操作码
详细介绍比特币的操作码。
比特币使用一种脚本系统进行交易。类似于Forth语言，比特币的脚本系统简单、基于堆栈且从左到右处理。
脚本本质上是记录在每笔交易中的一系列指令，描述了想要花费被转移的比特币的下一个人如何获得访问权限。将比特币转移到目标比特币地址的典型脚本只是用两件事来限制未来比特币的花费：花费者必须提供：
- 一个公钥，当被哈希时，得到嵌入在脚本中的目标地.
- 一个证明对应于刚提供的公钥的私钥所有权的签名。
MVC完善并拓展了比特币的脚本系统，使其更加强大和灵活。
操作码列表
操作码请参考：https://en.bitcoin.it/wiki/Script
常量
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_0, OP_FALSE | 0 | 0x00 | Nothing. | (empty value) | An empty array of bytes is pushed onto the stack. (This is not a no-op: an item is added to the stack.) |
| N/A | 1-75 | 0x01-0x4b | (special) | data | The next opcode bytes is data to be pushed onto the stack |
| OP_PUSHDATA1 | 76 | 0x4c | (special) | data | The next byte contains the number of bytes to be pushed onto the stack. |
| OP_PUSHDATA2 | 77 | 0x4d | (special) | data | The next two bytes contain the number of bytes to be pushed onto the stack in little endian order. |
| OP_PUSHDATA4 | 78 | 0x4e | (special) | data | The next four bytes contain the number of bytes to be pushed onto the stack in little endian order. |
| OP_1NEGATE | 79 | 0x4f | Nothing. | -1 | The number -1 is pushed onto the stack. |
| OP_1, OP_TRUE | 81 | 0x51 | Nothing. | 1 | The number 1 is pushed onto the stack. |
| OP_2-OP_16 | 82-96 | 0x52-0x60 | Nothing. | 2-16 | The number in the word name (2-16) is pushed onto the stack. |
流程控制
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_NOP | 97 | 0x61 | Nothing | Nothing | Does nothing. |
| OP_IF | 99 | 0x63 | <expression> | if [statements] [else [statements]]* endif | If the top stack value is not False, the statements are executed. The top stack value is removed. |
| OP_NOTIF | 100 | 0x64 | <expression> | notif [statements] [else [statements]]* endif | If the top stack value is False, the statements are executed. The top stack value is removed. |
| OP_ELSE | 103 | 0x67 | <expression> | if [statements] [else [statements]]* endif | If the preceding OP_IF or OP_NOTIF or OP_ELSE was not executed then these statements are, and if the preceding OP_IF or OP_NOTIF or OP_ELSE was executed then these statements are not. |
| OP_ENDIF | 104 | 0x68 | <expression> | if [statements] [else [statements]]* endif | Ends an if/else block. All blocks must end, or the transaction is invalid. An OP_ENDIF without OP_IF earlier is also invalid. |
| OP_VERIFY | 105 | 0x69 | True / false | Nothing / fail | Marks transaction as invalid if top stack value is not true. The top stack value is removed. |
| OP_RETURN | 106 | 0x6a | Nothing | fail | Marks transaction as invalid. Since bitcoin 0.9, a standard way of attaching extra data to transactions is to add a zero-value output with a scriptPubKey consisting of OP_RETURN followed by data. Such outputs are provably unspendable and specially discarded from storage in the UTXO set, reducing their cost to the network. Since 0.12, standard relay rules allow a single output with OP_RETURN, that contains any sequence of push statements (or OP_RESERVED[1]) after the OP_RETURN provided the total scriptPubKey length is at most 83 bytes. |
堆栈操作
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_TOALTSTACK | 107 | 0x6b | x1 | (alt)x1 | Puts the input onto the top of the alt stack. Removes it from the main stack. |
| OP_FROMALTSTACK | 108 | 0x6c | (alt)x1 | x1 | Puts the input onto the top of the main stack. Removes it from the alt stack. |
| OP_IFDUP | 115 | 0x73 | x | x / x x | If the top stack value is not 0, duplicate it. |
| OP_DEPTH | 116 | 0x74 | Nothing | <Stack size> | Puts the number of stack items onto the stack. |
| OP_DROP | 117 | 0x75 | x | Nothing | Removes the top stack item. |
| OP_DUP | 118 | 0x76 | x | x x | Duplicates the top stack item. |
| OP_NIP | 119 | 0x77 | x1 x2 | x2 | Removes the second-to-top stack item. |
| OP_OVER | 120 | 0x78 | x1 x2 | x1 x2 x1 | Copies the second-to-top stack item to the top. |
