GoToSocial/internal/ap/extract.go

932 lines
24 KiB
Go

// 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 (
"crypto"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"fmt"
"net/url"
"strings"
"time"
"github.com/superseriousbusiness/activity/pub"
"github.com/superseriousbusiness/gotosocial/internal/gtserror"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/util"
)
// ExtractPreferredUsername returns a string representation of
// an interface's preferredUsername property. Will return an
// error if preferredUsername is nil, not a string, or empty.
func ExtractPreferredUsername(i WithPreferredUsername) (string, error) {
u := i.GetActivityStreamsPreferredUsername()
if u == nil || !u.IsXMLSchemaString() {
return "", gtserror.New("preferredUsername nil or not a string")
}
if u.GetXMLSchemaString() == "" {
return "", gtserror.New("preferredUsername was empty")
}
return u.GetXMLSchemaString(), nil
}
// ExtractName returns the first string representation it
// can find of an interface's name property, or an empty
// string if this is not found.
func ExtractName(i WithName) string {
nameProp := i.GetActivityStreamsName()
if nameProp == nil {
return ""
}
for iter := nameProp.Begin(); iter != nameProp.End(); iter = iter.Next() {
// Name may be parsed as IRI, depending on
// how it's formatted, so account for this.
switch {
case iter.IsXMLSchemaString():
return iter.GetXMLSchemaString()
case iter.IsIRI():
return iter.GetIRI().String()
}
}
return ""
}
// ExtractInReplyToURI extracts the first inReplyTo URI
// property it can find from an interface. Will return
// nil if no valid URI can be found.
func ExtractInReplyToURI(i WithInReplyTo) *url.URL {
inReplyToProp := i.GetActivityStreamsInReplyTo()
if inReplyToProp == nil {
return nil
}
for iter := inReplyToProp.Begin(); iter != inReplyToProp.End(); iter = iter.Next() {
iri, err := pub.ToId(iter)
if err == nil && iri != nil {
// Found one we can use.
return iri
}
}
return nil
}
// ExtractItemsURIs extracts each URI it can
// find for an item from the provided WithItems.
func ExtractItemsURIs(i WithItems) []*url.URL {
itemsProp := i.GetActivityStreamsItems()
if itemsProp == nil {
return nil
}
uris := make([]*url.URL, 0, itemsProp.Len())
for iter := itemsProp.Begin(); iter != itemsProp.End(); iter = iter.Next() {
uri, err := pub.ToId(iter)
if err == nil {
// Found one we can use.
uris = append(uris, uri)
}
}
return uris
}
// ExtractToURIs returns a slice of URIs
// that the given WithTo addresses as To.
func ExtractToURIs(i WithTo) []*url.URL {
toProp := i.GetActivityStreamsTo()
if toProp == nil {
return nil
}
uris := make([]*url.URL, 0, toProp.Len())
for iter := toProp.Begin(); iter != toProp.End(); iter = iter.Next() {
uri, err := pub.ToId(iter)
if err == nil {
// Found one we can use.
uris = append(uris, uri)
}
}
return uris
}
// ExtractCcURIs returns a slice of URIs
// that the given WithCC addresses as Cc.
func ExtractCcURIs(i WithCC) []*url.URL {
ccProp := i.GetActivityStreamsCc()
if ccProp == nil {
return nil
}
urls := make([]*url.URL, 0, ccProp.Len())
for iter := ccProp.Begin(); iter != ccProp.End(); iter = iter.Next() {
uri, err := pub.ToId(iter)
if err == nil {
// Found one we can use.
urls = append(urls, uri)
}
}
return urls
}
// ExtractAttributedToURI returns the first URI it can find in the
// given WithAttributedTo, or an error if no URI can be found.
func ExtractAttributedToURI(i WithAttributedTo) (*url.URL, error) {
attributedToProp := i.GetActivityStreamsAttributedTo()
if attributedToProp == nil {
return nil, gtserror.New("attributedToProp was nil")
}
for iter := attributedToProp.Begin(); iter != attributedToProp.End(); iter = iter.Next() {
id, err := pub.ToId(iter)
if err == nil {
return id, nil
}
}
return nil, gtserror.New("couldn't find iri for attributed to")
}
// ExtractPublished extracts the published time from the given
// WithPublished. Will return an error if the published property
// is not set, is not a time.Time, or is zero.
