gotosocial/internal/typeutils/asextractionutil.go
Tobi Smethurst 6f5c045284
Ap (#14)
Big restructuring and initial work on activitypub
2021-05-08 14:25:55 +02:00

217 lines
6.4 KiB
Go

/*
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 typeutils
import (
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"errors"
"fmt"
"net/url"
"github.com/go-fed/activity/pub"
)
func extractPreferredUsername(i withPreferredUsername) (string, error) {
u := i.GetActivityStreamsPreferredUsername()
if u == nil || !u.IsXMLSchemaString() {
return "", errors.New("preferredUsername was not a string")
}
if u.GetXMLSchemaString() == "" {
return "", errors.New("preferredUsername was empty")
}
return u.GetXMLSchemaString(), nil
}
func extractName(i withDisplayName) (string, error) {
nameProp := i.GetActivityStreamsName()
if nameProp == nil {
return "", errors.New("activityStreamsName not found")
}
// take the first name string we can find
for nameIter := nameProp.Begin(); nameIter != nameProp.End(); nameIter = nameIter.Next() {
if nameIter.IsXMLSchemaString() && nameIter.GetXMLSchemaString() != "" {
return nameIter.GetXMLSchemaString(), nil
}
}
return "", errors.New("activityStreamsName not found")
}
// extractIconURL extracts a URL to a supported image file from something like:
// "icon": {
// "mediaType": "image/jpeg",
// "type": "Image",
// "url": "http://example.org/path/to/some/file.jpeg"
// },
func extractIconURL(i withIcon) (*url.URL, error) {
iconProp := i.GetActivityStreamsIcon()
if iconProp == nil {
return nil, errors.New("icon property was nil")
}
// icon can potentially contain multiple entries, so we iterate through all of them
// here in order to find the first one that meets these criteria:
// 1. is an image
// 2. has a URL so we can grab it
for iconIter := iconProp.Begin(); iconIter != iconProp.End(); iconIter = iconIter.Next() {
// 1. is an image
if !iconIter.IsActivityStreamsImage() {
continue
}
imageValue := iconIter.GetActivityStreamsImage()
if imageValue == nil {
continue
}
// 2. has a URL so we can grab it
url, err := extractURL(imageValue)
if err == nil && url != nil {
return url, nil
}
}
// if we get to this point we didn't find an icon meeting our criteria :'(
return nil, errors.New("could not extract valid image from icon")
}
// extractImageURL extracts a URL to a supported image file from something like:
// "image": {
// "mediaType": "image/jpeg",
// "type": "Image",
// "url": "http://example.org/path/to/some/file.jpeg"
// },
func extractImageURL(i withImage) (*url.URL, error) {
imageProp := i.GetActivityStreamsImage()
if imageProp == nil {
return nil, errors.New("icon property was nil")
}
// icon can potentially contain multiple entries, so we iterate through all of them
// here in order to find the first one that meets these criteria:
// 1. is an image
// 2. has a URL so we can grab it
for imageIter := imageProp.Begin(); imageIter != imageProp.End(); imageIter = imageIter.Next() {
// 1. is an image
if !imageIter.IsActivityStreamsImage() {
continue
}
imageValue := imageIter.GetActivityStreamsImage()
if imageValue == nil {
continue
}
// 2. has a URL so we can grab it
url, err := extractURL(imageValue)
if err == nil && url != nil {
return url, nil
}
}
// if we get to this point we didn't find an image meeting our criteria :'(
return nil, errors.New("could not extract valid image from image property")
}
func extractSummary(i withSummary) (string, error) {
summaryProp := i.GetActivityStreamsSummary()
if summaryProp == nil {
return "", errors.New("summary property was nil")
}
for summaryIter := summaryProp.Begin(); summaryIter != summaryProp.End(); summaryIter = summaryIter.Next() {
if summaryIter.IsXMLSchemaString() && summaryIter.GetXMLSchemaString() != "" {
return summaryIter.GetXMLSchemaString(), nil
}
}
return "", errors.New("could not extract summary")
}
func extractDiscoverable(i withDiscoverable) (bool, error) {
if i.GetTootDiscoverable() == nil {
return false, errors.New("discoverable was nil")
}
return i.GetTootDiscoverable().Get(), nil
}
func extractURL(i withURL) (*url.URL, error) {
urlProp := i.GetActivityStreamsUrl()
if urlProp == nil {
return nil, errors.New("url property was nil")
}
for urlIter := urlProp.Begin(); urlIter != urlProp.End(); urlIter = urlIter.Next() {
if urlIter.IsIRI() && urlIter.GetIRI() != nil {
return urlIter.GetIRI(), nil
}
}
return nil, errors.New("could not extract url")
}
func extractPublicKeyForOwner(i withPublicKey, forOwner *url.URL) (*rsa.PublicKey, *url.URL, error) {
publicKeyProp := i.GetW3IDSecurityV1PublicKey()
if publicKeyProp == nil {
return nil, nil, errors.New("public key property was nil")
}
for publicKeyIter := publicKeyProp.Begin(); publicKeyIter != publicKeyProp.End(); publicKeyIter = publicKeyIter.Next() {
pkey := publicKeyIter.Get()
if pkey == nil {
continue
}
pkeyID, err := pub.GetId(pkey)
if err != nil || pkeyID == nil {
continue
}
if pkey.GetW3IDSecurityV1Owner() == nil || pkey.GetW3IDSecurityV1Owner().Get() == nil || pkey.GetW3IDSecurityV1Owner().Get().String() != forOwner.String() {
continue
}
if pkey.GetW3IDSecurityV1PublicKeyPem() == nil {
continue
}
pkeyPem := pkey.GetW3IDSecurityV1PublicKeyPem().Get()
if pkeyPem == "" {
continue
}
block, _ := pem.Decode([]byte(pkeyPem))
if block == nil || block.Type != "PUBLIC KEY" {
return nil, nil, errors.New("could not decode publicKeyPem to PUBLIC KEY pem block type")
}
p, err := x509.ParsePKIXPublicKey(block.Bytes)
if err != nil {
return nil, nil, fmt.Errorf("could not parse public key from block bytes: %s", err)
}
if p == nil {
return nil, nil, errors.New("returned public key was empty")
}
if publicKey, ok := p.(*rsa.PublicKey); ok {
return publicKey, pkeyID, nil
}
}
return nil, nil, errors.New("couldn't find public key")
}