Fediverse-based authentication (#1846)

* Able to authenticate user against IndieAuth. For #1273

* WIP server indieauth endpoint. For https://github.com/owncast/owncast/issues/1272

* Add migration to remove access tokens from user

* Add authenticated bool to user for display purposes

* Add indieauth modal and auth flair to display names. For #1273

* Validate URLs and display errors

* Renames, cleanups

* Handle relative auth endpoint paths. Add error handling for missing redirects.

* Disallow using display names in use by registered users. Closes #1810

* Verify code verifier via code challenge on callback

* Use relative path to authorization_endpoint

* Post-rebase fixes

* Use a timestamp instead of a bool for authenticated

* Propertly handle and display error in modal

* Use auth'ed timestamp to derive authenticated flag to display in chat

* Fediverse chat auth via OTP

* Increase validity time just in case

* Add fediverse auth into auth modal

* Text, validation, cleanup updates for fedi auth

* Fix typo

* Remove unused images

* Remove unused file

* Add chat display name to auth modal text

activitypub/requests/http.go

@@ -1,12 +1,16 @@
 package requests
 
 import (
+	"bytes"
 	"encoding/json"
+	"fmt"
 	"net/http"
+	"net/url"
 
 	"github.com/go-fed/activity/streams"
 	"github.com/go-fed/activity/streams/vocab"
 	"github.com/owncast/owncast/activitypub/crypto"
+	"github.com/owncast/owncast/config"
 
 	log "github.com/sirupsen/logrus"
 )
@@ -50,3 +54,21 @@ func WriteResponse(payload []byte, w http.ResponseWriter, publicKey crypto.Publi
 
 	return nil
 }
+
+// CreateSignedRequest will create a signed POST request of a payload to the provided destination.
+func CreateSignedRequest(payload []byte, url *url.URL, fromActorIRI *url.URL) (*http.Request, error) {
+	log.Debugln("Sending", string(payload), "to", url)
+
+	req, _ := http.NewRequest(http.MethodPost, url.String(), bytes.NewBuffer(payload))
+
+	ua := fmt.Sprintf("%s; https://owncast.online", config.GetReleaseString())
+	req.Header.Set("User-Agent", ua)
+	req.Header.Set("Content-Type", "application/activity+json")
+
+	if err := crypto.SignRequest(req, payload, fromActorIRI); err != nil {
+		log.Errorln("error signing request:", err)
+		return nil, err
+	}
+
+	return req, nil
+}