Hello fellow selfhoster! on my debian server I use Caddy as reverse proxy, and would like to protect some services and files with a password. I would like, however, to be able to access some protected files programmatically, from a script. using Caddy’s built-in basic_auth works as intended, but I’d like to be able to use a login form instead of just a browser prompt. This is AFAIK not possible, so I’m looking for alternatives. Any idea?
Check out supertokens.io
I see voidauth already mentioned, great setup also
I use Authelia powered by LLDAP with Caddy to protect services. For accessing files I use copyparty, it can hook into Authelia for user auth.
I already looked into Authelia, and the “problem” I encountered is that it does not support “named policies” (I don’t know the actual name): what I mean is to be able to create “only_admin_policy”, “only_registered_users_policy” etc, and then in Caddy to be able to say something like this
service1.website.com { reverse_proxy container1:1234 apply_policy only_admin_policy } service2.website.com { reverse_proxy container2:1234 apply_policy only_registered_users_policy } service3.website.com { reverse_proxy container3:1234 }
Instead if I understood correctly (and I would gladly be proved wrong) this is not possible with Authelia, as these policies have to be specified inside Authelia, so I would have two different configurations in two different places instead of having everything in the Caddyfile
I hope I explained well what I mean
thanks for the help!
yes, it can do that, assuming you are using LDAP or have set up users/groups in the Authelia config. you don’t need to set it up in the caddyfile though, you can handle everything from Authelia’s end. for example, here is a typical protected item from my caddyfile.
# this is a bit of code at the top that I use for every protected item, and call it each time to save space (protected) { tls /ssl/home-cert.pem /ssl/home-key.pem forward_auth :4100 { uri /api/verify?rd=https://auth.myurl.xyz/ copy_headers Remote-User Remote-Groups Remote-Name Remote-Email header_up Host {upstream_hostport} } encode gzip } # UptimeKuma uptime.myurl.xyz { # now to call the code above for this item import protected * reverse_proxy :4000 }
that’s all I need in my caddyfile, just the bits that forward the information about the user to each site to log them in. I can then handle all the auth rules like saying which sites are only for admins or users in the Authelia config. since I use LDAP, I can set up the groups in that, then just specify which sites are DENY or TWO_FACTOR for each group in the Authelia config. or even in the apps themselves, if they support LDAP like Jellyfin and Forgejo.
I don’t use Caddy but Keycloak may be what you’re looking for.
This was actually pretty interesting until I found out that Caddy is not yet supported :(
Thank you anyway!
This looks very interesting! I see that it supports users groups, would it be possible to create “named access policies” (like “admin_only_policy”, “group_XXX_policy” ecc) and then assign them to the various services directly in the Caddyfile? thank you very much!
I don’t think you could do that directly in the Caddyfile, but you can create those groups/policies inside VoidAuth and assign them to users there.
The steps would be to (in VoidAuth) create the access group/policy, create the ProxyAuth Domain (protected.example.com/*) with the allowed group(s), make sure the user(s) have that group, then in Caddy add the forward_auth directive to the same route you want to protect.
Then when you go to access that route in a browser it will redirect you to VoidAuth login, or if you pass an Authentication header with Basic Auth (like when using an API) it will use that.
I use https://github.com/nosduco/nforwardauth for this purpose
There is an example implementation for caddy in https://github.com/nosduco/nforwardauth/tree/main/examples/caddy-v2
or maybe voidauth could do it https://sh.itjust.works/post/42016490
How does programmatic access tie into the desire for a login form?
Either way, you can do a login form -> basic auth forwarding page by rigging up some simple JS, or access programmatically in a direct way by simply setting a manual Authorization header.
How does programmatic access tie into the desire for a login form?
I would like to keep files with “private” information protected from public access, but I would like to access them from a script. An example: i wrote a karaoke application to use with my friends, they have to go to a webpage and select the songs they like, and then the karaoke app connects to the server to get the updated preference file. I would like that the users had a “nice login form” to select their songs, and then I’d like my karaoke app to easily download the file while still keeping it password-protected
Yeah, I believe you don’t need to extend Caddy at all for that.
Add a properly-formatted Authorization header to any requests you make to the server and it’ll work. See Wikipedia page for header string format:
https://en.wikipedia.org/wiki/Basic_access_authentication
On the webpage side, I’d have the login form make a POST to your login endpoint using a basic auth header to pull a JWT that acts as a “real” auth key for other pages.
This is all assuming you want to stick with basic auth as opposed to a more heavyweight option.