// Copyright (c) 2013 Conformal Systems LLC. // Use of this source code is governed by an ISC // license that can be found in the LICENSE file. package btcscript import ( "bytes" "code.google.com/p/go.crypto/ripemd160" "crypto/ecdsa" "crypto/sha1" "crypto/sha256" "fmt" "github.com/conformal/btcec" "github.com/conformal/btcwire" "github.com/davecgh/go-spew/spew" "hash" "math/big" ) // An opcode defines the information related to a btcscript opcode. // opfunc if present is the function to call to perform the opcode on // the script. The current script is passed in as a slice with the firs // member being the opcode itself. type opcode struct { value byte name string length int opfunc func(*parsedOpcode, *Script) error parsefunc func(*opcode, *Script, []byte) error } // These constants are the values of the official opcode used on the btc wiki, // in bitcoind and in most if not all other references and software related to // handling BTC scripts. const ( OP_FALSE byte = 0 // AKA OP_0 OP_0 = 0 OP_DATA_1 = 1 OP_DATA_2 = 2 OP_DATA_3 = 3 OP_DATA_4 = 4 OP_DATA_5 = 5 OP_DATA_6 = 6 OP_DATA_7 = 7 OP_DATA_8 = 8 OP_DATA_9 = 9 OP_DATA_10 = 10 OP_DATA_11 = 11 OP_DATA_12 = 12 OP_DATA_13 = 13 OP_DATA_14 = 14 OP_DATA_15 = 15 OP_DATA_16 = 16 OP_DATA_17 = 17 OP_DATA_18 = 18 OP_DATA_19 = 19 OP_DATA_20 = 20 OP_DATA_21 = 21 OP_DATA_22 = 22 OP_DATA_23 = 23 OP_DATA_24 = 24 OP_DATA_25 = 25 OP_DATA_26 = 26 OP_DATA_27 = 27 OP_DATA_28 = 28 OP_DATA_29 = 29 OP_DATA_30 = 30 OP_DATA_31 = 31 OP_DATA_32 = 32 OP_DATA_33 = 33 OP_DATA_34 = 34 OP_DATA_35 = 35 OP_DATA_36 = 36 OP_DATA_37 = 37 OP_DATA_38 = 38 OP_DATA_39 = 39 OP_DATA_40 = 40 OP_DATA_41 = 41 OP_DATA_42 = 42 OP_DATA_43 = 43 OP_DATA_44 = 44 OP_DATA_45 = 45 OP_DATA_46 = 46 OP_DATA_47 = 47 OP_DATA_48 = 48 OP_DATA_49 = 49 OP_DATA_50 = 50 OP_DATA_51 = 51 OP_DATA_52 = 52 OP_DATA_53 = 53 OP_DATA_54 = 54 OP_DATA_55 = 55 OP_DATA_56 = 56 OP_DATA_57 = 57 OP_DATA_58 = 58 OP_DATA_59 = 59 OP_DATA_60 = 60 OP_DATA_61 = 61 OP_DATA_62 = 62 OP_DATA_63 = 63 OP_DATA_64 = 64 OP_DATA_65 = 65 OP_DATA_66 = 66 OP_DATA_67 = 67 OP_DATA_68 = 68 OP_DATA_69 = 69 OP_DATA_70 = 70 OP_DATA_71 = 71 OP_DATA_72 = 72 OP_DATA_73 = 73 OP_DATA_74 = 74 OP_DATA_75 = 75 OP_PUSHDATA1 = 76 OP_PUSHDATA2 = 77 OP_PUSHDATA4 = 78 OP_1NEGATE = 79 OP_RESERVED = 80 OP_1 = 81 // AKA OP_TRUE OP_TRUE = 81 OP_2 = 82 OP_3 = 83 OP_4 = 84 OP_5 = 85 OP_6 = 86 OP_7 = 87 OP_8 = 88 OP_9 = 89 OP_10 = 90 OP_11 = 91 OP_12 = 92 OP_13 = 93 OP_14 = 94 OP_15 = 95 OP_16 = 96 OP_NOP = 97 OP_VER = 98 OP_IF = 99 OP_NOTIF = 100 OP_VERIF = 101 OP_VERNOTIF = 102 OP_ELSE = 103 OP_ENDIF = 104 OP_VERIFY = 105 OP_RETURN = 106 OP_TOALTSTACK = 107 OP_FROMALTSTACK = 108 OP_2DROP = 109 OP_2DUP = 110 OP_3DUP = 111 OP_2OVER = 112 OP_2ROT = 113 OP_2SWAP = 114 OP_IFDUP = 115 OP_DEPTH = 116 OP_DROP = 117 OP_DUP = 118 OP_NIP = 119 OP_OVER = 120 OP_PICK = 121 OP_ROLL = 122 OP_ROT = 123 OP_SWAP = 124 OP_TUCK = 125 OP_CAT = 126 OP_SUBSTR = 127 OP_LEFT = 128 OP_RIGHT = 129 OP_SIZE = 130 OP_INVERT = 131 OP_AND = 132 OP_OR = 133 OP_XOR = 134 OP_EQUAL = 135 OP_EQUALVERIFY = 136 OP_RESERVED1 = 137 OP_RESERVED2 = 138 OP_1ADD = 139 OP_1SUB = 140 OP_2MUL = 141 OP_2DIV = 142 OP_NEGATE = 143 OP_ABS = 144 OP_NOT = 145 OP_0NOTEQUAL = 146 OP_ADD = 147 OP_SUB = 148 OP_MUL = 149 OP_DIV = 150 OP_MOD = 151 OP_LSHIFT = 152 OP_RSHIFT = 153 OP_BOOLAND = 154 OP_BOOLOR = 155 OP_NUMEQUAL = 156 OP_NUMEQUALVERIFY = 157 OP_NUMNOTEQUAL = 158 OP_LESSTHAN = 159 OP_GREATERTHAN = 160 OP_LESSTHANOREQUAL = 161 OP_GREATERTHANOREQUAL = 162 OP_MIN = 163 OP_MAX = 164 OP_WITHIN = 165 OP_RIPEMD160 = 166 OP_SHA1 = 167 OP_SHA256 = 168 OP_HASH160 = 169 OP_HASH256 = 170 OP_CODESEPARATOR = 171 OP_CHECKSIG = 172 OP_CHECKSIGVERIFY = 173 OP_CHECK_MULTISIG = 174 OP_CHECKMULTISIGVERIFY = 175 OP_NOP1 = 176 OP_NOP2 = 177 OP_NOP3 = 178 OP_NOP4 = 179 OP_NOP5 = 180 OP_NOP6 = 181 OP_NOP7 = 182 OP_NOP8 = 183 OP_NOP9 = 184 OP_NOP10 = 185 OP_PUBKEYHASH = 253 // bitcoind internal, for completeness OP_PUBKEY = 254 // bitcoind internal, for completeness OP_INVALIDOPCODE = 255 // bitcoind internal, for completeness ) // conditional execution constants const ( OpCondFalse = 0 OpCondTrue = 1 OpCondSkip = 2 ) // Some of the functions in opcodemap call things that themselves then will // reference the opcodemap to make decisions (things like op_checksig which // needs to parse scripts to remove opcodes, for example). // The go compiler is very conservative in this matter and will think there // is an initialisation loop. In order to work around this we have the fake // ``prevariable'' opcodemapPreinit and then set the real variable to the // preinit in init() var opcodemap map[byte]*opcode func init() { opcodemap = opcodemapPreinit } var opcodemapPreinit = map[byte]*opcode{ OP_FALSE: {value: OP_FALSE, name: "OP_0", length: 