script.py

# script.py
#
# Distributed under the MIT/X11 software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.

from __future__ import absolute_import, division, print_function, unicode_literals

import struct

SIGHASH_ALL = 1
SIGHASH_NONE = 2
SIGHASH_SINGLE = 3
SIGHASH_ANYONECANPAY = 0x80

# push value
OP_0 = 0x00
OP_FALSE = OP_0
OP_PUSHDATA1 = 0x4c
OP_PUSHDATA2 = 0x4d
OP_PUSHDATA4 = 0x4e
OP_1NEGATE = 0x4f
OP_RESERVED = 0x50
OP_1 = 0x51
OP_TRUE=OP_1
OP_2 = 0x52
OP_3 = 0x53
OP_4 = 0x54
OP_5 = 0x55
OP_6 = 0x56
OP_7 = 0x57
OP_8 = 0x58
OP_9 = 0x59
OP_10 = 0x5a
OP_11 = 0x5b
OP_12 = 0x5c
OP_13 = 0x5d
OP_14 = 0x5e
OP_15 = 0x5f
OP_16 = 0x60

# control
OP_NOP = 0x61
OP_VER = 0x62
OP_IF = 0x63
OP_NOTIF = 0x64
OP_VERIF = 0x65
OP_VERNOTIF = 0x66
OP_ELSE = 0x67
OP_ENDIF = 0x68
OP_VERIFY = 0x69
OP_RETURN = 0x6a

# stack ops
OP_TOALTSTACK = 0x6b
OP_FROMALTSTACK = 0x6c
OP_2DROP = 0x6d
OP_2DUP = 0x6e
OP_3DUP = 0x6f
OP_2OVER = 0x70
OP_2ROT = 0x71
OP_2SWAP = 0x72
OP_IFDUP = 0x73
OP_DEPTH = 0x74
OP_DROP = 0x75
OP_DUP = 0x76
OP_NIP = 0x77
OP_OVER = 0x78
OP_PICK = 0x79
OP_ROLL = 0x7a
OP_ROT = 0x7b
OP_SWAP = 0x7c
OP_TUCK = 0x7d

# splice ops
OP_CAT = 0x7e
OP_SUBSTR = 0x7f
OP_LEFT = 0x80
OP_RIGHT = 0x81
OP_SIZE = 0x82

# bit logic
OP_INVERT = 0x83
OP_AND = 0x84
OP_OR = 0x85
OP_XOR = 0x86
OP_EQUAL = 0x87
OP_EQUALVERIFY = 0x88
OP_RESERVED1 = 0x89
OP_RESERVED2 = 0x8a

# numeric
OP_1ADD = 0x8b
OP_1SUB = 0x8c
OP_2MUL = 0x8d
OP_2DIV = 0x8e
OP_NEGATE = 0x8f
OP_ABS = 0x90
OP_NOT = 0x91
OP_0NOTEQUAL = 0x92

OP_ADD = 0x93
OP_SUB = 0x94
OP_MUL = 0x95
OP_DIV = 0x96
OP_MOD = 0x97
OP_LSHIFT = 0x98
OP_RSHIFT = 0x99

OP_BOOLAND = 0x9a
OP_BOOLOR = 0x9b
OP_NUMEQUAL = 0x9c
OP_NUMEQUALVERIFY = 0x9d
OP_NUMNOTEQUAL = 0x9e
OP_LESSTHAN = 0x9f
OP_GREATERTHAN = 0xa0
OP_LESSTHANOREQUAL = 0xa1
OP_GREATERTHANOREQUAL = 0xa2
OP_MIN = 0xa3
OP_MAX = 0xa4

OP_WITHIN = 0xa5

# crypto
OP_RIPEMD160 = 0xa6
OP_SHA1 = 0xa7
OP_SHA256 = 0xa8
OP_HASH160 = 0xa9
OP_HASH256 = 0xaa
OP_CODESEPARATOR = 0xab
OP_CHECKSIG = 0xac
OP_CHECKSIGVERIFY = 0xad
OP_CHECKMULTISIG = 0xae
OP_CHECKMULTISIGVERIFY = 0xaf

