def evaluate(self, tx_script, txTo=None, inIdx=0, flags=None, execution_data=None):
self.error = None
self.steps = []
if flags is None:
flags = ()
self.script_passed = None
self.script_verified = False
stack = get_script_engine()(tx_script, txTo, inIdx, flags, execution_data)
verifying = stack.verifying
iterator = iter(stack)
while 1:
try:
state, last_op, log = iterator.next()
self.steps.append(StackState(list(state), last_op, log))
except StopIteration:
break
except Exception as e:
self.error = e
break
if self.steps and self.steps[-1].stack and not self.error:
if verifying:
self.script_verified = True
top_value = _CastToBool(self.steps[-1].stack[-1])
self.script_passed = top_value
return self.steps
def evaluate(self,
tx_script,
txTo=None,
inIdx=0,
flags=None,
execution_data=None):
self.error = None
self.steps = []
if flags is None:
flags = ()
self.script_passed = None
self.script_verified = False
stack = get_script_engine()(tx_script, txTo, inIdx, flags,
execution_data)
verifying = stack.verifying
iterator = iter(stack)
while 1:
try:
state, last_op, log = iterator.next()
self.steps.append(StackState(list(state), last_op, log))
except StopIteration:
break
except Exception as e:
self.error = e
break
if self.steps and self.steps[-1].stack and not self.error:
if verifying:
self.script_verified = True
top_value = _CastToBool(self.steps[-1].stack[-1])
self.script_passed = top_value
return self.steps
def bytearray_to_bool(data):
return _CastToBool(data)
def step(self):
"""Generator for evaluating a script.
Re-implemented _EvalScript from python-bitcoinlib for stack log.
"""
init_stack = self.init_stack
stack = init_stack
scriptIn = self.tx_script
txTo = self.txTo
inIdx = self.inIdx
flags = self.flags
if len(scriptIn) > MAX_SCRIPT_SIZE:
raise EvalScriptError('script too large; got %d bytes; maximum %d bytes' %
(len(scriptIn), MAX_SCRIPT_SIZE),
stack=stack,
scriptIn=scriptIn,
txTo=txTo,
inIdx=inIdx,
flags=flags)
altstack = []
vfExec = []
pbegincodehash = 0
nOpCount = [0]
last = ''
for (sop, sop_data, sop_pc) in scriptIn.raw_iter():
last = ''
fExec = _CheckExec(vfExec)
def err_raiser(cls, *args):
"""Helper function for raising EvalScriptError exceptions
cls - subclass you want to raise
*args - arguments
Fills in the state of execution for you.
"""
raise cls(*args,
sop=sop,
sop_data=sop_data,
sop_pc=sop_pc,
stack=stack, scriptIn=scriptIn, txTo=txTo, inIdx=inIdx, flags=flags,
altstack=altstack, vfExec=vfExec, pbegincodehash=pbegincodehash, nOpCount=nOpCount[0])
if sop in DISABLED_OPCODES:
err_raiser(EvalScriptError, 'opcode %s is disabled' % OPCODE_NAMES[sop])
if sop > OP_16:
nOpCount[0] += 1
if nOpCount[0] > MAX_SCRIPT_OPCODES:
err_raiser(MaxOpCountError)
def check_args(n):
if len(stack) < n:
err_raiser(MissingOpArgumentsError, sop, stack, n)
if sop <= OP_PUSHDATA4:
if len(sop_data) > MAX_SCRIPT_ELEMENT_SIZE:
err_raiser(EvalScriptError,
'PUSHDATA of length %d; maximum allowed is %d' %
(len(sop_data), MAX_SCRIPT_ELEMENT_SIZE))
elif fExec:
stack.append(sop_data)
# continue
yield (stack, '%s was pushed to the stack.' % e(sop_data))
continue
elif fExec or (OP_IF <= sop <= OP_ENDIF):
