Add pkce

db/migrate/20251108090123_add_pkce_support_to_oidc_authorization_codes.rb

@@ -0,0 +1,9 @@
+class AddPkceSupportToOidcAuthorizationCodes < ActiveRecord::Migration[8.1]
+  def change
+    add_column :oidc_authorization_codes, :code_challenge, :string
+    add_column :oidc_authorization_codes, :code_challenge_method, :string
+
+    # Add index for code_challenge to improve query performance
+    add_index :oidc_authorization_codes, :code_challenge
+  end
+end

test/models/pkce_authorization_code_test.rb

@@ -0,0 +1,177 @@
+require "test_helper"
+
+class PkceAuthorizationCodeTest < ActiveSupport::TestCase
+  def setup
+    @user = User.create!(email_address: "pkce_test@example.com", password: "password123")
+    @application = Application.create!(
+      name: "PKCE Test App",
+      slug: "pkce-test-app",
+      app_type: "oidc",
+      redirect_uris: ["http://localhost:4000/callback"].to_json,
+      active: true
+    )
+  end
+
+  def teardown
+    # Clean up any authorization codes first to avoid foreign key constraints
+    OidcAuthorizationCode.where(application: @application).destroy_all
+    @user.destroy
+    @application.destroy
+  end
+
+  test "authorization code can store PKCE challenge with S256 method" do
+    code_challenge = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
+    code_challenge_method = "S256"
+
+    auth_code = OidcAuthorizationCode.create!(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      code_challenge: code_challenge,
+      code_challenge_method: code_challenge_method,
+      expires_at: 10.minutes.from_now
+    )
+
+    assert_equal code_challenge, auth_code.code_challenge
+    assert_equal code_challenge_method, auth_code.code_challenge_method
+    assert auth_code.uses_pkce?
+  end
+
+  test "authorization code can store PKCE challenge with plain method" do
+    code_challenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM"
+    code_challenge_method = "plain"
+
+    auth_code = OidcAuthorizationCode.create!(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      code_challenge: code_challenge,
+      code_challenge_method: code_challenge_method,
+      expires_at: 10.minutes.from_now
+    )
+
+    assert_equal code_challenge, auth_code.code_challenge
+    assert_equal code_challenge_method, auth_code.code_challenge_method
+    assert auth_code.uses_pkce?
+  end
+
+  test "authorization code works without PKCE (backward compatibility)" do
+    auth_code = OidcAuthorizationCode.create!(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      expires_at: 10.minutes.from_now
+    )
+
+    assert_nil auth_code.code_challenge
+    assert_nil auth_code.code_challenge_method
+    assert_not auth_code.uses_pkce?
+  end
+
+  test "code_challenge_method validation accepts valid methods" do
+    auth_code = OidcAuthorizationCode.new(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      code_challenge: "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk",
+      code_challenge_method: "S256",
+      expires_at: 10.minutes.from_now
+    )
+
+    assert auth_code.valid?
+  end
+
+  test "code_challenge_method validation rejects invalid methods" do
+    auth_code = OidcAuthorizationCode.new(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      code_challenge: "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk",
+      code_challenge_method: "invalid_method",
+      expires_at: 10.minutes.from_now
+    )
+
+    assert_not auth_code.valid?
+    assert_includes auth_code.errors[:code_challenge_method], "is not included in the list"
+  end
+
+  test "code_challenge format validation accepts valid base64url" do
+    # Valid base64url encoded string (43 characters, valid characters)
+    valid_challenge = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
+
+    auth_code = OidcAuthorizationCode.new(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      code_challenge: valid_challenge,
+      code_challenge_method: "S256",
+      expires_at: 10.minutes.from_now
+    )
+
+    assert auth_code.valid?
+  end
+
+  test "code_challenge format validation rejects invalid format" do
+    # Invalid: contains + character (not base64url)
+    invalid_challenge = "dBjftJeZ4CVP+mB92K27uhbUJU1p1r/wW1gFWFOEjXk"
+
+    auth_code = OidcAuthorizationCode.new(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      code_challenge: invalid_challenge,
+      code_challenge_method: "S256",
+      expires_at: 10.minutes.from_now
+    )
+
+    assert_not auth_code.valid?
+    assert_includes auth_code.errors[:code_challenge], "must be 43-128 characters of base64url encoding"
+  end
+
+  test "code_challenge format validation rejects wrong length" do
+    # Invalid: too short (42 characters)
+    short_challenge = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjX"
+
+    auth_code = OidcAuthorizationCode.new(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      code_challenge: short_challenge,
+      code_challenge_method: "S256",
+      expires_at: 10.minutes.from_now
+    )
+
+    assert_not auth_code.valid?
+    assert_includes auth_code.errors[:code_challenge], "must be 43-128 characters of base64url encoding"
+  end
+
+  test "code_challenge validation is skipped when no challenge present" do
+    auth_code = OidcAuthorizationCode.new(
+      application: @application,
+      user: @user,
+      code: SecureRandom.urlsafe_base64(32),
+      redirect_uri: "http://localhost:4000/callback",
+      scope: "openid profile",
+      expires_at: 10.minutes.from_now
+    )
+
+    # Should be valid even without code_challenge
+    assert auth_code.valid?
+  end
+end