diff options
Diffstat (limited to 'app/helpers')
| -rw-r--r-- | app/helpers/context_helper.rb | 55 | ||||
| -rw-r--r-- | app/helpers/jsonld_helper.rb | 80 |
2 files changed, 135 insertions, 0 deletions
diff --git a/app/helpers/context_helper.rb b/app/helpers/context_helper.rb new file mode 100644 index 000000000..2f5fecaae --- /dev/null +++ b/app/helpers/context_helper.rb @@ -0,0 +1,55 @@ +# frozen_string_literal: true + +module ContextHelper + NAMED_CONTEXT_MAP = { + activitystreams: 'https://www.w3.org/ns/activitystreams', + security: 'https://w3id.org/security/v1', + }.freeze + + CONTEXT_EXTENSION_MAP = { + direct_message: { 'litepub' => 'http://litepub.social/ns#', 'directMessage' => 'litepub:directMessage' }, + manually_approves_followers: { 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers' }, + sensitive: { 'sensitive' => 'as:sensitive' }, + hashtag: { 'Hashtag' => 'as:Hashtag' }, + moved_to: { 'movedTo' => { '@id' => 'as:movedTo', '@type' => '@id' } }, + also_known_as: { 'alsoKnownAs' => { '@id' => 'as:alsoKnownAs', '@type' => '@id' } }, + emoji: { 'toot' => 'http://joinmastodon.org/ns#', 'Emoji' => 'toot:Emoji' }, + featured: { 'toot' => 'http://joinmastodon.org/ns#', 'featured' => { '@id' => 'toot:featured', '@type' => '@id' }, 'featuredTags' => { '@id' => 'toot:featuredTags', '@type' => '@id' } }, + property_value: { 'schema' => 'http://schema.org#', 'PropertyValue' => 'schema:PropertyValue', 'value' => 'schema:value' }, + atom_uri: { 'ostatus' => 'http://ostatus.org#', 'atomUri' => 'ostatus:atomUri' }, + conversation: { 'ostatus' => 'http://ostatus.org#', 'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri', 'conversation' => 'ostatus:conversation' }, + focal_point: { 'toot' => 'http://joinmastodon.org/ns#', 'focalPoint' => { '@container' => '@list', '@id' => 'toot:focalPoint' } }, + blurhash: { 'toot' => 'http://joinmastodon.org/ns#', 'blurhash' => 'toot:blurhash' }, + discoverable: { 'toot' => 'http://joinmastodon.org/ns#', 'discoverable' => 'toot:discoverable' }, + voters_count: { 'toot' => 'http://joinmastodon.org/ns#', 'votersCount' => 'toot:votersCount' }, + olm: { 'toot' => 'http://joinmastodon.org/ns#', 'Device' => 'toot:Device', 'Ed25519Signature' => 'toot:Ed25519Signature', 'Ed25519Key' => 'toot:Ed25519Key', 'Curve25519Key' => 'toot:Curve25519Key', 'EncryptedMessage' => 'toot:EncryptedMessage', 'publicKeyBase64' => 'toot:publicKeyBase64', 'deviceId' => 'toot:deviceId', 'claim' => { '@type' => '@id', '@id' => 'toot:claim' }, 'fingerprintKey' => { '@type' => '@id', '@id' => 'toot:fingerprintKey' }, 'identityKey' => { '@type' => '@id', '@id' => 'toot:identityKey' }, 'devices' => { '@type' => '@id', '@id' => 'toot:devices' }, 'messageFranking' => 'toot:messageFranking', 'messageType' => 'toot:messageType', 'cipherText' => 'toot:cipherText' }, + suspended: { 'toot' => 'http://joinmastodon.org/ns#', 'suspended' => 'toot:suspended' }, + }.freeze + + def full_context + serialized_context(NAMED_CONTEXT_MAP, CONTEXT_EXTENSION_MAP) + end + + def serialized_context(named_contexts_map, context_extensions_map) + context_array = [] + + named_contexts = named_contexts_map.keys + context_extensions = context_extensions_map.keys + + named_contexts.each do |key| + context_array << NAMED_CONTEXT_MAP[key] + end + + extensions = context_extensions.each_with_object({}) do |key, h| + h.merge!