Method supports

lib/internal/crypto/webcrypto.js:1607–1767

(operation, algorithm, lengthOrAdditionalAlgorithm = null)

  // Implements https://wicg.github.io/webcrypto-modern-algos/#SubtleCrypto-method-supports
  static supports(operation, algorithm, lengthOrAdditionalAlgorithm = null) {
    emitExperimentalWarning('The supports Web Crypto API method');
    if (this !== SubtleCrypto) throw new ERR_INVALID_THIS('SubtleCrypto constructor');
    webidl ??= require('internal/crypto/webidl');
    const prefix = "Failed to execute 'supports' on 'SubtleCrypto'";
    webidl.requiredArguments(arguments.length, 2, { prefix });

    operation = webidl.converters.DOMString(operation, {
      prefix,
      context: '1st argument',
    });
    algorithm = webidl.converters.AlgorithmIdentifier(algorithm, {
      prefix,
      context: '2nd argument',
    });

    switch (operation) {
      case 'decapsulateBits':
      case 'decapsulateKey':
      case 'decrypt':
      case 'deriveBits':
      case 'deriveKey':
      case 'digest':
      case 'encapsulateBits':
      case 'encapsulateKey':
      case 'encrypt':
      case 'exportKey':
      case 'generateKey':
      case 'getPublicKey':
      case 'importKey':
      case 'sign':
      case 'unwrapKey':
      case 'verify':
      case 'wrapKey':
        break;
      default:
        return false;
    }

    let length;
    let additionalAlgorithm;
    if (operation === 'deriveKey') {
      additionalAlgorithm = webidl.converters.AlgorithmIdentifier(
        lengthOrAdditionalAlgorithm,
        {
          prefix,
          context: '3rd argument',
        },
      );

      if (!check('importKey', additionalAlgorithm)) {
        return false;
      }

      try {
        length = getKeyLength(normalizeAlgorithm(additionalAlgorithm, 'get key length'));
      } catch {
        return false;