if sop == OP_1NEGATE or ((sop >= OP_1) and (sop <= OP_16)):
v = sop - (OP_1 - 1)
stack.append(bitcoin.core._bignum.bn2vch(v))
elif sop in _ISA_BINOP:
last = _BinOp(sop, stack, err_raiser)
elif sop in _ISA_UNOP:
last = _UnaryOp(sop, stack, err_raiser)
elif sop == OP_2DROP:
check_args(2)
last1 = stack.pop()
last2 = stack.pop()
last = '%s and %s were dropped.' % e(last1, last2)
elif sop == OP_2DUP:
check_args(2)
v1 = stack[-2]
v2 = stack[-1]
stack.append(v1)
stack.append(v2)
last = '%s and %s were copied onto the top.' % e(v1, v2)
elif sop == OP_2OVER:
check_args(4)
v1 = stack[-4]
v2 = stack[-3]
stack.append(v1)
stack.append(v2)
last = '%s and %s were copied onto the top.' % e(v1, v2)
elif sop == OP_2ROT:
check_args(6)
v1 = stack[-6]
v2 = stack[-5]
del stack[-6]
del stack[-5]
stack.append(v1)
stack.append(v2)
last = '%s and %s were moved to the top.' % e(v1, v2)
elif sop == OP_2SWAP:
check_args(4)
tmp = stack[-4]
stack[-4] = stack[-2]
stack[-2] = tmp
tmp = stack[-3]
stack[-3] = stack[-1]
stack[-1] = tmp
last = '%s and %s were swapped with %s and %s' % e(*stack[-4:])
elif sop == OP_3DUP:
check_args(3)
v1 = stack[-3]
v2 = stack[-2]
v3 = stack[-1]
stack.append(v1)
stack.append(v2)
stack.append(v3)
last = '%s, %s and %s were copied onto the top.' % e(v1, v2, v3)
# TODO stack log
elif sop == OP_CHECKMULTISIG or sop == OP_CHECKMULTISIGVERIFY:
tmpScript = CScript(scriptIn[pbegincodehash:])
_CheckMultiSig(sop, tmpScript, stack, txTo, inIdx, err_raiser, nOpCount)
elif sop == OP_CHECKSIG or sop == OP_CHECKSIGVERIFY:
check_args(2)
vchPubKey = stack[-1]
vchSig = stack[-2]
tmpScript = CScript(scriptIn[pbegincodehash:])
# Drop the signature, since there's no way for a signature to sign itself
#
# Of course, this can only come up in very contrived cases now that
# scriptSig and scriptPubKey are processed separately.
tmpScript = FindAndDelete(tmpScript, CScript([vchSig]))
ok = _CheckSig(vchSig, vchPubKey, tmpScript, txTo, inIdx,
err_raiser)
if not ok and sop == OP_CHECKSIGVERIFY:
err_raiser(VerifyOpFailedError, sop)
else:
stack.pop()
stack.pop()
if ok:
if sop != OP_CHECKSIGVERIFY:
stack.append(b"\x01")
else:
stack.append(b"\x00")
# TODO implement
if txTo is None:
err_raiser(EvalScriptError, 'CHECKSIG opcodes require a spending transaction.')
else:
last1 = 'After %s %s,' % ('CHECKSIG' if sop == OP_CHECKSIG else 'CHECKSIGVERIFY', 'passed' if ok else 'failed')
last2 = '%s was pushed to the stack.' % e(stack[-1])
last = ' '.join([last1, last2])
elif sop == OP_CODESEPARATOR:
last = '(code separator)'
pbegincodehash = sop_pc
elif sop == OP_DEPTH:
bn = len(stack)
stack.append(bitcoin.core._bignum.bn2vch(bn))
last = '%s (number of stack items) was pushed to the stack.' % e(stack[-1])
elif sop == OP_DROP:
check_args(1)
last1 = stack.pop()
last = '%s was dropped.' % e(last1)
elif sop == OP_DUP:
check_args(1)
v = stack[-1]
stack.append(v)
last = '%s was copied onto the top.' % e(v)
elif sop == OP_ELSE:
if len(vfExec) == 0:
err_raiser(EvalScriptError, 'ELSE found without prior IF')
vfExec[-1] = not vfExec[-1]
elif sop == OP_ENDIF:
last = 'End of IF statement.'