| OP_PICK | 121 | 0x79 | xn ... x2 x1 x0 <n> | xn ... x2 x1 x0 xn | The item n back in the stack is copied to the top. |
| OP_ROLL | 122 | 0x7a | xn ... x2 x1 x0 <n> | ... x2 x1 x0 xn | The item n back in the stack is moved to the top. |
| OP_ROT | 123 | 0x7b | x1 x2 x3 | x2 x3 x1 | The 3rd item down the stack is moved to the top. |
| OP_SWAP | 124 | 0x7c | x1 x2 | x2 x1 | The top two items on the stack are swapped. |
| OP_TUCK | 125 | 0x7d | x1 x2 | x2 x1 x2 | The item at the top of the stack is copied and inserted before the second-to-top item. |
| OP_2DROP | 109 | 0x6d | x1 x2 | Nothing | Removes the top two stack items. |
| OP_2DUP | 110 | 0x6e | x1 x2 | x1 x2 x1 x2 | Duplicates the top two stack items. |
| OP_3DUP | 111 | 0x6f | x1 x2 x3 | x1 x2 x3 x1 x2 x3 | Duplicates the top three stack items. |
| OP_2OVER | 112 | 0x70 | x1 x2 x3 x4 | x1 x2 x3 x4 x1 x2 | Copies the pair of items two spaces back in the stack to the front. |
| OP_2ROT | 113 | 0x71 | x1 x2 x3 x4 x5 x6 | x3 x4 x5 x6 x1 x2 | The fifth and sixth items back are moved to the top of the stack. |
| OP_2SWAP | 114 | 0x72 | x1 x2 x3 x4 | x3 x4 x1 x2 | Swaps the top two pairs of items. |
拼接操作
如果脚本中存在任何标记为禁用的操作码，则必须中止并失败。
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_CAT | 126 | 0x7e | x1 x2 | out | 连接两个字符串。禁用。 |
| OP_SUBSTR | 127 | 0x7f | in begin size | out | 返回字符串的一部分。禁用。 |
| OP_LEFT | 128 | 0x80 | in size | out | 仅保留字符串中指定点左侧的字符。禁用。 |
| OP_RIGHT | 129 | 0x81 | in size | out | 仅保留字符串中指定点右侧的字符。禁用。 |
| OP_SIZE | 130 | 0x82 | in | in size | 将堆栈顶部元素的字符串长度压入堆栈（不弹出该元素）。 |
位逻辑操作
如果脚本中存在任何标记为禁用的操作码，则必须中止并失败。
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_INVERT | 131 | 0x83 | in | out | 翻转输入的所有位。禁用。 |
| OP_AND | 132 | 0x84 | x1 x2 | out | 对输入的每一位进行布尔与操作。禁用。 |
| OP_OR | 133 | 0x85 | x1 x2 | out | 对输入的每一位进行布尔或操作。禁用。 |
| OP_XOR | 134 | 0x86 | x1 x2 | out | 对输入的每一位进行布尔异或操作。禁用。 |
| OP_EQUAL | 135 | 0x87 | x1 x2 | True / false | 如果输入完全相等，则返回1，否则返回0。 |
| OP_EQUALVERIFY | 136 | 0x88 | x1 x2 | Nothing / fail | 与OP_EQUAL相同，但随后运行OP_VERIFY。 |
数值操作
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_1ADD | 139 | 0x8b | in | out | 1 is added to the input. |
| OP_1SUB | 140 | 0x8c | in | out | 1 is subtracted from the input. |
| OP_2MUL | 141 | 0x8d | in | out | The input is multiplied by 2. (disabled) |
| OP_2DIV | 142 | 0x8e | in | out | The input is divided by 2. (disabled) |
| OP_NEGATE | 143 | 0x8f | in | out | The sign of the input is flipped. |
| OP_ABS | 144 | 0x90 | in | out | The input is made positive. |
| OP_NOT | 145 | 0x91 | in | out | If the input is 0 or 1, it is flipped. Otherwise the output will be 0. |
| OP_0NOTEQUAL | 146 | 0x92 | in | out | Returns 0 if the input is 0. 1 otherwise. |
| OP_ADD | 147 | 0x93 | a b | out | a is added to b. |
| OP_SUB | 148 | 0x94 | a b | out | b is subtracted from a. |
| OP_MUL | 149 | 0x95 | a b | out | a is multiplied by b. (disabled) |
| OP_DIV | 150 | 0x96 | a b | out | a is divided by b. (disabled) |
| OP_MOD | 151 | 0x97 | a b | out | Returns the remainder after dividing a by b. (disabled) |
| OP_LSHIFT | 152 | 0x98 | a b | out | Shifts a left b bits, preserving sign. (disabled) |
| OP_RSHIFT | 153 | 0x99 | a b | out | Shifts a right b bits, preserving sign. (disabled) |
| OP_BOOLAND | 154 | 0x9a | a b | out | If both a and b are not 0, the output is 1. Otherwise 0. |
| OP_BOOLOR | 155 | 0x9b | a b | out | If a or b is not 0, the output is 1. Otherwise 0. |
| OP_NUMEQUAL | 156 | 0x9c | a b | out | Returns 1 if the numbers are equal, 0 otherwise. |
| OP_NUMEQUALVERIFY | 157 | 0x9d | a b | Nothing / fail | Same as OP_NUMEQUAL, but runs OP_VERIFY afterward. |
| OP_NUMNOTEQUAL | 158 | 0x9e | a b | out | Returns 1 if the numbers are not equal, 0 otherwise. |
| OP_LESSTHAN | 159 | 0x9f | a b | out | Returns 1 if a is less than b, 0 otherwise. |
| OP_GREATERTHAN | 160 | 0xa0 | a b | out | Returns 1 if a is greater than b, 0 otherwise. |
