The MgmtData element appears as a child of KeyInfo. It is defined as a string value used to convey in-band key distribution or agreement data as content.
MgmtData is much too poorly defined to be interoperable and its use is not recommended. You should use EncryptedKey or AgreementMethod instead.
The MgmtData element syntax follows:
<!-- MgmtData DTD --> <!ELEMENT MgmtData (#PCDATA)>
In schema notation, it has the following form:
<!-- MgmtData schema --> <element name="MgmtData" type="string"/>