message: Remove unused (non-working) commented out code paths.
diff: return Promise.resolve().then(function() {
  // Handle RSA keys.
  if (WebCryptoAlgorithm.isRsa(algorithm)) {
  - /* 'jsrsasign' */
  var algoName = jsrsasignAlgorithmName(algorithm, key);
  var sign = new rs.KJUR.crypto.Signature({alg: algoName});
  var rawkey = key.rawkey;
  var signatureHex = sign.signHex(bufferHex);
  var signature = rs.hextoArrayBuffer(signatureHex);
  return new Uint8Array(signature);
  -
  - /* 'ursa' */
  - /*
  - var algoName = normalizeAlgorithmName(algorithm, key);
  - var hashName = normalizeHashName(algorithm);
  - var rawkey = key.rawkey;
  - var privkey = ursa.coercePrivateKey(rawkey);
  - var bufferB64 = Base64.encode(buffer);
  - var signatureB64 = privkey.hashAndSign(algoName, bufferB64, 'base64', 'base64', false, null);
  - return Base64.decode(signatureB64);
  - */
  -
  - /* 'crypto' */
  - /*
  - var algoName = normalizeAlgorithmName(algorithm, key);
  - var sign = crypto.createSign(algoName);
  - sign.update(buffer);
  - var rawkey = key.rawkey;
  - try {
  - var signature = sign.sign(rawkey);
  - console.log("RSA signature: [" + Base64.encode(signature) + "]\n");
  - return signature;
  - } catch (e) {
  - console.log("RSA sign: [" + rawkey + "]\n");
  - throw e;
  - }
  - */
  }
  // Handle HMAC.
  // Handle EC keys.
  else if (WebCryptoAlgorithm.isEc(algorithm)) {
  - /* 'elliptic' */
  // Compute the hash.
  var hashName = normalizeHashName(algorithm);
  var hash = crypto.createHash(hashName);
  return Promise.resolve().then(function() {
  // Handle RSA keys.
  if (WebCryptoAlgorithm.isRsa(algorithm)) {
  - /* 'jsrsasign' */
  var algoName = jsrsasignAlgorithmName(algorithm, key);
  var rawkey = key.rawkey;
  var sign = new rs.KJUR.crypto.Signature({alg: algoName});
  sign.updateHex(bufferHex);
  var signatureHex = rs.ArrayBuffertohex(signature.buffer);
  return sign.verify(signatureHex);
  -
  - /* 'ursa'
  - var algoName = normalizeAlgorithmName(algorithm);
  - var rawkey = key.rawkey;
  - var pubkey = ursa.coercePublicKey(rawkey);
  - var bufferB64 = Base64.encode(buffer);
  - var signatureB64 = Base64.encode(signature);
  - return pubkey.hashAndVerify(algoName, bufferB64, signatureB64, 'base64', false, null);
  - */
  -
  - /* 'crypto' */
  - /*
  - var algoName = normalizeAlgorithmName(algorithm, key);
  - var verify = crypto.createVerify(algoName);
  - verify.update(buffer);
  - var rawkey = key.rawkey;
  - return verify.verify(rawkey, signature);
  - */
  }
  // Handle HMAC.
  