Ap (#14)

Big restructuring and initial work on activitypub

internal/api/s2s/user/userget.go

@@ -0,0 +1,67 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   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 user
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/sirupsen/logrus"
+)
+
+// UsersGETHandler should be served at https://example.org/users/:username.
+//
+// The goal here is to return the activitypub representation of an account
+// in the form of a vocab.ActivityStreamsPerson. This should only be served
+// to REMOTE SERVERS that present a valid signature on the GET request, on
+// behalf of a user, otherwise we risk leaking information about users publicly.
+//
+// And of course, the request should be refused if the account or server making the
+// request is blocked.
+func (m *Module) UsersGETHandler(c *gin.Context) {
+	l := m.log.WithFields(logrus.Fields{
+		"func": "UsersGETHandler",
+		"url":  c.Request.RequestURI,
+	})
+
+	requestedUsername := c.Param(UsernameKey)
+	if requestedUsername == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "no username specified in request"})
+		return
+	}
+
+	// make sure this actually an AP request
+	format := c.NegotiateFormat(ActivityPubAcceptHeaders...)
+	if format == "" {
+		c.JSON(http.StatusNotAcceptable, gin.H{"error": "could not negotiate format with given Accept header(s)"})
+		return
+	}
+	l.Tracef("negotiated format: %s", format)
+
+	// make a copy of the context to pass along so we don't break anything
+	cp := c.Copy()
+	user, err := m.processor.GetFediUser(requestedUsername, cp.Request) // GetAPUser handles auth as well
+	if err != nil {
+		l.Info(err.Error())
+		c.JSON(err.Code(), gin.H{"error": err.Safe()})
+		return
+	}
+
+	c.JSON(http.StatusOK, user)
+}