1, opfunc: opcodeFalse}, OP_DATA_1: {value: OP_DATA_1, name: "OP_DATA_1", length: 2, opfunc: opcodePushData}, OP_DATA_2: {value: OP_DATA_2, name: "OP_DATA_2", length: 3, opfunc: opcodePushData}, OP_DATA_3: {value: OP_DATA_3, name: "OP_DATA_3", length: 4, opfunc: opcodePushData}, OP_DATA_4: {value: OP_DATA_4, name: "OP_DATA_4", length: 5, opfunc: opcodePushData}, OP_DATA_5: {value: OP_DATA_5, name: "OP_DATA_5", length: 6, opfunc: opcodePushData}, OP_DATA_6: {value: OP_DATA_6, name: "OP_DATA_6", length: 7, opfunc: opcodePushData}, OP_DATA_7: {value: OP_DATA_7, name: "OP_DATA_7", length: 8, opfunc: opcodePushData}, OP_DATA_8: {value: OP_DATA_8, name: "OP_DATA_8", length: 9, opfunc: opcodePushData}, OP_DATA_9: {value: OP_DATA_9, name: "OP_DATA_9", length: 10, opfunc: opcodePushData}, OP_DATA_10: {value: OP_DATA_10, name: "OP_DATA_10", length: 11, opfunc: opcodePushData}, OP_DATA_11: {value: OP_DATA_11, name: "OP_DATA_11", length: 12, opfunc: opcodePushData}, OP_DATA_12: {value: OP_DATA_12, name: "OP_DATA_12", length: 13, opfunc: opcodePushData}, OP_DATA_13: {value: OP_DATA_13, name: "OP_DATA_13", length: 14, opfunc: opcodePushData}, OP_DATA_14: {value: OP_DATA_14, name: "OP_DATA_14", length: 15, opfunc: opcodePushData}, OP_DATA_15: {value: OP_DATA_15, name: "OP_DATA_15", length: 16, opfunc: opcodePushData}, OP_DATA_16: {value: OP_DATA_16, name: "OP_DATA_16", length: 17, opfunc: opcodePushData}, OP_DATA_17: {value: OP_DATA_17, name: "OP_DATA_17", length: 18, opfunc: opcodePushData}, OP_DATA_18: {value: OP_DATA_18, name: "OP_DATA_18", length: 19, opfunc: opcodePushData}, OP_DATA_19: {value: OP_DATA_19, name: "OP_DATA_19", length: 20, opfunc: opcodePushData}, OP_DATA_20: {value: OP_DATA_20, name: "OP_DATA_20", length: 21, opfunc: opcodePushData}, OP_DATA_21: {value: OP_DATA_21, name: "OP_DATA_21", length: 22, opfunc: opcodePushData}, OP_DATA_22: {value: OP_DATA_22, name: "OP_DATA_22", length: 23, opfunc: opcodePushData}, OP_DATA_23: {value: OP_DATA_23, name: "OP_DATA_23", length: 24, opfunc: opcodePushData}, OP_DATA_24: {value: OP_DATA_24, name: "OP_DATA_24", length: 25, opfunc: opcodePushData}, OP_DATA_25: {value: OP_DATA_25, name: "OP_DATA_25", length: 26, opfunc: opcodePushData}, OP_DATA_26: {value: OP_DATA_26, name: "OP_DATA_26", length: 27, opfunc: opcodePushData}, OP_DATA_27: {value: OP_DATA_27, name: "OP_DATA_27", length: 28, opfunc: opcodePushData}, OP_DATA_28: {value: OP_DATA_28, name: "OP_DATA_28", length: 29, opfunc: opcodePushData}, OP_DATA_29: {value: OP_DATA_29, name: "OP_DATA_29", length: 30, opfunc: opcodePushData}, OP_DATA_30: {value: OP_DATA_30, name: "OP_DATA_30", length: 31, opfunc: opcodePushData}, OP_DATA_31: {value: OP_DATA_31, name: "OP_DATA_31", length: 32, opfunc: opcodePushData}, OP_DATA_32: {value: OP_DATA_32, name: "OP_DATA_32", length: 33, opfunc: opcodePushData}, OP_DATA_33: {value: OP_DATA_33, name: "OP_DATA_33", length: 34, opfunc: opcodePushData}, OP_DATA_34: {value: OP_DATA_34, name: "OP_DATA_34", length: 35, opfunc: opcodePushData}, OP_DATA_35: {value: OP_DATA_35, name: "OP_DATA_35", length: 36, opfunc: opcodePushData}, OP_DATA_36: {value: OP_DATA_36, name: "OP_DATA_36", length: 37, opfunc: opcodePushData}, OP_DATA_37: {value: OP_DATA_37, name: "OP_DATA_37", length: 38, opfunc: opcodePushData}, OP_DATA_38: {value: OP_DATA_38, name: "OP_DATA_38", length: 39, opfunc: opcodePushData}, OP_DATA_39: {value: OP_DATA_39, name: "OP_DATA_39", length: 40, opfunc: opcodePushData}, OP_DATA_40: {value: OP_DATA_40, name: "OP_DATA_40", length: 41, opfunc: opcodePushData}, OP_DATA_41: {value: OP_DATA_41, name: "OP_DATA_41", length: 42, opfunc: opcodePushData}, OP_DATA_42: {value: OP_DATA_42, name: "OP_DATA_42", length: 43, opfunc: opcodePushData}, OP_DATA_43: {value: OP_DATA_43, name: "OP_DATA_43", length: 44, opfunc: opcodePushData}, OP_DATA_44: {value: OP_DATA_44, name: "OP_DATA_44", length: 45, opfunc: opcodePushData}, OP_DATA_45: {value: OP_DATA_45, name: "OP_DATA_45", length: 46, opfunc: opcodePushData}, OP_DATA_46: {value: OP_DATA_46, name: "OP_DATA_46", length: 47, opfunc: opcodePushData}, OP_DATA_47: {value: OP_DATA_47, name: "OP_DATA_47", length: 48, opfunc: opcodePushData}, OP_DATA_48: {value: OP_DATA_48, name: "OP_DATA_48", length: 49, opfunc: opcodePushData}, OP_DATA_49: {value: OP_DATA_49, name: "OP_DATA_49", length: 50, opfunc: opcodePushData}, OP_DATA_50: {value: OP_DATA_50, name: "OP_DATA_50", length: 51, opfunc: opcodePushData}, OP_DATA_51: {value: OP_DATA_51, name: "OP_DATA_51", length: 52, opfunc: opcodePushData}, OP_DATA_52: {value: OP_DATA_52, name: "OP_DATA_52", length: 53, opfunc: opcodePushData}, OP_DATA_53: {value: OP_DATA_53, name: "OP_DATA_53", length: 54, opfunc: opcodePushData}, OP_DATA_54: {value: OP_DATA_54, name: "OP_DATA_54", length: 55, opfunc: