[Sync] Move keystore key handling to SyncEncryptionHandlerImpl

sync/util/cryptographer.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.
 
 #include "sync/util/cryptographer.h"
 
 #include <algorithm>
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "sync/protocol/nigori_specifics.pb.h"
 #include "sync/util/encryptor.h"
 
 namespace syncer {
 
 const char kNigoriTag[] = "google_chrome_nigori";
 
 // We name a particular Nigori instance (ie. a triplet consisting of a hostname,
 // a username, and a password) by calling Permute on this string. Since the
 // output of Permute is always the same for a given triplet, clients will always
 // assign the same name to a particular triplet.
 const char kNigoriKeyName[] = "nigori-key";
 
 Cryptographer::Cryptographer(Encryptor* encryptor)
-    : encryptor_(encryptor),
-      default_nigori_(NULL),
-      keystore_nigori_(NULL) {
+    : encryptor_(encryptor) {
   DCHECK(encryptor);
 }
 
 Cryptographer::~Cryptographer() {}
 
 
 void Cryptographer::Bootstrap(const std::string& restored_bootstrap_token) {
   if (is_initialized()) {
     NOTREACHED();
     return;
   }
 
   scoped_ptr<Nigori> nigori(UnpackBootstrapToken(restored_bootstrap_token));
   if (nigori.get())
-    AddKeyImpl(nigori.release(), false);
-}
-
-void Cryptographer::BootstrapKeystoreKey(
-    const std::string& restored_bootstrap_token) {
-  if (keystore_nigori_) {
-    NOTREACHED();
-    return;
-  }
-
-  scoped_ptr<Nigori> nigori(UnpackBootstrapToken(restored_bootstrap_token));
-  if (nigori.get())
-    AddKeyImpl(nigori.release(), true);
+    AddKeyImpl(nigori.Pass());
 }
 
 bool Cryptographer::CanDecrypt(const sync_pb::EncryptedData& data) const {
   return nigoris_.end() != nigoris_.find(data.key_name());
 }
 
 bool Cryptographer::CanDecryptUsingDefaultKey(
     const sync_pb::EncryptedData& data) const {
-  return default_nigori_ && (data.key_name() == default_nigori_->first);
+  return default_nigori_.get() && (data.key_name() == default_nigori_name_);
 }
 
 bool Cryptographer::Encrypt(
     const ::google::protobuf::MessageLite& message,
     sync_pb::EncryptedData* encrypted) const {
   DCHECK(encrypted);
-  if (!default_nigori_) {
+  if (!default_nigori_.get()) {
     LOG(ERROR) << "Cryptographer not ready, failed to encrypt.";
     return false;
   }
+  DCHECK(nigoris_.find(default_nigori_name_) != nigoris_.end());

[akalin, 2012/08/27 22:06:55]

do we want to return false if either of these checks fail?

[Nicolas Zea, 2012/08/28 01:18:50]

Given that getting this wrong runs the risk of corrupting data (not setting the
proper key name on the blob), I suppose it makes sense to just do the lookup
always. I worry about letting sync continue on though, as opposed to forcing a
crash so we know something is very wrong. Leaving it as a LOG(ERROR) + return
false for now.

+  DCHECK_EQ(default_nigori_.get(),
+            nigoris_.find(default_nigori_name_)->second.get());
 
   std::string serialized;
   if (!message.SerializeToString(&serialized)) {
     LOG(ERROR) << "Message is invalid/missing a required field.";
     return false;
   }
 
   if (CanDecryptUsingDefaultKey(*encrypted)) {
     const std::string& original_serialized = DecryptToString(*encrypted);
     if (original_serialized == serialized) {
       DVLOG(2) << "Re-encryption unnecessary, encrypted data already matches.";
       return true;
     }
   }
 
-  encrypted->set_key_name(default_nigori_->first);
-  if (!default_nigori_->second->Encrypt(serialized,
-                                        encrypted->mutable_blob())) {
+  encrypted->set_key_name(default_nigori_name_);
+  if (!default_nigori_->Encrypt(serialized,
+                                encrypted->mutable_blob())) {
     LOG(ERROR) << "Failed to encrypt data.";
     return false;
   }
   return true;
 }
 
 bool Cryptographer::Decrypt(const sync_pb::EncryptedData& encrypted,
                             ::google::protobuf::MessageLite* message) const {
   DCHECK(message);
   std::string plaintext = DecryptToString(encrypted);
@@ skipping 38 matching lines @@
 
 bool Cryptographer::AddKey(const KeyParams& params) {
   // Create the new Nigori and make it the default encryptor.
   scoped_ptr<Nigori> nigori(new Nigori);
   if (!nigori->InitByDerivation(params.hostname,
                                 params.username,
                                 params.password)) {
     NOTREACHED();  // Invalid username or password.
     return false;
   }
-  return AddKeyImpl(nigori.release(), false);
+  return AddKeyImpl(nigori.Pass());
 }
 
 bool Cryptographer::AddKeyFromBootstrapToken(
     const std::string restored_bootstrap_token) {
   // Create the new Nigori and make it the default encryptor.
   scoped_ptr<Nigori> nigori(UnpackBootstrapToken(restored_bootstrap_token));
   if (!nigori.get())
     return false;
-  return AddKeyImpl(nigori.release(), false);
+  return AddKeyImpl(nigori.Pass());
 }
 
