public String getKeyWrapAlgorithm(Key kek) {
        String algorithm = kek.getAlgorithm();
        if (S3CryptoScheme.AES.equals(algorithm)) {
            return AESWrap;
        }
        if (S3CryptoScheme.RSA.equals(algorithm)) {
            if (CryptoRuntime.isRsaKeyWrapAvailable())
                return RSA_ECB_OAEPWithSHA256AndMGF1Padding;
        }
        return null;
    }
@param kek
           the key encrypting key, which is either an AES key or a public
           key
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/internal/crypto/v1/S3KeyWrapScheme.java