opcodePushData}, OP_DATA_55: {value: OP_DATA_55, name: "OP_DATA_55", length: 56, opfunc: opcodePushData}, OP_DATA_56: {value: OP_DATA_56, name: "OP_DATA_56", length: 57, opfunc: opcodePushData}, OP_DATA_57: {value: OP_DATA_57, name: "OP_DATA_57", length: 58, opfunc: opcodePushData}, OP_DATA_58: {value: OP_DATA_58, name: "OP_DATA_58", length: 59, opfunc: opcodePushData}, OP_DATA_59: {value: OP_DATA_59, name: "OP_DATA_59", length: 60, opfunc: opcodePushData}, OP_DATA_60: {value: OP_DATA_60, name: "OP_DATA_60", length: 61, opfunc: opcodePushData}, OP_DATA_61: {value: OP_DATA_61, name: "OP_DATA_61", length: 62, opfunc: opcodePushData}, OP_DATA_62: {value: OP_DATA_62, name: "OP_DATA_62", length: 63, opfunc: opcodePushData}, OP_DATA_63: {value: OP_DATA_63, name: "OP_DATA_63", length: 64, opfunc: opcodePushData}, OP_DATA_64: {value: OP_DATA_64, name: "OP_DATA_64", length: 65, opfunc: opcodePushData}, OP_DATA_65: {value: OP_DATA_65, name: "OP_DATA_65", length: 66, opfunc: opcodePushData}, OP_DATA_66: {value: OP_DATA_66, name: "OP_DATA_66", length: 67, opfunc: opcodePushData}, OP_DATA_67: {value: OP_DATA_67, name: "OP_DATA_67", length: 68, opfunc: opcodePushData}, OP_DATA_68: {value: OP_DATA_68, name: "OP_DATA_68", length: 69, opfunc: opcodePushData}, OP_DATA_69: {value: OP_DATA_69, name: "OP_DATA_69", length: 70, opfunc: opcodePushData}, OP_DATA_70: {value: OP_DATA_70, name: "OP_DATA_70", length: 71, opfunc: opcodePushData}, OP_DATA_71: {value: OP_DATA_71, name: "OP_DATA_71", length: 72, opfunc: opcodePushData}, OP_DATA_72: {value: OP_DATA_72, name: "OP_DATA_72", length: 73, opfunc: opcodePushData}, OP_DATA_73: {value: OP_DATA_73, name: "OP_DATA_73", length: 74, opfunc: opcodePushData}, OP_DATA_74: {value: OP_DATA_74, name: "OP_DATA_74", length: 75, opfunc: opcodePushData}, OP_DATA_75: {value: OP_DATA_75, name: "OP_DATA_75", length: 76, opfunc: opcodePushData}, OP_PUSHDATA1: {value: OP_PUSHDATA1, name: "OP_PUSHDATA1", length: -1, opfunc: opcodePushData}, OP_PUSHDATA2: {value: OP_PUSHDATA2, name: "OP_PUSHDATA2", length: -2, opfunc: opcodePushData}, OP_PUSHDATA4: {value: OP_PUSHDATA4, name: "OP_PUSHDATA4", length: -4, opfunc: opcodePushData}, OP_1NEGATE: {value: OP_1NEGATE, name: "OP_1NEGATE", length: 1, opfunc: opcode1Negate}, OP_RESERVED: {value: OP_RESERVED, name: "OP_RESERVED", length: 1, opfunc: opcodeReserved}, OP_TRUE: {value: OP_TRUE, name: "OP_1", length: 1, opfunc: opcodeN}, OP_2: {value: OP_2, name: "OP_2", length: 1, opfunc: opcodeN}, OP_3: {value: OP_3, name: "OP_3", length: 1, opfunc: opcodeN}, OP_4: {value: OP_4, name: "OP_4", length: 1, opfunc: opcodeN}, OP_5: {value: OP_5, name: "OP_5", length: 1, opfunc: opcodeN}, OP_6: {value: OP_6, name: "OP_6", length: 1, opfunc: opcodeN}, OP_7: {value: OP_7, name: "OP_7", length: 1, opfunc: opcodeN}, OP_8: {value: OP_8, name: "OP_8", length: 1, opfunc: opcodeN}, OP_9: {value: OP_9, name: "OP_9", length: 1, opfunc: opcodeN}, OP_10: {value: OP_10, name: "OP_10", length: 1, opfunc: opcodeN}, OP_11: {value: OP_11, name: "OP_11", length: 1, opfunc: opcodeN}, OP_12: {value: OP_12, name: "OP_12", length: 1, opfunc: opcodeN}, OP_13: {value: OP_13, name: "OP_13", length: 1, opfunc: opcodeN}, OP_14: {value: OP_14, name: "OP_14", length: 1, opfunc: opcodeN}, OP_15: {value: OP_15, name: "OP_15", length: 1, opfunc: opcodeN}, OP_16: {value: OP_16, name: "OP_16", length: 1, opfunc: opcodeN}, OP_NOP: {value: OP_NOP, name: "OP_NOP", length: 1, opfunc: opcodeNop}, OP_VER: {value: OP_VER, name: "OP_VER", length: 1, opfunc: opcodeReserved}, OP_IF: {value: OP_IF, name: "OP_IF", length: 1, opfunc: opcodeIf}, OP_NOTIF: {value: OP_NOTIF, name: "OP_NOTIF", length: 1, opfunc: opcodeNotIf}, OP_VERIF: {value: OP_VERIF, name: "OP_VERIF", length: 1, opfunc: opcodeReserved}, OP_VERNOTIF: {value: OP_VERNOTIF, name: "OP_VERNOTIF", length: 1, opfunc: opcodeReserved}, OP_ELSE: {value: OP_ELSE, name: "OP_ELSE", length: 1, opfunc: opcodeElse}, OP_ENDIF: {value: OP_ENDIF, name: "OP_ENDIF", length: 1, opfunc: opcodeEndif}, OP_VERIFY: {value: OP_VERIFY, name: "OP_VERIFY", length: 1, opfunc: opcodeVerify}, OP_RETURN: {value: OP_RETURN, name: "OP_RETURN", length: 1, opfunc: opcodeReturn}, OP_TOALTSTACK: {value: OP_TOALTSTACK, name: "OP_TOALTSTACK", length: 1, opfunc: opcodeToAltStack}, OP_FROMALTSTACK: {value: OP_FROMALTSTACK, name: "OP_FROMALTSTACK", length: 1, opfunc: opcodeFromAltStack}, OP_2DROP: {value: OP_2DROP, name: "OP_2DROP", length: 1, opfunc: opcode2Drop}, OP_2DUP: {value: OP_2DUP, name: "OP_2DUP", length: 1, opfunc: opcode2Dup}, OP_3DUP: {value: OP_3DUP, name: "OP_3DUP", length: 1, opfunc: opcode3Dup}, OP_2OVER: {value: OP_2OVER, name: "OP_2OVER", length: 1, opfunc: opcode2Over}, OP_2ROT: {value: OP_2ROT, name: "OP_2ROT", length: 1, opfunc: opcode2Rot}, OP_2SWAP: {value: