aes-cmac/test/main.test.ts

AES-CMAC implementation in typescript

import assert from "node:assert";
import { describe, it } from "node:test";
import { AesCmac } from "../src/AesCmac";

describe("index (module entry point)", () => {
  describe("aesCmac(message)", () => {
    it("performs the AES-CMAC algorithm", async () => {
      const key = Buffer.from("2b7e151628aed2a6abf7158809cf4f3c", "hex");
      const message = Buffer.from("6bc1bee22e409f96e93d7e117393172a", "hex");
      const result = await new AesCmac(key).calculate(message);
      assert.strictEqual(Buffer.from(result).toString("hex"), "070a16b46b4d4144f79bdd9dd04a287c");
    });

    it("returns a buffer as the response", async () => {
      const key = Buffer.from("k3Men*p/2.3j4abB");
      const message = Buffer.from("this|is|a|test|message");
      const result = await new AesCmac(key).calculate(message);
      assert.strictEqual(Buffer.from(result).toString("hex"), "0125c538f8be7c4eea370f992a4ffdcb");
    });

    it("throws an error if the key length is invalid", async () => {
      const expected = "Key size must be 128, 192, or 256 bits.";
      await assertAesCmacError(Buffer.from("key"), Buffer.from("some message"), expected);
    });

    it("throws an error if the key is not a Buffer", async () => {
      const expected = "The key must be provided as a Uint8Array.";
      assert.throws(
        () => new (AesCmac as any)(10),
        (error: Error) => {
          assert.equal(error.message, expected);
          return true;
        },
      );
      assert.throws(
        () => new (AesCmac as any)(null),
        (error: Error) => {
          assert.equal(error.message, expected);
          return true;
        },
      );
    });

    it("throws an error if the message is not a Buffer", async () => {
      const expected = "The message must be provided as a Uint8Array.";
      await assertAesCmacError(Buffer.from("averysecretvalue"), null, expected);
      await assertAesCmacError(Buffer.from("averysecretvalue"), {}, expected);
    });

    async function assertAesCmacError(
      key: Uint8Array,
      message: unknown,
      expectedErrorMessage: string,
    ) {
      try {
        const aesCmac = new AesCmac(key);
        await (aesCmac.calculate as any)(message);
        assert.fail("Expected an error to be thrown.");
      } catch (error) {
        assert("message" in error);
        assert.strictEqual(error.message, expectedErrorMessage);
      }
    }
  });
});