def from_bytes(b):
""" Deserializes a byte stream containing a script into a Script object.
Assumes the first part contains the length of the script in bytes.
Args:
b (bytes): A byte-stream containing the script, with the length
of the script in bytes prepended.
Returns:
(scr, b) (tuple): A tuple with the deserialized Script object and
the remainder of the byte stream.
"""
raw_script, b = unpack_var_str(b)
return (Script(raw_script), b)
def from_bytes(b):
""" Deserializes a byte stream containing a script into a Script object.
Assumes the first part contains the length of the script in bytes.
Args:
b (bytes): A byte-stream containing the script, with the length
of the script in bytes prepended.
Returns:
(scr, b) (tuple): A tuple with the deserialized Script object and
the remainder of the byte stream.
"""
raw_script, b = unpack_var_str(b)
return (Script(raw_script), b)
def extract_multisig_redeem_info(self):
""" Returns information about the multisig redeem script
Returns:
dict: Contains the following list of keys:
'm' (int): Required number of signatures.
'n' (int): Maximum number of signatures.
'public_keys' (list): List of byte strings
corresponding to public keys.
"""
exc = TypeError("This script is not a multisig redeem script.")
# The last byte of the raw script should be 0xae which is
# OP_CHECKMULTISIG
scr_bytes = bytes(self)
if scr_bytes[-1] != self.BTC_OPCODE_TABLE['OP_CHECKMULTISIG']:
raise exc
# Check m and n to be sure they are valid
m = scr_bytes[0] - 0x50
n = scr_bytes[-2] - 0x50
if m <= 0 or m >= 16:
raise exc
if n < m or n >= 16:
raise exc
# Now consume all the public keys and make sure those were
# the only things in.
b = scr_bytes[1:]
public_keys = []
for i in range(n):
pk, b = unpack_var_str(b)
public_keys.append(pk)
# May want to do additional checking to make
# sure it's a public key in the future.
# Should only be 2 bytes left
if len(b) != 2:
raise exc
if (b[0] - 0x50) != n or \
b[1] != self.BTC_OPCODE_TABLE['OP_CHECKMULTISIG']:
raise exc
return dict(m=m, n=n, public_keys=public_keys)
def extract_multisig_redeem_info(self):
""" Returns information about the multisig redeem script
Returns:
dict: Contains the following list of keys:
'm' (int): Required number of signatures.
'n' (int): Maximum number of signatures.
'public_keys' (list): List of byte strings corresponding to public keys.
"""
exc = TypeError("This script is not a multisig redeem script.")
# The last byte of the raw script should be 0xae which is
# OP_CHECKMULTISIG
scr_bytes = bytes(self)
if scr_bytes[-1] != self.BTC_OPCODE_TABLE['OP_CHECKMULTISIG']:
raise exc
# Check m and n to be sure they are valid
m = scr_bytes[0] - 0x50
n = scr_bytes[-2] - 0x50
if m <= 0 or m >= 16:
raise exc
if n < m or n >= 16:
raise exc
# Now consume all the public keys and make sure those were
# the only things in.
b = scr_bytes[1:]
public_keys = []
for i in range(n):
pk, b = unpack_var_str(b)
public_keys.append(pk)
# May want to do additional checking to make
# sure it's a public key in the future.
# Should only be 2 bytes left
if len(b) != 2:
raise exc
if (b[0] - 0x50) != n or \
b[1] != self.BTC_OPCODE_TABLE['OP_CHECKMULTISIG']:
raise exc
return dict(m=m, n=n, public_keys=public_keys)