-bool Cryptographer::AddKeyImpl(Nigori* initialized_nigori,
-                               bool is_keystore_key) {
-  scoped_ptr<Nigori> nigori(initialized_nigori);
+bool Cryptographer::AddKeyImpl(scoped_ptr<Nigori> initialized_nigori) {
   std::string name;
-  if (!nigori->Permute(Nigori::Password, kNigoriKeyName, &name)) {
+  if (!initialized_nigori->Permute(Nigori::Password, kNigoriKeyName, &name)) {
     NOTREACHED();
     return false;
   }
-  nigoris_[name] = make_linked_ptr(nigori.release());
-  if (is_keystore_key)
-    keystore_nigori_ = &*nigoris_.find(name);
-  else
-    default_nigori_ = &*nigoris_.find(name);
+  default_nigori_ = make_linked_ptr(initialized_nigori.release());
+  nigoris_[name] = default_nigori_;
+  default_nigori_name_ = name;
   return true;
 }
 
 void Cryptographer::InstallKeys(const sync_pb::EncryptedData& encrypted) {
   DCHECK(CanDecrypt(encrypted));
 
   sync_pb::NigoriKeyBag bag;
   if (!Decrypt(encrypted, &bag))
     return;
   InstallKeyBag(bag);
 }
 
 void Cryptographer::SetDefaultKey(const std::string& key_name) {
   DCHECK(nigoris_.end() != nigoris_.find(key_name));
-  default_nigori_ = &*nigoris_.find(key_name);
+  default_nigori_ = nigoris_.find(key_name)->second;

[akalin, 2012/08/27 22:06:55]

it seems like this'll crash (in release) if the DCHECK above fails.  Perhaps
something like:

NigoriMap::const_iterator it = nigoris_.find(key_name);
// or CHECK(it != nigoris_.end());
if (it == nigoris_.end()) {
  NOTREACHED();
  return;
}
default_nigori_name_ = key_name;
default_nigori_ = it->second;

[Nicolas Zea, 2012/08/28 01:18:50]

I think a crash would be appropriate here. If this is called improperly,
something is broken and we shouldn't be attempting to go further.

+  default_nigori_name_ = key_name;
 }
 
 void Cryptographer::SetPendingKeys(const sync_pb::EncryptedData& encrypted) {
   DCHECK(!CanDecrypt(encrypted));
   DCHECK(!encrypted.blob().empty());
   pending_keys_.reset(new sync_pb::EncryptedData(encrypted));
 }
 
 const sync_pb::EncryptedData& Cryptographer::GetPendingKeys() const {
   DCHECK(has_pending_keys());
@@ skipping 12 matching lines @@
   std::string plaintext;
   if (!nigori.Decrypt(pending_keys_->blob(), &plaintext))
     return false;
 
   sync_pb::NigoriKeyBag bag;
   if (!bag.ParseFromString(plaintext)) {
     NOTREACHED();
     return false;
   }
   InstallKeyBag(bag);
   const std::string& new_default_key_name = pending_keys_->key_name();

[akalin, 2012/08/27 22:06:55]

can you use SetDefaultKey here?

[Nicolas Zea, 2012/08/28 01:18:50]

Done.

   DCHECK(nigoris_.end() != nigoris_.find(new_default_key_name));
-  default_nigori_ = &*nigoris_.find(new_default_key_name);
+  default_nigori_ = nigoris_.find(new_default_key_name)->second;
+  default_nigori_name_ = new_default_key_name;
   pending_keys_.reset();
   return true;
 }
 
 bool Cryptographer::GetBootstrapToken(std::string* token) const {
   DCHECK(token);
   if (!is_initialized())
     return false;
 
-  return PackBootstrapToken(default_nigori_->second.get(), token);
-}
-
-bool Cryptographer::GetKeystoreKeyBootstrapToken(
-    std::string* token) const {
-  DCHECK(token);
-  if (!HasKeystoreKey())
-    return false;
-
-  return PackBootstrapToken(keystore_nigori_->second.get(), token);
+  return PackBootstrapToken(default_nigori_.get(), token);
 }
 
 bool Cryptographer::PackBootstrapToken(const Nigori* nigori,
                                        std::string* pack_into) const {
   DCHECK(pack_into);
   DCHECK(nigori);
 
   sync_pb::NigoriKey key;
   if (!nigori->ExportKeys(key.mutable_user_key(),
                           key.mutable_encryption_key(),
@@ skipping 46 matching lines @@
   scoped_ptr<Nigori> nigori(new Nigori);
   if (!nigori->InitByImport(key.user_key(), key.encryption_key(),
                             key.mac_key())) {
     NOTREACHED();
     return NULL;
   }
 
   return nigori.release();
 }
 
-bool Cryptographer::SetKeystoreKey(const std::string& keystore_key) {
-  if (keystore_key.empty())
-    return false;
-  KeyParams params = {"localhost", "dummy", keystore_key};
-
-  // Create the new Nigori and make it the default keystore encryptor.
-  scoped_ptr<Nigori> nigori(new Nigori);
-  if (!nigori->InitByDerivation(params.hostname,
-                                params.username,
-                                params.password)) {
-    NOTREACHED();  // Invalid username or password.
-    return false;
-  }
-
-  return AddKeyImpl(nigori.release(), true);
-}
-
-bool Cryptographer::HasKeystoreKey() const {
-  return keystore_nigori_ != NULL;
-}
-
 void Cryptographer::InstallKeyBag(const sync_pb::NigoriKeyBag& bag) {
   int key_size = bag.key_size();
   for (int i = 0; i < key_size; ++i) {
     const sync_pb::NigoriKey key = bag.key(i);
     // Only use this key if we don't already know about it.
     if (nigoris_.end() == nigoris_.find(key.name())) {
       scoped_ptr<Nigori> new_nigori(new Nigori);
       if (!new_nigori->InitByImport(key.user_key(),
                                     key.encryption_key(),
                                     key.mac_key())) {
         NOTREACHED();
         continue;
       }
       nigoris_[key.name()] = make_linked_ptr(new_nigori.release());
     }
   }
 }
 
 }  // namespace syncer