1    :  // Copyright 2014 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  
  15    :  #include "syzygy/block_graph/block_hash.h"
  16    :  
  17    :  #include "gmock/gmock.h"
  18    :  #include "gtest/gtest.h"
  19    :  
  20    :  namespace block_graph {
  21    :  
  22  E :  TEST(BlockHash, HashAndCompare) {
  23  E :    BlockGraph block_graph;
  24  E :    const size_t kBlockSize = 0x20;
  25  E :    const uint8_t kMagicValue = 0xAB;
  26    :  
  27  E :    BlockGraph::Block* code_block_1 = block_graph.AddBlock(BlockGraph::CODE_BLOCK,
  28    :                                                           kBlockSize,
  29    :                                                           "code block");
  30    :  
  31  E :    EXPECT_NE(reinterpret_cast<uint8_t*>(NULL),
  32  E :              code_block_1->ResizeData(kBlockSize));
  33    :  
  34  E :    ::memset(code_block_1->GetMutableData(), kMagicValue, kBlockSize);
  35  E :    BlockHash code_block_1_hash(code_block_1);
  36    :  
  37  E :    BlockGraph::Block* test_block = block_graph.AddBlock(BlockGraph::DATA_BLOCK,
  38    :                                                         kBlockSize,
  39    :                                                         "test block");
  40  E :    EXPECT_NE(reinterpret_cast<uint8_t*>(NULL),
  41  E :              test_block->ResizeData(kBlockSize));
  42  E :    ::memset(test_block->GetMutableData(), kMagicValue, kBlockSize);
  43    :  
  44    :    // The blocks don't have the same type, they should have a different hash.
  45  E :    EXPECT_NE(0, code_block_1_hash.Compare(BlockHash(test_block)));
  46  E :    test_block->set_type(BlockGraph::CODE_BLOCK);
  47  E :    EXPECT_EQ(0, code_block_1_hash.Compare(BlockHash(test_block)));
  48    :  
  49    :    // Change the data size and make sure that this results in a different hash
  50    :    // value.
  51  E :    test_block->ResizeData(kBlockSize + 1);
  52  E :    EXPECT_NE(0, code_block_1_hash.Compare(BlockHash(test_block)));
  53  E :    test_block->ResizeData(kBlockSize);
  54  E :    ::memset(test_block->GetMutableData(), kMagicValue, kBlockSize);
  55  E :    EXPECT_EQ(0, code_block_1_hash.Compare(BlockHash(test_block)));
  56    :  
  57  E :    BlockGraph::Block* code_block_2 = block_graph.AddBlock(BlockGraph::CODE_BLOCK,
  58    :                                                           kBlockSize,
  59    :                                                           "code block 2");
  60  E :    BlockGraph::Reference block_reference_abs(BlockGraph::ABSOLUTE_REF,
  61    :        4, code_block_2, 0, 0);
  62  E :    BlockGraph::Reference block_reference_pc(BlockGraph::PC_RELATIVE_REF,
  63    :        4, code_block_2, 0, 0);
  64  E :    const size_t kReferenceOffset = 4;
  65    :  
  66    :    // |test_block| has a reference but not |code_block_1|, their hashes should
  67    :    // be different.
  68  E :    EXPECT_TRUE(test_block->SetReference(kReferenceOffset, block_reference_abs));
  69  E :    EXPECT_NE(0, code_block_1_hash.Compare(BlockHash(test_block)));
  70    :  
  71  E :    EXPECT_TRUE(code_block_1->SetReference(kReferenceOffset,
  72  E :                                           block_reference_abs));
  73  E :    code_block_1_hash.Hash(code_block_1);
  74    :    // |test_block| and |code_block_1| have the same reference, they should have
  75    :    // the same hash.
  76  E :    EXPECT_EQ(0, code_block_1_hash.Compare(BlockHash(test_block)));
  77    :  
  78    :    // Alter the data in |test_block| (outside of the reference) and make sure
  79    :    // that this results in a different hash.
  80  E :    test_block->GetMutableData()[0] = static_cast<uint8_t>(~kMagicValue);
  81  E :    EXPECT_NE(0, code_block_1_hash.Compare(BlockHash(test_block)));
  82  E :    test_block->GetMutableData()[0] = kMagicValue;
  83  E :    EXPECT_EQ(0, code_block_1_hash.Compare(BlockHash(test_block)));
  84    :  
  85    :    // Alter the data in |test_block| in the reference and make sure that this
  86    :    // doesn't alter the hash.
  87  E :    test_block->GetMutableData()[kReferenceOffset] =
  88    :        static_cast<uint8_t>(~kMagicValue);
  89  E :    EXPECT_EQ(0, code_block_1_hash.Compare(BlockHash(test_block)));
  90  E :    test_block->GetMutableData()[kReferenceOffset] = kMagicValue;
  91    :  
  92    :    // Modify the reference of |test_block| and make sure that this results in a
  93    :    // different hash.
  94  E :    EXPECT_TRUE(test_block->RemoveReference(kReferenceOffset));
  95  E :    test_block->SetReference(kReferenceOffset + 1, block_reference_abs);
  96  E :    EXPECT_NE(0, code_block_1_hash.Compare(BlockHash(test_block)));
  97  E :    EXPECT_TRUE(test_block->RemoveReference(kReferenceOffset + 1));
  98    :  
  99  E :    test_block->SetReference(kReferenceOffset, block_reference_pc);
 100  E :    EXPECT_NE(0, code_block_1_hash.Compare(BlockHash(test_block)));
 101  E :  }
 102    :  
 103    :  }  // namespace block_graph