KeyStorage: rework key upgrade handling

Remove the error-prone 'keepOld' parameter, and instead make begin()
(renamed to BeginKeymasterOp()) do all the key upgrade handling.

Don't handle /data and /metadata differently anymore.  Previously, when
a checkpoint is active, key blob files were replaced on /data
immediately; only the actual Keymaster key deletion was delayed until
checkpoint commit.  But it's easier to just delay the key blob file
replacement too, as we have to implement that for /metadata anyway.

Also be more vigilant about deleting any leftover upgraded keys.

Test: Tested on bramble using an OTA rvc-d1-release => master.  In OTA
      success case, verified via logcat that the keys were upgraded and
      then were committed after the boot succeeded.  In OTA failure
      case, verified that the device still boots -- i.e., the old keys
      weren't lost.  Verified that in either case, no
      keymaster_key_blob_upgraded files were left over.  Finally, also
      tried 'pm create-user' and 'pm remove-user' and verified via
      logcat that the Keymaster keys still get deleted.
Change-Id: Ic9c3e63e0bcae0c608fc79050ca4a1676b3852ee

1 files changed, 2 insertions, 0 deletions

diff --git a/Utils.h b/Utils.h
index 27889c6b..cf3fd9b8 100644
--- a/Utils.h
+++ b/Utils.h
@@ -155,6 +155,8 @@ std::string BuildDataUserDePath(const std::string& volumeUuid, userid_t userid);
 
 dev_t GetDevice(const std::string& path);
 
+bool IsSameFile(const std::string& path1, const std::string& path2);
+
 status_t EnsureDirExists(const std::string& path, mode_t mode, uid_t uid, gid_t gid);
 
 status_t RestoreconRecursive(const std::string& path);