madmin: Strip 80/443 from the endpoint when http/https (#9937)

Users having endpoints with this format http://url:80 or http://url:443
will face signature mismatch error.

The reason is that  S3 spec ignores :80 or :443 port in the endpoint
when calculating the signature, so this PR will just strip them.

pkg/madmin/utils.go

@@ -67,12 +67,22 @@ func getEndpointURL(endpoint string, secure bool) (*url.URL, error) {
 			return nil, ErrInvalidArgument(msg)
 		}
 	}
+
 	// If secure is false, use 'http' scheme.
 	scheme := "https"
 	if !secure {
 		scheme = "http"
 	}
 
+	// Strip the obvious :443 and :80 from the endpoint
+	// to avoid the signature mismatch error.
+	if secure && strings.HasSuffix(endpoint, ":443") {
+		endpoint = strings.TrimSuffix(endpoint, ":443")
+	}
+	if !secure && strings.HasSuffix(endpoint, ":80") {
+		endpoint = strings.TrimSuffix(endpoint, ":80")
+	}
+
 	// Construct a secured endpoint URL.
 	endpointURLStr := scheme + "://" + endpoint
 	endpointURL, err := url.Parse(endpointURLStr)