refactoring of buildQuery to accept a list of maintained headers to l… (

#2773)

.changelog/2ab6aa4259a34a4d966c84b440837c93.json

@@ -0,0 +1,8 @@
+{
+    "id": "2ab6aa42-59a3-4a4d-966c-84b440837c93",
+    "type": "bugfix",
+    "description": "refactoring of buildQuery to accept a map of hand maintained headers to lowercase because of an S3 limitation",
+    "modules": [
+        "."
+    ]
+}

aws/signer/v4/v4.go

@@ -394,11 +394,16 @@ func (s *httpSigner) buildCredentialScope() string {
 func buildQuery(r v4Internal.Rule, header http.Header) (url.Values, http.Header) {
 	query := url.Values{}
 	unsignedHeaders := http.Header{}
+
+	// A list of headers to be converted to lower case to mitigate a limitation from S3
+	lowerCaseHeaders := map[string]string{
+		"X-Amz-Expected-Bucket-Owner": "x-amz-expected-bucket-owner", // see #2508
+		"X-Amz-Request-Payer":         "x-amz-request-payer",         // see #2764
+	}
+
 	for k, h := range header {
-		// literally just this header has this constraint for some stupid reason,
-		// see #2508
-		if k == "X-Amz-Expected-Bucket-Owner" {
-			k = "x-amz-expected-bucket-owner"
+		if newKey, ok := lowerCaseHeaders[k]; ok {
+			k = newKey
 		}
 
 		if r.IsValid(k) {