From 4b9893cad4786d5c70238a8a0b5d2465beeb331c Mon Sep 17 00:00:00 2001
From: Liangliang He <lliang.he@gmail.com>
Date: Tue, 9 Jan 2018 16:23:05 +0800
Subject: [PATCH] Obfuscate tuning parameters

---
 mace/core/BUILD                               |  1 +
 .../core/runtime/opencl/opencl_development.cc | 21 ++++---------------
 mace/python/tools/binary_codegen.py           |  1 +
 mace/utils/tuner.h                            |  7 +++++--
 mace/utils/utils.h                            | 10 +++++++++
 5 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/mace/core/BUILD b/mace/core/BUILD
index 48d74616..1fbeed2f 100644
--- a/mace/core/BUILD
+++ b/mace/core/BUILD
@@ -96,6 +96,7 @@ cc_library(
     deps = [
         ":opencl_headers",
         "//mace/codegen:generated_opencl_dev",
+        "//mace/utils:utils_hdrs",
     ],
 )
 
diff --git a/mace/core/runtime/opencl/opencl_development.cc b/mace/core/runtime/opencl/opencl_development.cc
index a13bb9a3..864a4712 100644
--- a/mace/core/runtime/opencl/opencl_development.cc
+++ b/mace/core/runtime/opencl/opencl_development.cc
@@ -5,24 +5,11 @@
 #include <vector>
 
 #include "mace/core/runtime/opencl/cl2_header.h"
+#include "mace/utils/utils.h"
 
 
 namespace mace {
 
-namespace {
-inline void DecryptOpenCLSource(const std::vector<unsigned char> &src,
-                                std::vector<unsigned char> *dst) {
-  dst->reserve(src.size());
-
-  // Keep consistent with encrypt in python tool
-  const std::string decrypt_lookup_table = "Xiaomi-AI-Platform-Mace";
-  size_t lookup_table_size = decrypt_lookup_table.size();
-  for (int i = 0; i < src.size(); i++) {
-    dst->push_back(src[i] ^ decrypt_lookup_table[i % lookup_table_size]);
-  }
-}
-}  // namespace
-
 bool GetSourceOrBinaryProgram(const std::string &program_name,
                               const std::string &binary_file_name_prefix,
                               cl::Context &context,
@@ -36,9 +23,9 @@ bool GetSourceOrBinaryProgram(const std::string &program_name,
     return false;
   }
   cl::Program::Sources sources;
-  std::vector<unsigned char> decrypt_source;
-  DecryptOpenCLSource(it_source->second, &decrypt_source);
-  sources.push_back(std::string(decrypt_source.begin(), decrypt_source.end()));
+  std::string kernel_source(it_source->second.begin(), it_source->second.end());
+  ObfuscateString(&kernel_source);
+  sources.push_back(kernel_source);
   *program = cl::Program(context, sources);
 
   return true;
diff --git a/mace/python/tools/binary_codegen.py b/mace/python/tools/binary_codegen.py
index cb1b1280..0deadf6c 100644
--- a/mace/python/tools/binary_codegen.py
+++ b/mace/python/tools/binary_codegen.py
@@ -27,6 +27,7 @@ def generate_cpp_source():
     key_size, = struct.unpack("i", binary_array[idx:idx+4])
     idx += 4
     key, = struct.unpack(str(key_size) + "s", binary_array[idx:idx+key_size])
+    key = ''.join(['\\x{:02x}'.format(ord(c)) for c in key])
     idx += key_size
     params_size, = struct.unpack("i", binary_array[idx:idx+4])
     idx += 4
diff --git a/mace/utils/tuner.h b/mace/utils/tuner.h
index 6296934d..34a62bdf 100644
--- a/mace/utils/tuner.h
+++ b/mace/utils/tuner.h
@@ -15,6 +15,7 @@
 
 #include "mace/utils/logging.h"
 #include "mace/utils/timer.h"
+#include "mace/utils/utils.h"
 
 namespace mace {
 
@@ -42,17 +43,19 @@ class Tuner {
           &param_generator,
       const std::function<RetType(const std::vector<param_type> &)> &func,
       Timer *timer) {
+    std::string obfucated_param_key = param_key;
+    ObfuscateString(&obfucated_param_key);
     if (IsTuning() && param_generator != nullptr) {
       // tune
       std::vector<param_type> opt_param = default_param;
       RetType res = Tune<RetType>(param_generator, func, timer, &opt_param);
       VLOG(1) << "Tuning result. "
               << param_key << ": " << internal::MakeString(opt_param);
-      param_table_[param_key] = opt_param;
+      param_table_[obfucated_param_key] = opt_param;
       return res;
     } else {
       // run
-      if (param_table_.find(param_key) != param_table_.end()) {
+      if (param_table_.find(obfucated_param_key) != param_table_.end()) {
         VLOG(1) << param_key << ": "
                 << internal::MakeString(param_table_[param_key]);
         return func(param_table_[param_key]);
diff --git a/mace/utils/utils.h b/mace/utils/utils.h
index a8b13828..6bd0be52 100644
--- a/mace/utils/utils.h
+++ b/mace/utils/utils.h
@@ -48,5 +48,15 @@ inline std::string ToString(T v) {
   return ss.str();
 }
 
+// ObfuscateString(ObfuscateString(str)) ==> str
+inline void ObfuscateString(std::string *str) {
+  // Keep consistent with obfuscation in python tools
+  const std::string kLookupTable = "Xiaomi-AI-Platform-Mace";
+  size_t lookup_table_size = kLookupTable.size();
+  for (int i = 0; i < str->size(); i++) {
+    (*str)[i] = (*str)[i] ^ kLookupTable[i % lookup_table_size];
+  }
+}
+
 }  //  namespace mace
 #endif  //  MACE_UTILS_UTILS_H_
-- 
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