add opcode module op.py

op.py

@@ -0,0 +1,168 @@
+"""
+Operation Codes (Opcodes)
+"""
+from helper import hash256, hash160, encode_num, decode_num
+from ecc import S256Point, Signature
+
+def op_dup(stack) -> bool:
+    """
+    Duplicates an element on the stack
+    """
+    if len(stack) < 1:
+        return False
+
+    stack.append(stack[-1])
+    return True
+
+def op_hash256(stack) -> bool:
+    """
+    Performs two rounds of sha256
+    """
+    if len(stack) < 1:
+        return False
+
+    element = stack.pop()
+    stack.append(hash256(element))
+    return True
+
+def op_hash160(stack) -> bool:
+    """
+    Performs SHA256 followed by RIPEMD160
+    """
+    if len(stack) < 1:
+        return False
+
+    element = stack.pop()
+    stack.append(hash160(element))
+    return True
+
+def op_0(stack):
+    """
+    Append 0, i.e. b'', to the stack
+    """
+    stack.append(encode_num(0))
+    return True
+
+def op_checksig(stack, z) -> bool:
+    """
+    Operation Check Signature
+    """
+    if len(stack) < 2:
+        return False
+
+    sec_pubkey = stack.pop()
+    der_signature = stack.pop()[:-1]
+
+    try:
+        point = S256Point.parse(sec_pubkey)
+        sig = Signature.parse(der_signature)
+
+    except (ValueError, SyntaxError) as e:
+        return False
+
+    if point.verify(z, sig):
+        stack.append(encode_num(1))
+    else:
+        stack.append(encode_num(0))
+    return True
+
+
+OP_CODE_FUNCTIONS = {
+    118: op_dup,  # 0x76
+    170: op_hash256, 
+    169: op_hash160,  #0xa9
+}
+
+OP_CODE_NAMES = {
+    0: 'OP_0',
+    76: 'OP_PUSHDATA1',
+    77: 'OP_PUSHDATA2',
+    78: 'OP_PUSHDATA4',
+    79: 'OP_1NEGATE',
+    81: 'OP_1',
+    82: 'OP_2',
+    83: 'OP_3',
+    84: 'OP_4',
+    85: 'OP_5',
+    86: 'OP_6',
+    87: 'OP_7',
+    88: 'OP_8',
+    89: 'OP_9',
+    90: 'OP_10',
+    91: 'OP_11',
+    92: 'OP_12',
+    93: 'OP_13',
+    94: 'OP_14',
+    95: 'OP_15',
+    96: 'OP_16',
+    97: 'OP_NOP',
+    99: 'OP_IF',
+    100: 'OP_NOTIF',
+    103: 'OP_ELSE',
+    104: 'OP_ENDIF',
+    105: 'OP_VERIFY',
+    106: 'OP_RETURN',
+    107: 'OP_TOALTSTACK',
+    108: 'OP_FROMALTSTACK',
+    109: 'OP_2DROP',
+    110: 'OP_2DUP',
+    111: 'OP_3DUP',
+    112: 'OP_2OVER',
+    113: 'OP_2ROT',
+    114: 'OP_2SWAP',
+    115: 'OP_IFDUP',
+    116: 'OP_DEPTH',
+    117: 'OP_DROP',
+    118: 'OP_DUP',
+    119: 'OP_NIP',
+    120: 'OP_OVER',
+    121: 'OP_PICK',
+    122: 'OP_ROLL',
+    123: 'OP_ROT',
+    124: 'OP_SWAP',
+    125: 'OP_TUCK',
+    130: 'OP_SIZE',
+    135: 'OP_EQUAL',
+    136: 'OP_EQUALVERIFY',
+    139: 'OP_1ADD',
+    140: 'OP_1SUB',
+    143: 'OP_NEGATE',
+    144: 'OP_ABS',
+    145: 'OP_NOT',
+    146: 'OP_0NOTEQUAL',
+    147: 'OP_ADD',
+    148: 'OP_SUB',
+    149: 'OP_MUL',
+    154: 'OP_BOOLAND',
+    155: 'OP_BOOLOR',
+    156: 'OP_NUMEQUAL',
+    157: 'OP_NUMEQUALVERIFY',
+    158: 'OP_NUMNOTEQUAL',
+    159: 'OP_LESSTHAN',
+    160: 'OP_GREATERTHAN',
+    161: 'OP_LESSTHANOREQUAL',
+    162: 'OP_GREATERTHANOREQUAL',
+    163: 'OP_MIN',
+    164: 'OP_MAX',
+    165: 'OP_WITHIN',
+    166: 'OP_RIPEMD160',
+    167: 'OP_SHA1',
+    168: 'OP_SHA256',
+    169: 'OP_HASH160',
+    170: 'OP_HASH256',
+    171: 'OP_CODESEPARATOR',
+    172: 'OP_CHECKSIG',
+    173: 'OP_CHECKSIGVERIFY',
+    174: 'OP_CHECKMULTISIG',
+    175: 'OP_CHECKMULTISIGVERIFY',
+    176: 'OP_NOP1',
+    177: 'OP_CHECKLOCKTIMEVERIFY',
+    178: 'OP_CHECKSEQUENCEVERIFY',
+    179: 'OP_NOP4',
+    180: 'OP_NOP5',
+    181: 'OP_NOP6',
+    182: 'OP_NOP7',
+    183: 'OP_NOP8',
+    184: 'OP_NOP9',
+    185: 'OP_NOP10',
+}