From 882e8ec59878ea78bd5a4fec30c8756ad55367b3 Mon Sep 17 00:00:00 2001
From: Mononaut <github@monospace.live>
Date: Tue, 27 Feb 2024 16:48:52 +0000
Subject: [PATCH] Check in missing script utility file

---
 backend/src/utils/bitcoin-script.ts | 203 ++++++++++++++++++++++++++++
 1 file changed, 203 insertions(+)
 create mode 100644 backend/src/utils/bitcoin-script.ts

diff --git a/backend/src/utils/bitcoin-script.ts b/backend/src/utils/bitcoin-script.ts
new file mode 100644
index 000000000..3414e8269
--- /dev/null
+++ b/backend/src/utils/bitcoin-script.ts
@@ -0,0 +1,203 @@
+const opcodes = {
+  OP_FALSE: 0,
+  OP_0: 0,
+  OP_PUSHDATA1: 76,
+  OP_PUSHDATA2: 77,
+  OP_PUSHDATA4: 78,
+  OP_1NEGATE: 79,
+  OP_PUSHNUM_NEG1: 79,
+  OP_RESERVED: 80,
+  OP_TRUE: 81,
+  OP_1: 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_PUSHNUM_1: 81,
+  OP_PUSHNUM_2: 82,
+  OP_PUSHNUM_3: 83,
+  OP_PUSHNUM_4: 84,
+  OP_PUSHNUM_5: 85,
+  OP_PUSHNUM_6: 86,
+  OP_PUSHNUM_7: 87,
+  OP_PUSHNUM_8: 88,
+  OP_PUSHNUM_9: 89,
+  OP_PUSHNUM_10: 90,
+  OP_PUSHNUM_11: 91,
+  OP_PUSHNUM_12: 92,
+  OP_PUSHNUM_13: 93,
+  OP_PUSHNUM_14: 94,
+  OP_PUSHNUM_15: 95,
+  OP_PUSHNUM_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_CHECKMULTISIG: 174,
+  OP_CHECKMULTISIGVERIFY: 175,
+  OP_NOP1: 176,
+  OP_NOP2: 177,
+  OP_CHECKLOCKTIMEVERIFY: 177,
+  OP_CLTV: 177,
+  OP_NOP3: 178,
+  OP_CHECKSEQUENCEVERIFY: 178,
+  OP_CSV: 178,
+  OP_NOP4: 179,
+  OP_NOP5: 180,
+  OP_NOP6: 181,
+  OP_NOP7: 182,
+  OP_NOP8: 183,
+  OP_NOP9: 184,
+  OP_NOP10: 185,
+  OP_CHECKSIGADD: 186,
+  OP_PUBKEYHASH: 253,
+  OP_PUBKEY: 254,
+  OP_INVALIDOPCODE: 255,
+};
+// add unused opcodes
+for (let i = 187; i <= 255; i++) {
+  opcodes[`OP_RETURN_${i}`] = i;
+}
+
+export { opcodes };
+
+/** extracts m and n from a multisig script (asm), returns nothing if it is not a multisig script */
+export function parseMultisigScript(script: string): void | { m: number, n: number } {
+  if (!script) {
+    return;
+  }
+  const ops = script.split(' ');
+  if (ops.length < 3 || ops.pop() !== 'OP_CHECKMULTISIG') {
+    return;
+  }
+  const opN = ops.pop();
+  if (!opN) {
+    return;
+  }
+  if (!opN.startsWith('OP_PUSHNUM_')) {
+    return;
+  }
+  const n = parseInt(opN.match(/[0-9]+/)?.[0] || '', 10);
+  if (ops.length < n * 2 + 1) {
+    return;
+  }
+  // pop n public keys
+  for (let i = 0; i < n; i++) {
+    if (!/^0((2|3)\w{64}|4\w{128})$/.test(ops.pop() || '')) {
+      return;
+    }
+    if (!/^OP_PUSHBYTES_(33|65)$/.test(ops.pop() || '')) {
+      return;
+    }
+  }
+  const opM = ops.pop();
+  if (!opM) {
+    return;
+  }
+  if (!opM.startsWith('OP_PUSHNUM_')) {
+    return;
+  }
+  const m = parseInt(opM.match(/[0-9]+/)?.[0] || '', 10);
+
+  if (ops.length) {
+    return;
+  }
+
+  return { m, n };
+}
+
+export function getVarIntLength(n: number): number {
+  if (n < 0xfd) {
+    return 1;
+  } else if (n <= 0xffff) {
+    return 3;
+  } else if (n <= 0xffffffff) {
+    return 5;
+  } else {
+    return 9;
+  }
+}
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