[feature] Support new model of interaction flow for forward compat with v0.21.0 (#4394)

~~Still WIP!~~

This PR allows v0.20.0 of GtS to be forward-compatible with the interaction request / authorization flow that will fully replace the current flow in v0.21.0.

Basically, this means we need to recognize LikeRequest, ReplyRequest, and AnnounceRequest, and in response to those requests, deliver either a Reject or an Accept, with the latter pointing towards a LikeAuthorization, ReplyAuthorization, or AnnounceAuthorization, respectively. This can then be used by the remote instance to prove to third parties that the interaction has been accepted by the interactee. These Authorization types need to be dereferencable to third parties, so we need to serve them.

As well as recognizing the above "polite" interaction request types, we also need to still serve appropriate responses to "impolite" interaction request types, where an instance that's unaware of interaction policies tries to interact with a post by sending a reply, like, or boost directly, without wrapping it in a WhateverRequest type.

Doesn't fully close https://codeberg.org/superseriousbusiness/gotosocial/issues/4026 but gets damn near (just gotta update the federating with GtS documentation).

Migrations tested on both Postgres and SQLite.

Co-authored-by: kim <grufwub@gmail.com>
Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4394
Co-authored-by: tobi <tobi.smethurst@protonmail.com>
Co-committed-by: tobi <tobi.smethurst@protonmail.com>

1 files changed, 37 insertions, 21 deletions

diff --git a/internal/uris/uri.go b/internal/uris/uri.go
index d7ae9fe75..1a5ed7fbf 100644
--- a/internal/uris/uri.go
+++ b/internal/uris/uri.go
@@ -27,27 +27,28 @@ import (
 )
 
 const (
-	UsersPath        = "users"         // UsersPath is for serving users info
-	StatusesPath     = "statuses"      // StatusesPath is for serving statuses
-	InboxPath        = "inbox"         // InboxPath represents the activitypub inbox location
-	OutboxPath       = "outbox"        // OutboxPath represents the activitypub outbox location
-	FollowersPath    = "followers"     // FollowersPath represents the activitypub followers location
-	FollowingPath    = "following"     // FollowingPath represents the activitypub following location
-	LikedPath        = "liked"         // LikedPath represents the activitypub liked location
-	CollectionsPath  = "collections"   // CollectionsPath represents the activitypub collections location
-	FeaturedPath     = "featured"      // FeaturedPath represents the activitypub featured location
-	PublicKeyPath    = "main-key"      // PublicKeyPath is for serving an account's public key
-	FollowPath       = "follow"        // FollowPath used to generate the URI for an individual follow or follow request
-	UpdatePath       = "updates"       // UpdatePath is used to generate the URI for an account update
-	BlocksPath       = "blocks"        // BlocksPath is used to generate the URI for a block
-	MovesPath        = "moves"         // MovesPath is used to generate the URI for a move
-	ReportsPath      = "reports"       // ReportsPath is used to generate the URI for a report/flag
-	ConfirmEmailPath = "confirm_email" // ConfirmEmailPath is used to generate the URI for an email confirmation link
-	FileserverPath   = "fileserver"    // FileserverPath is a path component for serving attachments + media
-	EmojiPath        = "emoji"         // EmojiPath represents the activitypub emoji location
-	TagsPath         = "tags"          // TagsPath represents the activitypub tags location
-	AcceptsPath      = "accepts"       // AcceptsPath represents the activitypub Accept's location
-	RejectsPath      = "rejects"       // RejectsPath represents the activitypub Reject's location
+	UsersPath          = "users"          // UsersPath is for serving users info
+	StatusesPath       = "statuses"       // StatusesPath is for serving statuses
+	InboxPath          = "inbox"          // InboxPath represents the activitypub inbox location
+	OutboxPath         = "outbox"         // OutboxPath represents the activitypub outbox location
+	FollowersPath      = "followers"      // FollowersPath represents the activitypub followers location
+	FollowingPath      = "following"      // FollowingPath represents the activitypub following location
+	LikedPath          = "liked"          // LikedPath represents the activitypub liked location
+	CollectionsPath    = "collections"    // CollectionsPath represents the activitypub collections location
+	FeaturedPath       = "featured"       // FeaturedPath represents the activitypub featured location
+	PublicKeyPath      = "main-key"       // PublicKeyPath is for serving an account's public key
+	FollowPath         = "follow"         // FollowPath used to generate the URI for an individual follow or follow request
+	UpdatePath         = "updates"        // UpdatePath is used to generate the URI for an account update
+	BlocksPath         = "blocks"         // BlocksPath is used to generate the URI for a block
+	MovesPath          = "moves"          // MovesPath is used to generate the URI for a move
+	ReportsPath        = "reports"        // ReportsPath is used to generate the URI for a report/flag
+	ConfirmEmailPath   = "confirm_email"  // ConfirmEmailPath is used to generate the URI for an email confirmation link
+	FileserverPath     = "fileserver"     // FileserverPath is a path component for serving attachments + media
+	EmojiPath          = "emoji"          // EmojiPath represents the activitypub emoji location
+	TagsPath           = "tags"           // TagsPath represents the activitypub tags location
+	AcceptsPath        = "accepts"        // AcceptsPath represents the activitypub Accept's location
+	AuthorizationsPath = "authorizations" // AuthorizationsPath represents the location of an Authorization type such as LikeAuthorization, ReplyAuthorization, etc.
+	RejectsPath        = "rejects"        // RejectsPath represents the activitypub Reject's location
 )
 
 // UserURIs contains a bunch of UserURIs
@@ -210,6 +211,21 @@ func GenerateURIForAccept(username string, thisAcceptID string) string {
 	)
 }
 
+// GenerateURIForAuthorization returns the AP URI for a new Authorization object,
+// ie., LikeAuthorization, ReplyAuthorization, or AnnounceAuthorization.
+// Eg., https://example.org/users/whatever_user/authorizations/01F7XTH1QGBAPMGF49WJZ91XGC
+func GenerateURIForAuthorization(username string, id string) string {
+	proto := config.GetProtocol()
+	host := config.GetHost()
+	return buildURL4(proto,
+		host,
+		UsersPath,
+		username,
+		AuthorizationsPath,
+		id,
+	)
+}
+
 // GenerateURIForReject returns the AP URI for a new Reject activity -- something like:
 // https://example.org/users/whatever_user/rejects/01F7XTH1QGBAPMGF49WJZ91XGC
 func GenerateURIForReject(username string, thisRejectID string) string {