if errCode != ErrNone {
		return errCode
	}

	cred, _, s3Err := checkKeyValid(r, signV4Values.Credential.accessKey)
	if s3Err != ErrNone {
		return s3Err
	}

	// Extract date, if not present throw error.
	var date string
	if date = req.Header.Get(xhttp.AmzDate); date == "" {
		if date = r.Header.Get(xhttp.Date); date == "" {
			return ErrMissingDateHeader
		}
	}

	// Parse date header.