if len(vfExec) == 0:
err_raiser(EvalScriptError, 'ENDIF found without prior IF')
vfExec.pop()
elif sop == OP_EQUAL:
check_args(2)
v1 = stack.pop()
v2 = stack.pop()
if v1 == v2:
stack.append(b"\x01")
else:
stack.append(b"\x00")
last = '%s EQUALSIGN %s, so %s was pushed to the stack.' % e(v1, v2, stack[-1])
last = last.replace('EQUALSIGN', '==' if v1 == v2 else '!=')
elif sop == OP_EQUALVERIFY:
check_args(2)
v1 = stack[-1]
v2 = stack[-2]
if v1 == v2:
last1 = stack.pop()
last2 = stack.pop()
last = 'EQUALVERIFY passed so %s and %s were dropped.' % e(last1, last2)
else:
err_raiser(VerifyOpFailedError, sop)
elif sop == OP_FROMALTSTACK:
if len(altstack) < 1:
err_raiser(MissingOpArgumentsError, sop, altstack, 1)
v = altstack.pop()
stack.append(v)
last = '%s was pushed from the altstack to the stack.' % e(v)
elif sop == OP_HASH160:
check_args(1)
last1 = stack.pop()
stack.append(bitcoin.core.serialize.Hash160(last1))
last = '%s (HASH160 of %s) was pushed to the stack.' % e(stack[-1], last1)
elif sop == OP_HASH256:
check_args(1)
last1 = stack.pop()
stack.append(bitcoin.core.serialize.Hash(last1))
last = '%s (HASH256 of %s) was pushed to the stack.' % e(stack[-1], last1)
elif sop == OP_IF or sop == OP_NOTIF:
val = False
if fExec:
check_args(1)
vch = stack.pop()
val = _CastToBool(vch)
if sop == OP_NOTIF:
val = not val
if val:
last = 'Entered IF statement.'
else:
last = 'Skipped IF statement.'
vfExec.append(val)
elif sop == OP_IFDUP:
check_args(1)
vch = stack[-1]
if _CastToBool(vch):
stack.append(vch)
last = 'The top stack item %s was duplicated.' % e(stack[-1])
else:
last = 'The top stack item %s was not duplicated.' % e(stack[-1])
elif sop == OP_NIP:
check_args(2)
last1 = stack[-2]
del stack[-2]
last = '%s was removed.' % e(last1)
elif sop == OP_NOP or (sop >= OP_NOP1 and sop <= OP_NOP10):
last = '(NOP)'
elif sop == OP_OVER:
check_args(2)
vch = stack[-2]
stack.append(vch)
last = '%s was copied onto the top.' % e(vch)
elif sop == OP_PICK or sop == OP_ROLL:
check_args(2)
n = _CastToBigNum(stack.pop(), err_raiser)
if n < 0 or n >= len(stack):
err_raiser(EvalScriptError, "Argument for %s out of bounds" % OPCODE_NAMES[sop])
vch = stack[-n-1]
rolled = False # for "last"
if sop == OP_ROLL:
rolled = True
del stack[-n-1]
stack.append(vch)
if rolled:
last = '%s was moved to the top.' % e(vch)
else:
last = '%s was copied onto the top.' % e(vch)
elif sop == OP_RETURN:
err_raiser(EvalScriptError, "OP_RETURN called")
elif sop == OP_RIPEMD160:
check_args(1)
elif sop == OP_ROT:
check_args(3)
tmp = stack[-3]
stack[-3] = stack[-2]
stack[-2] = tmp
tmp = stack[-2]
stack[-2] = stack[-1]
stack[-1] = tmp
last = '%s, %s and %s were rotated to the left.' % e(stack[-1], stack[-3], stack[-2])
elif sop == OP_SIZE:
check_args(1)
bn = len(stack[-1])
stack.append(bitcoin.core._bignum.bn2vch(bn))
last = '%s (string length of %s) was pushed to the stack.' % e(stack[-1], stack[-2])
elif sop == OP_SHA1:
check_args(1)
