// Set prefix value for "s3:prefix" policy conditionals.
	r.Header.Set("prefix", "")

	// Set delimiter value for "s3:delimiter" policy conditionals.
	r.Header.Set("delimiter", SlashSeparator)

	isAllowedAccess := func(bucketName string) (rd, wr bool) {
		if globalIAMSys.IsAllowed(policy.Args{
			AccountName:     cred.AccessKey,
			Groups:          cred.Groups,
			Action:          policy.GetObjectAction,

	r.Header.Set("delimiter", SlashSeparator)

	// Check if we are asked to return prefix usage
	enablePrefixUsage := r.Form.Get("prefix-usage") == "true"

	isAllowedAccess := func(bucketName string) (rd, wr bool) {
		if globalIAMSys.IsAllowed(policy.Args{
			AccountName:     cred.AccessKey,
			Groups:          cred.Groups,
			Action:          policy.ListBucketAction,