DEV: Add Windows Hello webauthn authentication spec (#15871)

Follow up to 6f7364e48b to add a spec
that tests the full authentication of a Windows Hello algorithm (-257)
webauthn verification. The test added in that commit only tested that
we know about that algorithm, not whether it was actually usable.

spec/lib/webauthn/security_key_authentication_service_spec.rb

@@ -3,18 +3,54 @@ require 'rails_helper'
 require 'webauthn'
 require 'webauthn/security_key_registration_service'
 
+##
+# These tests use the following parameters generated on a local discourse
+# instance to test an actual authentication flow:
+#
+# - credential_id
+# - public_key
+# - challenge
+# - signature
+# - authenticator_data
+# - client_data_origin
+# - challenge_params_origin
+#
+# To create another test (e.g. for a different COSE algorithm) you need to:
+#
+# 1. Add a security key for a user on a local discourse instance. Go into
+# the console and get the credential_id and public_key params from there.
+# 2. Log out and try to log back in to that user to get the security
+# key challenge
+# 3. Touch the security key. Inside the authenticate_security_key method
+# you need to add puts debugger statements (or use binding.pry) like so:
+#
+# puts client_data
+# puts signature
+# puts auth_data
+#
+# The auth_data will have the challenge param, but you must Base64.decode64 to
+# use it in the let(:challenge) variable. The signature and auth_data params
+# can be used as is.
+#
+# You also need to make sure that client_data_param has the exact same structure
+# and order of keys as auth_data, otherwise even with everything else right the
+# public key verification will fail.
+#
+# The origin params just need to be whatever your localhost URL for Discourse is.
+
 describe Webauthn::SecurityKeyAuthenticationService do
   let(:security_key_user) { current_user }
-  let(:security_key) do
+  let!(:security_key) do
     Fabricate(
       :user_security_key,
-      credential_id: 'mJAJ4CznTO0SuLkJbYwpgK75ao4KMNIPlU5KWM92nq39kRbXzI9mSv6GxTcsMYoiPgaouNw7b7zBiS4vsQaO6A==',
-      public_key: 'pQECAyYgASFYIMNgw4GCpwBUlR2SznJ1yY7B9yFvsuxhfo+C9kcA4IitIlggRdofrCezymy2B/YarX+gfB6gZKg648/cHIMjf6wWmmU=',
+      credential_id: credential_id,
+      public_key: public_key,
       user: security_key_user,
       last_used: nil
     )
   end
-  let(:credential_id) { security_key.credential_id }
+  let(:public_key) { 'pQECAyYgASFYIMNgw4GCpwBUlR2SznJ1yY7B9yFvsuxhfo+C9kcA4IitIlggRdofrCezymy2B/YarX+gfB6gZKg648/cHIMjf6wWmmU=' }
+  let(:credential_id) { 'mJAJ4CznTO0SuLkJbYwpgK75ao4KMNIPlU5KWM92nq39kRbXzI9mSv6GxTcsMYoiPgaouNw7b7zBiS4vsQaO6A==' }
   let(:challenge) { '81d4acfbd69eafa8f02bc2ecbec5267be8c9b28c1e0ba306d52b79f0f13d' }
   let(:client_data_challenge) { Base64.strict_encode64(challenge) }
   let(:client_data_webauthn_type) { 'webauthn.get' }
@@ -33,7 +69,7 @@ describe Webauthn::SecurityKeyAuthenticationService do
   }
   ##
   # These are sourced from an actual login using the UserSecurityKey credential
-  # defined in this spec.
+  # defined in this spec, generated via a local discourse.
   let(:signature) { "MEUCIBppPyK8blxBDoktU54mI1vWEY96r1V5H1rEBtPDxwcGAiEAoi7LCmMoEAuWYu0krZpflZlULsbURCGcqOwP06amXYE=" }
   let(:authenticator_data) { "SZYN5YgOjGh0NBcPZHZgW4/krrmihjLHmVzzuoMdl2MBAAAAVw==" }
   let(:params) do
@@ -47,18 +83,19 @@ describe Webauthn::SecurityKeyAuthenticationService do
   ##
   # The original key was generated in localhost
   let(:rp_id) { 'localhost' }
+  let(:challenge_params_origin) { 'http://localhost:3000' }
   let(:challenge_params) do
     {
       challenge: challenge,
       rp_id: rp_id,
-      origin: 'http://localhost:3000'
+      origin: challenge_params_origin
     }
   end
   let(:current_user) { Fabricate(:user) }
   let(:subject) { described_class.new(current_user, params, challenge_params) }
 
