public String getKMSMasterKeyID() {
        return kmsMasterKeyID;
    }
<p>
Amazon Web Services Key Management Service (KMS) customer Amazon Web Services KMS key ID to use for the default
encryption. This parameter is allowed if and only if <code>SSEAlgorithm</code> is set to <code>aws:kms</code>.
</p>
<p>
You can specify the key ID or the Amazon Resource Name (ARN) of the KMS key. However, if you are using encryption
with cross-account or Amazon Web Services service operations you must use a fully qualified KMS key ARN. For more
information, see <a href=
"https://docs.aws.amazon.com/AmazonS3/latest/dev/bucket-encryption.html#bucket-encryption-update-bucket-policy"
>Using encryption for cross-account operations</a>.
</p>
<p>
<b>For example:</b>
</p>
<ul>
<li>
<p>
Key ID: <code>1234abcd-12ab-34cd-56ef-1234567890ab</code>
</p>
</li>
<li>
<p>
Key ARN: <code>arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab</code>
</p>
</li>
</ul>
<important>
<p>
Amazon S3 only supports symmetric encryption KMS keys. For more information, see <a
href="https://docs.aws.amazon.com/kms/latest/developerguide/symmetric-asymmetric.html">Asymmetric keys in Amazon
Web Services KMS</a> in the <i>Amazon Web Services Key Management Service Developer Guide</i>.
</p>
</important>

@return Amazon Web Services Key Management Service (KMS) customer Amazon Web Services KMS key ID to use for the
        default encryption. This parameter is allowed if and only if <code>SSEAlgorithm</code> is set to
        <code>aws:kms</code>.</p>
        <p>
        You can specify the key ID or the Amazon Resource Name (ARN) of the KMS key. However, if you are using
        encryption with cross-account or Amazon Web Services service operations you must use a fully qualified
        KMS key ARN. For more information, see <a href=
        "https://docs.aws.amazon.com/AmazonS3/latest/dev/bucket-encryption.html#bucket-encryption-update-bucket-policy"
        >Using encryption for cross-account operations</a>.
        </p>
        <p>
        <b>For example:</b>
        </p>
        <ul>
        <li>
        <p>
        Key ID: <code>1234abcd-12ab-34cd-56ef-1234567890ab</code>
        </p>
        </li>
        <li>
        <p>
        Key ARN: <code>arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab</code>
        </p>
        </li>
        </ul>
        <important>
        <p>
        Amazon S3 only supports symmetric encryption KMS keys. For more information, see <a
        href="https://docs.aws.amazon.com/kms/latest/developerguide/symmetric-asymmetric.html">Asymmetric keys in Amazon
        Web Services KMS</a> in the <i>Amazon Web Services Key Management Service Developer Guide</i>.
        </p>
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/ServerSideEncryptionByDefault.java