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

dimitarvp
As a part of my new job I’ll have to learn to manage a local k8s cluster. The tools used are microk8s, tilt and helm. I’ll appreciate an...
New
mrmurphy
I’ve run into a situation where I’ve got a list of posts inside of a container that uses phx-update=“prepend”, and the posts on the socke...
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
Fl4m3Ph03n1x
Background I am trying out polymorphic typing with dialyzer. As an example I am using the famous Option type (aka, Maybe Monad) that is n...
New
JimmyCarterSon
Hello, I am working on a new application with Elixir, Dish_out. I want to see Data I follow this tutorial with Elixir Casts. However, I ...
New
Fl4m3Ph03n1x
Background I have recently been delving into more functional code. My objective right now is to get something similar to the IO Monad (in...
New
Fl4m3Ph03n1x
Background I have a personal project that is an elixir desktop application for PC Windows. It works pretty well, but now I want to give i...
New
Fl4m3Ph03n1x
Background I have an umbrella project, where I run mix test from the root. In one of the apps, I am mocking the File module using the Mo...
New
apoorv-2204
Anyone know how to get in golang? I am from elixir background?.
New
Shiny
Hey community, this is my first post here so I will try to be as concise as possible and I appreciate any feedback. I’ve been writing Ro...
New

Other popular topics Top

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
PragmaticBookshelf
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
New
mafinar
This is going to be a long an frequently posted thread. While talking to a friend of mine who has taken data structure and algorithm cou...
New
AstonJ
If you get Can't find emacs in your PATH when trying to install Doom Emacs on your Mac you… just… need to install Emacs first! :lol: bre...
New
PragmaticBookshelf
Author Spotlight: VM Brasseur @vmbrasseur We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...
New
AnfaengerAlex
Hello, I’m a beginner in Android development and I’m facing an issue with my project setup. In my build.gradle.kts file, I have the foll...
New
AstonJ
This is cool! DEEPSEEK-V3 ON M4 MAC: BLAZING FAST INFERENCE ON APPLE SILICON We just witnessed something incredible: the largest open-s...
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
PragmaticBookshelf
Use advanced functional programming principles, practical Domain-Driven Design techniques, and production-ready Elixir code to build scal...
New
xiji2646-netizen
There’s a GitHub repo at forrestchang/andrej-karpathy-skills that’s sitting at 97.8k stars. It’s a single CLAUDE.md file with four behavi...
New