Added HostKeyPair class, signatures for heartbeat messages.

remoting/host/host_key_pair.cc

+// Copyright (c) 2010 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.
+
+#include "remoting/host/host_key_pair.h"
+
+#include <vector>

[awong, 2010/08/02 19:53:49]

Alphabetical order

[Sergey Ulanov, 2010/08/03 02:10:39]

Done.

+#include <string>
+
+#include "base/base64.h"
+#include "base/crypto/rsa_private_key.h"
+#include "base/crypto/signature_creator.h"
+#include "base/logging.h"
+#include "base/task.h"
+#include "remoting/host/host_config.h"
+
+namespace remoting {
+
+HostKeyPair::HostKeyPair() { };

[awong, 2010/08/02 19:53:49]

Trailing semicolons not needed. Here and below.

[Sergey Ulanov, 2010/08/03 02:10:39]

Done.

+
+HostKeyPair::~HostKeyPair() { };
+
+void HostKeyPair::Generate() {
+  key_.reset(base::RSAPrivateKey::Create(2048));
+}
+
+bool HostKeyPair::LoadFromString(const std::string& key_base64) {
+  std::string key_str;
+  if (!base::Base64Decode(key_base64, &key_str)) {
+    LOG(ERROR) << "Failed to decode private key." << key_base64;

[awong, 2010/08/02 19:53:49]

Do we want to dump the private key to screen even if it doesn't parse?

[Sergey Ulanov, 2010/08/03 02:10:39]

Done.

+    return false;
+  }
+
+  std::vector<uint8> key_buf(key_str.begin(), key_str.end());
+  base::RSAPrivateKey *new_key =

[awong, 2010/08/02 19:53:49]

Just use key_.reset() here?

[Sergey Ulanov, 2010/08/03 02:10:39]

This would reset key_ even if the key cannot be parsed. It will probably never
matter, still it is better to avoid this side-effect.

[awong, 2010/08/03 19:21:02]

hmm...I feel like this may actually even be preferable.  If we want to get all
crazy, I'd be tempted to make LoadFromString a static factory method and make
the HostKeyPair constructor private.  But that also might be overkill :P

+      base::RSAPrivateKey::CreateFromPrivateKeyInfo(key_buf);
+  if (new_key == NULL) {
+    LOG(ERROR) << "Invalid private key.";
+    return false;
+  }
+
+  key_.reset(new_key);
+
+  return true;
+}
+
+bool HostKeyPair::Load(HostConfig* host_config) {

[awong, 2010/08/02 19:53:49]

These functions feel funny...almost like they should be in HostConfig instead of
here.

[Sergey Ulanov, 2010/08/03 02:10:39]

HostConfig is just a store for all config settings, and it is agnostic to the
format of each setting in the config. If we make HostConfig aware of format of
each and every setting in the config, it would eventually become too fat
(Get/Set for each setting in the config). We could add HostKeyPairStore class
that would read/write HostKeyPair from/to HostConfig, but IMHO it is overkill in
this case.

[awong, 2010/08/03 19:21:02]

A third class is deifnitely overkill.  Why would a host not have a keypair
though?  Isn't this common for all configs?

[Sergey Ulanov, 2010/08/04 01:41:12]

HostConfig is probably a bad name for the class, should have named it
HostConfigStore or something. Basically it is similar to PrefStore interfaces
for the browser prefs.

+  std::string key_base64;
+  if (!host_config->GetString(kPrivateKeyConfigPath, &key_base64)) {
+    LOG(ERROR) << "Private key wasn't found in the config file.";
+    return false;
+  }
+  return LoadFromString(key_base64);
+}
+
+void HostKeyPair::Save(MutableHostConfig* host_config) {
+  // Check that the key initialized.
+  DCHECK(key_.get() != NULL);
+
+  host_config->Update(
+      NewRunnableMethod(this, &HostKeyPair::DoSave, host_config));
+}
+
+void HostKeyPair::DoSave(MutableHostConfig* host_config) const {
+  std::vector<uint8> key_buf;
+  key_->ExportPrivateKey(&key_buf);
+  std::string key_str(key_buf.begin(), key_buf.end());
+  std::string key_base64;
+  base::Base64Encode(key_str, &key_base64);
+  host_config->SetString(kPrivateKeyConfigPath, key_base64);
+}
+
+std::string HostKeyPair::GetPublicKey() const {
+  std::vector<uint8> public_key;
+  key_->ExportPublicKey(&public_key);
+  std::string public_key_str(public_key.begin(), public_key.end());
+  std::string public_key_base64;
+  base::Base64Encode(public_key_str, &public_key_base64);
+  return public_key_base64;
+}
+
+std::string HostKeyPair::GetSignature(const std::string& message) const {
+  scoped_ptr<base::SignatureCreator> signature_creator(
+      base::SignatureCreator::Create(key_.get()));
+  signature_creator->Update(reinterpret_cast<const uint8*>(message.c_str()),
+                            message.length());
+  std::vector<uint8> signature_buf;
+  signature_creator->Final(&signature_buf);
+  std::string signature_str(signature_buf.begin(), signature_buf.end());
+  std::string signature_base64;
+  base::Base64Encode(signature_str, &signature_base64);
+  return signature_base64;
+}
+
+}  // namespace remoting