mirror of
https://github.com/mastodon/mastodon.git
synced 2026-07-29 05:58:52 -05:00
83 lines
3.3 KiB
Ruby
83 lines
3.3 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
# This is an implementation of https://codeberg.org/fediverse/fep/src/branch/main/fep/8b32/fep-8b32.md
|
|
class ActivityPub::ObjectIntegrityProof
|
|
include JsonLdHelper
|
|
|
|
SUPPORTED_CRYPTOSUITES = %w(eddsa-jcs-2022 mldsa44-jcs-2024).freeze
|
|
|
|
def initialize(json)
|
|
@json = json
|
|
end
|
|
|
|
def verify_actor!(proof_purpose: 'assertionMethod')
|
|
return unless @json.is_a?(Hash) && @json['proof'].is_a?(Hash)
|
|
|
|
proof = @json['proof']
|
|
return unless proof['type'] == 'DataIntegrityProof' && proof['verificationMethod'].present? && proof['proofPurpose'] == proof_purpose
|
|
|
|
return if proof['expires']&.to_datetime&.past?
|
|
|
|
cryptosuite = proof['cryptosuite']
|
|
key_uri = proof['verificationMethod']
|
|
|
|
return unless SUPPORTED_CRYPTOSUITES.include?(cryptosuite) && proof['proofValue'].present?
|
|
|
|
keypair = Keypair.from_keyid(key_uri)
|
|
keypair = ActivityPub::FetchRemoteKeyService.new.call(key_uri) if keypair&.public_key.blank?
|
|
return if keypair.nil? || !keypair.usable?
|
|
|
|
case cryptosuite
|
|
when 'eddsa-jcs-2022'
|
|
return if keypair.type != 'ed25519'
|
|
|
|
keypair.actor if ActivityPub::ObjectIntegrityProof.verify_eddsa_jcs_2022(@json, keypair.keypair)
|
|
when 'mldsa44-jcs-2024'
|
|
return if keypair.type != 'ml-dsa-44'
|
|
|
|
keypair.actor if ActivityPub::ObjectIntegrityProof.verify_mldsa44_jcs_2024(@json, keypair.keypair)
|
|
end
|
|
rescue Multibase::Error, OpenSSL::PKey::PKeyError
|
|
false
|
|
end
|
|
|
|
# https://www.w3.org/TR/vc-di-eddsa/#verify-proof-eddsa-jcs-2022
|
|
def self.verify_eddsa_jcs_2022(document, keypair) # rubocop:disable Naming/VariableNumber
|
|
unsecured_document = document.without('proof')
|
|
proof_options = document['proof'].without('proofValue')
|
|
proof_bytes = Multibase.decode(document['proof']['proofValue'])
|
|
|
|
if proof_options['@context'].present?
|
|
return unless unsecured_document['@context'].is_a?(Array)
|
|
return unless unsecured_document['@context'][...proof_options['@context'].length] == proof_options['@context']
|
|
|
|
# Step 4.2. from the aforementioned algorithm, it's useful when vocabulary necessary to the cryptosuite had to be added on top of the to-be-signed document
|
|
unsecured_document['@context'] = proof_options['@context']
|
|
end
|
|
|
|
transformed_data = unsecured_document.to_json_c14n
|
|
proof_config = proof_options.to_json_c14n
|
|
|
|
to_be_verified = Digest::SHA256.digest(proof_config) + Digest::SHA256.digest(transformed_data)
|
|
|
|
keypair.verify(nil, proof_bytes, to_be_verified)
|
|
end
|
|
|
|
# https://www.w3.org/TR/2026/WD-vc-di-quantum-resistant-1.0-20260616/#verify-proof-ml-dsa
|
|
def self.verify_mldsa44_jcs_2024(document, keypair) # rubocop:disable Naming/VariableNumber
|
|
unsecured_document = document.without('proof')
|
|
proof_options = document['proof'].without('proofValue')
|
|
proof_bytes = Multibase.decode(document['proof']['proofValue'])
|
|
|
|
# This is inconsistent with eddsa-jcs-2022 but described in https://www.w3.org/TR/2026/WD-vc-di-quantum-resistant-1.0-20260616/#ProofConfigurationAlg
|
|
proof_options['@context'] = unsecured_document['@context']
|
|
|
|
transformed_data = unsecured_document.to_json_c14n
|
|
proof_config = proof_options.to_json_c14n
|
|
|
|
to_be_verified = Digest::SHA256.digest(proof_config) + Digest::SHA256.digest(transformed_data)
|
|
|
|
keypair.verify(nil, proof_bytes, to_be_verified)
|
|
end
|
|
end
|