retStr := "{"
	retStr = retStr + expirationStr + ","
	retStr += conditionStr
	retStr += "}"

	return []byte(retStr)
}

// newPostPolicyBytesV4 - creates a bare bones postpolicy string with key and bucket matches.
func newPostPolicyBytesV4(credential, bucketName, objectKey string, expiration time.Time) []byte {
	t := UTCNow()
	// Add the expiration date.