func ExtractPublished(i WithPublished) (time.Time, error) {
t := time.Time{}
publishedProp := i.GetActivityStreamsPublished()
if publishedProp == nil {
return t, gtserror.New("published prop was nil")
}
if !publishedProp.IsXMLSchemaDateTime() {
return t, gtserror.New("published prop was not date time")
}
t = publishedProp.Get()
if t.IsZero() {
return t, gtserror.New("published time was zero")
}
return t, nil
}
// ExtractIconURI extracts the first URI it can find from
// the given WithIcon which links to a supported image file.
// Input will look something like this:
//
// "icon": {
// "mediaType": "image/jpeg",
// "type": "Image",
// "url": "http://example.org/path/to/some/file.jpeg"
// },
//
// If no valid URI can be found, this will return an error.
func ExtractIconURI(i WithIcon) (*url.URL, error) {
iconProp := i.GetActivityStreamsIcon()
if iconProp == nil {
return nil, gtserror.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 that we can use to derefereince it.
for iter := iconProp.Begin(); iter != iconProp.End(); iter = iter.Next() {
if !iter.IsActivityStreamsImage() {
continue
}
image := iter.GetActivityStreamsImage()
if image == nil {
continue
}
imageURL, err := ExtractURL(image)
if err == nil && imageURL != nil {
return imageURL, nil
}
}
return nil, gtserror.New("could not extract valid image URI from icon")
}
// ExtractImageURI extracts the first URI it can find from
// the given WithImage which links to a supported image file.
// Input will look something like this:
//
// "image": {
// "mediaType": "image/jpeg",
// "type": "Image",
// "url": "http://example.org/path/to/some/file.jpeg"
// },
//
// If no valid URI can be found, this will return an error.
func ExtractImageURI(i WithImage) (*url.URL, error) {
imageProp := i.GetActivityStreamsImage()
if imageProp == nil {
return nil, gtserror.New("image property was nil")
}
// Image 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 that we can use to derefereince it.
for iter := imageProp.Begin(); iter != imageProp.End(); iter = iter.Next() {
if !iter.IsActivityStreamsImage() {
continue
}
image := iter.GetActivityStreamsImage()
if image == nil {
continue
}
imageURL, err := ExtractURL(image)
if err == nil && imageURL != nil {
return imageURL, nil
}
}
return nil, gtserror.New("could not extract valid image URI from image")
}
// ExtractSummary extracts the summary/content warning of
// the given WithSummary interface. Will return an empty
// string if no summary/content warning was present.
func ExtractSummary(i WithSummary) string {
summaryProp := i.GetActivityStreamsSummary()
if summaryProp == nil {
return ""
}
for iter := summaryProp.Begin(); iter != summaryProp.End(); iter = iter.Next() {
// Summary may be parsed as IRI, depending on
// how it's formatted, so account for this.
switch {
case iter.IsXMLSchemaString():
return iter.GetXMLSchemaString()
case iter.IsIRI():
return iter.GetIRI().String()
}
}
return ""
}
// ExtractFields extracts property/value fields from the given
// WithAttachment interface. Will return an empty slice if no
// property/value fields can be found. Attachments that are not
// (well-formed) PropertyValues will be ignored.
func ExtractFields(i WithAttachment) []*gtsmodel.Field {
attachmentProp := i.GetActivityStreamsAttachment()
if attachmentProp == nil {
// Nothing to do.
return nil
}
l := attachmentProp.Len()
if l == 0 {
// Nothing to do.
return nil
}
fields := make([]*gtsmodel.Field, 0, l)
for iter := attachmentProp.Begin(); iter != attachmentProp.End(); iter = iter.Next() {
if !iter.IsSchemaPropertyValue() {
continue
}
propertyValue := iter.GetSchemaPropertyValue()
if propertyValue == nil {
continue
}
nameProp := propertyValue.GetActivityStreamsName()
if nameProp == nil || nameProp.Len() != 1 {
continue
}
name := nameProp.At(0).GetXMLSchemaString()
if name == "" {
continue
}
valueProp := propertyValue.GetSchemaValue()
if valueProp == nil || !valueProp.IsXMLSchemaString() {
continue
}
value := valueProp.Get()
if value == "" {
continue
}
fields = append(fields, &gtsmodel.Field{
Name: name,
Value: value,
})
}
return fields
}
// ExtractDiscoverable extracts the Discoverable boolean
// of the given WithDiscoverable interface. Will return
// an error if Discoverable was nil.