(CONTEXT_EXTENSION_MAP[key]) + end + + context_array << extensions unless extensions.empty? + + if context_array.size == 1 + context_array.first + else + context_array + end + end +end diff --git a/app/helpers/jsonld_helper.rb b/app/helpers/jsonld_helper.rb index c24d2ddf1..c6557817d 100644 --- a/app/helpers/jsonld_helper.rb +++ b/app/helpers/jsonld_helper.rb @@ -1,6 +1,8 @@ # frozen_string_literal: true module JsonLdHelper + include ContextHelper + def equals_or_includes?(haystack, needle) haystack.is_a?(Array) ? haystack.include?(needle) : haystack == needle end @@ -69,6 +71,84 @@ module JsonLdHelper graph.dump(:normalize) end + def compact(json) + compacted = JSON::LD::API.compact(json.without('signature'), full_context, documentLoader: method(:load_jsonld_context)) + compacted['signature'] = json['signature'] + compacted + end + + # Patches a JSON-LD document to avoid compatibility issues on redistribution + # + # Since compacting a JSON-LD document against Mastodon's built-in vocabulary + # means other extension namespaces will be expanded, malformed JSON-LD + # attributes lost, and some values “unexpectedly” compacted this method + # patches the following likely sources of incompatibility: + # - 'https://www.w3.org/ns/activitystreams#Public' being compacted to + # 'as:Public' (for instance, pre-3.4.0 Mastodon does not understand + # 'as:Public') + # - single-item arrays being compacted to the item itself (`[foo]` being + # compacted to `foo`) + # + # It is not always possible for `patch_for_forwarding!` to produce a document + # deemed safe for forwarding. Use `safe_for_forwarding?` to check the status + # of the output document. + # + # @param original [Hash] The original JSON-LD document used as reference + # @param compacted [Hash] The compacted JSON-LD document to be patched + # @return [void] + def patch_for_forwarding!(original, compacted) + original.without('@context', 'signature').each do |key, value| + next if value.nil? || !compacted.key?(key) + + compacted_value = compacted[key] + if value.is_a?(Hash) && compacted_value.is_a?(Hash) + patch_for_forwarding!(value, compacted_value) + elsif value.is_a?(Array) + compacted_value = [compacted_value] unless compacted_value.is_a?(Array) + return if value.size != compacted_value.size + + compacted[key] = value.zip(compacted_value).map do |v, vc| + if v.is_a?(Hash) && vc.is_a?(Hash) + patch_for_forwarding!(v, vc) + vc + elsif v == 'https://www.w3.org/ns/activitystreams#Public' && vc == 'as:Public' + v + else + vc + end + end + elsif value == 'https://www.w3.org/ns/activitystreams#Public' && compacted_value == 'as:Public' + compacted[key] = value + end + end + end + + # Tests whether a JSON-LD compaction is deemed safe for redistribution, + # that is, if it doesn't change its meaning to consumers that do not actually + # handle JSON-LD, but rely on values being serialized in a certain way. + # + # See `patch_for_forwarding!` for details. + # + # @param original [Hash] The original JSON-LD document used as reference + # @param compacted [Hash] The compacted JSON-LD document to be patched + # @return [Boolean] Whether the patched document is deemed safe + def safe_for_forwarding?(original, compacted) + original.without('@context', 'signature').all? do |key, value| + compacted_value = compacted[key] + return false unless value.class == compacted_value.class + + if value.is_a?(Hash) + safe_for_forwarding?(value, compacted_value) + elsif value.is_a?(Array) + value.zip(compacted_value).all? do |v, vc| + v.is_a?(Hash) ? (vc.is_a?(Hash) && safe_for_forwarding?(v, vc)) : v == vc + end + else + value == compacted_value + end + end + end + def fetch_resource(uri, id, on_behalf_of = nil) unless id json = fetch_resource_without_id_validation(uri, on_behalf_of) |