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import { RawBinary } from "./../binary.ts";import { concat } from "./../helper.ts";import { digest } from "../hash.ts";
/** * https://tools.ietf.org/html/rfc4868 *  * @param algorithm  * @param key  * @param data  */export function hmac(  algorithm: "sha1" | "sha256",  key: Uint8Array | string,  data: Uint8Array | string,) {  const blockSize = 64;
  const computedData: Uint8Array = typeof data === "string"    ? new TextEncoder().encode(data)    : data;
  let computedKey: Uint8Array = typeof key === "string"    ? new TextEncoder().encode(key)    : key;
  // Hash if key is bigger block size  if (computedKey.length > blockSize) {    computedKey = digest(algorithm, computedKey);  }
  // Adding zero padding  if (computedKey.length < blockSize) {    const tmp = new Uint8Array(blockSize);    tmp.set(computedKey, 0);    computedKey = tmp;  }
  const opad = new Uint8Array(computedKey);  const ipad = new Uint8Array(computedKey);  for (let i = 0; i < blockSize; i++) {    opad[i] = computedKey[i] ^ 0x5c;    ipad[i] = computedKey[i] ^ 0x36;  }
  const output = digest(    algorithm,    concat(opad, digest(algorithm, concat(ipad, computedData))),  );
  return new RawBinary(output);}