OP_2SWAP, name: "OP_2SWAP", length: 1, opfunc: opcode2Swap}, OP_IFDUP: {value: OP_IFDUP, name: "OP_IFDUP", length: 1, opfunc: opcodeIfDup}, OP_DEPTH: {value: OP_DEPTH, name: "OP_DEPTH", length: 1, opfunc: opcodeDepth}, OP_DROP: {value: OP_DROP, name: "OP_DROP", length: 1, opfunc: opcodeDrop}, OP_DUP: {value: OP_DUP, name: "OP_DUP", length: 1, opfunc: opcodeDup}, OP_NIP: {value: OP_NIP, name: "OP_NIP", length: 1, opfunc: opcodeNip}, OP_OVER: {value: OP_OVER, name: "OP_OVER", length: 1, opfunc: opcodeOver}, OP_PICK: {value: OP_PICK, name: "OP_PICK", length: 1, opfunc: opcodePick}, OP_ROLL: {value: OP_ROLL, name: "OP_ROLL", length: 1, opfunc: opcodeRoll}, OP_ROT: {value: OP_ROT, name: "OP_ROT", length: 1, opfunc: opcodeRot}, OP_SWAP: {value: OP_SWAP, name: "OP_SWAP", length: 1, opfunc: opcodeSwap}, OP_TUCK: {value: OP_TUCK, name: "OP_TUCK", length: 1, opfunc: opcodeTuck}, OP_CAT: {value: OP_CAT, name: "OP_CAT", length: 1, opfunc: opcodeDisabled}, OP_SUBSTR: {value: OP_SUBSTR, name: "OP_SUBSTR", length: 1, opfunc: opcodeDisabled}, OP_LEFT: {value: OP_LEFT, name: "OP_LEFT", length: 1, opfunc: opcodeDisabled}, OP_RIGHT: {value: OP_RIGHT, name: "OP_RIGHT", length: 1, opfunc: opcodeDisabled}, OP_SIZE: {value: OP_SIZE, name: "OP_SIZE", length: 1, opfunc: opcodeSize}, OP_INVERT: {value: OP_INVERT, name: "OP_INVERT", length: 1, opfunc: opcodeDisabled}, OP_AND: {value: OP_AND, name: "OP_AND", length: 1, opfunc: opcodeDisabled}, OP_OR: {value: OP_OR, name: "OP_OR", length: 1, opfunc: opcodeDisabled}, OP_XOR: {value: OP_XOR, name: "OP_XOR", length: 1, opfunc: opcodeDisabled}, OP_EQUAL: {value: OP_EQUAL, name: "OP_EQUAL", length: 1, opfunc: opcodeEqual}, OP_EQUALVERIFY: {value: OP_EQUALVERIFY, name: "OP_EQUALVERIFY", length: 1, opfunc: opcodeEqualVerify}, OP_RESERVED1: {value: OP_RESERVED1, name: "OP_RESERVED1", length: 1, opfunc: opcodeReserved}, OP_RESERVED2: {value: OP_RESERVED2, name: "OP_RESERVED2", length: 1, opfunc: opcodeReserved}, OP_1ADD: {value: OP_1ADD, name: "OP_1ADD", length: 1, opfunc: opcode1Add}, OP_1SUB: {value: OP_1SUB, name: "OP_1SUB", length: 1, opfunc: opcode1Sub}, OP_2MUL: {value: OP_2MUL, name: "OP_2MUL", length: 1, opfunc: opcodeDisabled}, OP_2DIV: {value: OP_2DIV, name: "OP_2DIV", length: 1, opfunc: opcodeDisabled}, OP_NEGATE: {value: OP_NEGATE, name: "OP_NEGATE", length: 1, opfunc: opcodeNegate}, OP_ABS: {value: OP_ABS, name: "OP_ABS", length: 1, opfunc: opcodeAbs}, OP_NOT: {value: OP_NOT, name: "OP_NOT", length: 1, opfunc: opcodeNot}, OP_0NOTEQUAL: {value: OP_0NOTEQUAL, name: "OP_0NOTEQUAL", length: 1, opfunc: opcode0NotEqual}, OP_ADD: {value: OP_ADD, name: "OP_ADD", length: 1, opfunc: opcodeAdd}, OP_SUB: {value: OP_SUB, name: "OP_SUB", length: 1, opfunc: opcodeSub}, OP_MUL: {value: OP_MUL, name: "OP_MUL", length: 1, opfunc: opcodeDisabled}, OP_DIV: {value: OP_DIV, name: "OP_DIV", length: 1, opfunc: opcodeDisabled}, OP_MOD: {value: OP_MOD, name: "OP_MOD", length: 1, opfunc: opcodeDisabled}, OP_LSHIFT: {value: OP_LSHIFT, name: "OP_LSHIFT", length: 1, opfunc: opcodeDisabled}, OP_RSHIFT: {value: OP_RSHIFT, name: "OP_RSHIFT", length: 1, opfunc: opcodeDisabled}, OP_BOOLAND: {value: OP_BOOLAND, name: "OP_BOOLAND", length: 1, opfunc: opcodeBoolAnd}, OP_BOOLOR: {value: OP_BOOLOR, name: "OP_BOOLOR", length: 1, opfunc: opcodeBoolOr}, OP_NUMEQUAL: {value: OP_NUMEQUAL, name: "OP_NUMEQUAL", length: 1, opfunc: opcodeNumEqual}, OP_NUMEQUALVERIFY: {value: OP_NUMEQUALVERIFY, name: "OP_NUMEQUALVERIFY", length: 1, opfunc: opcodeNumEqualVerify}, OP_NUMNOTEQUAL: {value: OP_NUMNOTEQUAL, name: "OP_NUMNOTEQUAL", length: 1, opfunc: opcodeNumNotEqual}, OP_LESSTHAN: {value: OP_LESSTHAN, name: "OP_LESSTHAN", length: 1, opfunc: opcodeLessThan}, OP_GREATERTHAN: {value: OP_GREATERTHAN, name: "OP_GREATERTHAN", length: 1, opfunc: opcodeGreaterThan}, OP_LESSTHANOREQUAL: {value: OP_LESSTHANOREQUAL, name: "OP_LESSTHANOREQUAL", length: 1, opfunc: opcodeLessThanOrEqual}, OP_GREATERTHANOREQUAL: {value: OP_GREATERTHANOREQUAL, name: "OP_GREATERTHANOREQUAL", length: 1, opfunc: opcodeGreaterThanOrEqual}, OP_MIN: {value: OP_MIN, name: "OP_MIN", length: 1, opfunc: opcodeMin}, OP_MAX: {value: OP_MAX, name: "OP_MAX", length: 1, opfunc: opcodeMax}, OP_WITHIN: {value: OP_WITHIN, name: "OP_WITHIN", length: 1, opfunc: opcodeWithin}, OP_RIPEMD160: {value: OP_RIPEMD160, name: "OP_RIPEMD160", length: 1, opfunc: opcodeRipemd160}, OP_SHA1: {value: OP_SHA1, name: "OP_SHA1", length: 1, opfunc: opcodeSha1}, OP_SHA256: {value: OP_SHA256, name: "OP_SHA256", length: 1, opfunc: opcodeSha256}, OP_HASH160: {value: OP_HASH160, name: "OP_HASH160", length: 1, opfunc: opcodeHash160}, OP_HASH256: {value: OP_HASH256, name: "OP_HASH256", length: 1, opfunc: opcodeHash256}, OP_CODESEPARATOR: {value: OP_CODESEPARATOR, name: "OP_CODESEPARATOR", length: 