last1 = stack.pop()
stack.append(hashlib.sha1(last1).digest())
last = '%s (SHA1 of %s) was pushed to the stack.' % e(stack[-1], last1)
elif sop == OP_SHA256:
check_args(1)
last1 = stack.pop()
stack.append(hashlib.sha256(last1).digest())
last = '%s (SHA256 of %s) was pushed to the stack.' % e(stack[-1], last1)
elif sop == OP_SWAP:
check_args(2)
tmp = stack[-2]
stack[-2] = stack[-1]
stack[-1] = tmp
last = '%s and %s were swapped.' % e(stack[-1], stack[-2])
elif sop == OP_TOALTSTACK:
check_args(1)
v = stack.pop()
altstack.append(v)
last = '%s was pushed to the altstack.' % e(v)
elif sop == OP_TUCK:
check_args(2)
vch = stack[-1]
stack.insert(len(stack) - 2, vch)
last = '%s was copied into the second-to-top position.' % e(vch)
elif sop == OP_VERIFY:
check_args(1)
v = _CastToBool(stack[-1])
if v:
last1 = stack.pop()
last = '%s was dropped after VERIFY passed.' % e(last1)
else:
raise err_raiser(VerifyOpFailedError, sop)
elif sop == OP_WITHIN:
check_args(3)
bn3 = _CastToBigNum(stack[-1], err_raiser)
bn2 = _CastToBigNum(stack[-2], err_raiser)
bn1 = _CastToBigNum(stack[-3], err_raiser)
stack.pop()
stack.pop()
stack.pop()
v = (bn2 <= bn1) and (bn1 < bn3)
if v:
stack.append(b"\x01")
else:
stack.append(b"\x00")
last = '%s (the result of %s <= %s < %s) was pushed to the stack.' % e(stack[-1], bn2, bn1, bn3)
else:
err_raiser(EvalScriptError, 'unsupported opcode 0x%x' % sop)
yield (stack, last)
# size limits
if len(stack) + len(altstack) > MAX_STACK_ITEMS:
err_raiser(EvalScriptError, 'max stack items limit reached')
# Unterminated IF/NOTIF/ELSE block
if len(vfExec):
raise EvalScriptError('Unterminated IF/ELSE block',
stack=stack,
scriptIn=scriptIn,
txTo=txTo,
inIdx=inIdx,
flags=flags)
def bytearray_to_bool(data):
return _CastToBool(data)
def verify_step(self):
"""Generator for verifying a script.
Re-implemented VerifyScript from python-bitcoinlib for stack log.
"""
if not self.txTo:
raise VerifyScriptError('Verification requires a transaction')
# Store original tx script.
tx_script = self.tx_script
self.init_stack = []
# Set tx_script to scriptSig of transaction.
self.tx_script = scriptSig = self.txTo.vin[self.inIdx].scriptSig
iterator = self.step()
while 1:
try:
yield iterator.next()
except StopIteration:
break
# Store copy of current stack for P2SH verification.
stack_copy = list(self.init_stack)
# Set tx_script to the original script being tested.
self.tx_script = tx_script
iterator = self.step()
while 1:
try:
yield iterator.next()
except StopIteration:
break
if len(self.init_stack) == 0:
raise VerifyScriptError("scriptPubKey left an empty stack")
if not _CastToBool(self.init_stack[-1]):
raise VerifyScriptError("scriptPubKey returned false")
# Pay-To-Script-Hash verification.
if tx_script.is_p2sh():
if not scriptSig.is_push_only():
raise VerifyScriptError("P2SH scriptSig not is_push_only()")
if not len(stack_copy):
raise VerifyScriptError("scriptSig left an empty stack")
