bkolobara
Erlang :cryto.generate_key() trouble
Hi,
I’m trying to generate an ED25519 public key from a secret key using Erlang’s crypto application. I’m able to generate a random keypair using:
iex(3)> {p, s} = :crypto.generate_key(:ecdh, :x25519)
{<<139, 150, 158, 47, 97, 82, 64, 37, 96, 216, 224, 34, 120, 116, 57, 178, 35,
123, 99, 142, 109, 65, 68, 80, 236, 154, 22, 112, 0, 37, 68, 114>>,
<<32, 123, 30, 206, 152, 213, 66, 101, 231, 22, 173, 128, 18, 84, 98, 91, 73,
205, 66, 27, 0, 12, 241, 122, 6, 207, 155, 100, 134, 170, 29, 125>>}
But if I want just to generate a public key from an existing secret key I get the following error:
iex(4)> :crypto.generate_key(:ecdh, :x25519, s)
** (ArgumentError) argument error
(crypto) :crypto.ec_key_generate({:evp, :x25519}, <<32, 123, 30, 206, 152, 213, 66, 101, 231, 22, 173, 128, 18, 84, 98, 91, 73, 205, 66, 27, 0, 12, 241, 122, 6, 207, 155, 100, 134, 170, 29, 125>>)
It looks like the ec_key_generate() function is implemented as a NIF and I can’t figure out what I’m doing wrong here.
Trending in Questions
Other Trending Topics
Latest on Elixir Forum
Sponsor Spotlight
Producing high quality Elixir screencasts since 2017.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #deployment
- #library
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #channels
- #elixirconf
- #exunit
- #discussion
- #code-sync
- #javascript
- #podcasts
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixir-ls
- #phoenix_html
- #iex
- #blog-post
- #graphql
- #genstage
- #ai
- #elixirconf-us
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #metaprogramming
- #performance
- #security
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Error tracking, logs, uptime, and Just Enough APM. Built for developers.
Practical resources that improve the lives of professional developers.
Enabling companies to succeed by building software people love.
The deployment platform built for Elixir: PaaS ease, VPS control.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"
First Post!
bkolobara
I learned now that X25519 and ED25519 public keys are derived in a different way. So you can’t actually use
:crypto.generate_key(:ecdh, :x25519)to generate a ED25519 keypairs. You would need something like:crypto.generate_key(:eddsa, :ed25519), but this is currently not possible with Erlang’s crypto app.So you can only sign/verify with ED25519, but not actually generate the keys.
Most Liked
smanza
Hello. I think the issue is now resolved with the last OTP version. Add ed25519 & ed448 support to crypto:generate_key by bkolobara · Pull Request #2329 · erlang/otp · GitHub
We are now able to generate ed22519 keys from the crypto app.
bkolobara
I contributed that PR
.
I don’t think it’s part of an OTP release yet. Not that familiar with the release structure, but I think the master branch is going to be the next major version? So it may take some time.
Last Post!
smanza
I just upgraded yesterday my OTP version using asdf to take the master, so you can try out.