1, opfunc: opcodeCodeSeparator}, OP_CHECKSIG: {value: OP_CHECKSIG, name: "OP_CHECKSIG", length: 1, opfunc: opcodeCheckSig}, OP_CHECKSIGVERIFY: {value: OP_CHECKSIGVERIFY, name: "OP_CHECKSIGVERIFY", length: 1, opfunc: opcodeCheckSigVerify}, OP_CHECK_MULTISIG: {value: OP_CHECK_MULTISIG, name: "OP_CHECK_MULTISIG", length: 1, opfunc: opcodeCheckMultiSig}, OP_CHECKMULTISIGVERIFY: {value: OP_CHECKMULTISIGVERIFY, name: "OP_CHECKMULTISIGVERIFY", length: 1, opfunc: opcodeCheckMultiSigVerify}, OP_NOP1: {value: OP_NOP1, name: "OP_NOP1", length: 1, opfunc: opcodeNop}, OP_NOP2: {value: OP_NOP2, name: "OP_NOP2", length: 1, opfunc: opcodeNop}, OP_NOP3: {value: OP_NOP3, name: "OP_NOP3", length: 1, opfunc: opcodeNop}, OP_NOP4: {value: OP_NOP4, name: "OP_NOP4", length: 1, opfunc: opcodeNop}, OP_NOP5: {value: OP_NOP5, name: "OP_NOP5", length: 1, opfunc: opcodeNop}, OP_NOP6: {value: OP_NOP6, name: "OP_NOP6", length: 1, opfunc: opcodeNop}, OP_NOP7: {value: OP_NOP7, name: "OP_NOP7", length: 1, opfunc: opcodeNop}, OP_NOP8: {value: OP_NOP8, name: "OP_NOP8", length: 1, opfunc: opcodeNop}, OP_NOP9: {value: OP_NOP9, name: "OP_NOP9", length: 1, opfunc: opcodeNop}, OP_NOP10: {value: OP_NOP10, name: "OP_NOP10", length: 1, opfunc: opcodeNop}, OP_PUBKEYHASH: {value: OP_PUBKEYHASH, name: "OP_PUBKEYHASH", length: 1, opfunc: opcodeInvalid}, OP_PUBKEY: {value: OP_PUBKEY, name: "OP_PUBKEY", length: 1, opfunc: opcodeInvalid}, OP_INVALIDOPCODE: {value: OP_INVALIDOPCODE, name: "OP_INVALIDOPCODE", length: 1, opfunc: opcodeInvalid}, } type parsedOpcode struct { opcode *opcode data []byte opfunc func(op parsedOpcode, s Script) error } func (pop *parsedOpcode) conditional() bool { switch pop.opcode.value { case OP_IF: return true case OP_NOTIF: return true case OP_ELSE: return true case OP_ENDIF: return true default: return false } } func (pop *parsedOpcode) exec(s *Script) error { // *sigh* bitcoind pretty much mandates that we violate layering here. // Any opcode that isn't just adding data to the stack counts here // as an operation. if pop.opcode.value > OP_16 { s.numOps++ if s.numOps > MaxOpsPerScript { return StackErrTooManyOperations } } return pop.opcode.opfunc(pop, s) } func (pop *parsedOpcode) print(oneline bool) string { retString := pop.opcode.name if pop.opcode.length == 1 { return retString } if oneline { retString = "" } if !oneline && pop.opcode.length < 0 { //add length to the end of retString retString += fmt.Sprintf(" 0x%0*x", 2*-pop.opcode.length, len(pop.data)) } for _, val := range pop.data { if !oneline { retString += " " } retString += fmt.Sprintf("%02x", val) } return retString } func (pop *parsedOpcode) bytes() []byte { retbytes := []byte{pop.opcode.value} if pop.opcode.length == 1 { return retbytes } if pop.opcode.length < 0 { l := len(pop.data) // tempting just to hardcode to avoid the complexity here. switch pop.opcode.length { case -1: retbytes = append(retbytes, byte(l)) case -2: retbytes = append(retbytes, byte(l&0xff), byte(l>>8&0xff)) case -4: retbytes = append(retbytes, byte(l&0xff), byte((l>>8)&0xff), byte((l>>16)&0xff), byte((l>>24)&0xff)) } } for i := range pop.data { retbytes = append(retbytes, pop.data[i]) } return retbytes } // opcode implementation functions from here func opcodeDisabled(op *parsedOpcode, s *Script) error { return StackErrOpDisabled } func opcodeReserved(op *parsedOpcode, s *Script) error { return StackErrReservedOpcode } // Recognised opcode, but for bitcoind internal use only. func opcodeInvalid(op *parsedOpcode, s *Script) error { return StackErrInvalidOpcode } func opcodeFalse(op *parsedOpcode, s *Script) error { s.dstack.PushByteArray([]byte("")) return nil } func opcodePushData(op *parsedOpcode, s *Script) error { s.dstack.PushByteArray(op.data) return nil } func opcode1Negate(op *parsedOpcode, s *Script) error { s.dstack.PushInt(big.NewInt(-1)) return nil } func opcodeN(op *parsedOpcode, s *Script) error { // 16 consecutive opcodes add increasing numbers to the stack. s.dstack.PushInt(big.NewInt(int64(op.opcode.value - (OP_1 - 1)))) return nil } func opcodeNop(op *parsedOpcode, s *Script) error { // This page left intentionally blank return nil } // opcodeIf computes true/false based on the value on the stack and pushes // the condition on the condStack (conditional execution stack) func opcodeIf(op *parsedOpcode, s *Script) error { // opcodeIf will be executed even if it is on the non-execute side // of the conditional, this is so proper nesting is maintained var condval int if s.condStack[0] == OpCondTrue { ok, err := s.dstack.PopBool() if err != nil { return err } if ok { condval = OpCondTrue } } else { condval = OpCondSkip } cond := []int{condval} // push condition to the 'head' of the slice s.condStack = append(cond, s.condStack...) // TODO(drahn) check if