hub/scribe/blockchain/transaction/script.py

299 lines
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Python
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2022-03-08 17:01:19 +01:00
import typing
from scribe.blockchain.transaction import NameClaim, ClaimUpdate, ClaimSupport
from scribe.blockchain.transaction import unpack_le_uint16_from, unpack_le_uint32_from, pack_le_uint16, pack_le_uint32
class _OpCodes(typing.NamedTuple):
def whatis(self, value: int):
try:
return self._fields[self.index(value)]
except (ValueError, IndexError):
return -1
OP_PUSHDATA1: int = 0x4c
OP_PUSHDATA2: int = 0x4d
OP_PUSHDATA4: int = 0x4e
OP_1NEGATE: int = 0x4f
OP_RESERVED: int = 0x50
OP_1: int = 0x51
OP_2: int = 0x52
OP_3: int = 0x53
OP_4: int = 0x54
OP_5: int = 0x55
OP_6: int = 0x56
OP_7: int = 0x57
OP_8: int = 0x58
OP_9: int = 0x59
OP_10: int = 0x5a
OP_11: int = 0x5b
OP_12: int = 0x5c
OP_13: int = 0x5d
OP_14: int = 0x5e
OP_15: int = 0x5f
OP_16: int = 0x60
OP_NOP: int = 0x61
OP_VER: int = 0x62
OP_IF: int = 0x63
OP_NOTIF: int = 0x64
OP_VERIF: int = 0x65
OP_VERNOTIF: int = 0x66
OP_ELSE: int = 0x67
OP_ENDIF: int = 0x68
OP_VERIFY: int = 0x69
OP_RETURN: int = 0x6a
OP_TOALTSTACK: int = 0x6b
OP_FROMALTSTACK: int = 0x6c
OP_2DROP: int = 0x6d
OP_2DUP: int = 0x6e
OP_3DUP: int = 0x6f
OP_2OVER: int = 0x70
OP_2ROT: int = 0x71
OP_2SWAP: int = 0x72
OP_IFDUP: int = 0x73
OP_DEPTH: int = 0x74
OP_DROP: int = 0x75
OP_DUP: int = 0x76
OP_NIP: int = 0x77
OP_OVER: int = 0x78
OP_PICK: int = 0x79
OP_ROLL: int = 0x7a
OP_ROT: int = 0x7b
OP_SWAP: int = 0x7c
OP_TUCK: int = 0x7d
OP_CAT: int = 0x7e
OP_SUBSTR: int = 0x7f
OP_LEFT: int = 0x80
OP_RIGHT: int = 0x81
OP_SIZE: int = 0x82
OP_INVERT: int = 0x83
OP_AND: int = 0x84
OP_OR: int = 0x85
OP_XOR: int = 0x86
OP_EQUAL: int = 0x87
OP_EQUALVERIFY: int = 0x88
OP_RESERVED1: int = 0x89
OP_RESERVED2: int = 0x8a
OP_1ADD: int = 0x8b
OP_1SUB: int = 0x8c
OP_2MUL: int = 0x8d
OP_2DIV: int = 0x8e
OP_NEGATE: int = 0x8f
OP_ABS: int = 0x90
OP_NOT: int = 0x91
OP_0NOTEQUAL: int = 0x92
OP_ADD: int = 0x93
OP_SUB: int = 0x94
OP_MUL: int = 0x95
OP_DIV: int = 0x96
OP_MOD: int = 0x97
OP_LSHIFT: int = 0x98
OP_RSHIFT: int = 0x99
OP_BOOLAND: int = 0x9a
OP_BOOLOR: int = 0x9b
OP_NUMEQUAL: int = 0x9c
OP_NUMEQUALVERIFY: int = 0x9d
OP_NUMNOTEQUAL: int = 0x9e
OP_LESSTHAN: int = 0x9f
OP_GREATERTHAN: int = 0xa0
OP_LESSTHANOREQUAL: int = 0xa1
OP_GREATERTHANOREQUAL: int = 0xa2
OP_MIN: int = 0xa3
OP_MAX: int = 0xa4
OP_WITHIN: int = 0xa5
OP_RIPEMD160: int = 0xa6
OP_SHA1: int = 0xa7
OP_SHA256: int = 0xa8
OP_HASH160: int = 0xa9
OP_HASH256: int = 0xaa
OP_CODESEPARATOR: int = 0xab
OP_CHECKSIG: int = 0xac
OP_CHECKSIGVERIFY: int = 0xad
OP_CHECKMULTISIG: int = 0xae
OP_CHECKMULTISIGVERIFY: int = 0xaf
OP_NOP1: int = 0xb0
