From cad2b3ee775876b3d59268cb66e9e1aa3eae4222 Mon Sep 17 00:00:00 2001 From: Jeremy Rubin Date: Thu, 28 Apr 2022 09:45:13 -0700 Subject: [BIP-119] Remove C++ Spec from BIP-119 entirely. --- bip-0119.mediawiki | 125 +---------------------------------------------------- 1 file changed, 2 insertions(+), 123 deletions(-) diff --git a/bip-0119.mediawiki b/bip-0119.mediawiki index f4e65a8..e0e3b05 100644 --- a/bip-0119.mediawiki +++ b/bip-0119.mediawiki @@ -163,7 +163,8 @@ forming a "Payment Pool". The below code is the main logic for verifying CHECKTEMPLATEVERIFY, described in pythonic pseduocode. The canonical specification for the semantics of -OP_CHECKTEMPLATEVERIFY can be seen in the reference implementations. +OP_CHECKTEMPLATEVERIFY as implemented in C++ in the context of Bitcoin Core can +be seen in the reference implementation. The execution of the opcode is as follows: def execute_bip_119(self): @@ -236,128 +237,6 @@ optimization. return sha256(r) - -The C++ is below: - - case OP_CHECKTEMPLATEVERIFY: - { - // if flags not enabled; treat as a NOP4 - if (!(flags & SCRIPT_VERIFY_DEFAULT_CHECK_TEMPLATE_VERIFY_HASH)) { - if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) - return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); - break; - } - - if (stack.size() < 1) - return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); - - // If the argument was not 32 bytes, treat as OP_NOP4: - switch (stack.back().size()) { - case 32: - if (!checker.CheckDefaultCheckTemplateVerifyHash(stack.back())) { - return set_error(serror, SCRIPT_ERR_TEMPLATE_MISMATCH); - } - break; - default: - // future upgrade can add semantics for this opcode with different length args - // so discourage use when applicable - if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) { - return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); - } - } - } - break; - -Where - - bool CheckDefaultCheckTemplateVerifyHash(const std::vector& hash) { - return GetDefaultCheckTemplateVerifyHash(current_tx, current_input_index) == uint256(hash); - } - -The hash is computed as follows, where the outputs_hash and sequences_hash are computed as defined in BIP-341. - - /** Compute the (single) SHA256 of the concatenation of all scriptSigs in a tx. */ - template - uint256 GetScriptSigsSHA256(const T& txTo) - { - CHashWriter ss(SER_GETHASH, 0); - for (const auto& in : txTo.vin) { - ss << in.scriptSig; - } - return ss.GetSHA256(); - } - // not DoS safe, for reference/testing! - uint256 GetDefaultCheckTemplateVerifyHash(const CTransaction& tx, uint32_t input_index) { - return GetDefaultCheckTemplateVerifyHash(tx, GetOutputsSHA256(tx), GetSequenceSHA256(tx), input_index); - } - // not DoS safe for reference/testing! - uint256 GetDefaultCheckTemplateVerifyHash(const CTransaction& tx, const uint256& outputs_hash, const uint256& sequences_hash, - const uint32_t input_index) { - bool skip_scriptSigs = std::find_if(tx.vin.begin(), tx.vin.end(), - [](const CTxIn& c) { return c.scriptSig != CScript(); }) == tx.vin.end(); - return skip_scriptSigs ? GetDefaultCheckTemplateVerifyHashEmptyScript(tx, outputs_hash, sequences_hash, input_index) : - GetDefaultCheckTemplateVerifyHashWithScript(tx, outputs_hash, sequences_hash, GetScriptSigsSHA256(tx), input_index); - } - // DoS safe, fixed length hash! - uint256 GetDefaultCheckTemplateVerifyHashWithScript(const CTransaction& tx, const uint256& outputs_hash, const uint256& sequences_hash, - const uint256& scriptSig_hash, const uint32_t input_index) { - auto h = CHashWriter(SER_GETHASH, 0) - << tx.nVersion - << tx.nLockTime - << scriptSig_hash - << uint32_t(tx.vin.size()) - << sequences_hash - << uint32_t(tx.vout.size()) - << outputs_hash - << input_index; - return h.GetSHA256(); - } - // DoS safe, fixed length hash! - uint256 GetDefaultCheckTemplateVerifyHashEmptyScript(const CTransaction& tx, const uint256& outputs_hash, const uint256& sequences_hash, - const uint32_t input_index) { - auto h = CHashWriter(SER_GETHASH, 0) - << tx.nVersion - << tx.nLockTime - << uint32_t(tx.vin.size()) - << sequences_hash - << uint32_t(tx.vout.size()) - << outputs_hash - << input_index; - return h.GetSHA256(); - } - - - - case OP_CHECKTEMPLATEVERIFY: - { - // if flags not enabled; treat as a NOP4 - if (!(flags & SCRIPT_VERIFY_DEFAULT_CHECK_TEMPLATE_VERIFY_HASH)) { - if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) - return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); - break; - } - - if (stack.size() < 1) - return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); - - // If the argument was not 32 bytes, treat as OP_NOP4: - switch (stack.back().size()) { - case 32: - if (!checker.CheckDefaultCheckTemplateVerifyHash(stack.back())) { - return set_error(serror, SCRIPT_ERR_TEMPLATE_MISMATCH); - } - break; - default: - // future upgrade can add semantics for this opcode with different length args - // so discourage use when applicable - if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) { - return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); - } - } - } - - - A PayToBareDefaultCheckTemplateVerifyHash output matches the following template: bool CScript::IsPayToBareDefaultCheckTemplateVerifyHash() const -- cgit v1.2.3