Fix Sign to not sign sigv2 cases

gems/aws-sdk-core/CHANGELOG.md

@@ -1,6 +1,8 @@
 Unreleased Changes
 ------------------
 
+* Issue - Fix Sign to not sign Sigv2 requests to S3.
+
 3.168.3 (2022-12-02)
 ------------------
 

gems/aws-sdk-core/lib/aws-sdk-core/plugins/sign.rb

@@ -37,15 +37,25 @@ def self.signer_for(auth_scheme, config, region_override = nil)
 
       class Handler < Seahorse::Client::Handler
         def call(context)
-          signer = Sign.signer_for(
-            context[:auth_scheme],
-            context.config,
-            context[:sigv4_region]
-          )
-
-          signer.sign(context)
+          # Skip signing if using sigv2 signing from s3_signer in S3
+          unless v2_signing?(context.config)
+            signer = Sign.signer_for(
+              context[:auth_scheme],
+              context.config,
+              context[:sigv4_region]
+            )
+            signer.sign(context)
+          end
           @handler.call(context)
         end
+
+        private
+
+        def v2_signing?(config)
+          # 's3' is legacy signing, 'v4' is default
+          config.respond_to?(:signature_version) &&
+            config.signature_version == 's3'
+        end
       end
 
       # @api private

gems/aws-sdk-core/spec/aws/plugins/sign_spec.rb

@@ -43,8 +43,8 @@ module Plugins
         }
       end
 
-
       let(:client) { TestClient.new(client_options) }
+
       context 'sigv4' do
         let(:auth_scheme) do
           {
@@ -222,10 +222,23 @@ module Plugins
         end
 
         it 'raises an error when attempting to sign a request w/out a token' do
-          client = TestClient.new(client_options.merge(token_provider: nil) )
-          expect {
+          client = TestClient.new(client_options.merge(token_provider: nil))
+          expect do
             client.operation
-          }.to raise_error(Errors::MissingBearerTokenError)
+          end.to raise_error(Errors::MissingBearerTokenError)
+        end
+      end
+
+      context 'sigv2' do
+        before do
+          allow(Struct).to receive(:responds_to?).with(:signature_version).and_return(true)
+          allow(Struct).to receive(:signature_version).and_return('s3')
+        end
+
+        it 'skips signing' do
+          resp = client.operation
+          req = resp.context.http_request
+          expect(req.headers['authorization']).to be_nil
         end
       end