Adding DropBox logging support for keystore functionality

This will allow us to track the actual usage patterns of keystore
functions and error occurences.

Bug: 36549319
Test: DropBox logging works for keystore tags
Change-Id: Iadfba3afebaa0be753212b1111b68f50b77f9978
(cherry picked from commit d6d8952b346f08b4b74199adc1215579f4faeeff)
diff --git a/keystore/operation_config.proto b/keystore/operation_config.proto
new file mode 100644
index 0000000..37b4cbb
--- /dev/null
+++ b/keystore/operation_config.proto
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+syntax = "proto2";
+
+package keystore;
+
+option optimize_for = LITE_RUNTIME;
+
+message OperationConfig {
+  // What type of encryption algorithm is the key being used in the op for.
+  optional string algorithm = 1;
+
+  // Size of the key being used in this op
+  optional int32 key_size = 2;
+
+  // Log whether the key in this op was generated, imported,
+  // securely imported, or derived.
+  optional string origin = 3;
+
+  // What auth types does this op require? If none, then no auth required.
+  optional string user_auth_type = 4;
+
+  // If user authentication is required, is the requirement time based? If it
+  // is not time based then this field will not be used and the key is per
+  // operation. Per operation keys must be user authenticated on each usage.
+  optional int32 user_auth_key_timeout = 5;
+
+  // Track which padding mode was used for this operation.
+  optional string padding = 6;
+
+  // Keep track of the digest algorithm being used.
+  optional string digest = 7;
+
+  // Check what block mode is being used depending on the mode of encryption
+  optional string block_mode = 8;
+
+  // Did the operation succeed? If it didn't, this represents bugs or
+  // error cases occurring.
+  optional bool was_op_successful = 9;
+
+  // What purpose is this operation serving? Encrypt, decrypt, sign verify?
+  optional string purpose = 10;
+
+  // Which ec curve was selected if elliptic curve cryptography is in use
+  optional string ec_curve = 11;
+
+  // Standalone or is a file system required
+  optional string key_blob_usage_reqs = 12;
+}