FEATURE: Support RS256 algorithm for webauthn (#8385)

* Add support for RS256 webauthn algorithm (-257)

lib/webauthn.rb

@@ -6,7 +6,10 @@ require 'webauthn/security_key_authentication_service'
 module Webauthn
   ACCEPTABLE_REGISTRATION_TYPE = "webauthn.create".freeze
   ACCEPTABLE_AUTHENTICATION_TYPE = "webauthn.get".freeze
-  SUPPORTED_ALGORITHMS = [-7].freeze
+
+  # -7   - ES256
+  # -257 - RS256 (Windows Hello supported alg.)
+  SUPPORTED_ALGORITHMS = [-7, -257].freeze
   VALID_ATTESTATION_FORMATS = ['none', 'packed', 'fido-u2f'].freeze
 
   class SecurityKeyError < StandardError; end

lib/webauthn/security_key_registration_service.rb

@@ -49,7 +49,7 @@ module Webauthn
       #     attribute of one of the items in options.pubKeyCredParams.
       #     https://w3c.github.io/webauthn/#table-attestedCredentialData
       #     See https://www.iana.org/assignments/cose/cose.xhtml#algorithms for supported algorithm
-      #     codes, -7 which Discourse uses is ECDSA w/ SHA-256
+      #     codes.
       credential_public_key, credential_public_key_bytes, credential_id = extract_public_key_and_credential_from_attestation(auth_data)
       raise(UnsupportedPublicKeyAlgorithmError, I18n.t('webauthn.validation.unsupported_public_key_algorithm_error')) if ::Webauthn::SUPPORTED_ALGORITHMS.exclude?(credential_public_key.alg)
 

spec/lib/webauthn/security_key_registration_service_spec.rb

@@ -87,7 +87,7 @@ describe Webauthn::SecurityKeyRegistrationService do
     before do
       @original_supported_alg_value = Webauthn::SUPPORTED_ALGORITHMS
       silence_warnings do
-        Webauthn::SUPPORTED_ALGORITHMS = [-257]
+        Webauthn::SUPPORTED_ALGORITHMS = [-999]
       end
     end