# Set tx script to the pubkey from scriptSig.
self.tx_script = pubkey = CScript(stack_copy.pop())
self.init_stack = stack_copy
iterator = self.step()
while 1:
try:
yield iterator.next()
except StopIteration:
break
if not len(stack_copy):
raise VerifyScriptError("P2SH inner scriptPubKey left an empty stack")
if not _CastToBool(stack_copy[-1]):
raise VerifyScriptError("P2SH inner scriptPubKey returned false")
def peek_bool(self, idx):
val = self.peek_bytearray(idx)
return _CastToBool(val)
def pop_bool(self):
val = self.pop_bytearray()
return _CastToBool(val)
def peek_bool(self, idx):
val = self.peek_bytearray(idx)
return _CastToBool(val)
def pop_bool(self):
val = self.pop_bytearray()
return _CastToBool(val)
def step(self):
"""Generator for evaluating a script.
Re-implemented _EvalScript from python-bitcoinlib for stack log.
"""
stack = self.init_stack
scriptIn = self.tx_script
txTo = self.txTo
inIdx = self.inIdx
flags = self.flags
execution_data = self.execution_data
if len(scriptIn) > MAX_SCRIPT_SIZE:
raise EvalScriptError(
'script too large; got %d bytes; maximum %d bytes' %
(len(scriptIn), MAX_SCRIPT_SIZE),
stack=stack,
scriptIn=scriptIn,
txTo=txTo,
inIdx=inIdx,
flags=flags)
altstack = []
vfExec = []
pbegincodehash = 0
nOpCount = [0]
last = ''
for (sop, sop_data, sop_pc) in scriptIn.raw_iter():
last = ''
fExec = _CheckExec(vfExec)
def err_raiser(cls, *args):
"""Helper function for raising EvalScriptError exceptions
cls - subclass you want to raise
*args - arguments
Fills in the state of execution for you.
"""
raise cls(*args,
sop=sop,
sop_data=sop_data,
sop_pc=sop_pc,
stack=stack,
scriptIn=scriptIn,
txTo=txTo,
inIdx=inIdx,
flags=flags,
altstack=altstack,
vfExec=vfExec,
pbegincodehash=pbegincodehash,
nOpCount=nOpCount[0])
if sop in opcodes.disabled_opcodes:
err_raiser(EvalScriptError,
'opcode %s is disabled' % opcodes.opcode_names[sop])
if sop > OP_16:
nOpCount[0] += 1
if nOpCount[0] > MAX_SCRIPT_OPCODES:
err_raiser(MaxOpCountError)
def check_args(n):
if len(stack) < n:
err_raiser(MissingOpArgumentsError, sop, stack, n)
if sop <= OP_PUSHDATA4:
if len(sop_data) > MAX_SCRIPT_ELEMENT_SIZE:
err_raiser(
EvalScriptError,
'PUSHDATA of length %d; maximum allowed is %d' %
(len(sop_data), MAX_SCRIPT_ELEMENT_SIZE))
elif fExec:
stack.append(sop_data)
# continue
yield (stack, sop,
'%s was pushed to the stack.' % e(sop_data))
continue
elif fExec or (OP_IF <= sop <= OP_ENDIF):
if opcodes.is_overridden(sop):
yield opcodes.override(sop, stack, txTo, inIdx, flags,
execution_data, err_raiser)
continue
elif sop == OP_1NEGATE or ((sop >= OP_1) and (sop <= OP_16)):
v = sop - (OP_1 - 1)
stack.append(bitcoin.core._bignum.bn2vch(v))
last = '%s was pushed to the stack.' % e(stack[-1])
elif sop in _ISA_BINOP:
last = _BinOp(sop, stack, err_raiser)
elif sop in _ISA_UNOP:
last = _UnaryOp(sop, stack, err_raiser)
elif sop == OP_2DROP:
check_args(2)