func ExtractDiscoverable(i WithDiscoverable) (bool, error) {
discoverableProp := i.GetTootDiscoverable()
if discoverableProp == nil {
return false, gtserror.New("discoverable was nil")
}
return discoverableProp.Get(), nil
}
// ExtractURL extracts the first URI it can find from the
// given WithURL interface, or an error if no URL was set.
// The ID of a type will not work, this function wants a URI
// specifically.
func ExtractURL(i WithURL) (*url.URL, error) {
urlProp := i.GetActivityStreamsUrl()
if urlProp == nil {
return nil, gtserror.New("url property was nil")
}
for iter := urlProp.Begin(); iter != urlProp.End(); iter = iter.Next() {
if !iter.IsIRI() {
continue
}
// Found it.
return iter.GetIRI(), nil
}
return nil, gtserror.New("no valid URL property found")
}
// ExtractPublicKey extracts the public key, public key ID, and public
// key owner ID from an interface, or an error if something goes wrong.
func ExtractPublicKey(i WithPublicKey) (
*rsa.PublicKey, // pubkey
*url.URL, // pubkey ID
*url.URL, // pubkey owner
error,
) {
pubKeyProp := i.GetW3IDSecurityV1PublicKey()
if pubKeyProp == nil {
return nil, nil, nil, gtserror.New("public key property was nil")
}
for iter := pubKeyProp.Begin(); iter != pubKeyProp.End(); iter = iter.Next() {
if !iter.IsW3IDSecurityV1PublicKey() {
continue
}
pkey := iter.Get()
if pkey == nil {
continue
}
pubKeyID, err := pub.GetId(pkey)
if err != nil {
continue
}
pubKeyOwnerProp := pkey.GetW3IDSecurityV1Owner()
if pubKeyOwnerProp == nil {
continue
}
pubKeyOwner := pubKeyOwnerProp.GetIRI()
if pubKeyOwner == nil {
continue
}
pubKeyPemProp := pkey.GetW3IDSecurityV1PublicKeyPem()
if pubKeyPemProp == nil {
continue
}
pkeyPem := pubKeyPemProp.Get()
if pkeyPem == "" {
continue
}
block, _ := pem.Decode([]byte(pkeyPem))
if block == nil {
continue
}
var p crypto.PublicKey
switch block.Type {
case "PUBLIC KEY":
p, err = x509.ParsePKIXPublicKey(block.Bytes)
case "RSA PUBLIC KEY":
p, err = x509.ParsePKCS1PublicKey(block.Bytes)
default:
err = fmt.Errorf("unknown block type: %q", block.Type)
}
if err != nil {
err = gtserror.Newf("could not parse public key from block bytes: %w", err)
return nil, nil, nil, err
}
if p == nil {
return nil, nil, nil, gtserror.New("returned public key was empty")
}
pubKey, ok := p.(*rsa.PublicKey)
if !ok {
continue
}
return pubKey, pubKeyID, pubKeyOwner, nil
}
return nil, nil, nil, gtserror.New("couldn't find public key")
}
// ExtractContent returns a string representation of the
// given interface's Content property, or an empty string
// if no Content is found.
func ExtractContent(i WithContent) string {
contentProperty := i.GetActivityStreamsContent()
if contentProperty == nil {
return ""
}
for iter := contentProperty.Begin(); iter != contentProperty.End(); iter = iter.Next() {
switch {
// Content may be parsed as IRI, depending on
// how it's formatted, so account for this.
case iter.IsXMLSchemaString():
return iter.GetXMLSchemaString()
case iter.IsIRI():
return iter.GetIRI().String()
}
}
return ""
}
// ExtractAttachment extracts a minimal gtsmodel.Attachment
// (just remote URL, description, and blurhash) from the given
// Attachmentable interface, or an error if no remote URL is set.
func ExtractAttachment(i Attachmentable) (*gtsmodel.MediaAttachment, error) {
// Get the URL for the attachment file.
