kevacoin/src/test/pmt_tests.cpp
Wladimir J. van der Laan 5eaaa83ac1 Kill insecure_random and associated global state
There are only a few uses of `insecure_random` outside the tests.
This PR replaces uses of insecure_random (and its accompanying global
state) in the core code with an FastRandomContext that is automatically
seeded on creation.

This is meant to be used for inner loops. The FastRandomContext
can be in the outer scope, or the class itself, then rand32() is used
inside the loop. Useful e.g. for pushing addresses in CNode or the fee
rounding, or randomization for coin selection.

As a context is created per purpose, thus it gets rid of
cross-thread unprotected shared usage of a single set of globals, this
should also get rid of the potential race conditions.

- I'd say TxMempool::check is not called enough to warrant using a special
  fast random context, this is switched to GetRand() (open for
  discussion...)

- The use of `insecure_rand` in ConnectThroughProxy has been replaced by
  an atomic integer counter. The only goal here is to have a different
  credentials pair for each connection to go on a different Tor circuit,
  it does not need to be random nor unpredictable.

- To avoid having a FastRandomContext on every CNode, the context is
  passed into PushAddress as appropriate.

There remains an insecure_random for test usage in `test_random.h`.
2016-10-17 13:08:35 +02:00

130 lines
4.5 KiB
C++

// Copyright (c) 2012-2015 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "consensus/merkle.h"
#include "merkleblock.h"
#include "serialize.h"
#include "streams.h"
#include "uint256.h"
#include "arith_uint256.h"
#include "version.h"
#include "test_random.h"
#include "test/test_bitcoin.h"
#include <vector>
#include <boost/assign/list_of.hpp>
#include <boost/test/unit_test.hpp>
using namespace std;
class CPartialMerkleTreeTester : public CPartialMerkleTree
{
public:
// flip one bit in one of the hashes - this should break the authentication
void Damage() {
unsigned int n = insecure_rand() % vHash.size();
int bit = insecure_rand() % 256;
*(vHash[n].begin() + (bit>>3)) ^= 1<<(bit&7);
}
};
BOOST_FIXTURE_TEST_SUITE(pmt_tests, BasicTestingSetup)
BOOST_AUTO_TEST_CASE(pmt_test1)
{
seed_insecure_rand(false);
static const unsigned int nTxCounts[] = {1, 4, 7, 17, 56, 100, 127, 256, 312, 513, 1000, 4095};
for (int i = 0; i < 12; i++) {
unsigned int nTx = nTxCounts[i];
// build a block with some dummy transactions
CBlock block;
for (unsigned int j=0; j<nTx; j++) {
CMutableTransaction tx;
tx.nLockTime = j; // actual transaction data doesn't matter; just make the nLockTime's unique
block.vtx.push_back(CTransaction(tx));
}
// calculate actual merkle root and height
uint256 merkleRoot1 = BlockMerkleRoot(block);
std::vector<uint256> vTxid(nTx, uint256());
for (unsigned int j=0; j<nTx; j++)
vTxid[j] = block.vtx[j].GetHash();
int nHeight = 1, nTx_ = nTx;
while (nTx_ > 1) {
nTx_ = (nTx_+1)/2;
nHeight++;
}
// check with random subsets with inclusion chances 1, 1/2, 1/4, ..., 1/128
for (int att = 1; att < 15; att++) {
// build random subset of txid's
std::vector<bool> vMatch(nTx, false);
std::vector<uint256> vMatchTxid1;
for (unsigned int j=0; j<nTx; j++) {
bool fInclude = (insecure_rand() & ((1 << (att/2)) - 1)) == 0;
vMatch[j] = fInclude;
if (fInclude)
vMatchTxid1.push_back(vTxid[j]);
}
// build the partial merkle tree
CPartialMerkleTree pmt1(vTxid, vMatch);
// serialize
CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
ss << pmt1;
// verify CPartialMerkleTree's size guarantees
unsigned int n = std::min<unsigned int>(nTx, 1 + vMatchTxid1.size()*nHeight);
BOOST_CHECK(ss.size() <= 10 + (258*n+7)/8);
// deserialize into a tester copy
CPartialMerkleTreeTester pmt2;
ss >> pmt2;
// extract merkle root and matched txids from copy
std::vector<uint256> vMatchTxid2;
std::vector<unsigned int> vIndex;
uint256 merkleRoot2 = pmt2.ExtractMatches(vMatchTxid2, vIndex);
// check that it has the same merkle root as the original, and a valid one
BOOST_CHECK(merkleRoot1 == merkleRoot2);
BOOST_CHECK(!merkleRoot2.IsNull());
// check that it contains the matched transactions (in the same order!)
BOOST_CHECK(vMatchTxid1 == vMatchTxid2);
// check that random bit flips break the authentication
for (int j=0; j<4; j++) {
CPartialMerkleTreeTester pmt3(pmt2);
pmt3.Damage();
std::vector<uint256> vMatchTxid3;
uint256 merkleRoot3 = pmt3.ExtractMatches(vMatchTxid3, vIndex);
BOOST_CHECK(merkleRoot3 != merkleRoot1);
}
}
}
}
BOOST_AUTO_TEST_CASE(pmt_malleability)
{
std::vector<uint256> vTxid = boost::assign::list_of
(ArithToUint256(1))(ArithToUint256(2))
(ArithToUint256(3))(ArithToUint256(4))
(ArithToUint256(5))(ArithToUint256(6))
(ArithToUint256(7))(ArithToUint256(8))
(ArithToUint256(9))(ArithToUint256(10))
(ArithToUint256(9))(ArithToUint256(10));
std::vector<bool> vMatch = boost::assign::list_of(false)(false)(false)(false)(false)(false)(false)(false)(false)(true)(true)(false);
CPartialMerkleTree tree(vTxid, vMatch);
std::vector<unsigned int> vIndex;
BOOST_CHECK(tree.ExtractMatches(vTxid, vIndex).IsNull());
}
BOOST_AUTO_TEST_SUITE_END()