-  it 'updates last_used when valid' do
-    subject.authenticate_security_key
+  it 'updates last_used when the security key and params are valid' do
+    expect(subject.authenticate_security_key).to eq(true)
     expect(security_key.reload.last_used).not_to eq(nil)
   end
 
@@ -77,7 +114,9 @@ describe Webauthn::SecurityKeyAuthenticationService do
   end
 
   context 'when the credential ID does not match any user security key in the database' do
-    let(:credential_id) { 'badid' }
+    before do
+      security_key.destroy
+    end
 
     it 'raises a NotFoundError' do
       expect { subject.authenticate_security_key }.to raise_error(
@@ -158,6 +197,36 @@ describe Webauthn::SecurityKeyAuthenticationService do
     end
   end
 
+  context 'for windows hello (alg -257)' do
+    ##
+    # These are sourced from an actual login using the UserSecurityKey credential
+    # defined in this spec, generated via a local discourse.
+    let(:challenge) { "fa7cb122f8713745dc08e16863e087ffa2d3bfda7f1b0386ea4b14635bb6" }
+    let(:signature) { "OKEP/8oiojjE+LBwg6F37yJzjOTT9mBPukrW1E8Sih5Vh/3p9WHrqZdylxr1x9z/c8GplC0ABayanpAqN/miQezt3wm97gIwoHq/6rrmHDZu6irQhpjeX9yHRlu0lQw+SUEZfoW3iB4oP/d2ryYlafFA9intm++lLlP/qI3mvpCQwkAeotaelx7fn0RwiY767dG+bGVPyYuUicGHcLLvCY2k0G8kRQ7I5SQqB+dIcOINWikC9I2xvUKu6Br7hZZIrDy+soFtdnnCnvi2q/3ocOPYL5jy58wdpCTsh1RRPIEF/fQFVDOXtdS7PVgaa0PMBcWMCe5TimwGlTlICnsm+g==" }
+    let(:authenticator_data) { "SZYN5YgOjGh0NBcPZHZgW4/krrmihjLHmVzzuoMdl2MFAAAABA==" }
+    let(:credential_id) { "8AddFow3jT87k1UPWvjn+rOetCEambpESGZ+z/63hOE=" }
+    let(:public_key) { "pAEDAzkBACBZAQCqsl50KrR5zVm/QT9vWkeGTGxby32m0QRtCRh2UWseqoG0ZmBhGeWEYvkdoYlB1jObQKEHsAeB+1NBf5q69/88AA5zv4fzrvCydCtL41EUsHYFEbaPGnB61zZmYVLTPI7BYa+fu4F4MzFa924s36tVlU/L7n04peviJVZW2C1YIQfwOGDZJSvUpqJoZMQtw1vGRfrb4cQKlHfrpDZUpa3QLE8phh4ce4nwtX1tUnUGgCy8sOaFVkDNufENGTNr8HdAIHcinUiax3yy/Q8LjSZb8UR2ha6oXSe1vRHhj001B/P/mr5AdVMxSrOT1sUNXWkHv8L8IzS/iTBQpsC8CADZIUMBAAE=" }
+    let(:challenge_params_origin) { 'http://localhost:4200' }
+    let(:client_data_origin) { 'http://localhost:4200' }
+
+    # This has to be in the exact same order with the same data as it was originally
+    # generated.
+    let(:client_data_param) {
+      {
+        type: client_data_webauthn_type,
+        challenge: client_data_challenge,
+        origin: client_data_origin,
+        crossOrigin: false,
+        other_keys_can_be_added_here: "do not compare clientDataJSON against a template. See https://goo.gl/yabPex"
+      }
+    }
+
+    it 'updates last_used when the security key and params are valid' do
+      expect(subject.authenticate_security_key).to eq(true)
+      expect(security_key.reload.last_used).not_to eq(nil)
+    end
+  end
+
   it 'all supported algorithms are implemented' do
     Webauthn::SUPPORTED_ALGORITHMS.each do |alg|
       expect(COSE::Algorithm.find(alg)).not_to be_nil