js-libp2p-crypto/src/webcrypto.js

/* eslint-env browser */

'use strict'

// Check native crypto exists and is enabled (In insecure context `self.crypto`
// exists but `self.crypto.subtle` does not).
exports.get = (win = self) => {
  const nativeCrypto = win.crypto || win.msCrypto

  if (!nativeCrypto || !nativeCrypto.subtle) {
    throw Object.assign(
      new Error(
        'Missing Web Crypto API. ' +
        'The most likely cause of this error is that this page is being accessed ' +
        'from an insecure context (i.e. not HTTPS). For more information and ' +
        'possible resolutions see ' +
        'https://github.com/libp2p/js-libp2p-crypto/blob/master/README.md#web-crypto-api'
      ),
      { code: 'ERR_MISSING_WEB_CRYPTO' }
    )
  }

  return nativeCrypto
}