| OP_LESSTHANOREQUAL | 161 | 0xa1 | a b | out | Returns 1 if a is less than or equal to b, 0 otherwise. |
| OP_GREATERTHANOREQUAL | 162 | 0xa2 | a b | out | Returns 1 if a is greater than or equal to b, 0 otherwise. |
| OP_MIN | 163 | 0xa3 | a b | out | Returns the smaller of a and b. |
| OP_MAX | 164 | 0xa4 | a b | out | Returns the larger of a and b. |
| OP_WITHIN | 165 | 0xa5 | x min max | out | Returns 1 if x is within the specified range (left-inclusive), 0 otherwise. |
密码学操作
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_RIPEMD160 | 166 | 0xa6 | in | hash | The input is hashed using RIPEMD-160. |
| OP_SHA1 | 167 | 0xa7 | in | hash | The input is hashed using SHA-1. |
| OP_SHA256 | 168 | 0xa8 | in | hash | The input is hashed using SHA-256. |
| OP_HASH160 | 169 | 0xa9 | in | hash | The input is hashed twice: first with SHA-256 and then with RIPEMD-160. |
| OP_HASH256 | 170 | 0xaa | in | hash | The input is hashed two times with SHA-256. |
| OP_CODESEPARATOR | 171 | 0xab | None | None | All of the signature checking words will only match signatures to the data after the most recently-executed OP_CODESEPARATOR. |
| OP_CHECKSIG | 172 | 0xac | sig pubkey | True / false | The entire transaction's outputs, inputs, and script are hashed. The signature used by OP_CHECKSIG must be a valid signature for this hash and public key. If it is, 1 is returned, 0 otherwise. |
| OP_CHECKSIGVERIFY | 173 | 0xad | sig pubkey | Nothing / fail | Same as OP_CHECKSIG, but OP_VERIFY is executed afterward. |
| OP_CHECKMULTISIG | 174 | 0xae | x sig1 sig2 ... <number of signatures> pub1 pub2 <number of public keys> | True / False | Compares the first signature against each public key until it finds an ECDSA match. Starting with the subsequent public key, it compares the second signature against each remaining public key until it finds an ECDSA match. The process is repeated until all signatures have been checked or not enough public keys remain to produce a successful result. All signatures need to match a public key. Because public keys are not checked again if they fail any signature comparison, signatures must be placed in the scriptSig using the same order as their corresponding public keys were placed in the scriptPubKey or redeemScript. If all signatures are valid, 1 is returned, 0 otherwise. Due to a bug, one extra unused value is removed from the stack. |
| OP_CHECKMULTISIGVERIFY | 175 | 0xaf | x sig1 sig2 ... <number of signatures> pub1 pub2 ... <number of public keys> | Nothing / fail | Same as OP_CHECKMULTISIG, but OP_VERIFY is executed afterward. |
| OP_CHECKSIGADD | 186 | 0xba | sig n pub | out | Three values are popped from the stack. The integer n is incremented by one and returned to the stack if the signature is valid for the public key and transaction. The integer n is returned to the stack unchanged if the signature is the empty vector (OP_0). In any other case, the script is invalid. This opcode is only available in tapscript. |
时间锁定
| Word | Opcode | Hex | Input | Output | Description |
|---|---|---|---|---|---|
| OP_CHECKLOCKTIMEVERIFY | 177 | 0xb1 | x | x / fail | Marks transaction as invalid if the top stack item is greater than the transaction's nLockTime field, otherwise script evaluation continues as though an OP_NOP was executed. Transaction is also invalid if 1. the stack is empty; or 2. the top stack item is negative; or 3. the top stack item is greater than or equal to 500000000 while the transaction's nLockTime field is less than 500000000, or vice versa; or 4. the input's nSequence field is equal to 0xffffffff. The precise semantics are described in BIP 0065. |
| OP_CHECKSEQUENCEVERIFY | 178 | 0xb2 | x | x / fail | Marks transaction as invalid if the relative lock time of the input (enforced by BIP 0068 with nSequence) is not equal to or longer than the value of the top stack item. The precise semantics are described in BIP 0112. |