a maximum condtitional stack limit exists return nil } // opcodeNotIf computes true/false based on the value on the stack and pushes // the (inverted) condition on the condStack (conditional execution stack) func opcodeNotIf(op *parsedOpcode, s *Script) error { // opcodeIf will be executed even if it is on the non-execute side // of the conditional, this is so proper nesting is maintained var condval int if s.condStack[0] == OpCondTrue { ok, err := s.dstack.PopBool() if err != nil { return err } if !ok { condval = OpCondTrue } } else { condval = OpCondSkip } cond := []int{condval} // push condition to the 'head' of the slice s.condStack = append(cond, s.condStack...) // TODO(drahn) check if a maximum condtitional stack limit exists return nil } // opcodeElse inverts conditional execution for other half of if/else/endif func opcodeElse(op *parsedOpcode, s *Script) error { if len(s.condStack) < 2 { // intial true cannot be toggled, only pushed conditionals return StackErrNoIf } switch s.condStack[0] { case OpCondTrue: s.condStack[0] = OpCondFalse case OpCondFalse: s.condStack[0] = OpCondTrue case OpCondSkip: // value doesn't change in skip } return nil } // opcodeEndif terminates a conditional block, removing the value from the // conditional execution stack. func opcodeEndif(op *parsedOpcode, s *Script) error { if len(s.condStack) < 2 { // intial true cannot be popped, only pushed conditionals return StackErrNoIf } s.condStack = s.condStack[1:] return nil } func opcodeVerify(op *parsedOpcode, s *Script) error { verified, err := s.dstack.PopBool() if err != nil { return err } if verified != true { return StackErrVerifyFailed } return nil } func opcodeReturn(op *parsedOpcode, s *Script) error { return StackErrEarlyReturn } func opcodeToAltStack(op *parsedOpcode, s *Script) error { so, err := s.dstack.PopByteArray() if err != nil { return err } s.astack.PushByteArray(so) return nil } func opcodeFromAltStack(op *parsedOpcode, s *Script) error { so, err := s.astack.PopByteArray() if err != nil { return err } s.dstack.PushByteArray(so) return nil } func opcode2Drop(op *parsedOpcode, s *Script) error { return s.dstack.DropN(2) } func opcode2Dup(op *parsedOpcode, s *Script) error { return s.dstack.DupN(2) } func opcode3Dup(op *parsedOpcode, s *Script) error { return s.dstack.DupN(3) } func opcode2Over(op *parsedOpcode, s *Script) error { return s.dstack.OverN(2) } func opcode2Rot(op *parsedOpcode, s *Script) error { return s.dstack.RotN(2) } func opcode2Swap(op *parsedOpcode, s *Script) error { return s.dstack.SwapN(2) } func opcodeIfDup(op *parsedOpcode, s *Script) error { val, err := s.dstack.PeekInt(0) if err != nil { return err } // Push copy of data iff it isn't zero if val.Sign() != 0 { s.dstack.PushInt(val) } return nil } func opcodeDepth(op *parsedOpcode, s *Script) error { s.dstack.PushInt(big.NewInt(int64(s.dstack.Depth()))) return nil } func opcodeDrop(op *parsedOpcode, s *Script) error { return s.dstack.DropN(1) } func opcodeDup(op *parsedOpcode, s *Script) error { return s.dstack.DupN(1) } func opcodeNip(op *parsedOpcode, s *Script) error { return s.dstack.NipN(1) } func opcodeOver(op *parsedOpcode, s *Script) error { return s.dstack.OverN(1) } // Copy object N items back in the stack to the top. Where N is the value in // the top of the stack. func opcodePick(op *parsedOpcode, s *Script) error { pidx, err := s.dstack.PopInt() if err != nil { return err } if pidx.BitLen() > 32 { return StackErrNumberTooBig } val := int(pidx.Int64()) return s.dstack.PickN(val) } // Move object N items back in the stack to the top. Where N is the value in // the top of the stack. func opcodeRoll(op *parsedOpcode, s *Script) error { ridx, err := s.dstack.PopInt() if err != nil { return err } if ridx.BitLen() > 32 { return StackErrNumberTooBig } val := int(ridx.Int64()) return s.dstack.RollN(val) } // Rotate top three items on the stack to the left. // e.g. 1,2,3 -> 2,3,1 func opcodeRot(op *parsedOpcode, s *Script) error { return s.dstack.RotN(1) } // Swap the top two items on the stack: 1,2 -> 2,1 func opcodeSwap(op *parsedOpcode, s *Script) error { return s.dstack.SwapN(1) } // The item at the top of the stack is copied and inserted before the // second-to-top item. e.g.: 2,1, -> 2,1,2 func opcodeTuck(op *parsedOpcode, s *Script) error { return s.dstack.Tuck() } // Push the size of the item on top of the stack onto the stack. func opcodeSize(op *parsedOpcode, s *Script) error { i, err := s.dstack.PeekByteArray(0) if err != nil { return err } s.dstack.PushInt(big.NewInt(int64(len(i)))) return nil } func opcodeEqual(op *parsedOpcode, s *Script) error { a, err := s.dstack.PopByteArray() if err != nil { return err } b, err := s.dstack.PopByteArray() if err != nil { return err } s.dstack.PushBool(bytes.Equal(a, b)) return