last1 = stack.pop()
last2 = stack.pop()
last = '%s and %s were dropped.' % e(last1, last2)
elif sop == OP_2DUP:
check_args(2)
v1 = stack[-2]
v2 = stack[-1]
stack.append(v1)
stack.append(v2)
last = '%s and %s were copied onto the top.' % e(v1, v2)
elif sop == OP_2OVER:
check_args(4)
v1 = stack[-4]
v2 = stack[-3]
stack.append(v1)
stack.append(v2)
last = '%s and %s were copied onto the top.' % e(v1, v2)
elif sop == OP_2ROT:
check_args(6)
v1 = stack[-6]
v2 = stack[-5]
del stack[-6]
del stack[-5]
stack.append(v1)
stack.append(v2)
last = '%s and %s were moved to the top.' % e(v1, v2)
elif sop == OP_2SWAP:
check_args(4)
tmp = stack[-4]
stack[-4] = stack[-2]
stack[-2] = tmp
tmp = stack[-3]
stack[-3] = stack[-1]
stack[-1] = tmp
last = '%s and %s were swapped with %s and %s' % e(
*stack[-4:])
elif sop == OP_3DUP:
check_args(3)
v1 = stack[-3]
v2 = stack[-2]
v3 = stack[-1]
stack.append(v1)
stack.append(v2)
stack.append(v3)
last = '%s, %s and %s were copied onto the top.' % e(
v1, v2, v3)
# TODO stack log
elif sop == OP_CHECKMULTISIG or sop == OP_CHECKMULTISIGVERIFY:
tmpScript = CScript(scriptIn[pbegincodehash:])
_CheckMultiSig(sop, tmpScript, stack, txTo, inIdx,
err_raiser, nOpCount)
elif sop == OP_CHECKSIG or sop == OP_CHECKSIGVERIFY:
check_args(2)
vchPubKey = stack[-1]
vchSig = stack[-2]
tmpScript = CScript(scriptIn[pbegincodehash:])
# Drop the signature, since there's no way for a signature to sign itself
#
# Of course, this can only come up in very contrived cases now that
# scriptSig and scriptPubKey are processed separately.
tmpScript = FindAndDelete(tmpScript, CScript([vchSig]))
ok = _CheckSig(vchSig, vchPubKey, tmpScript, txTo, inIdx,
err_raiser)
if not ok and sop == OP_CHECKSIGVERIFY:
err_raiser(VerifyOpFailedError, sop)
else:
stack.pop()
stack.pop()
if ok:
if sop != OP_CHECKSIGVERIFY:
stack.append(b"\x01")
else:
stack.append(b"\x00")
# TODO implement
if txTo is None:
err_raiser(
EvalScriptError,
'CHECKSIG opcodes require a spending transaction.'
)
else:
last1 = 'After %s %s,' % (
'CHECKSIG' if sop == OP_CHECKSIG else
'CHECKSIGVERIFY', 'passed' if ok else 'failed')
last2 = '%s was pushed to the stack.' % e(
stack[-1])
last = ' '.join([last1, last2])
elif sop == OP_CODESEPARATOR:
last = '(code separator)'
pbegincodehash = sop_pc
elif sop == OP_DEPTH:
bn = len(stack)
stack.append(bitcoin.core._bignum.bn2vch(bn))
last = '%s (number of stack items) was pushed to the stack.' % e(
stack[-1])
elif sop == OP_DROP:
check_args(1)
last1 = stack.pop()
last = '%s was dropped.' % e(last1)
elif sop == OP_DUP:
check_args(1)
v = stack[-1]
stack.append(v)
last = '%s was copied onto the top.' % e(v)
elif sop == OP_ELSE:
if len(vfExec) == 0:
err_raiser(EvalScriptError,
'ELSE found without prior IF')
vfExec[-1] = not vfExec[-1]
last = 'Skipped ELSE statement.'
if vfExec[-1]:
last = 'Entered ELSE statement.'
elif sop == OP_ENDIF:
last = 'End of IF statement.'
