// Get signining key.
	signingkey := getSigningKey(secretAccessKey, t, location, "s3")
	// Calculate signature.
	signature := getSignature(signingkey, policyBase64)
	return signature
}

func newPostRequestV2(endPoint, bucketName, objectName string, accessKey, secretKey string) (*http.Request, error) {
	// Expire the request five minutes from now.