Ports omniauth-jwt gem onto GitLab OmniAuth Strategies suite

1 files changed, 62 insertions, 0 deletions

diff --git a/lib/omni_auth/strategies/jwt.rb b/lib/omni_auth/strategies/jwt.rb
new file mode 100644
index 00000000000..2349b2a28aa
--- /dev/null
+++ b/lib/omni_auth/strategies/jwt.rb
@@ -0,0 +1,62 @@
+require 'omniauth'
+require 'jwt'
+
+module OmniAuth
+  module Strategies
+    class JWT
+      ClaimInvalid = Class.new(StandardError)
+
+      include OmniAuth::Strategy
+
+      args [:secret]
+
+      option :secret, nil
+      option :algorithm, 'HS256'
+      option :uid_claim, 'email'
+      option :required_claims, %w(name email)
+      option :info_map, { name: "name", email: "email" }
+      option :auth_url, nil
+      option :valid_within, nil
+
+      uid { decoded[options.uid_claim] }
+
+      extra do
+        { raw_info: decoded }
+      end
+
+      info do
+        options.info_map.each_with_object({}) do |(k, v), h|
+          h[k.to_s] = decoded[v.to_s]
+        end
+      end
+
+      def request_phase
+        redirect options.auth_url
+      end
+
+      def decoded
+        @decoded ||= ::JWT.decode(request.params['jwt'], options.secret, options.algorithm).first
+
+        (options.required_claims || []).each do |field|
+          raise ClaimInvalid, "Missing required '#{field}' claim" unless @decoded.key?(field.to_s)
+        end
+
+        raise ClaimInvalid, "Missing required 'iat' claim" if options.valid_within && !@decoded["iat"]
+
+        if options.valid_within && (Time.now.to_i - @decoded["iat"]).abs > options.valid_within
+          raise ClaimInvalid, "'iat' timestamp claim is too skewed from present"
+        end
+
+        @decoded
+      end
+
+      def callback_phase
+        super
+      rescue ClaimInvalid => e
+        fail! :claim_invalid, e
+      end
+    end
+
+    class Jwt < JWT; end
+  end
+end