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author | Wladimir J. van der Laan <laanwj@gmail.com> | 2018-06-14 19:38:19 +0200 |
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committer | Wladimir J. van der Laan <laanwj@gmail.com> | 2018-06-14 19:40:02 +0200 |
commit | cc7cbd756acd79623230f7a1b0b0e40c772a82e1 (patch) | |
tree | 2b145481e06ef3e837d2cf443bdad9a780160eda /test/functional | |
parent | 4a7e64fc85461a205f2b51da52d1455795d43b91 (diff) | |
parent | 86edf4a2a502416ba8d6cebbce61030992f7ff6f (diff) | |
download | bitcoin-cc7cbd756acd79623230f7a1b0b0e40c772a82e1.tar.xz |
Merge #13451: rpc: expose CBlockIndex::nTx in getblock(header)
86edf4a2a502416ba8d6cebbce61030992f7ff6f expose CBlockIndex::nTx in getblock(header) (Gregory Sanders)
Pull request description:
Recent publication of a weakness in Bitcoin's merkle tree construction demonstrates many SPV applications vulnerable to an expensive to pull off yet still plausible attack: https://bitslog.wordpress.com/2018/06/09/leaf-node-weakness-in-bitcoin-merkle-tree-design/
Including the coinbase in the txoutproof seems the most effective fix, however results in a significant efficiency downgrade. Transactors will not even know a priori what the size of their proof will be within a couple orders of magnitude, unless they use the mid-state of SHA2 as detailed in the blog post.
Some applications, like Elements blockchain platform that take SPV-style proofs have optional access to a bitcoind to verify these proofs of inclusion and check depth in the chain. Returning `CBlockIndex::nTx` would allow an extremely easy and compact way of checking the depth of the tree, with no additional overhead to the codebase, and works with pruned nodes.
`getblockheader` is arguably not the place for it, but as mentioned before, is a natural workflow for us checking depth of a block in a possibly pruned node.
We should also ensure that `verifytxoutproof` ends up validating this depth fact as well, but left this for another PR.
Tree-SHA512: af4cf48e704c6088f8da06a477fda1aaa6f8770cee9b876c4465d1075966d6a95831a88817673fe5a0d6bbcdc1ffcbc1892e2be0d838c60fc6958d33eacdcc14
Diffstat (limited to 'test/functional')
-rwxr-xr-x | test/functional/feature_pruning.py | 7 | ||||
-rwxr-xr-x | test/functional/rpc_blockchain.py | 1 |
2 files changed, 8 insertions, 0 deletions
diff --git a/test/functional/feature_pruning.py b/test/functional/feature_pruning.py index 11a52b9ee2..d400507a66 100755 --- a/test/functional/feature_pruning.py +++ b/test/functional/feature_pruning.py @@ -260,10 +260,17 @@ class PruneTest(BitcoinTestFramework): # should not prune because chain tip of node 3 (995) < PruneAfterHeight (1000) assert_raises_rpc_error(-1, "Blockchain is too short for pruning", node.pruneblockchain, height(500)) + # Save block transaction count before pruning, assert value + block1_details = node.getblock(node.getblockhash(1)) + assert_equal(block1_details["nTx"], len(block1_details["tx"])) + # mine 6 blocks so we are at height 1001 (i.e., above PruneAfterHeight) node.generate(6) assert_equal(node.getblockchaininfo()["blocks"], 1001) + # Pruned block should still know the number of transactions + assert_equal(node.getblockheader(node.getblockhash(1))["nTx"], block1_details["nTx"]) + # negative heights should raise an exception assert_raises_rpc_error(-8, "Negative", node.pruneblockchain, -10) diff --git a/test/functional/rpc_blockchain.py b/test/functional/rpc_blockchain.py index 17e24453e5..7acc59c2c6 100755 --- a/test/functional/rpc_blockchain.py +++ b/test/functional/rpc_blockchain.py @@ -217,6 +217,7 @@ class BlockchainTest(BitcoinTestFramework): assert_equal(header['confirmations'], 1) assert_equal(header['previousblockhash'], secondbesthash) assert_is_hex_string(header['chainwork']) + assert_equal(header['nTx'], 1) assert_is_hash_string(header['hash']) assert_is_hash_string(header['previousblockhash']) assert_is_hash_string(header['merkleroot']) |