// If no URL is set, we can't do anything.
remoteURL, err := ExtractURL(i)
if err != nil {
return nil, gtserror.Newf("error extracting attachment URL: %w", err)
}
return &gtsmodel.MediaAttachment{
RemoteURL: remoteURL.String(),
Description: ExtractName(i),
Blurhash: ExtractBlurhash(i),
Processing: gtsmodel.ProcessingStatusReceived,
}, nil
}
// ExtractBlurhash extracts the blurhash string value
// from the given WithBlurhash interface, or returns
// an empty string if nothing is found.
func ExtractBlurhash(i WithBlurhash) string {
blurhashProp := i.GetTootBlurhash()
if blurhashProp == nil {
return ""
}
return blurhashProp.Get()
}
// ExtractHashtags extracts a slice of minimal gtsmodel.Tags
// from a WithTag. If an entry in the WithTag is not a hashtag,
// it will be quietly ignored.
//
// TODO: find a better heuristic for determining if something
// is a hashtag or not, since looking for type name "Hashtag"
// is non-normative. Perhaps look for things that are either
// type "Hashtag" or have no type name set at all?
func ExtractHashtags(i WithTag) ([]*gtsmodel.Tag, error) {
tagsProp := i.GetActivityStreamsTag()
if tagsProp == nil {
return nil, nil
}
var (
l = tagsProp.Len()
tags = make([]*gtsmodel.Tag, 0, l)
keys = make(map[string]any, l) // Use map to dedupe items.
)
for iter := tagsProp.Begin(); iter != tagsProp.End(); iter = iter.Next() {
t := iter.GetType()
if t == nil {
continue
}
if t.GetTypeName() != TagHashtag {
continue
}
hashtaggable, ok := t.(Hashtaggable)
if !ok {
continue
}
tag, err := ExtractHashtag(hashtaggable)
if err != nil {
continue
}
// Only append this tag if we haven't
// seen it already, to avoid duplicates
// in the slice.
if _, set := keys[tag.URL]; !set {
keys[tag.URL] = nil // Value doesn't matter.
tags = append(tags, tag)
tags = append(tags, tag)
tags = append(tags, tag)
}
}
return tags, nil
}
// ExtractEmoji extracts a minimal gtsmodel.Tag
// from the given Hashtaggable.
func ExtractHashtag(i Hashtaggable) (*gtsmodel.Tag, error) {
// Extract href/link for this tag.
hrefProp := i.GetActivityStreamsHref()
if hrefProp == nil || !hrefProp.IsIRI() {
return nil, gtserror.New("no href prop")
}
tagURL := hrefProp.GetIRI().String()
// Extract name for the tag; trim leading hash
// character, so '#example' becomes 'example'.
name := ExtractName(i)
if name == "" {
return nil, gtserror.New("name prop empty")
}
tagName := strings.TrimPrefix(name, "#")
return &gtsmodel.Tag{
URL: tagURL,
Name: tagName,
}, nil
}
// ExtractEmojis extracts a slice of minimal gtsmodel.Emojis
// from a WithTag. If an entry in the WithTag is not an emoji,
// it will be quietly ignored.
func ExtractEmojis(i WithTag) ([]*gtsmodel.Emoji, error) {
tagsProp := i.GetActivityStreamsTag()
if tagsProp == nil {
return nil, nil
}
var (
l = tagsProp.Len()
emojis = make([]*gtsmodel.Emoji, 0, l)
keys = make(map[string]any, l) // Use map to dedupe items.
