Implement OP_TEMPLATEHASH #3
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The deployment is never active on mainnet or testnet. Activation parameters are intentionally left to be defined eventually and out of scope for this patchset. The deployment is always active on regtest, allowing us to extensively test expected behaviour of the proposed operation using the functional test suite. Co-Authored-By: Greg Sanders <[email protected]>
Script validation of OP_TEMPLATE is enabled past its activation height, which means it is currently never enabled on mainnet/testnet and always is on regtest. Tapscript spends making use of OP_TEMPLATE do not get relayed nor included in blocks until the soft fork is active. Note how the standardness script verify flags are set such as even post activation, an OP_TEMPLATEHASH related error would not be reported as a consensus error (and lead to peer disconnection). This can be changed in a future release, once the soft fork activation isn't recent anymore. Co-Authored-by: Greg Sanders <[email protected]>
This introduces a new Script operation exclusively available in Tapscript context: OP_TEMPLATEHASH. This operation pushes the hash of the spending transaction on the stack. See BIP xx for details. This operation is introduced as replacing OP_SUCCESS187 (0xbb). Co-Authored-By: Greg Sanders <[email protected]>
Sanity check the template hash by using it to commit to the transaction that must spend an output. Malleating committed fields must lead to a consensus failure, and changing non-committed fields is fine. We also add the option to generate test vectors from this unit test.
We introduce one specialized target focused on exercising the new `GetTemplateHash()` logic introduced for OP_TEMPLATEHASH, and one broader fuzz target which exercises using OP_TEMPLATEHASH on a variety of transactions while asserting invariants.
This leverages the extensive feature_taproot.py test framework to generate coverage for the numerous scenarii and mutations exercised there. Additionally, a separate feature_templatehash.py functional test is introduced for end-to-end testing of the commit-to-next-transaction use case, which does not fit nicely into the feature_taproot.py framework (assumes input independence).
instagibbs
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Aug 14, 2025
…xec in RunCommandJSON" faa1c3e Revert "Merge bitcoin#32343: common: Close non-std fds before exec in RunCommandJSON" (MarcoFalke) Pull request description: After a fork() in a multithreaded program, the child can safely call only async-signal-safe functions (see [signal-safety(7)](https://www.man7.org/linux/man-pages/man7/signal-safety.7.html)) until such time as it calls execv. The standard library (`std` namespace) is not async-signal-safe. Also, `throw`, isn't. There was an alternative implementation using `readdir` (bitcoin#32529), but that isn't async-signal-safe either, and that implementation was still using `throw`. So temporarily revert this feature. A follow-up in the future can add it back, using only async-signal-safe functions, or by using a different approach. Fixes bitcoin#32524 Fixes bitcoin#33015 Fixes bitcoin#32855 For reference, a failure can manifest in the GCC debug mode: * While `fork`ing, a debug mode mutex is held (by any other thread). * The `fork`ed child tries to use the stdard libary before `execv` and deadlocks. This may look like the following: ``` (gdb) thread apply all bt Thread 1 (Thread 0xf58f4b40 (LWP 774911) "b-httpworker.2"): #0 0xf7f4f589 in __kernel_vsyscall () #1 0xf79e467e in ?? () from /lib32/libc.so.6 #2 0xf79eb582 in pthread_mutex_lock () from /lib32/libc.so.6 #3 0xf7d93bf2 in ?? () from /lib32/libstdc++.so.6 bitcoin#4 0xf7d93f36 in __gnu_debug::_Safe_iterator_base::_M_attach(__gnu_debug::_Safe_sequence_base*, bool) () from /lib32/libstdc++.so.6 bitcoin#5 0x5668810a in __gnu_debug::_Safe_iterator_base::_Safe_iterator_base (this=0xf58f13ac, __seq=0xf58f13f8, __constant=false) at /bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/debug/safe_base.h:91 bitcoin#6 0x56ddfb50 in __gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<int*, std::__cxx1998::vector<int, std::allocator<int> > >, std::__debug::vector<int, std::allocator<int> >, std::forward_iterator_tag>::_Safe_iterator (this=0xf58f13a8, __i=3, __seq=0xf58f13f8) at /bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/debug/safe_iterator.h:162 bitcoin#7 0x56ddfacb in __gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<int*, std::__cxx1998::vector<int, std::allocator<int> > >, std::__debug::vector<int, std::allocator<int> >, std::bidirectional_iterator_tag>::_Safe_iterator (this=0xf58f13a8, __i=3, __seq=0xf58f13f8) at /bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/debug/safe_iterator.h:539 bitcoin#8 0x56ddfa5b in __gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<int*, std::__cxx1998::vector<int, std::allocator<int> > >, std::__debug::vector<int, std::allocator<int> >, std::random_access_iterator_tag>::_Safe_iterator (this=0xf58f13a8, __i=3, __seq=0xf58f13f8) at /bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/debug/safe_iterator.h:687 bitcoin#9 0x56ddd3f6 in std::__debug::vector<int, std::allocator<int> >::begin (this=0xf58f13f8) at /bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/debug/vector:300 bitcoin#10 0x57d83701 in subprocess::detail::Child::execute_child (this=0xf58f156c) at ./util/subprocess.h:1372 bitcoin#11 0x57d80a7c in subprocess::Popen::execute_process (this=0xf58f1cd8) at ./util/subprocess.h:1231 bitcoin#12 0x57d6d2b4 in subprocess::Popen::Popen<subprocess::input, subprocess::output, subprocess::error, subprocess::close_fds> (this=0xf58f1cd8, cmd_args="fake.py enumerate", args=..., args=..., args=..., args=...) at ./util/subprocess.h:964 bitcoin#13 0x57d6b597 in RunCommandParseJSON (str_command="fake.py enumerate", str_std_in="") at ./common/run_command.cpp:27 bitcoin#14 0x57a90547 in ExternalSigner::Enumerate (command="fake.py", signers=std::__debug::vector of length 0, capacity 0, chain="regtest") at ./external_signer.cpp:28 bitcoin#15 0x56defdab in enumeratesigners()::$_0::operator()(RPCHelpMan const&, JSONRPCRequest const&) const (this=0xf58f2ba0, self=..., request=...) at ./rpc/external_signer.cpp:51 ... (truncated, only one thread exists) ``` ACKs for top commit: fanquake: ACK faa1c3e darosior: ACK faa1c3e Tree-SHA512: 602da5f2eba08d7fe01ba19baf411e287ae27fe2d4b82f41734e05b7b1d938ce94cc0041e86ba677284fa92838e96ebee687023ff28047e2b036fd9a53567e0a
instagibbs
commented
Aug 27, 2025
| standard = hashtype in VALID_SIGHASHES_ECDSA and (p2sh or witv0) | ||
| add_spender(spenders, "compat/nocsa", hashtype=hashtype, p2sh=p2sh, witv0=witv0, standard=standard, script=CScript([OP_IF, OP_11, pubkey1, OP_CHECKSIGADD, OP_12, OP_EQUAL, OP_ELSE, pubkey1, OP_CHECKSIG, OP_ENDIF]), key=eckey1, sigops_weight=4-3*witv0, inputs=[getter("sign"), b''], failure={"inputs": [getter("sign"), b'\x01']}, **ERR_BAD_OPCODE) | ||
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| # Should still fail if not in executed branch |
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comment seems wrong; spender succeeds unless branch is taken
instagibbs
commented
Sep 3, 2025
| add_spender(spenders, "compat/nocsa", hashtype=hashtype, p2sh=p2sh, witv0=witv0, standard=standard, script=CScript([OP_IF, OP_11, pubkey1, OP_CHECKSIGADD, OP_12, OP_EQUAL, OP_ELSE, pubkey1, OP_CHECKSIG, OP_ENDIF]), key=eckey1, sigops_weight=4-3*witv0, inputs=[getter("sign"), b''], failure={"inputs": [getter("sign"), b'\x01']}, **ERR_BAD_OPCODE) | ||
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| # Should still fail if not in executed branch | ||
| add_spender(spenders, "compat/noth", p2sh=p2sh, witv0=witv0, standard=p2sh or witv0, script=CScript([OP_IF, OP_TEMPLATEHASH, OP_ENDIF, OP_1]), inputs=[b''], failure={"inputs": [b'\x01']}, **ERR_BAD_OPCODE) |
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for non-witv0, the failure path it will be non-standard, in addition to invalid, because of the inputs vector being interpreted as a serialized CScript.
Seems ok enough
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Implementation of instagibbs/bips#1