Are there any one-way hashing functions available in native JavaScript?

JavaScript does not have native hashing, but there are many libraries.

I recommend crypto-js: https://code.google.com/p/crypto-js/

For example, to use SHA1, you simply:

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/crypto-js/3.1.2/rollups/sha1.js"></script>
<script>
    var hash = CryptoJS.SHA1("Message");
</script>

In 2020, there is a native API:

SubtleCrypto.digest()

https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest

example:

crypto.subtle
  .digest("SHA-256", new TextEncoder().encode("hello"))
  .then(console.log);

hex string conversion:

const digest = async ({ algorithm = "SHA-256", message }) =>
  Array.prototype.map
    .call(
      new Uint8Array(
        await crypto.subtle.digest(algorithm, new TextEncoder().encode(message))
      ),
      (x) => ("0" + x.toString(16)).slice(-2)
    )
    .join("");

digest({message: "hello"}).then(console.log)