},
		UserIdentity: levent.Identity{
			Type:        "IAMUser",
			PrincipalID: cred.ParentUser,
			AccessKeyID: cred.AccessKey,
		},
	}
	return eventData, nil
}

func fwdHeadersToS3(h http.Header, w http.ResponseWriter) {
	const trim = "x-amz-fwd-header-"
	for k, v := range h {
		if stringsHasPrefixFold(k, trim) {
			w.Header()[k[len(trim):]] = v
		}
	}
}