From 168064f3c1ddb36004b1c0e2e0bf70954084f5bc Mon Sep 17 00:00:00 2001
From: Steven Yuan <yuasteve@amazon.com>
Date: Fri, 7 Jul 2023 15:25:06 -0700
Subject: [PATCH] Check S3 signer customization insensitively (#2179)

* Check S3 signer customization insensitively
* Check EventBridge signer customization insensitively
---
 .../internal/customizations/signer_wrapper.go | 21 +++++++++----------
 .../internal/customizations/signer_wrapper.go | 20 +++++++++---------
 2 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/service/eventbridge/internal/customizations/signer_wrapper.go b/service/eventbridge/internal/customizations/signer_wrapper.go
index 76877f5889e..6fb237acc73 100644
--- a/service/eventbridge/internal/customizations/signer_wrapper.go
+++ b/service/eventbridge/internal/customizations/signer_wrapper.go
@@ -3,6 +3,7 @@ package customizations
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
 	v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
@@ -81,9 +82,8 @@ func (s *SignHTTPRequestMiddleware) HandleFinalize(ctx context.Context, in middl
 ) {
 	// fetch signer type from context
 	signerVersion := GetSignerVersion(ctx)
-
-	switch signerVersion {
-	case v4a.Version:
+	// SigV4a
+	if strings.EqualFold(signerVersion, v4a.Version) {
 		v4aCredentialProvider, ok := s.credentialsProvider.(v4a.CredentialsProvider)
 		if !ok {
 			return out, metadata, fmt.Errorf("invalid credential-provider provided for sigV4a Signer")
@@ -95,15 +95,14 @@ func (s *SignHTTPRequestMiddleware) HandleFinalize(ctx context.Context, in middl
 			LogSigning:  s.logSigning,
 		})
 		return mw.HandleFinalize(ctx, in, next)
-
-	default:
-		mw := v4.NewSignHTTPRequestMiddleware(v4.SignHTTPRequestMiddlewareOptions{
-			CredentialsProvider: s.credentialsProvider,
-			Signer:              s.v4Signer,
-			LogSigning:          s.logSigning,
-		})
-		return mw.HandleFinalize(ctx, in, next)
 	}
+	// SigV4
+	mw := v4.NewSignHTTPRequestMiddleware(v4.SignHTTPRequestMiddlewareOptions{
+		CredentialsProvider: s.credentialsProvider,
+		Signer:              s.v4Signer,
+		LogSigning:          s.logSigning,
+	})
+	return mw.HandleFinalize(ctx, in, next)
 }
 
 // RegisterSigningMiddleware registers the wrapper signing middleware to the stack. If a signing middleware is already
diff --git a/service/s3/internal/customizations/signer_wrapper.go b/service/s3/internal/customizations/signer_wrapper.go
index 6689acb8e9e..4408f3e8a2e 100644
--- a/service/s3/internal/customizations/signer_wrapper.go
+++ b/service/s3/internal/customizations/signer_wrapper.go
@@ -3,6 +3,7 @@ package customizations
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
 	v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
@@ -83,8 +84,8 @@ func (s *SignHTTPRequestMiddleware) HandleFinalize(ctx context.Context, in middl
 	// fetch signer type from context
 	signerVersion := GetSignerVersion(ctx)
 
-	switch signerVersion {
-	case v4a.Version:
+	// SigV4a
+	if strings.EqualFold(signerVersion, v4a.Version) {
 		v4aCredentialProvider, ok := s.credentialsProvider.(v4a.CredentialsProvider)
 		if !ok {
 			return out, metadata, fmt.Errorf("invalid credential-provider provided for sigV4a Signer")
@@ -96,15 +97,14 @@ func (s *SignHTTPRequestMiddleware) HandleFinalize(ctx context.Context, in middl
 			LogSigning:  s.logSigning,
 		})
 		return mw.HandleFinalize(ctx, in, next)
-
-	default:
-		mw := v4.NewSignHTTPRequestMiddleware(v4.SignHTTPRequestMiddlewareOptions{
-			CredentialsProvider: s.credentialsProvider,
-			Signer:              s.v4Signer,
-			LogSigning:          s.logSigning,
-		})
-		return mw.HandleFinalize(ctx, in, next)
 	}
+	// SigV4
+	mw := v4.NewSignHTTPRequestMiddleware(v4.SignHTTPRequestMiddlewareOptions{
+		CredentialsProvider: s.credentialsProvider,
+		Signer:              s.v4Signer,
+		LogSigning:          s.logSigning,
+	})
+	return mw.HandleFinalize(ctx, in, next)
 }
 
 // RegisterSigningMiddleware registers the wrapper signing middleware to the stack. If a signing middleware is already