected())
     return ERR_SOCKET_NOT_CONNECTED;
@@ skipping 1714 matching lines @@
       tb_was_negotiated_ = true;
       return 1;
     }
   }
 
   *out_alert_value = SSL_AD_ILLEGAL_PARAMETER;
   return 0;
 }
 
 }  // namespace net