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-rw-r--r--src/Makefile.test.include1
-rw-r--r--src/chainparams.cpp3
-rw-r--r--src/consensus/merkle.cpp20
-rw-r--r--src/consensus/merkle.h15
-rw-r--r--src/main.cpp3
-rw-r--r--src/miner.cpp3
-rw-r--r--src/primitives/block.cpp63
-rw-r--r--src/primitives/block.h6
-rw-r--r--src/test/main_tests.cpp1
-rw-r--r--src/test/merkle_tests.cpp136
-rw-r--r--src/test/miner_tests.cpp3
-rw-r--r--src/test/pmt_tests.cpp3
12 files changed, 182 insertions, 75 deletions
diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index fafc1a2944..c377183ad5 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -57,6 +57,7 @@ BITCOIN_TESTS =\
test/dbwrapper_tests.cpp \
test/main_tests.cpp \
test/mempool_tests.cpp \
+ test/merkle_tests.cpp \
test/miner_tests.cpp \
test/mruset_tests.cpp \
test/multisig_tests.cpp \
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 5d6d1ef9d8..a46866a2be 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -4,6 +4,7 @@
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "chainparams.h"
+#include "consensus/merkle.h"
#include "tinyformat.h"
#include "util.h"
@@ -32,7 +33,7 @@ static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesi
genesis.nVersion = nVersion;
genesis.vtx.push_back(txNew);
genesis.hashPrevBlock.SetNull();
- genesis.hashMerkleRoot = genesis.ComputeMerkleRoot();
+ genesis.hashMerkleRoot = BlockMerkleRoot(genesis);
return genesis;
}
diff --git a/src/consensus/merkle.cpp b/src/consensus/merkle.cpp
index 6be9c26df2..9a8afa8a33 100644
--- a/src/consensus/merkle.cpp
+++ b/src/consensus/merkle.cpp
@@ -150,3 +150,23 @@ uint256 ComputeMerkleRootFromBranch(const uint256& leaf, const std::vector<uint2
}
return hash;
}
+
+uint256 BlockMerkleRoot(const CBlock& block, bool* mutated)
+{
+ std::vector<uint256> leaves;
+ leaves.resize(block.vtx.size());
+ for (size_t s = 0; s < block.vtx.size(); s++) {
+ leaves[s] = block.vtx[s].GetHash();
+ }
+ return ComputeMerkleRoot(leaves, mutated);
+}
+
+std::vector<uint256> BlockMerkleBranch(const CBlock& block, uint32_t position)
+{
+ std::vector<uint256> leaves;
+ leaves.resize(block.vtx.size());
+ for (size_t s = 0; s < block.vtx.size(); s++) {
+ leaves[s] = block.vtx[s].GetHash();
+ }
+ return ComputeMerkleBranch(leaves, position);
+}
diff --git a/src/consensus/merkle.h b/src/consensus/merkle.h
index 7fd13d3e43..6ef59745ac 100644
--- a/src/consensus/merkle.h
+++ b/src/consensus/merkle.h
@@ -8,10 +8,25 @@
#include <stdint.h>
#include <vector>
+#include "primitives/transaction.h"
+#include "primitives/block.h"
#include "uint256.h"
uint256 ComputeMerkleRoot(const std::vector<uint256>& leaves, bool* mutated = NULL);
std::vector<uint256> ComputeMerkleBranch(const std::vector<uint256>& leaves, uint32_t position);
uint256 ComputeMerkleRootFromBranch(const uint256& leaf, const std::vector<uint256>& branch, uint32_t position);
+/*
+ * Compute the Merkle root of the transactions in a block.
+ * *mutated is set to true if a duplicated subtree was found.
+ */
+uint256 BlockMerkleRoot(const CBlock& block, bool* mutated = NULL);
+
+/*
+ * Compute the Merkle branch for the tree of transactions in a block, for a
+ * given position.
+ * This can be verified using ComputeMerkleRootFromBranch.
