Method parseMultisigRedeemScript

modules/ecash-lib/src/script.ts:373–403

Parse an OP_m ... OP_CHECKMULTISIG redeem script (used by multisig PSBT flows).

()

    /** Parse an OP_m ... OP_CHECKMULTISIG redeem script (used by multisig PSBT flows). */
    public parseMultisigRedeemScript(): {
        numSignatures: number;
        numPubkeys: number;
        pubkeys: Uint8Array[];
    } {
        const ops: Op[] = [];
        const iter = this.ops();
        let op: Op | undefined;
        while ((op = iter.next()) !== undefined) {
            ops.push(op);
        }
        if (ops.length < 4) {
            throw new Error('Invalid multisig redeem script');
        }
        const first = ops[0];
        const lastBeforeCheck = ops[ops.length - 2];
        const numSignatures = Number(parseNumberFromOp(first));
        const numPubkeys = Number(parseNumberFromOp(lastBeforeCheck));
        const pubkeys = ops
            .slice(1, -2)
            .filter((op): op is { opcode: number; data: Uint8Array } =>
                isPushOp(op),
            )
            .map(op => op.data);
        if (pubkeys.length !== numPubkeys) {
            throw new Error(
                `Invalid multisig redeem script: expected ${numPubkeys} pubkeys, got ${pubkeys.length}`,
            );
        }
        return { numSignatures, numPubkeys, pubkeys };
    }

    private static parseMultisigScriptSig(
        ops: Op[],