ethers.js/src.ts/crypto/hmac.ts
2022-12-09 18:21:45 -05:00

52 lines
1.5 KiB
TypeScript

/**
* An **HMAC** enables verification that a given key was used
* to authenticate a payload.
*
* See: [[link-wiki-hmac]]
*
* @_subsection: api/crypto:HMAC [about-hmac]
*/
import { createHmac } from "./crypto.js";
import { getBytes, hexlify } from "../utils/index.js";
import type { BytesLike } from "../utils/index.js";
let locked = false;
const _computeHmac = function(algorithm: "sha256" | "sha512", key: Uint8Array, data: Uint8Array): BytesLike {
return createHmac(algorithm, key).update(data).digest();
}
let __computeHmac = _computeHmac;
/**
* Return the HMAC for %%data%% using the %%key%% key with the underlying
* %%algo%% used for compression.
*
* @example:
* key = id("some-secret")
*
* // Compute the HMAC
* computeHmac("sha256", key, "0x1337")
* //_result:
*
* // To compute the HMAC of UTF-8 data, the data must be
* // converted to UTF-8 bytes
* computeHmac("sha256", key, toUtf8Bytes("Hello World"))
* //_result:
*
*/
export function computeHmac(algorithm: "sha256" | "sha512", _key: BytesLike, _data: BytesLike): string {
const key = getBytes(_key, "key");
const data = getBytes(_data, "data");
return hexlify(__computeHmac(algorithm, key, data));
}
computeHmac._ = _computeHmac;
computeHmac.lock = function() { locked = true; }
computeHmac.register = function(func: (algorithm: "sha256" | "sha512", key: Uint8Array, data: Uint8Array) => BytesLike) {
if (locked) { throw new Error("computeHmac is locked"); }
__computeHmac = func;
}
Object.freeze(computeHmac);