+ */
+std::vector<uint256> BlockMerkleBranch(const CBlock& block, uint32_t position);
+
#endif
diff --git a/src/main.cpp b/src/main.cpp
index ceb5cb66f3..191b2b3c12 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -12,6 +12,7 @@
#include "checkpoints.h"
#include "checkqueue.h"
#include "consensus/consensus.h"
+#include "consensus/merkle.h"
#include "consensus/validation.h"
#include "hash.h"
#include "init.h"
@@ -2876,7 +2877,7 @@ bool CheckBlock(const CBlock& block, CValidationState& state, bool fCheckPOW, bo
// Check the merkle root.
if (fCheckMerkleRoot) {
bool mutated;
- uint256 hashMerkleRoot2 = block.ComputeMerkleRoot(&mutated);
+ uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
if (block.hashMerkleRoot != hashMerkleRoot2)
return state.DoS(100, error("CheckBlock(): hashMerkleRoot mismatch"),
REJECT_INVALID, "bad-txnmrklroot", true);
diff --git a/src/miner.cpp b/src/miner.cpp
index bb6b513372..8187e58186 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -10,6 +10,7 @@
#include "chainparams.h"
#include "coins.h"
#include "consensus/consensus.h"
+#include "consensus/merkle.h"
#include "consensus/validation.h"
#include "hash.h"
#include "main.h"
@@ -373,7 +374,7 @@ void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned
assert(txCoinbase.vin[0].scriptSig.size() <= 100);
pblock->vtx[0] = txCoinbase;
- pblock->hashMerkleRoot = pblock->ComputeMerkleRoot();
+ pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
}
//////////////////////////////////////////////////////////////////////////////
diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index 7a58074d24..7280c18f77 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -15,69 +15,6 @@ uint256 CBlockHeader::GetHash() const
return SerializeHash(*this);
}
-uint256 CBlock::ComputeMerkleRoot(bool* fMutated) const
-{
- /* WARNING! If you're reading this because you're learning about crypto
- and/or designing a new system that will use merkle trees, keep in mind
- that the following merkle tree algorithm has a serious flaw related to
- duplicate txids, resulting in a vulnerability (CVE-2012-2459).
-
- The reason is that if the number of hashes in the list at a given time
- is odd, the last one is duplicated before computing the next level (which
- is unusual in Merkle trees). This results in certain sequences of
- transactions leading to the same merkle root. For example, these two
- trees:
-
- A A
- / \ / \
- B C B C
- / \ | / \ / \
- D E F D E F F
- / \ / \ / \ / \ / \ / \ / \
- 1 2 3 4 5 6 1 2 3 4 5 6 5 6
-
- for transaction lists [1,2,3,4,5,6] and [1,2,3,4,5,6,5,6] (where 5 and
- 6 are repeated) result in the same root hash A (because the hash of both
- of (F) and (F,F) is C).
-
- The vulnerability results from being able to send a block with such a
- transaction list, with the same merkle root, and the same block hash as
- the original without duplication, resulting in failed validation. If the
- receiving node proceeds to mark that block as permanently invalid
- however, it will fail to accept further unmodified (and thus potentially
- valid) versions of the same block. We defend against this by detecting
- the case where we would hash two identical hashes at the end of the list
- together, and treating that identically to the block having an invalid
- merkle root. Assuming no double-SHA256 collisions, this will detect all
- known ways of changing the transactions without affecting the merkle
- root.
- */
- std::vector<uint256> vMerkleTree;
- vMerkleTree.reserve(vtx.size() * 2 + 16); // Safe upper bound for the number of total nodes.
- for (std::vector<CTransaction>::const_iterator it(vtx.begin()); it != vtx.end(); ++it)
- vMerkleTree.push_back(it->GetHash());
- int j = 0;
- bool mutated = false;
- for (int nSize = vtx.size(); nSize > 1; nSize = (nSize + 1) / 2)
- {
- for (int i = 0; i < nSize; i += 2)
- {
- int i2 = std::min(i+1, nSize-1);
- if (i2 == i + 1 && i2 + 1 == nSize && vMerkleTree[j+i] == vMerkleTree[j+i2]) {
- // Two identical hashes at the end of the list at a particular level.
- mutated = true;
- }
- vMerkleTree.push_back(Hash(BEGIN(vMerkleTree[j+i]), END(vMerkleTree[j+i]),
- BEGIN(vMerkleTree[j+i2]), END(vMerkleTree[j+i2])));
- }
- j += nSize;
- }
- if (fMutated) {
- *fMutated = mutated;
- }
- return (vMerkleTree.empty() ? uint256() : vMerkleTree.back());
-}
-
std::string CBlock::ToString() const
{
std::stringstream s;
diff --git a/src/primitives/block.h b/src/primitives/block.h
index 54731ff557..5c017d436f 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -118,12 +118,6 @@ public:
return block;
}
- // Build the merkle tree for this block and return the merkle root.
