AesCtrParams
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AesCtrParams

Caution

The experimental module k6/experimental/webcrypto has graduated, and its functionality is now available globally through the crypto object. The k6/experimental/webcrypto is deprecated and will be removed in the near future.

To migrate your scripts, remove the k6/experimental/webcrypto imports and use the crypto object instead.

The AesCtrParams object represents the object that should be passed as the algorithm parameter into the encrypt and decrypt operation when using the AES-CTR algorithm.

For more details, head to the MDN Web Crypto API documentation on AES-CTR.

Properties

PropertyTypeDescription
namestringShould be set to AES-CTR.
counterArrayBuffer, TypedArray, or DataViewThe initial value of the counter block. This must be 16-bytes long, like the AES block size.
lengthnumberThe number of bits in the counter block that are used for the actual counter. It is recommended to use 64 (half of the counter block).

Example

JavaScript 
import { crypto } from 'k6/experimental/webcrypto';

export default async function () {
  const plaintext = stringToArrayBuffer('Hello, World!');

  /**
   * Generate a symmetric key using the AES-CTR algorithm.
   */
  const key = await crypto.subtle.generateKey(
    {
      name: 'AES-CTR',
      length: 256,
    },
    true,
    ['encrypt', 'decrypt']
  );

  /**
   * Encrypt the plaintext using the AES-CTR key with
   * have generated.
   */
  const ciphertext = await crypto.subtle.encrypt(
    {
      name: 'AES-CTR',
      counter: crypto.getRandomValues(new Uint8Array(16)),
      length: 128,
    },
    key,
    plaintext
  );
}

function stringToArrayBuffer(str) {
  const buf = new ArrayBuffer(str.length * 2); // 2 bytes for each char
  const bufView = new Uint16Array(buf);
  for (let i = 0, strLen = str.length; i < strLen; i++) {
    bufView[i] = str.charCodeAt(i);
  }
  return buf;
}