import minioCmd "github.com/minio/minio/cmd"

if err := minioCmd.ReqSignatureV4Verify(req,
    region, minioCmd.ServiceType("kms-xks-proxy"),
    minioCmd.SignatureV4VerifyCredential(cred.AccessKeyID, cred.SecretAccessKey),
); err != nil {
    return errors.Wrap(err, "verify aws v4 signature")
}