# expansion
OP_NOP1 = 0xb0
OP_NOP2 = 0xb1
OP_NOP3 = 0xb2
OP_NOP4 = 0xb3
OP_NOP5 = 0xb4
OP_NOP6 = 0xb5
OP_NOP7 = 0xb6
OP_NOP8 = 0xb7
OP_NOP9 = 0xb8
OP_NOP10 = 0xb9

# template matching params
OP_SMALLINTEGER = 0xfa
OP_PUBKEYS = 0xfb
OP_PUBKEYHASH = 0xfd
OP_PUBKEY = 0xfe

OP_INVALIDOPCODE = 0xff

VALID_OPCODES = {
    OP_1NEGATE,
    OP_RESERVED,
    OP_1,
    OP_2,
    OP_3,
    OP_4,
    OP_5,
    OP_6,
    OP_7,
    OP_8,
    OP_9,
    OP_10,
    OP_11,
    OP_12,
    OP_13,
    OP_14,
    OP_15,
    OP_16,

    OP_NOP,
    OP_VER,
    OP_IF,
    OP_NOTIF,
    OP_VERIF,
    OP_VERNOTIF,
    OP_ELSE,
    OP_ENDIF,
    OP_VERIFY,
    OP_RETURN,

    OP_TOALTSTACK,
    OP_FROMALTSTACK,
    OP_2DROP,
    OP_2DUP,
    OP_3DUP,
    OP_2OVER,
    OP_2ROT,
    OP_2SWAP,
    OP_IFDUP,
    OP_DEPTH,
    OP_DROP,
    OP_DUP,
    OP_NIP,
    OP_OVER,
    OP_PICK,
    OP_ROLL,
    OP_ROT,
    OP_SWAP,
    OP_TUCK,

    OP_CAT,
    OP_SUBSTR,
    OP_LEFT,
    OP_RIGHT,
    OP_SIZE,

    OP_INVERT,
    OP_AND,
    OP_OR,
    OP_XOR,
    OP_EQUAL,
    OP_EQUALVERIFY,
    OP_RESERVED1,
    OP_RESERVED2,

    OP_1ADD,
    OP_1SUB,
    OP_2MUL,
    OP_2DIV,
    OP_NEGATE,
    OP_ABS,
    OP_NOT,
    OP_0NOTEQUAL,

    OP_ADD,
    OP_SUB,
    OP_MUL,
    OP_DIV,
    OP_MOD,
    OP_LSHIFT,
    OP_RSHIFT,

    OP_BOOLAND,
    OP_BOOLOR,
    OP_NUMEQUAL,
    OP_NUMEQUALVERIFY,
    OP_NUMNOTEQUAL,
    OP_LESSTHAN,
    OP_GREATERTHAN,
    OP_LESSTHANOREQUAL,
    OP_GREATERTHANOREQUAL,
    OP_MIN,
    OP_MAX,

    OP_WITHIN,

    OP_RIPEMD160,
    OP_SHA1,
    OP_SHA256,
    OP_HASH160,
    OP_HASH256,
    OP_CODESEPARATOR,
    OP_CHECKSIG,
    OP_CHECKSIGVERIFY,
    OP_CHECKMULTISIG,
    OP_CHECKMULTISIGVERIFY,

    OP_NOP1,
    OP_NOP2,
    OP_NOP3,
    OP_NOP4,
    OP_NOP5,
    OP_NOP6,
    OP_NOP7,
    OP_NOP8,
    OP_NOP9,
    OP_NOP10,

