src/test/pmt_tests.cpp

   1 // Copyright (c) 2012-2016 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include "consensus/merkle.h"
   6 #include "merkleblock.h"
   7 #include "serialize.h"
   8 #include "streams.h"
   9 #include "uint256.h"
  10 #include "arith_uint256.h"
  11 #include "version.h"
  12 #include "test/test_bitcoin.h"
  13
  14 #include <vector>
  15
  16 #include <boost/assign/list_of.hpp>
  17 #include <boost/test/unit_test.hpp>
  18
  19 class CPartialMerkleTreeTester : public CPartialMerkleTree
  20 {
  21 public:
  22     // flip one bit in one of the hashes - this should break the authentication
  23     void Damage() {
  24         unsigned int n = insecure_randrange(vHash.size());
  25         int bit = insecure_randrange(256);
  26         *(vHash[n].begin() + (bit>>3)) ^= 1<<(bit&7);
  27     }
  28 };
  29
  30 BOOST_FIXTURE_TEST_SUITE(pmt_tests, BasicTestingSetup)
  31
  32 BOOST_AUTO_TEST_CASE(pmt_test1)
  33 {
  34     seed_insecure_rand(false);
  35     static const unsigned int nTxCounts[] = {1, 4, 7, 17, 56, 100, 127, 256, 312, 513, 1000, 4095};
  36
  37     for (int i = 0; i < 12; i++) {
  38         unsigned int nTx = nTxCounts[i];
  39
  40         // build a block with some dummy transactions
  41         CBlock block;
  42         for (unsigned int j=0; j<nTx; j++) {
  43             CMutableTransaction tx;
  44             tx.nLockTime = j; // actual transaction data doesn't matter; just make the nLockTime's unique
  45             block.vtx.push_back(MakeTransactionRef(std::move(tx)));
  46         }
  47
  48         // calculate actual merkle root and height
  49         uint256 merkleRoot1 = BlockMerkleRoot(block);
  50         std::vector<uint256> vTxid(nTx, uint256());
  51         for (unsigned int j=0; j<nTx; j++)
  52             vTxid[j] = block.vtx[j]->GetHash();
  53         int nHeight = 1, nTx_ = nTx;
  54         while (nTx_ > 1) {
  55             nTx_ = (nTx_+1)/2;
  56             nHeight++;
  57         }
  58
  59         // check with random subsets with inclusion chances 1, 1/2, 1/4, ..., 1/128
  60         for (int att = 1; att < 15; att++) {
  61             // build random subset of txid's
  62             std::vector<bool> vMatch(nTx, false);
  63             std::vector<uint256> vMatchTxid1;
  64             for (unsigned int j=0; j<nTx; j++) {
  65                 bool fInclude = insecure_randbits(att / 2) == 0;
  66                 vMatch[j] = fInclude;
  67                 if (fInclude)
  68                     vMatchTxid1.push_back(vTxid[j]);
  69             }
  70
  71             // build the partial merkle tree
  72             CPartialMerkleTree pmt1(vTxid, vMatch);
  73
  74             // serialize
  75             CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
  76             ss << pmt1;
  77
  78             // verify CPartialMerkleTree's size guarantees
  79             unsigned int n = std::min<unsigned int>(nTx, 1 + vMatchTxid1.size()*nHeight);
  80             BOOST_CHECK(ss.size() <= 10 + (258*n+7)/8);
  81
  82             // deserialize into a tester copy
  83             CPartialMerkleTreeTester pmt2;
  84             ss >> pmt2;
  85
  86             // extract merkle root and matched txids from copy
  87             std::vector<uint256> vMatchTxid2;
  88             std::vector<unsigned int> vIndex;
  89             uint256 merkleRoot2 = pmt2.ExtractMatches(vMatchTxid2, vIndex);
  90
  91             // check that it has the same merkle root as the original, and a valid one
  92             BOOST_CHECK(merkleRoot1 == merkleRoot2);
  93             BOOST_CHECK(!merkleRoot2.IsNull());
  94
  95             // check that it contains the matched transactions (in the same order!)
  96             BOOST_CHECK(vMatchTxid1 == vMatchTxid2);
  97
  98             // check that random bit flips break the authentication
  99             for (int j=0; j<4; j++) {
 100                 CPartialMerkleTreeTester pmt3(pmt2);
 101                 pmt3.Damage();
 102                 std::vector<uint256> vMatchTxid3;
 103                 uint256 merkleRoot3 = pmt3.ExtractMatches(vMatchTxid3, vIndex);
 104                 BOOST_CHECK(merkleRoot3 != merkleRoot1);
 105             }
 106         }
 107     }
 108 }
 109
 110 BOOST_AUTO_TEST_CASE(pmt_malleability)
 111 {
 112     std::vector<uint256> vTxid = boost::assign::list_of
 113         (ArithToUint256(1))(ArithToUint256(2))
 114         (ArithToUint256(3))(ArithToUint256(4))
 115         (ArithToUint256(5))(ArithToUint256(6))
 116         (ArithToUint256(7))(ArithToUint256(8))
 117         (ArithToUint256(9))(ArithToUint256(10))
 118         (ArithToUint256(9))(ArithToUint256(10));
 119     std::vector<bool> vMatch = boost::assign::list_of(false)(false)(false)(false)(false)(false)(false)(false)(false)(true)(true)(false);
 120
 121     CPartialMerkleTree tree(vTxid, vMatch);
 122     std::vector<unsigned int> vIndex;
 123     BOOST_CHECK(tree.ExtractMatches(vTxid, vIndex).IsNull());
 124 }
 125
 126 BOOST_AUTO_TEST_SUITE_END()