if len(vfExec) == 0:
err_raiser(EvalScriptError,
'ENDIF found without prior IF')
vfExec.pop()
elif sop == OP_EQUAL:
check_args(2)
v1 = stack.pop()
v2 = stack.pop()
if v1 == v2:
stack.append(b"\x01")
else:
stack.append(b"\x00")
last = '%s EQUALSIGN %s, so %s was pushed to the stack.' % e(
v1, v2, stack[-1])
last = last.replace('EQUALSIGN',
'==' if v1 == v2 else '!=')
elif sop == OP_EQUALVERIFY:
check_args(2)
v1 = stack[-1]
v2 = stack[-2]
if v1 == v2:
last1 = stack.pop()
last2 = stack.pop()
last = 'EQUALVERIFY passed so %s and %s were dropped.' % e(
last1, last2)
else:
err_raiser(VerifyOpFailedError, sop)
elif sop == OP_FROMALTSTACK:
if len(altstack) < 1:
err_raiser(MissingOpArgumentsError, sop, altstack, 1)
v = altstack.pop()
stack.append(v)
last = '%s was pushed from the altstack to the stack.' % e(
v)
elif sop == OP_HASH160:
check_args(1)
last1 = stack.pop()
stack.append(bitcoin.core.serialize.Hash160(last1))
last = '%s (HASH160 of %s) was pushed to the stack.' % e(
stack[-1], last1)
elif sop == OP_HASH256:
check_args(1)
last1 = stack.pop()
stack.append(bitcoin.core.serialize.Hash(last1))
last = '%s (HASH256 of %s) was pushed to the stack.' % e(
stack[-1], last1)
elif sop == OP_IF or sop == OP_NOTIF:
val = False
if fExec:
check_args(1)
vch = stack.pop()
val = _CastToBool(vch)
if sop == OP_NOTIF:
val = not val
if val:
last = 'Entered IF statement.'
else:
last = 'Skipped IF statement.'
vfExec.append(val)
elif sop == OP_IFDUP:
check_args(1)
vch = stack[-1]
if _CastToBool(vch):
stack.append(vch)
last = 'The top stack item %s was duplicated.' % e(
stack[-1])
else:
last = 'The top stack item %s was not duplicated.' % e(
stack[-1])
elif sop == OP_NIP:
check_args(2)
last1 = stack[-2]
del stack[-2]
last = '%s was removed.' % e(last1)
elif sop == OP_NOP or (sop >= OP_NOP1 and sop <= OP_NOP10):
last = '(NOP)'
elif sop == OP_OVER:
check_args(2)
vch = stack[-2]
stack.append(vch)
last = '%s was copied onto the top.' % e(vch)
elif sop == OP_PICK or sop == OP_ROLL:
check_args(2)
n = _CastToBigNum(stack.pop(), err_raiser)
if n < 0 or n >= len(stack):
err_raiser(
EvalScriptError, "Argument for %s out of bounds" %
opcodes.opcode_names[sop])
vch = stack[-n - 1]
rolled = False # for "last"
if sop == OP_ROLL:
rolled = True
del stack[-n - 1]
stack.append(vch)
if rolled:
last = '%s was moved to the top.' % e(vch)
else:
last = '%s was copied onto the top.' % e(vch)
elif sop == OP_RETURN:
err_raiser(EvalScriptError, "OP_RETURN called")
elif sop == OP_RIPEMD160:
check_args(1)
h = hashlib.new('ripemd160')
tmp = stack.pop()
h.update(tmp)
stack.append(h.digest())
last = '%s (RIPEMD160 of %s) was pushed to the stack.' % e(
stack[-1], tmp)
elif sop == OP_ROT:
check_args(3)
tmp = stack[-3]
stack[-3] = stack[-2]
stack[-2] = tmp
tmp = stack[-2]
stack[-2] = stack[-1]
stack[-1] = tmp
last = '%s, %s and %s were rotated to the left.' % e(
stack[-1], stack[-3], stack[-2])
elif sop == OP_SIZE:
check_args(1)
bn = len(stack[-1])
stack.append(bitcoin.core._bignum.bn2vch(bn))
last = '%s (string length of %s) was pushed to the stack.' % e(
stack[-1], stack[-2])
elif sop == OP_SHA1:
check_args(1)
last1 = stack.pop()
stack.append(hashlib.sha1(last1).digest())
last = '%s (SHA1 of %s) was pushed to the stack.' % e(