    OP_SMALLINTEGER,
    OP_PUBKEYS,
    OP_PUBKEYHASH,
    OP_PUBKEY,
}

OPCODE_NAMES = {
    OP_0 : 'OP_0',
    OP_PUSHDATA1 : 'OP_PUSHDATA1',
    OP_PUSHDATA2 : 'OP_PUSHDATA2',
    OP_PUSHDATA4 : 'OP_PUSHDATA4',
    OP_1NEGATE : 'OP_1NEGATE',
    OP_RESERVED : 'OP_RESERVED',
    OP_1 : 'OP_1',
    OP_2 : 'OP_2',
    OP_3 : 'OP_3',
    OP_4 : 'OP_4',
    OP_5 : 'OP_5',
    OP_6 : 'OP_6',
    OP_7 : 'OP_7',
    OP_8 : 'OP_8',
    OP_9 : 'OP_9',
    OP_10 : 'OP_10',
    OP_11 : 'OP_11',
    OP_12 : 'OP_12',
    OP_13 : 'OP_13',
    OP_14 : 'OP_14',
    OP_15 : 'OP_15',
    OP_16 : 'OP_16',
    OP_NOP : 'OP_NOP',
    OP_VER : 'OP_VER',
    OP_IF : 'OP_IF',
    OP_NOTIF : 'OP_NOTIF',
    OP_VERIF : 'OP_VERIF',
    OP_VERNOTIF : 'OP_VERNOTIF',
    OP_ELSE : 'OP_ELSE',
    OP_ENDIF : 'OP_ENDIF',
    OP_VERIFY : 'OP_VERIFY',
    OP_RETURN : 'OP_RETURN',
    OP_TOALTSTACK : 'OP_TOALTSTACK',
    OP_FROMALTSTACK : 'OP_FROMALTSTACK',
    OP_2DROP : 'OP_2DROP',
    OP_2DUP : 'OP_2DUP',
    OP_3DUP : 'OP_3DUP',
    OP_2OVER : 'OP_2OVER',
    OP_2ROT : 'OP_2ROT',
    OP_2SWAP : 'OP_2SWAP',
    OP_IFDUP : 'OP_IFDUP',
    OP_DEPTH : 'OP_DEPTH',
    OP_DROP : 'OP_DROP',
    OP_DUP : 'OP_DUP',
    OP_NIP : 'OP_NIP',
    OP_OVER : 'OP_OVER',
    OP_PICK : 'OP_PICK',
    OP_ROLL : 'OP_ROLL',
    OP_ROT : 'OP_ROT',
    OP_SWAP : 'OP_SWAP',
    OP_TUCK : 'OP_TUCK',
    OP_CAT : 'OP_CAT',
    OP_SUBSTR : 'OP_SUBSTR',
    OP_LEFT : 'OP_LEFT',
    OP_RIGHT : 'OP_RIGHT',
    OP_SIZE : 'OP_SIZE',
    OP_INVERT : 'OP_INVERT',
    OP_AND : 'OP_AND',
    OP_OR : 'OP_OR',
    OP_XOR : 'OP_XOR',
    OP_EQUAL : 'OP_EQUAL',
    OP_EQUALVERIFY : 'OP_EQUALVERIFY',
    OP_RESERVED1 : 'OP_RESERVED1',
    OP_RESERVED2 : 'OP_RESERVED2',
    OP_1ADD : 'OP_1ADD',
    OP_1SUB : 'OP_1SUB',
    OP_2MUL : 'OP_2MUL',
    OP_2DIV : 'OP_2DIV',
    OP_NEGATE : 'OP_NEGATE',
    OP_ABS : 'OP_ABS',
    OP_NOT : 'OP_NOT',
    OP_0NOTEQUAL : 'OP_0NOTEQUAL',
    OP_ADD : 'OP_ADD',
    OP_SUB : 'OP_SUB',
    OP_MUL : 'OP_MUL',
    OP_DIV : 'OP_DIV',
    OP_MOD : 'OP_MOD',
    OP_LSHIFT : 'OP_LSHIFT',
    OP_RSHIFT : 'OP_RSHIFT',
    OP_BOOLAND : 'OP_BOOLAND',
    OP_BOOLOR : 'OP_BOOLOR',
    OP_NUMEQUAL : 'OP_NUMEQUAL',
    OP_NUMEQUALVERIFY : 'OP_NUMEQUALVERIFY',
    OP_NUMNOTEQUAL : 'OP_NUMNOTEQUAL',
    OP_LESSTHAN : 'OP_LESSTHAN',
    OP_GREATERTHAN : 'OP_GREATERTHAN',
    OP_LESSTHANOREQUAL : 'OP_LESSTHANOREQUAL',
    OP_GREATERTHANOREQUAL : 'OP_GREATERTHANOREQUAL',
    OP_MIN : 'OP_MIN',
    OP_MAX : 'OP_MAX',
    OP_WITHIN : 'OP_WITHIN',
    OP_RIPEMD160 : 'OP_RIPEMD160',
    OP_SHA1 : 'OP_SHA1',
    OP_SHA256 : 'OP_SHA256',
    OP_HASH160 : 'OP_HASH160',
    OP_HASH256 : 'OP_HASH256',
    OP_CODESEPARATOR : 'OP_CODESEPARATOR',
    OP_CHECKSIG : 'OP_CHECKSIG',
    OP_CHECKSIGVERIFY : 'OP_CHECKSIGVERIFY',
    OP_CHECKMULTISIG : 'OP_CHECKMULTISIG',
    OP_CHECKMULTISIGVERIFY : 'OP_CHECKMULTISIGVERIFY',
    OP_NOP1 : 'OP_NOP1',
    OP_NOP2 : 'OP_NOP2',
    OP_NOP3 : 'OP_NOP3',
    OP_NOP4 : 'OP_NOP4',
    OP_NOP5 : 'OP_NOP5',
    OP_NOP6 : 'OP_NOP6',
    OP_NOP7 : 'OP_NOP7',
    OP_NOP8 : 'OP_NOP8',
    OP_NOP9 : 'OP_NOP9',
    OP_NOP10 : 'OP_NOP10',
    OP_SMALLINTEGER : 'OP_SMALLINTEGER',
    OP_PUBKEYS : 'OP_PUBKEYS',
    OP_PUBKEYHASH : 'OP_PUBKEYHASH',
    OP_PUBKEY : 'OP_PUBKEY',
}

