[feature] Federate interaction policies + Accepts; enforce policies (#3138)

* [feature] Federate interaction policies + Accepts; enforce policies

* use Acceptable type

* fix index

* remove appendIRIStrs

* add GetAccept federatingdb function

* lock on object IRI

2 files changed, 59 insertions, 0 deletions

diff --git a/internal/api/activitypub/users/acceptget.go b/internal/api/activitypub/users/acceptget.go
new file mode 100644
index 000000000..c2b438330
--- /dev/null
+++ b/internal/api/activitypub/users/acceptget.go
@@ -0,0 +1,55 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package users
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+)
+
+// AcceptGETHandler serves an interactionApproval as an ActivityStreams Accept.
+func (m *Module) AcceptGETHandler(c *gin.Context) {
+	username, errWithCode := apiutil.ParseUsername(c.Param(apiutil.UsernameKey))
+	if errWithCode != nil {
+		apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
+		return
+	}
+
+	acceptID, errWithCode := apiutil.ParseID(c.Param(apiutil.IDKey))
+	if errWithCode != nil {
+		apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
+		return
+	}
+
+	contentType, err := apiutil.NegotiateAccept(c, apiutil.ActivityPubHeaders...)
+	if err != nil {
+		apiutil.ErrorHandler(c, gtserror.NewErrorNotAcceptable(err, err.Error()), m.processor.InstanceGetV1)
+		return
+	}
+
+	resp, errWithCode := m.processor.Fedi().AcceptGet(c.Request.Context(), username, acceptID)
+	if errWithCode != nil {
+		apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
+		return
+	}
+
+	apiutil.JSONType(c, http.StatusOK, contentType, resp)
+}
diff --git a/internal/api/activitypub/users/user.go b/internal/api/activitypub/users/user.go
index 5e3d5d187..5122e610e 100644
--- a/internal/api/activitypub/users/user.go
+++ b/internal/api/activitypub/users/user.go
@@ -21,6 +21,7 @@ import (
 	"net/http"
 
 	"github.com/gin-gonic/gin"
+	apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
 	"github.com/superseriousbusiness/gotosocial/internal/processing"
 	"github.com/superseriousbusiness/gotosocial/internal/uris"
 )
@@ -55,6 +56,8 @@ const (
 	StatusPath = BasePath + "/" + uris.StatusesPath + "/:" + StatusIDKey
 	// StatusRepliesPath is for serving the replies collection of a status.
 	StatusRepliesPath = StatusPath + "/replies"
+	// AcceptPath is for serving accepts of a status.
+	AcceptPath = BasePath + "/" + uris.AcceptsPath + "/:" + apiutil.IDKey
 )
 
 type Module struct {
@@ -76,4 +79,5 @@ func (m *Module) Route(attachHandler func(method string, path string, f ...gin.H
 	attachHandler(http.MethodGet, StatusPath, m.StatusGETHandler)
 	attachHandler(http.MethodGet, StatusRepliesPath, m.StatusRepliesGETHandler)
 	attachHandler(http.MethodGet, OutboxPath, m.OutboxGETHandler)
+	attachHandler(http.MethodGet, AcceptPath, m.AcceptGETHandler)
 }