stack[-1], last1)
elif sop == OP_SHA256:
check_args(1)
last1 = stack.pop()
stack.append(hashlib.sha256(last1).digest())
last = '%s (SHA256 of %s) was pushed to the stack.' % e(
stack[-1], last1)
elif sop == OP_SWAP:
check_args(2)
tmp = stack[-2]
stack[-2] = stack[-1]
stack[-1] = tmp
last = '%s and %s were swapped.' % e(stack[-1], stack[-2])
elif sop == OP_TOALTSTACK:
check_args(1)
v = stack.pop()
altstack.append(v)
last = '%s was pushed to the altstack.' % e(v)
elif sop == OP_TUCK:
check_args(2)
vch = stack[-1]
stack.insert(len(stack) - 2, vch)
last = '%s was copied into the second-to-top position.' % e(
vch)
elif sop == OP_VERIFY:
check_args(1)
v = _CastToBool(stack[-1])
if v:
last1 = stack.pop()
last = '%s was dropped after VERIFY passed.' % e(last1)
else:
raise err_raiser(VerifyOpFailedError, sop)
elif sop == OP_WITHIN:
check_args(3)
bn3 = _CastToBigNum(stack[-1], err_raiser)
bn2 = _CastToBigNum(stack[-2], err_raiser)
bn1 = _CastToBigNum(stack[-3], err_raiser)
l3 = stack.pop()
l2 = stack.pop()
l1 = stack.pop()
v = (bn2 <= bn1) and (bn1 < bn3)
if v:
stack.append(b"\x01")
else:
stack.append(b"\x00")
last = '%s (the result of %s <= %s < %s) was pushed to the stack.' % e(
stack[-1], l2, l1, l3)
else:
err_raiser(EvalScriptError,
'unsupported opcode 0x%x' % sop)
yield (stack, sop, last)
# size limits
if len(stack) + len(altstack) > MAX_STACK_ITEMS:
err_raiser(EvalScriptError, 'max stack items limit reached')
# Unterminated IF/NOTIF/ELSE block
if len(vfExec):
raise EvalScriptError('Unterminated IF/ELSE block',
stack=stack,
scriptIn=scriptIn,
txTo=txTo,
inIdx=inIdx,
flags=flags)
def verify_step(self):
"""Generator for verifying a script.
Re-implemented VerifyScript from python-bitcoinlib for stack log.
"""
if not self.txTo:
raise VerifyScriptError('Verification requires a transaction')
# Store original tx script.
tx_script = self.tx_script
self.init_stack = []
# Set tx_script to scriptSig of transaction.
self.tx_script = scriptSig = self.txTo.vin[self.inIdx].scriptSig
iterator = self.step()
while 1:
try:
yield iterator.next()
except StopIteration:
break
# Store copy of current stack for P2SH verification.
stack_copy = list(self.init_stack)
# Set tx_script to the original script being tested.
self.tx_script = tx_script
iterator = self.step()
while 1:
try:
yield iterator.next()
except StopIteration:
break
if len(self.init_stack) == 0:
raise VerifyScriptError("scriptPubKey left an empty stack")
if not _CastToBool(self.init_stack[-1]):
raise VerifyScriptError("scriptPubKey returned false")
# Pay-To-Script-Hash verification.
if tx_script.is_p2sh():
if not scriptSig.is_push_only():
raise VerifyScriptError("P2SH scriptSig not is_push_only()")
if not len(stack_copy):
raise VerifyScriptError("scriptSig left an empty stack")
# Set tx script to the pubkey from scriptSig.
self.tx_script = pubkey = CScript(stack_copy.pop())
self.init_stack = stack_copy
iterator = self.step()
while 1:
try:
yield iterator.next()
except StopIteration:
break
if not len(stack_copy):
raise VerifyScriptError(
"P2SH inner scriptPubKey left an empty stack")
if not _CastToBool(stack_copy[-1]):
raise VerifyScriptError(
"P2SH inner scriptPubKey returned false")
