adds the security cookie check hook transform.

syzygy/instrument/transforms/security_cookie_check_hook_transform_unittest.cc

+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// 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.
+//
+
+#include "syzygy/instrument/transforms/security_cookie_check_hook_transform.h"
+
+#include "gtest/gtest.h"
+#include "syzygy/block_graph/basic_block.h"
+#include "syzygy/block_graph/basic_block_decomposer.h"
+#include "syzygy/block_graph/basic_block_subgraph.h"
+#include "syzygy/block_graph/block_graph.h"
+#include "syzygy/core/unittest_util.h"
+#include "syzygy/instrument/transforms/unittest_util.h"
+#include "syzygy/pe/unittest_util.h"
+
+#include "mnemonics.h"  // NOLINT
+
+namespace instrument {
+namespace transforms {
+namespace {
+
+using block_graph::BasicBlock;
+using block_graph::BasicBlockDecomposer;
+using block_graph::BasicBlockSubGraph;
+using block_graph::BasicCodeBlock;
+using block_graph::BlockGraph;
+using block_graph::Instruction;
+
+class TestSecurityCookieCheckHookTransform
+    : public SecurityCookieCheckHookTransform {

[chrisha, 2017/05/09 19:18:40]

You've no need to expose anything via this inheritance, so simply test the
original class directly.

+
+};
+
+class SecurityCookieCheckHookTransformTest
+    : public testing::TestDllTransformTest {
+protected:
+  void CheckBasicBlockInstrumentation();
+
+  TestSecurityCookieCheckHookTransform security_cookie_check_hook_;
+};
+
+void SecurityCookieCheckHookTransformTest::CheckBasicBlockInstrumentation() {
+  bool hit = false;
+
+  BlockGraph::BlockMap::const_iterator block_iter =
+      block_graph_.blocks().begin();
+  for (; block_iter != block_graph_.blocks().end(); ++block_iter) {
+    const BlockGraph::Block& block = block_iter->second;
+
+    // Skip everything but __my_report_gsfailure.
+    if (block.name() != "__my_report_gsfailure")

[chrisha, 2017/05/09 19:18:40]

Expose the string as a class static member in the transform, and refer to that
instead of duplicating it here.

+      continue;
+
+    hit = true;
+
+    // Decompose the block to basic-blocks.
+    BasicBlockSubGraph subgraph;
+    BasicBlockDecomposer bb_decomposer(&block, &subgraph);
+    ASSERT_TRUE(bb_decomposer.Decompose());
+
+    // Retrieve the first basic block.
+    ASSERT_EQ(1, subgraph.block_descriptions().size());
+    const BasicBlockSubGraph::BasicBlockOrdering& original_order =
+        subgraph.block_descriptions().front().basic_block_order;
+    BasicCodeBlock* first_bb = BasicCodeBlock::Cast(*original_order.begin());
+    ASSERT_NE(first_bb, nullptr);
+
+    // Check if the stub is a 'mov [deadbeef], eax' instruction

[chrisha, 2017/05/09 19:18:40]

Missing period on comment.

+    BasicBlockSubGraph::BBCollection::const_iterator bb_iter =
+        subgraph.basic_blocks().begin();
+    for (; bb_iter != subgraph.basic_blocks().end(); ++bb_iter) {
+      const BasicCodeBlock* bb = BasicCodeBlock::Cast(*bb_iter);
+      if (bb == nullptr || bb->is_padding())
+        continue;
+
+      BasicBlock::Instructions::const_iterator
+          inst_iter = bb->instructions().begin(),
+          end_iter = bb->instructions().end();
+      ASSERT_NE(inst_iter, end_iter);
+      // mov [deadbeef], eax
+      const Instruction& inst = *inst_iter;
+      EXPECT_EQ(I_MOV, inst.representation().opcode);
+    }

[chrisha, 2017/05/09 19:18:40]

Instead of using the disassembler and everything, it would be totally fine to
simply check the bytes match the expected assembly directly.

+  }
+
+  EXPECT_TRUE(hit);
+}
+
+}  // namespace
+
+TEST_F(SecurityCookieCheckHookTransformTest, ApplyTranform) {
+  ASSERT_NO_FATAL_FAILURE(DecomposeTestDll());
+
+  ASSERT_TRUE(block_graph::ApplyBlockGraphTransform(
+    &security_cookie_check_hook_, policy_,
+    &block_graph_, header_block_

[chrisha, 2017/05/09 19:18:40]

Indent these lines another 2 spaces.

+  ));

[chrisha, 2017/05/09 19:18:40]

Move to end of previous line.

+
+  ASSERT_NO_FATAL_FAILURE(CheckBasicBlockInstrumentation());
+}
+
+}  // namespace transforms
+}  // namespace instrument