- // If non-NULL, *mutated is set to whether mutation was detected in the merkle
- // tree (a duplication of transactions in the block leading to an identical
- // merkle root).
- uint256 ComputeMerkleRoot(bool* mutated = NULL) const;
-
std::string ToString() const;
};
diff --git a/src/test/main_tests.cpp b/src/test/main_tests.cpp
index 21ae46d6e9..2b92d239e9 100644
--- a/src/test/main_tests.cpp
+++ b/src/test/main_tests.cpp
@@ -72,5 +72,4 @@ BOOST_AUTO_TEST_CASE(test_combiner_all)
Test.disconnect(&ReturnTrue);
BOOST_CHECK(Test());
}
-
BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/merkle_tests.cpp b/src/test/merkle_tests.cpp
new file mode 100644
index 0000000000..1e31f2e679
--- /dev/null
+++ b/src/test/merkle_tests.cpp
@@ -0,0 +1,136 @@
+// Copyright (c) 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 "test/test_bitcoin.h"
+#include "random.h"
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_FIXTURE_TEST_SUITE(merkle_tests, TestingSetup)
+
+// Older version of the merkle root computation code, for comparison.
+static uint256 BlockBuildMerkleTree(const CBlock& block, bool* fMutated, std::vector<uint256>& vMerkleTree)
+{
+ vMerkleTree.clear();
+ vMerkleTree.reserve(block.vtx.size() * 2 + 16); // Safe upper bound for the number of total nodes.
+ for (std::vector<CTransaction>::const_iterator it(block.vtx.begin()); it != block.vtx.end(); ++it)
+ vMerkleTree.push_back(it->GetHash());
+ int j = 0;
+ bool mutated = false;
+ for (int nSize = block.vtx.size(); nSize > 1; nSize = (nSize + 1) / 2)
+ {
+ for (int i = 0; i < nSize; i += 2)
+ {
+ int i2 = std::min(i+1, nSize-1);
+ if (i2 == i + 1 && i2 + 1 == nSize && vMerkleTree[j+i] == vMerkleTree[j+i2]) {
+ // Two identical hashes at the end of the list at a particular level.
+ mutated = true;
+ }
+ vMerkleTree.push_back(Hash(vMerkleTree[j+i].begin(), vMerkleTree[j+i].end(),
+ vMerkleTree[j+i2].begin(), vMerkleTree[j+i2].end()));
+ }
+ j += nSize;
+ }
+ if (fMutated) {
+ *fMutated = mutated;
+ }
+ return (vMerkleTree.empty() ? uint256() : vMerkleTree.back());
+}
+
+// Older version of the merkle branch computation code, for comparison.
+static std::vector<uint256> BlockGetMerkleBranch(const CBlock& block, const std::vector<uint256>& vMerkleTree, int nIndex)
+{
+ std::vector<uint256> vMerkleBranch;
+ int j = 0;
+ for (int nSize = block.vtx.size(); nSize > 1; nSize = (nSize + 1) / 2)
+ {
+ int i = std::min(nIndex^1, nSize-1);
+ vMerkleBranch.push_back(vMerkleTree[j+i]);
+ nIndex >>= 1;
+ j += nSize;
+ }
+ return vMerkleBranch;
+}
+
+static inline int ctz(uint32_t i) {
+ if (i == 0) return 0;
+ int j = 0;
+ while (!(i & 1)) {
+ j++;
+ i >>= 1;
+ }
+ return j;
+}
+
+BOOST_AUTO_TEST_CASE(merkle_test)
+{
+ for (int i = 0; i < 32; i++) {
+ // Try 32 block sizes: all sizes from 0 to 16 inclusive, and then 15 random sizes.
+ int ntx = (i <= 16) ? i : 17 + (insecure_rand() % 4000);
+ // Try up to 3 mutations.
+ for (int mutate = 0; mutate <= 3; mutate++) {
+ int duplicate1 = mutate >= 1 ? 1 << ctz(ntx) : 0; // The last how many transactions to duplicate first.
+ if (duplicate1 >= ntx) break; // Duplication of the entire tree results in a different root (it adds a level).
+ int ntx1 = ntx + duplicate1; // The resulting number of transactions after the first duplication.
+ int duplicate2 = mutate >= 2 ? 1 << ctz(ntx1) : 0; // Likewise for the second mutation.
+ if (duplicate2 >= ntx1) break;
+ int ntx2 = ntx1 + duplicate2;
+ int duplicate3 = mutate >= 3 ? 1 << ctz(ntx2) : 0; // And for the the third mutation.