)
for iter := tagsProp.Begin(); iter != tagsProp.End(); iter = iter.Next() {
if !iter.IsTootEmoji() {
continue
}
tootEmoji := iter.GetTootEmoji()
if tootEmoji == nil {
continue
}
emoji, err := ExtractEmoji(tootEmoji)
if err != nil {
return nil, err
}
// Only append this emoji if we haven't
// seen it already, to avoid duplicates
// in the slice.
if _, set := keys[emoji.URI]; !set {
keys[emoji.URI] = nil // Value doesn't matter.
emojis = append(emojis, emoji)
}
}
return emojis, nil
}
// ExtractEmoji extracts a minimal gtsmodel.Emoji
// from the given Emojiable.
func ExtractEmoji(i Emojiable) (*gtsmodel.Emoji, error) {
// Use AP ID as emoji URI.
idProp := i.GetJSONLDId()
if idProp == nil || !idProp.IsIRI() {
return nil, gtserror.New("no id for emoji")
}
uri := idProp.GetIRI()
// Extract emoji last updated time (optional).
var updatedAt time.Time
updatedProp := i.GetActivityStreamsUpdated()
if updatedProp != nil && updatedProp.IsXMLSchemaDateTime() {
updatedAt = updatedProp.Get()
}
// Extract emoji name aka shortcode.
name := ExtractName(i)
if name == "" {
return nil, gtserror.New("name prop empty")
}
shortcode := strings.Trim(name, ":")
// Extract emoji image URL from Icon property.
imageRemoteURL, err := ExtractIconURI(i)
if err != nil {
return nil, gtserror.New("no url for emoji image")
}
imageRemoteURLStr := imageRemoteURL.String()
return &gtsmodel.Emoji{
UpdatedAt: updatedAt,
Shortcode: shortcode,
Domain: uri.Host,
ImageRemoteURL: imageRemoteURLStr,
URI: uri.String(),
Disabled: new(bool), // Assume false by default.
VisibleInPicker: new(bool), // Assume false by default.
}, nil
}
// ExtractMentions extracts a slice of minimal gtsmodel.Mentions
// from a WithTag. If an entry in the WithTag is not a mention,
// it will be quietly ignored.
func ExtractMentions(i WithTag) ([]*gtsmodel.Mention, error) {
tagsProp := i.GetActivityStreamsTag()
if tagsProp == nil {
return nil, nil
}
var (
l = tagsProp.Len()
mentions = make([]*gtsmodel.Mention, 0, l)
keys = make(map[string]any, l) // Use map to dedupe items.
)
for iter := tagsProp.Begin(); iter != tagsProp.End(); iter = iter.Next() {
if !iter.IsActivityStreamsMention() {
continue
}
asMention := iter.GetActivityStreamsMention()
if asMention == nil {
continue
}
mention, err := ExtractMention(asMention)
if err != nil {
return nil, err
}
// Only append this mention if we haven't
// seen it already, to avoid duplicates
// in the slice.
if _, set := keys[mention.TargetAccountURI]; !set {
keys[mention.TargetAccountURI] = nil // Value doesn't matter.
mentions = append(mentions, mention)
}
}
return mentions, nil
}
// ExtractMention extracts a minimal gtsmodel.Mention from a Mentionable.
func ExtractMention(i Mentionable) (*gtsmodel.Mention, error) {
nameString := ExtractName(i)
if nameString == "" {
return nil, gtserror.New("name prop empty")
}
// Ensure namestring is valid so we
// can handle it properly later on.
if _, _, err := util.ExtractNamestringParts(nameString); err != nil {
return nil, err
}
// The href prop should be the AP URI
// of the target account.
hrefProp := i.GetActivityStreamsHref()
if hrefProp == nil || !hrefProp.IsIRI() {
return nil, gtserror.New("no href prop")
}
return &gtsmodel.Mention{
NameString: nameString,
TargetAccountURI: hrefProp.GetIRI().String(),
}, nil
}
// ExtractActorURI extracts the first Actor URI
// it can find from a WithActor interface.
func ExtractActorURI(withActor WithActor) (*url.URL, error) {
actorProp := withActor.GetActivityStreamsActor()
if actorProp == nil {
return nil, gtserror.New("actor property was nil")
}
for iter := actorProp.Begin(); iter != actorProp.End(); iter = iter.Next() {
id, err := pub.ToId(iter)
if err == nil {
// Found one we can use.
return id, nil
}
}
return nil, gtserror.New("no iri found for actor prop")
}
// ExtractObjectURI extracts the first Object URI
// it can find from a WithObject interface.
