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83 lines
3.4 KiB
83 lines
3.4 KiB
#!/usr/bin/env python3 |
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# Copyright (c) 2019-2020 The Bitcoin Core developers |
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# Distributed under the MIT software license, see the accompanying |
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# file COPYING or http://www.opensource.org/licenses/mit-license.php. |
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"""Useful Script constants and utils.""" |
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from test_framework.script import CScript, hash160, sha256, OP_0, OP_DUP, OP_HASH160, OP_CHECKSIG, OP_EQUAL, OP_EQUALVERIFY |
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from test_framework.util import hex_str_to_bytes |
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# To prevent a "tx-size-small" policy rule error, a transaction has to have a |
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# non-witness size of at least 82 bytes (MIN_STANDARD_TX_NONWITNESS_SIZE in |
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# src/policy/policy.h). Considering a Tx with the smallest possible single |
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# input (blank, empty scriptSig), and with an output omitting the scriptPubKey, |
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# we get to a minimum size of 60 bytes: |
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# |
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# Tx Skeleton: 4 [Version] + 1 [InCount] + 1 [OutCount] + 4 [LockTime] = 10 bytes |
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# Blank Input: 32 [PrevTxHash] + 4 [Index] + 1 [scriptSigLen] + 4 [SeqNo] = 41 bytes |
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# Output: 8 [Amount] + 1 [scriptPubKeyLen] = 9 bytes |
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# |
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# Hence, the scriptPubKey of the single output has to have a size of at |
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# least 22 bytes, which corresponds to the size of a P2WPKH scriptPubKey. |
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# The following script constant consists of a single push of 21 bytes of 'a': |
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# <PUSH_21> <21-bytes of 'a'> |
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# resulting in a 22-byte size. It should be used whenever (small) fake |
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# scriptPubKeys are needed, to guarantee that the minimum transaction size is |
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# met. |
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DUMMY_P2WPKH_SCRIPT = CScript([b'a' * 21]) |
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DUMMY_2_P2WPKH_SCRIPT = CScript([b'b' * 21]) |
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def keyhash_to_p2pkh_script(hash, main = False): |
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assert len(hash) == 20 |
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return CScript([OP_DUP, OP_HASH160, hash, OP_EQUALVERIFY, OP_CHECKSIG]) |
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def scripthash_to_p2sh_script(hash, main = False): |
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assert len(hash) == 20 |
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return CScript([OP_HASH160, hash, OP_EQUAL]) |
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def key_to_p2pkh_script(key, main = False): |
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key = check_key(key) |
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return keyhash_to_p2pkh_script(hash160(key), main) |
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def script_to_p2sh_script(script, main = False): |
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script = check_script(script) |
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return scripthash_to_p2sh_script(hash160(script), main) |
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def key_to_p2sh_p2wpkh_script(key, main = False): |
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key = check_key(key) |
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p2shscript = CScript([OP_0, hash160(key)]) |
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return script_to_p2sh_script(p2shscript, main) |
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def program_to_witness_script(version, program, main = False): |
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if isinstance(program, str): |
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program = hex_str_to_bytes(program) |
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assert 0 <= version <= 16 |
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assert 2 <= len(program) <= 40 |
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assert version > 0 or len(program) in [20, 32] |
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return CScript([version, program]) |
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def script_to_p2wsh_script(script, main = False): |
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script = check_script(script) |
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return program_to_witness_script(0, sha256(script), main) |
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def key_to_p2wpkh_script(key, main = False): |
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key = check_key(key) |
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return program_to_witness_script(0, hash160(key), main) |
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def script_to_p2sh_p2wsh_script(script, main = False): |
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script = check_script(script) |
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p2shscript = CScript([OP_0, sha256(script)]) |
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return script_to_p2sh_script(p2shscript, main) |
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def check_key(key): |
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if isinstance(key, str): |
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key = hex_str_to_bytes(key) # Assuming this is hex string |
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if isinstance(key, bytes) and (len(key) == 33 or len(key) == 65): |
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return key |
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assert False |
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def check_script(script): |
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if isinstance(script, str): |
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script = hex_str_to_bytes(script) # Assuming this is hex string |
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if isinstance(script, bytes) or isinstance(script, CScript): |
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return script |
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assert False
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