osbre

osbre

Is there a specification or recommendations on implementing “one-time authentication” link?

Hello everyone

I’m trying to implement a “magic link” or “one-time login link” functionality

I wonder what a secure way to implement it would be.

The obvious and most simple solution to me seems to be generating a long enough string and storing it in the database.

When the link is opened, the app will just check the value against the database, and verify that it has not expired based on the creation date

But, an alternative way is to use encryption. Seems beneficial because it does not involve the generation of long enough string? As we can encrypt only database identifier which leads to a record of when the login request was made (to check if not expired)

I appreciate any feedback or tips, thanks :pray:

Marked As Solved

OvermindDL1

OvermindDL1

That’s basically what that “long enough string” is, when its long enough and random then you have enough entropy to not worry about it. Just using a UUIDv4 is enough entropy to not worry about it if it expires anywhere in the next thousand years, lol.

Except you encrypt it, which means it’s going to balloon in size to get enough entropy to be worth encrypting, which is going to end up longer in the URL anyway.

Also Liked

AstonJ

AstonJ

If the user has an account then I generally use SecureRandom to generate a random url-safe string then put that in the db associated with the user and an expiry, then in the URL params I will add the user’s ID as well as the generated string, that way the ID must correspond with the string, or it won’t work :023:

There’s an Elixir library for SecureRandom:

iex> SecureRandom.urlsafe_base64
"xYQcVfWuq6THMY_ZVmG0mA"

Where Next?

Popular Backend topics Top

pillaiindu
Cross posting from HashNode. A friend of mine is creating Uber-like app for a small company with 200 to 1000 cars. The app will operate ...
New
IhorYachmenov
Hello. I have an iOS app where needs a proxying website through private server(HTTP / HTTPS proxy), but its idea each time has some trou...
New
Jsdr3398
I’ve been working on and rewriting my messaging platform several times for the past two years. With Discords new rebranding, it has reall...
New
TwistingTwists
Hello Folks, I am a novice developer from India. Intending to learn Elixir and web apps (phoenix framework). What are things that I MUS...
New
bsek43
Hello everyone, I’ve started learning Elixir and Phoenix few months ago and while I mostly grasped Elixir’s functional concepts and Phoe...
New
JimmyCarterSon
I am following this tutorial . I have followed carefully correcting errors as I go. The app allows you to create a blog post and add comm...
New
osbre
Hello everyone I’m trying to implement a “magic link” or “one-time login link” functionality I wonder what a secure way to implement it...
New
GermaVinsmoke
Does anyone know beginner friendly Elixir/Phoenix Open source projects? For learning purpose :slightly_smiling_face:
New
Manish_bose
Can anyone help me how to convert a long data to wide data in SQL without using hard coding? Regards Manish
New
Fl4m3Ph03n1x
Background I have a phoenix application in Windows 11. Unfortunately for me, I cannot compile the application because of a dependency err...
New

Other popular topics Top

PragmaticBookshelf
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
New
AstonJ
You might be thinking we should just ask who’s not using VSCode :joy: however there are some new additions in the space that might give V...
New
PragmaticBookshelf
Tailwind CSS is an exciting new CSS framework that allows you to design your site by composing simple utility classes to create complex e...
New
Exadra37
Oh just spent so much time on this to discover now that RancherOS is in end of life but Rancher is refusing to mark the Github repo as su...
New
DevotionGeo
I have always used antique keyboards like Cherry MX 1800 or Cherry MX 8100 and almost always have modified the switches in some way, like...
New
First poster: bot
zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig. General-purpose programming language and toolchain for maintaini...
New
New
First poster: AstonJ
Jan | Rethink the Computer. Jan turns your computer into an AI machine by running LLMs locally on your computer. It’s a privacy-focus, l...
New
AstonJ
If you’re getting errors like this: psql: error: connection to server on socket “/tmp/.s.PGSQL.5432” failed: No such file or directory ...
New
AstonJ
This is a very quick guide, you just need to: Download LM Studio: https://lmstudio.ai/ Click on search Type DeepSeek, then select the o...
New