func ExtractObjectURI(withObject WithObject) (*url.URL, error) {
objectProp := withObject.GetActivityStreamsObject()
if objectProp == nil {
return nil, gtserror.New("object property was nil")
}
for iter := objectProp.Begin(); iter != objectProp.End(); iter = iter.Next() {
id, err := pub.ToId(iter)
if err == nil {
// Found one we can use.
return id, nil
}
}
return nil, gtserror.New("no iri found for object prop")
}
// ExtractObjectURIs extracts the URLs of each Object
// it can find from a WithObject interface.
func ExtractObjectURIs(withObject WithObject) ([]*url.URL, error) {
objectProp := withObject.GetActivityStreamsObject()
if objectProp == nil {
return nil, gtserror.New("object property was nil")
}
urls := make([]*url.URL, 0, objectProp.Len())
for iter := objectProp.Begin(); iter != objectProp.End(); iter = iter.Next() {
id, err := pub.ToId(iter)
if err == nil {
// Found one we can use.
urls = append(urls, id)
}
}
return urls, nil
}
// ExtractVisibility extracts the gtsmodel.Visibility
// of a given addressable with a To and CC property.
//
// ActorFollowersURI is needed to check whether the
// visibility is FollowersOnly or not. The passed-in
// value should just be the string value representation
// of the followers URI of the actor who created the activity,
// eg., `https://example.org/users/whoever/followers`.
func ExtractVisibility(addressable Addressable, actorFollowersURI string) (gtsmodel.Visibility, error) {
var (
to = ExtractToURIs(addressable)
cc = ExtractCcURIs(addressable)
)
if len(to) == 0 && len(cc) == 0 {
return "", gtserror.Newf("message wasn't TO or CC anyone")
}
// Assume most restrictive visibility,
// and work our way up from there.
visibility := gtsmodel.VisibilityDirect
if isFollowers(to, actorFollowersURI) {
// Followers in TO: it's at least followers only.
visibility = gtsmodel.VisibilityFollowersOnly
}
if isPublic(cc) {
// CC'd to public: it's at least unlocked.
visibility = gtsmodel.VisibilityUnlocked
}
if isPublic(to) {
// TO'd to public: it's a public post.
visibility = gtsmodel.VisibilityPublic
}
return visibility, nil
}
// ExtractSensitive extracts whether or not an item should
// be marked as sensitive according to its ActivityStreams
// sensitive property.
//
// If no sensitive property is set on the item at all, or
// if this property isn't a boolean, then false will be
// returned by default.
func ExtractSensitive(withSensitive WithSensitive) bool {
sensitiveProp := withSensitive.GetActivityStreamsSensitive()
if sensitiveProp == nil {
return false
}
for iter := sensitiveProp.Begin(); iter != sensitiveProp.End(); iter = iter.Next() {
if iter.IsXMLSchemaBoolean() {
return iter.Get()
}
}
return false
}
// ExtractSharedInbox extracts the sharedInbox URI property
// from an Actor. Returns nil if this property is not set.
func ExtractSharedInbox(withEndpoints WithEndpoints) *url.URL {
endpointsProp := withEndpoints.GetActivityStreamsEndpoints()
if endpointsProp == nil {
return nil
}
for iter := endpointsProp.Begin(); iter != endpointsProp.End(); iter = iter.Next() {
if !iter.IsActivityStreamsEndpoints() {
continue
}
endpoints := iter.Get()
if endpoints == nil {
continue
}
sharedInboxProp := endpoints.GetActivityStreamsSharedInbox()
if sharedInboxProp == nil || !sharedInboxProp.IsIRI() {
continue
}
return sharedInboxProp.GetIRI()
}
return nil
}
// isPublic checks if at least one entry in the given
// uris slice equals the activitystreams public uri.
func isPublic(uris []*url.URL) bool {
for _, uri := range uris {
if pub.IsPublic(uri.String()) {
return true
}
}
return false
}
// isFollowers checks if at least one entry in the given
// uris slice equals the given followersURI.
func isFollowers(uris []*url.URL, followersURI string) bool {
for _, uri := range uris {
if strings.EqualFold(uri.String(), followersURI) {
return true
}
}
return false
}