OP_CHECKLOCKTIMEVERIFY: int = 0xb1
OP_CHECKSEQUENCEVERIFY: int = 0xb2
OP_NOP4: int = 0xb3
OP_NOP5: int = 0xb4
OP_CLAIM_NAME: int = 0xb5
OP_SUPPORT_CLAIM: int = 0xb6
OP_UPDATE_CLAIM: int = 0xb7
OP_NOP9: int = 0xb8
OP_NOP10: int = 0xb9
OpCodes = _OpCodes()
# Paranoia to make it hard to create bad scripts
assert OpCodes.OP_DUP == 0x76
assert OpCodes.OP_HASH160 == 0xa9
assert OpCodes.OP_EQUAL == 0x87
assert OpCodes.OP_EQUALVERIFY == 0x88
assert OpCodes.OP_CHECKSIG == 0xac
assert OpCodes.OP_CHECKMULTISIG == 0xae
assert OpCodes.OP_CLAIM_NAME == 0xb5
assert OpCodes.OP_SUPPORT_CLAIM == 0xb6
assert OpCodes.OP_UPDATE_CLAIM == 0xb7
def P2SH_script(hash160_bytes: bytes):
return bytes([OpCodes.OP_HASH160]) + script_push_data(hash160_bytes) + bytes([OpCodes.OP_EQUAL])
def P2PKH_script(hash160_bytes: bytes):
return (bytes([OpCodes.OP_DUP, OpCodes.OP_HASH160])
+ script_push_data(hash160_bytes)
+ bytes([OpCodes.OP_EQUALVERIFY, OpCodes.OP_CHECKSIG]))
def script_push_data(data: bytes):
n = len(data)
if n < OpCodes.OP_PUSHDATA1:
return bytes([n]) + data
if n < 256:
return bytes([OpCodes.OP_PUSHDATA1, n]) + data
if n < 65536:
return bytes([OpCodes.OP_PUSHDATA2]) + pack_le_uint16(n) + data
return bytes([OpCodes.OP_PUSHDATA4]) + pack_le_uint32(n) + data
def script_GetOp(script_bytes: bytes):
i = 0
while i < len(script_bytes):
vch = None
opcode = script_bytes[i]
i += 1
if opcode <= OpCodes.OP_PUSHDATA4:
n_size = opcode
if opcode == OpCodes.OP_PUSHDATA1:
n_size = script_bytes[i]
i += 1
elif opcode == OpCodes.OP_PUSHDATA2:
(n_size,) = unpack_le_uint16_from(script_bytes, i)
i += 2
elif opcode == OpCodes.OP_PUSHDATA4:
(n_size,) = unpack_le_uint32_from(script_bytes, i)
i += 4
if i + n_size > len(script_bytes):
vch = b"_INVALID_" + script_bytes[i:]
i = len(script_bytes)
else:
vch = script_bytes[i:i + n_size]
i += n_size
yield opcode, vch, i
_SCRIPT_TEMPLATES = (
# claim related templates
(OpCodes.OP_CLAIM_NAME, -1, -1, OpCodes.OP_2DROP, OpCodes.OP_DROP),
(OpCodes.OP_UPDATE_CLAIM, -1, -1, OpCodes.OP_2DROP, OpCodes.OP_DROP),
(OpCodes.OP_UPDATE_CLAIM, -1, -1, -1, OpCodes.OP_2DROP, OpCodes.OP_2DROP),
(OpCodes.OP_SUPPORT_CLAIM, -1, -1, OpCodes.OP_2DROP, OpCodes.OP_DROP),
(OpCodes.OP_SUPPORT_CLAIM, -1, -1, -1, OpCodes.OP_2DROP, OpCodes.OP_2DROP),
# receive script templates
(OpCodes.OP_DUP, OpCodes.OP_HASH160, -1, OpCodes.OP_EQUALVERIFY, OpCodes.OP_CHECKSIG),
(OpCodes.OP_HASH160, -1, OpCodes.OP_EQUAL),
(-1, OpCodes.OP_CHECKSIG)
)
_CLAIM_TEMPLATE = 0
_UPDATE_NO_DATA_TEMPLATE = 1
_UPDATE_TEMPLATE = 2
_SUPPORT_TEMPLATE = 3
_SUPPORT_WITH_DATA_TEMPLATE = 4
_TO_ADDRESS_TEMPLATE = 5
_TO_P2SH_TEMPLATE = 6
_TO_PUBKEY_TEMPLATE = 7
def txo_script_parser(script: bytes):
template = None
template_idx = None
