For those wondering here's the idea based on the answer I got here: https://security.stackexchange.com/questions/129846/implementing-an-autologin-link-in-an-email/129850#129850:
It will containg the links
- link id
- token hash
- customer email
- expiration date
To make them secure, the link token should have at least 72 bits of entropy (9 bytes, or 12 Base64 characters) but you need to use an internal PHP random generator or read bytes directly from
/dev/urandom. Have a read at this article to understand how most of the PHP random methods are not really random: http://phpsecurity.readthedocs.io/en/latest/Insufficient-Entropy-For-Random-Values.html?highlight=hash
In the database you need to store the hash of the token and not the token itself in case the database is stolen so the token can only be seen in the email.
Securing your custom controller
Every link must be secured thus you need to add the following for your custom route in your
Then when you generate the URL don't forget to make the URL secure:
One use only
In your custom controller you'll have to retrieve the token parameter then look for a corresponding entry in the database table that matches the hash. If found, retrieve the corresponding customer email and delete the corresponding link row in the database
After that you can log in your customer the standard way.
Choose a relatively small expiration time: 24, 48, 72 hours.
Whenever you create a link set the expiration time as today + expiration.
Then you need a cronjob that runs every 5 minutes and that generates a collection of links where the expiration date is less or equal to today datetime.
And delete all those entries.