[Sync] Unrevert r75287 (initial support for sync encryption of all datatypes). Fix passphrase race.

BUG=73218,59242
TEST=unit,sync_unit,sync_integration

Review URL: http://codereview.chromium.org/6561001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@75920 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 13 insertions, 4 deletions

diff --git a/chrome/browser/sync/util/cryptographer.cc b/chrome/browser/sync/util/cryptographer.cc
index 747b094..da94681 100644
--- a/chrome/browser/sync/util/cryptographer.cc
+++ b/chrome/browser/sync/util/cryptographer.cc
@@ -59,19 +59,24 @@ bool Cryptographer::Encrypt(const ::google::protobuf::MessageLite& message,
 bool Cryptographer::Decrypt(const sync_pb::EncryptedData& encrypted,
                             ::google::protobuf::MessageLite* message) const {
   DCHECK(message);
+  std::string plaintext = DecryptToString(encrypted);
+  return message->ParseFromString(plaintext);
+}
 
+std::string Cryptographer::DecryptToString(
+    const sync_pb::EncryptedData& encrypted) const {
   NigoriMap::const_iterator it = nigoris_.find(encrypted.key_name());
   if (nigoris_.end() == it) {
     NOTREACHED() << "Cannot decrypt message";
-    return false;  // Caller should have called CanDecrypt(encrypt).
+    return std::string("");  // Caller should have called CanDecrypt(encrypt).
   }
 
   std::string plaintext;
   if (!it->second->Decrypt(encrypted.blob(), &plaintext)) {
-    return false;
+    return std::string("");
   }
 
-  return message->ParseFromString(plaintext);
+  return plaintext;
 }
 
 bool Cryptographer::GetKeys(sync_pb::EncryptedData* encrypted) const {
@@ -204,7 +209,7 @@ Nigori* Cryptographer::UnpackBootstrapToken(const std::string& token) const {
     return NULL;
 
   std::string encrypted_data;
-  if (!base::Base64Decode(token, &encrypted_data)){
+  if (!base::Base64Decode(token, &encrypted_data)) {
     DLOG(WARNING) << "Could not decode token.";
     return NULL;
   }
diff --git a/chrome/browser/sync/util/cryptographer.h b/chrome/browser/sync/util/cryptographer.h
index ada084cc..adb809b 100644
--- a/chrome/browser/sync/util/cryptographer.h
+++ b/chrome/browser/sync/util/cryptographer.h
@@ -71,6 +71,10 @@ class Cryptographer {
   bool Decrypt(const sync_pb::EncryptedData& encrypted,
                ::google::protobuf::MessageLite* message) const;
 
+  // Decrypts |encrypted| and returns plaintext decrypted data. If decryption
+  // fails, returns empty string.
+  std::string DecryptToString(const sync_pb::EncryptedData& encrypted) const;
+
   // Encrypts the set of currently known keys into |encrypted|. Returns true if
   // successful.
   bool GetKeys(sync_pb::EncryptedData* encrypted) const;