values = []
receive_values = []
finished_decoding_claim = False
receive_cur = 0
claim, support, pubkey_hash, pubkey, script_hash = None, None, None, None, None
for cur, (op, data, _) in enumerate(script_GetOp(script)):
if finished_decoding_claim: # we're decoding the receiving part of the script (the last part)
if receive_cur == 0:
if op == OpCodes.OP_DUP:
template_idx = _TO_ADDRESS_TEMPLATE
elif op == OpCodes.OP_HASH160:
template_idx = _TO_P2SH_TEMPLATE
elif op == -1:
template_idx = _TO_PUBKEY_TEMPLATE
else:
break # return the decoded part
template = _SCRIPT_TEMPLATES[template_idx]
expected = template[receive_cur]
if expected == -1 and data is None: # if data data is expected make sure it's there
# print("\texpected data", OpCodes.whatis(op), data)
return
elif expected == -1 and data:
receive_values.append(data)
elif op != expected:
# print("\top mismatch")
return
receive_cur += 1
continue
if cur == 0: # initialize the template
if op == OpCodes.OP_CLAIM_NAME:
template_idx = _CLAIM_TEMPLATE
elif op == OpCodes.OP_UPDATE_CLAIM:
template_idx = _UPDATE_NO_DATA_TEMPLATE
elif op == OpCodes.OP_SUPPORT_CLAIM:
template_idx = _SUPPORT_TEMPLATE # could be a support w/ data
elif op == OpCodes.OP_DUP:
template_idx = _TO_ADDRESS_TEMPLATE
elif op == OpCodes.OP_HASH160:
template_idx = _TO_P2SH_TEMPLATE
elif op == -1:
template_idx = _TO_PUBKEY_TEMPLATE
else:
return
template = _SCRIPT_TEMPLATES[template_idx]
elif cur == 3 and template_idx == _SUPPORT_TEMPLATE and data:
template_idx = _SUPPORT_WITH_DATA_TEMPLATE
template = _SCRIPT_TEMPLATES[template_idx]
elif cur == 3 and template_idx == _UPDATE_NO_DATA_TEMPLATE and data:
template_idx = _UPDATE_TEMPLATE
template = _SCRIPT_TEMPLATES[template_idx]
if cur >= len(template):
return
expected = template[cur]
if expected == -1 and data is None: # if data data is expected make sure it's there
# print("\texpected data", OpCodes.whatis(op), data)
return
elif expected == -1 and data:
if template_idx in (_TO_ADDRESS_TEMPLATE, _TO_P2SH_TEMPLATE, _TO_ADDRESS_TEMPLATE):
receive_values.append(data)
else:
values.append(data)
elif op != expected:
# print("\top mismatch")
return
if cur + 1 == len(template):
finished_decoding_claim = True
if template_idx == _CLAIM_TEMPLATE:
claim = NameClaim(*values)
elif template_idx in (_UPDATE_NO_DATA_TEMPLATE, _UPDATE_TEMPLATE):
claim = ClaimUpdate(*values)
elif template_idx in (_SUPPORT_TEMPLATE, _SUPPORT_WITH_DATA_TEMPLATE):
support = ClaimSupport(*values)
if template_idx == _TO_ADDRESS_TEMPLATE:
pubkey_hash = receive_values[0]
elif template_idx == _TO_P2SH_TEMPLATE:
script_hash = receive_values[0]
elif template_idx == _TO_PUBKEY_TEMPLATE:
pubkey = receive_values[0]
return claim, support, pubkey_hash, script_hash, pubkey