Verify Signatures Without Wallet

import { decodeSparkAddress } from "@buildonspark/spark-sdk";
import * as secp256k1 from "@noble/secp256k1";

// Extract identity public key from Spark address
const { identityPublicKey } = decodeSparkAddress(address, network);

// Verify the signature
const isValid = secp256k1.verify(signature, message, identityPublicKey);

import { decodeSparkAddress } from "@buildonspark/spark-sdk";
import type { NetworkType } from "@buildonspark/spark-sdk";
import * as secp256k1 from "@noble/secp256k1";
import { sha256 } from "@noble/hashes/sha256";

async function verifySparkSignature(
  address: string,
  message: string,
  signature: string,
  network: NetworkType = "MAINNET"
): Promise<boolean> {
  // Decode address to get identity public key
  const { identityPublicKey } = decodeSparkAddress(address, network);

  // Hash the message (signatures are typically over message hashes)
  const messageHash = sha256(new TextEncoder().encode(message));

  // Convert signature from hex if needed
  const sigBytes = typeof signature === "string"
    ? Uint8Array.from(Buffer.from(signature, "hex"))
    : signature;

  // Verify using secp256k1
  return secp256k1.verify(sigBytes, messageHash, identityPublicKey);
}

// Usage
const isValid = await verifySparkSignature(
  "sp1qw508d6qejxtdg4y5r3zarvary0c5xw7k...",
  "Hello, Spark!",
  "304402..."
);
console.log("Signature valid:", isValid);