gecko-dev/dom/base/test/unit/test_chromeutils_base64.js

"use strict";

function run_test() {
  test_base64URLEncode();
  test_base64URLDecode();
}

// Test vectors from RFC 4648, section 10.
let textTests = {
  "": "",
  f: "Zg",
  fo: "Zm8",
  foo: "Zm9v",
  foob: "Zm9vYg",
  fooba: "Zm9vYmE",
  foobar: "Zm9vYmFy",
};

// Examples from RFC 4648, section 9.
let binaryTests = [
  {
    decoded: new Uint8Array([0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e]),
    encoded: "FPucA9l-",
  },
  {
    decoded: new Uint8Array([0x14, 0xfb, 0x9c, 0x03, 0xd9]),
    encoded: "FPucA9k",
  },
  {
    decoded: new Uint8Array([0x14, 0xfb, 0x9c, 0x03]),
    encoded: "FPucAw",
  },
];

function padEncodedValue(value) {
  switch (value.length % 4) {
    case 0:
      return value;
    case 2:
      return value + "==";
    case 3:
      return value + "=";
    default:
      throw new TypeError("Invalid encoded value");
  }
}

function testEncode(input, encoded) {
  equal(
    ChromeUtils.base64URLEncode(input, { pad: false }),
    encoded,
    encoded + " without padding"
  );
  equal(
    ChromeUtils.base64URLEncode(input, { pad: true }),
    padEncodedValue(encoded),
    encoded + " with padding"
  );
}

function test_base64URLEncode() {
  throws(
    _ => ChromeUtils.base64URLEncode(new Uint8Array(0)),
    /TypeError/,
    "Should require encoding options"
  );
  throws(
    _ => ChromeUtils.base64URLEncode(new Uint8Array(0), {}),
    /TypeError/,
    "Encoding should require the padding option"
  );

  for (let { decoded, encoded } of binaryTests) {
    testEncode(decoded, encoded);
  }

  let textEncoder = new TextEncoder("utf-8");
  for (let decoded of Object.keys(textTests)) {
    let input = textEncoder.encode(decoded);
    testEncode(input, textTests[decoded]);
  }
}

function testDecode(input, decoded) {
  let buffer = ChromeUtils.base64URLDecode(input, { padding: "reject" });
  deepEqual(new Uint8Array(buffer), decoded, input + " with padding rejected");

  let paddedValue = padEncodedValue(input);
  buffer = ChromeUtils.base64URLDecode(paddedValue, { padding: "ignore" });
  deepEqual(new Uint8Array(buffer), decoded, input + " with padding ignored");

  if (paddedValue.length > input.length) {
    throws(
      _ => ChromeUtils.base64URLDecode(paddedValue, { padding: "reject" }),
      /NS_ERROR_ILLEGAL_VALUE/,
      paddedValue + " with padding rejected should throw"
    );

    throws(
      _ => ChromeUtils.base64URLDecode(input, { padding: "require" }),
      /NS_ERROR_ILLEGAL_VALUE/,
      input + " with padding required should throw"
    );

    buffer = ChromeUtils.base64URLDecode(paddedValue, { padding: "require" });
    deepEqual(
      new Uint8Array(buffer),
      decoded,
      paddedValue + " with padding required"
    );
  }
}

function test_base64URLDecode() {
  throws(
    _ => ChromeUtils.base64URLDecode(""),
    /TypeError/,
    "Should require decoding options"
  );
  throws(
    _ => ChromeUtils.base64URLDecode("", {}),
    /TypeError/,
    "Decoding should require the padding option"
  );
  throws(
    _ => ChromeUtils.base64URLDecode("", { padding: "chocolate" }),
    /TypeError/,
    "Decoding should throw for invalid padding policy"
  );

  for (let { decoded, encoded } of binaryTests) {
    testDecode(encoded, decoded);
  }

  let textEncoder = new TextEncoder("utf-8");
  for (let decoded of Object.keys(textTests)) {
    let expectedBuffer = textEncoder.encode(decoded);
    testDecode(textTests[decoded], expectedBuffer);
  }
}