How to parse opaque token to get user when using socket io

[tuandungbrse]

I'm implementing authentication on socket connection, getting token from the client but do not know how to parse an opaque token like parse token with JWT, anyone can help? Much appreciate.

[aayush123]

Here's a function I use to extract ID from an OAT:

/**
 * Function to get id of token from token generated at time of login.
 * Note that this is not the hash stored in DB, but the token generated when login method is called.
 * Token can be accessed from request headers
 * @param   {string}  token  Token from request Authorization Header
 * @return  {string | null}         Id of token as string or null if token extraction failed
 */
export const getTokenId = (token?: string | null) => {
  if (!token) {
    return null;
  }
  const tokenParts = token.split('.');
  if (tokenParts.length !== 2) {
    return null;
  }
  const parsedWordArray = CryptoJS.enc.Base64.parse(tokenParts[0]);
  const tokenId: number = +parsedWordArray.toString(CryptoJS.enc.Utf8);
  if (!tokenId || Number.isNaN(tokenId)) {
    return null;
  }
  return tokenId;
};