+ if (duplicate3 >= ntx2) break;
+ int ntx3 = ntx2 + duplicate3;
+ // Build a block with ntx different transactions.
+ CBlock block;
+ block.vtx.resize(ntx);
+ for (int j = 0; j < ntx; j++) {
+ CMutableTransaction mtx;
+ mtx.nLockTime = j;
+ block.vtx[j] = mtx;
+ }
+ // Compute the root of the block before mutating it.
+ bool unmutatedMutated = false;
+ uint256 unmutatedRoot = BlockMerkleRoot(block, &unmutatedMutated);
+ BOOST_CHECK(unmutatedMutated == false);
+ // Optionally mutate by duplicating the last transactions, resulting in the same merkle root.
+ block.vtx.resize(ntx3);
+ for (int j = 0; j < duplicate1; j++) {
+ block.vtx[ntx + j] = block.vtx[ntx + j - duplicate1];
+ }
+ for (int j = 0; j < duplicate2; j++) {
+ block.vtx[ntx1 + j] = block.vtx[ntx1 + j - duplicate2];
+ }
+ for (int j = 0; j < duplicate3; j++) {
+ block.vtx[ntx2 + j] = block.vtx[ntx2 + j - duplicate3];
+ }
+ // Compute the merkle root and merkle tree using the old mechanism.
+ bool oldMutated = false;
+ std::vector<uint256> merkleTree;
+ uint256 oldRoot = BlockBuildMerkleTree(block, &oldMutated, merkleTree);
+ // Compute the merkle root using the new mechanism.
+ bool newMutated = false;
+ uint256 newRoot = BlockMerkleRoot(block, &newMutated);
+ BOOST_CHECK(oldRoot == newRoot);
+ BOOST_CHECK(newRoot == unmutatedRoot);
+ BOOST_CHECK((newRoot == uint256()) == (ntx == 0));
+ BOOST_CHECK(oldMutated == newMutated);
+ BOOST_CHECK(newMutated == !!mutate);
+ // If no mutation was done (once for every ntx value), try up to 16 branches.
+ if (mutate == 0) {
+ for (int loop = 0; loop < std::min(ntx, 16); loop++) {
+ // If ntx <= 16, try all branches. Otherise, try 16 random ones.
+ int mtx = loop;
+ if (ntx > 16) {
+ mtx = insecure_rand() % ntx;
+ }
+ std::vector<uint256> newBranch = BlockMerkleBranch(block, mtx);
+ std::vector<uint256> oldBranch = BlockGetMerkleBranch(block, merkleTree, mtx);
+ BOOST_CHECK(oldBranch == newBranch);
+ BOOST_CHECK(ComputeMerkleRootFromBranch(block.vtx[mtx].GetHash(), newBranch, mtx) == oldRoot);
+ }
+ }
+ }
+ }
+}
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index dc20e34634..1d7c9f65c0 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -5,6 +5,7 @@
#include "chainparams.h"
#include "coins.h"
#include "consensus/consensus.h"
+#include "consensus/merkle.h"
#include "consensus/validation.h"
#include "main.h"
#include "miner.h"
@@ -93,7 +94,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
pblock->vtx[0] = CTransaction(txCoinbase);
if (txFirst.size() < 2)
txFirst.push_back(new CTransaction(pblock->vtx[0]));
- pblock->hashMerkleRoot = pblock->ComputeMerkleRoot();
+ pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
pblock->nNonce = blockinfo[i].nonce;
CValidationState state;
BOOST_CHECK(ProcessNewBlock(state, chainparams, NULL, pblock, true, NULL));
diff --git a/src/test/pmt_tests.cpp b/src/test/pmt_tests.cpp
index d9f3c3e467..0d7fb2bc35 100644
--- a/src/test/pmt_tests.cpp
+++ b/src/test/pmt_tests.cpp
@@ -2,6 +2,7 @@
// 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"
@@ -48,7 +49,7 @@ BOOST_AUTO_TEST_CASE(pmt_test1)
}
// calculate actual merkle root and height
- uint256 merkleRoot1 = block.ComputeMerkleRoot();
+ uint256 merkleRoot1 = BlockMerkleRoot(block);
std::vector<uint256> vTxid(nTx, uint256());
for (unsigned int j=0; j<nTx; j++)
vTxid[j] = block.vtx[j].GetHash();
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-10 08:29:14 +0000