nil } func opcodeEqualVerify(op *parsedOpcode, s *Script) error { err := opcodeEqual(op, s) if err == nil { err = opcodeVerify(op, s) } return err } func opcode1Add(op *parsedOpcode, s *Script) error { m, err := s.dstack.PopInt() if err != nil { return err } s.dstack.PushInt(new(big.Int).Add(m, big.NewInt(1))) return nil } func opcode1Sub(op *parsedOpcode, s *Script) error { m, err := s.dstack.PopInt() if err != nil { return err } s.dstack.PushInt(new(big.Int).Sub(m, big.NewInt(1))) return nil } func opcodeNegate(op *parsedOpcode, s *Script) error { // XXX when we remove types just flip the 0x80 bit of msb m, err := s.dstack.PopInt() if err != nil { return err } s.dstack.PushInt(new(big.Int).Neg(m)) return nil } func opcodeAbs(op *parsedOpcode, s *Script) error { // XXX when we remove types just &= ~0x80 on msb m, err := s.dstack.PopInt() if err != nil { return err } s.dstack.PushInt(new(big.Int).Abs(m)) return nil } // If then input is 0 or 1, it is flipped. Otherwise the output will be 0. // (n.b. official client just has 1 is 0, else 0) func opcodeNot(op *parsedOpcode, s *Script) error { m, err := s.dstack.PopInt() if err != nil { return err } if m.Sign() == 0 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } // opcode returns 0 if the input is 0, 1 otherwise. func opcode0NotEqual(op *parsedOpcode, s *Script) error { m, err := s.dstack.PopInt() if err != nil { return err } if m.Sign() != 0 { m.SetInt64(1) } s.dstack.PushInt(m) return nil } // Push result of adding top two entries on stack func opcodeAdd(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } s.dstack.PushInt(new(big.Int).Add(v0, v1)) return nil } // Push result of subtracting 2nd entry on stack from first. func opcodeSub(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } s.dstack.PushInt(new(big.Int).Sub(v1, v0)) return nil } // If both of the top two entries on the stack are not zero output is 1. // Otherwise, 0. func opcodeBoolAnd(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v0.Sign() != 0 && v1.Sign() != 0 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } // If either of the top two entries on the stack are not zero output is 1. // Otherwise, 0. func opcodeBoolOr(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v0.Sign() != 0 || v1.Sign() != 0 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } func opcodeNumEqual(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v0.Cmp(v1) == 0 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } func opcodeNumEqualVerify(op *parsedOpcode, s *Script) error { err := opcodeNumEqual(op, s) if err == nil { err = opcodeVerify(op, s) } return err } func opcodeNumNotEqual(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v0.Cmp(v1) != 0 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } func opcodeLessThan(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v1.Cmp(v0) == -1 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } func opcodeGreaterThan(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v1.Cmp(v0) == 1 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } func opcodeLessThanOrEqual(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v1.Cmp(v0) <= 0 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } func opcodeGreaterThanOrEqual(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v1.Cmp(v0) >= 0 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } func opcodeMin(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v1.Cmp(v0) == -1 { s.dstack.PushInt(new(big.Int).Set(v1)) } else { s.dstack.PushInt(new(big.Int).Set(v0)) } return nil } func opcodeMax(op *parsedOpcode, s *Script) error { v0, err := s.dstack.PopInt() if err != nil { return err } v1, err := s.dstack.PopInt() if err != nil { return err } if v1.Cmp(v0) == 1 { s.dstack.PushInt(new(big.Int).Set(v1)) } else { s.dstack.PushInt(new(big.Int).Set(v0)) } return nil } // stack input: x, min, max. Returns 1 if x is within specified range // (left inclusive), 0 otherwise func opcodeWithin(op *parsedOpcode, s *Script) error { maxVal, err := s.dstack.PopInt() if err != nil { return err } minVal, err := s.dstack.PopInt() if err != nil { return err } x, err := s.dstack.PopInt() if err != nil { return err } if x.Cmp(minVal) >= 0 && x.Cmp(maxVal) == -1 { s.dstack.PushInt(big.NewInt(1)) } else { s.dstack.PushInt(big.NewInt(0)) } return nil } // Calculate the hash of hasher over buf. func calcHash(buf []byte, hasher hash.Hash) []byte { hasher.Write(buf) return hasher.Sum(nil) } // calculate hash160 which is ripemd160(sha256(data)) func calcHash160(buf []byte) []byte { return calcHash(calcHash(buf, sha256.New()), ripemd160.New()) } func opcodeRipemd160(op *parsedOpcode, s *Script) error { buf, err := s.dstack.PopByteArray() if err != nil { return err } s.dstack.PushByteArray(calcHash(buf, ripemd160.New())) return nil } func opcodeSha1(op *parsedOpcode, s *Script) error { buf, err := s.dstack.PopByteArray() if err != nil { return err } s.dstack.PushByteArray(calcHash(buf, sha1.New())) return nil } func opcodeSha256(op *parsedOpcode, s *Script) error { buf, err := s.dstack.PopByteArray() if err != nil { return err } s.dstack.PushByteArray(calcHash(buf, sha256.New())) return nil } func opcodeHash160(op *parsedOpcode, s *Script) error { buf, err := s.dstack.PopByteArray() if err != nil { return err } s.dstack.PushByteArray(calcHash160(buf)) return nil } func opcodeHash256(op *parsedOpcode, s *Script) error { buf, err := s.dstack.PopByteArray() if err != nil { return err } s.dstack.PushByteArray(btcwire.DoubleSha256(buf)) return nil } func opcodeCodeSeparator(op *parsedOpcode, s *Script) error { s.lastcodesep = s.scriptoff return nil } func opcodeCheckSig(op *parsedOpcode, s *Script) error { pkStr, err := s.dstack.PopByteArray() if err != nil { return err } sigStr, err := s.dstack.PopByteArray() if err != nil { return err } // Trim off hashtype from the signature string. hashType := sigStr[len(sigStr)-1] sigStr = sigStr[:len(sigStr)-1] // Get script from the last OP_CODESEPARATOR and without any subsequent // OP_CODESEPARATORs subScript := s.subScript() // Unlikely to hit any cases here, but remove the signature from // the script if present. subScript = removeOpcodeByData(subScript, sigStr) hash := s.calcScriptHash(subScript, hashType) pubKey, err := btcec.ParsePubKey(pkStr, btcec.S256()) if err != nil { log.Warnf("can't parse public key from string: %v", err) return err } signature, err := btcec.ParseSignature(sigStr, btcec.S256()) if err != nil { log.Warnf("can't parse signature from string: %v", err) return err } log.Tracef("%v", newLogClosure(func() string { return fmt.Sprintf("op_checksig pubKey %v\npk.x: %v\n "+ "pk.y: %v\n r: %v\n s: %v\ncheckScriptHash %v", spew.Sdump(pkStr), pubKey.X, pubKey.Y, signature.R, signature.S, spew.Sdump(hash)) })) ok := ecdsa.Verify(pubKey, hash, signature.R, signature.S) if !ok { log.Warnf("ecdsa.Verify valid: %v", ok) } s.dstack.PushBool(ok) return nil } func opcodeCheckSigVerify(op *parsedOpcode, s *Script) error { err := opcodeCheckSig(op, s) if err == nil { err = opcodeVerify(op, s) } return err } // stack; sigs pubkeys func opcodeCheckMultiSig(op *parsedOpcode, s *Script) error { numPubkeys, err := s.dstack.PopInt() if err != nil { return err } // XXX arbitrary limits // nore more than 20 pubkeyhs, or 201 operations if numPubkeys.BitLen() > 32 { return StackErrNumberTooBig } npk := int(numPubkeys.Int64()) if npk < 0 || npk > MaxPubKeysPerMultiSig { return StackErrTooManyPubkeys } s.numOps += npk if s.numOps > MaxOpsPerScript { return StackErrTooManyOperations } pubKeyStrings := make([][]byte, npk) pubKeys := make([]*ecdsa.PublicKey, npk) for i := range pubKeys { pubKeyStrings[i], err = s.dstack.PopByteArray() if err != nil { return err } } numSignatures, err := s.dstack.PopInt() if err != nil { return err } if numSignatures.BitLen() > 32 { return StackErrNumberTooBig } nsig := int(numSignatures.Int64()) sigStrings := make([][]byte, nsig) signatures := make([]*btcec.Signature, nsig) for i := range signatures { sigStrings[i], err = s.dstack.PopByteArray() if err != nil { return err } // skip off the last byte for hashtype signatures[i], err = btcec.ParseSignature( sigStrings[i][:len(sigStrings[i])-1], btcec.S256()) if err != nil { return err } } // bug in bitcoind mean we pop one more stack value than should be used. _, err = s.dstack.PopByteArray() if err != nil { return nil } // Trim OP_CODESEPARATORs script := s.subScript() // Remove any of the signatures that happen to be in the script. // can't sign somthing containing the signature you're making, after // all for i := range sigStrings { script = removeOpcodeByData(script, sigStrings[i]) } curPk := 0 for i := range signatures { // check signatures. success := false // get hashtype from original byte string hashType := sigStrings[i][len(sigStrings[i])-1] hash := s.calcScriptHash(script, hashType) inner: // Find first pubkey that successfully validates signature. // we start off the search from the key that was successful // last time. for ; curPk < len(pubKeys); curPk++ { if pubKeys[curPk] == nil { pubKeys[curPk], err = btcec.ParsePubKey(pubKeyStrings[curPk], btcec.S256()) if err != nil { continue } } success = ecdsa.Verify(pubKeys[curPk], hash, signatures[i].R, signatures[i].S) if success { break inner } } if success == false { s.dstack.PushBool(false) return nil } } s.dstack.PushBool(true) return nil } func opcodeCheckMultiSigVerify(op *parsedOpcode, s *Script) error { err := opcodeCheckMultiSig(op, s) if err == nil { err = opcodeVerify(op, s) } return err }