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

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’m trying to create a router where everything is in a collection of routes (similar to how I do my routes in expressjs). But it doesn’t ...
New
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
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
JimmyCarterSon
I am confused about the Schema setup, I am setting up a new application and I want to seed files in it as well. I tried to mix to create...
New
harwind
I received this error for a binary search programme in C, despite the fact that it requested for inputs and produced the right output. Th...
/c
New
pillaiindu
Currently reading the book “Programming Phoenix LiveView”. At the end of the Chapter 1, I’m trying to solve the guess game. If the user ...
New
jaeyson
Hi! I have clarifications (please correct me, as I mostly mix/confuse this details) with the following: The term RAG here where it read...
New
theodor
I have this app where there are a bunch of users that cannot access their account anymore after they updated their Android device to Andr...
New

Other popular topics Top

PragmaticBookshelf
Write Elixir tests that you can be proud of. Dive into Elixir’s test philosophy and gain mastery over the terminology and concepts that u...
New
PragmaticBookshelf
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
DevotionGeo
The V Programming Language Simple language for building maintainable programs V is already mentioned couple of times in the forum, but I...
New
foxtrottwist
A few weeks ago I started using Warp a terminal written in rust. Though in it’s current state of development there are a few caveats (tab...
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
PragmaticBookshelf
Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
PragmaticBookshelf
Programming Ruby is the most complete book on Ruby, covering both the language itself and the standard library as well as commonly used t...
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
PragmaticBookshelf
A concise guide to MySQL 9 database administration, covering fundamental concepts, techniques, and best practices. Neil Smyth MySQL...
New
xiji2646-netizen
Woke up to this today: Claude Code’s complete source code exposed via npm source map. Not a snippet. All 512,000 lines. 1,900 TypeScript ...
New