gotosocial/internal/ap/normalize.go

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// 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 ap
import (
"github.com/superseriousbusiness/activity/pub"
"github.com/superseriousbusiness/activity/streams"
"github.com/superseriousbusiness/gotosocial/internal/text"
)
/*
NORMALIZE INCOMING
The below functions should be called to normalize the content
of messages *COMING INTO* GoToSocial via the federation API,
either as the result of delivery from a remote instance to this
instance, or as a result of this instance doing an http call to
another instance to dereference something.
*/
// NormalizeIncomingActivityObject normalizes the 'object'.'content' field of the given Activity.
//
// The rawActivity map should the freshly deserialized json representation of the Activity.
//
// This function is a noop if the type passed in is anything except a Create or Update with a Statusable or Accountable as its Object.
func NormalizeIncomingActivityObject(activity pub.Activity, rawJSON map[string]interface{}) {
if typeName := activity.GetTypeName(); typeName != ActivityCreate && typeName != ActivityUpdate {
// Only interested in Create or Update right now.
return
}
withObject, ok := activity.(WithObject)
if !ok {
// Create was not a WithObject.
return
}
createObject := withObject.GetActivityStreamsObject()
if createObject == nil {
// No object set.
return
}
if createObject.Len() != 1 {
// Not interested in Object arrays.
return
}
// We now know length is 1 so get the first
// item from the iter. We need this to be
// a Statusable or Accountable if we're to continue.
i := createObject.At(0)
if i == nil {
// This is awkward.
return
}
t := i.GetType()
if t == nil {
// This is also awkward.
return
}
switch t.GetTypeName() {
case ObjectArticle, ObjectDocument, ObjectImage, ObjectVideo, ObjectNote, ObjectPage, ObjectEvent, ObjectPlace, ObjectProfile:
statusable, ok := t.(Statusable)
if !ok {
// Object is not Statusable;
// we're not interested.
return
}
rawObject, ok := rawJSON["object"]
if !ok {
// No object in raw map.
return
}
rawStatusableJSON, ok := rawObject.(map[string]interface{})
if !ok {
// Object wasn't a json object.
return
}
// Normalize everything we can on the statusable.
NormalizeIncomingContent(statusable, rawStatusableJSON)
NormalizeIncomingAttachments(statusable, rawStatusableJSON)
NormalizeIncomingSummary(statusable, rawStatusableJSON)
NormalizeIncomingName(statusable, rawStatusableJSON)
case ActorApplication, ActorGroup, ActorOrganization, ActorPerson, ActorService:
accountable, ok := t.(Accountable)
if !ok {
// Object is not Accountable;
// we're not interested.
return
}
rawObject, ok := rawJSON["object"]
if !ok {
// No object in raw map.
return
}
rawAccountableJSON, ok := rawObject.(map[string]interface{})
if !ok {
// Object wasn't a json object.
return
}
// Normalize everything we can on the accountable.
NormalizeIncomingSummary(accountable, rawAccountableJSON)
}
}
// NormalizeIncomingContent replaces the Content of the given item
// with the sanitized version of the raw 'content' value from the
// raw json object map.
//
// noop if there was no content in the json object map or the
// content was not a plain string.
func NormalizeIncomingContent(item WithSetContent, rawJSON map[string]interface{}) {
rawContent, ok := rawJSON["content"]
if !ok {
// No content in rawJSON.
// TODO: In future we might also
// look for "contentMap" property.
return
}
content, ok := rawContent.(string)
if !ok {
// Not interested in content arrays.
return
}
// Content should be HTML encoded by default:
// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-content
//
// TODO: sanitize differently based on mediaType.
// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-mediatype
content = text.SanitizeToHTML(content)
content = text.MinifyHTML(content)
// Set normalized content property from the raw string;
// this replaces any existing content property on the item.
contentProp := streams.NewActivityStreamsContentProperty()
contentProp.AppendXMLSchemaString(content)
item.SetActivityStreamsContent(contentProp)
}
// NormalizeIncomingAttachments normalizes all attachments (if any) of the given
// item, replacing the 'name' (aka content warning) field of each attachment
// with the raw 'name' value from the raw json object map, and doing sanitization
// on the result.
//
// noop if there are no attachments; noop if attachment is not a format
// we can understand.
func NormalizeIncomingAttachments(item WithAttachment, rawJSON map[string]interface{}) {
rawAttachments, ok := rawJSON["attachment"]
if !ok {
// No attachments in rawJSON.
return
}
// Convert to slice if not already,
// so we can iterate through it.
var attachments []interface{}
if attachments, ok = rawAttachments.([]interface{}); !ok {
attachments = []interface{}{rawAttachments}
}
attachmentProperty := item.GetActivityStreamsAttachment()
if attachmentProperty == nil {
// Nothing to do here.
return
}
if l := attachmentProperty.Len(); l == 0 || l != len(attachments) {
// Mismatch between item and
// JSON, can't normalize.
return
}
// Keep an index of where we are in the iter;
// we need this so we can modify the correct
// attachment, in case of multiples.
i := -1
for iter := attachmentProperty.Begin(); iter != attachmentProperty.End(); iter = iter.Next() {
i++
t := iter.GetType()
if t == nil {
continue
}
attachmentable, ok := t.(Attachmentable)
if !ok {
continue
}
rawAttachment, ok := attachments[i].(map[string]interface{})
if !ok {
continue
}
NormalizeIncomingName(attachmentable, rawAttachment)
}
}
// NormalizeIncomingSummary replaces the Summary of the given item
// with the sanitized version of the raw 'summary' value from the
// raw json object map.
//
// noop if there was no summary in the json object map or the
// summary was not a plain string.
func NormalizeIncomingSummary(item WithSetSummary, rawJSON map[string]interface{}) {
rawSummary, ok := rawJSON["summary"]
if !ok {
// No summary in rawJSON.
return
}
summary, ok := rawSummary.(string)
if !ok {
// Not interested in non-string summary.
return
}
// Summary should be HTML encoded:
// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-summary
summary = text.SanitizeToHTML(summary)
summary = text.MinifyHTML(summary)
// Set normalized summary property from the raw string; this
// will replace any existing summary property on the item.
summaryProp := streams.NewActivityStreamsSummaryProperty()
summaryProp.AppendXMLSchemaString(summary)
item.SetActivityStreamsSummary(summaryProp)
}
// NormalizeIncomingName replaces the Name of the given item
// with the raw 'name' value from the raw json object map.
//
// noop if there was no name in the json object map or the
// name was not a plain string.
func NormalizeIncomingName(item WithSetName, rawJSON map[string]interface{}) {
rawName, ok := rawJSON["name"]
if !ok {
// No name in rawJSON.
return
}
name, ok := rawName.(string)
if !ok {
// Not interested in non-string name.
return
}
// Name *must not* include any HTML markup:
// https://www.w3.org/TR/activitystreams-vocabulary/#dfn-name
//
// todo: We probably want to update this to allow
// *escaped* HTML markup, but for now just nuke it.
name = text.SanitizeToPlaintext(name)
// Set normalized name property from the raw string; this
// will replace any existing name property on the item.
nameProp := streams.NewActivityStreamsNameProperty()
nameProp.AppendXMLSchemaString(name)
item.SetActivityStreamsName(nameProp)
}