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# frozen_string_literal: true
# Registration information for U2F (universal 2nd factor) devices, like Yubikeys
class U2fRegistration < ApplicationRecord
belongs_to :user
after_commit :schedule_webauthn_migration, on: :create
after_commit :update_webauthn_registration, on: :update, if: :counter_changed?
def schedule_webauthn_migration
BackgroundMigrationWorker.perform_async('MigrateU2fWebauthn', [id, id])
end
def update_webauthn_registration
# When we update the sign count of this registration
# we need to update the sign count of the corresponding webauthn registration
# as well if it exists already
WebauthnRegistration.find_by_credential_xid(webauthn_credential_xid)&.update_attribute(:counter, counter)
end
def self.register(user, app_id, params, challenges)
u2f = U2F::U2F.new(app_id)
registration = self.new
begin
response = U2F::RegisterResponse.load_from_json(params[:device_response])
registration_data = u2f.register!(challenges, response)
registration.update(certificate: registration_data.certificate,
key_handle: registration_data.key_handle,
public_key: registration_data.public_key,
counter: registration_data.counter,
user: user,
name: params[:name])
rescue JSON::ParserError, NoMethodError, ArgumentError
registration.errors.add(:base, _('Your U2F device did not send a valid JSON response.'))
rescue U2F::Error => e
registration.errors.add(:base, e.message)
end
registration
end
def self.authenticate(user, app_id, json_response, challenges)
response = U2F::SignResponse.load_from_json(json_response)
registration = user.u2f_registrations.find_by_key_handle(response.key_handle)
u2f = U2F::U2F.new(app_id)
if registration
u2f.authenticate!(challenges, response, Base64.decode64(registration.public_key), registration.counter)
registration.update(counter: response.counter)
true
end
rescue JSON::ParserError, NoMethodError, ArgumentError, U2F::Error
false
end
private
def webauthn_credential_xid
# To find the corresponding webauthn registration, we use that
# the key handle of the u2f reg corresponds to the credential xid of the webauthn reg
# (with some base64 back and forth)
Base64.strict_encode64(Base64.urlsafe_decode64(key_handle))
end
end
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