TEMPLATES = [
    [ OP_PUBKEY, OP_CHECKSIG ],
    [ OP_DUP, OP_HASH160, OP_PUBKEYHASH, OP_EQUALVERIFY, OP_CHECKSIG ],
]

class CScriptOp(object):
    def __init__(self):
        self.op = OP_INVALIDOPCODE
        self.data = ''
        self.ser_len = 0

class CScript(object):
    def __init__(self, vch=None):
        self.vch = vch

        self.reset()

    def reset(self):
        self.pc = 0
        if self.vch is None:
            self.pend = 0
        else:
            self.pend = len(self.vch)
        self.pbegincodehash = 0
        self.sop = None

    def getchars(self, n):
        if (self.pc + n) > self.pend:
            return None

        s = self.vch[self.pc:self.pc+n]
        self.pc += n

        return s

    def getop(self):
        s = self.getchars(1)
        if s is None:
            return False
        opcode = ord(s)

        sop = CScriptOp()
        sop.op = opcode
        sop.ser_len = 1

        if opcode > OP_PUSHDATA4:
            if opcode not in VALID_OPCODES:
                return False
            self.sop = sop
            return True

        if opcode < OP_PUSHDATA1:
            datasize = opcode

        elif opcode == OP_PUSHDATA1:
            sop.ser_len += 1
            s = self.getchars(1)
            if s is None:
                return False
            datasize = ord(s)

        elif opcode == OP_PUSHDATA2:
            sop.ser_len += 2
            s = self.getchars(2)
            if s is None:
                return False
            datasize = struct.unpack(b"<H", s)[0]

        elif opcode == OP_PUSHDATA4:
            sop.ser_len += 4
            s = self.getchars(4)
            if s is None:
                return False
            datasize = struct.unpack(b"<I", s)[0]

        sop.ser_len += datasize
        sop.data = self.getchars(datasize)
        if sop.data is None:
            return False

        self.sop = sop
        return True

    def tokenize(self, vch_in=None):
        if vch_in is not None:
            self.vch = vch_in

        self.reset()
        while self.pc < self.pend:
            if not self.getop():
                return False

        return True

    def match_temp(self, template, vch_in=None):
        l = []
        i = 0

        if vch_in is not None:
            self.vch = vch_in

        self.reset()
        while self.pc < self.pend:
            if i >= len(template):
                return None
            if not self.getop():
                return None

            expected_op = template[i]
            if expected_op == OP_PUBKEYHASH or expected_op == OP_PUBKEY:
                if self.sop.op > OP_PUSHDATA4:
                    return None
                l.append(self.sop.data)

            elif self.sop.op != expected_op:
                return None

            i += 1

        return l

    def match_alltemp(self, vch_in=None):
        for temp in TEMPLATES:
            l = self.match_temp(temp, vch_in)
            if l is not None:
                return l
        return None

    def __repr__(self):
        return "CScript(vchsz %d)" % (len(self.vch),)