decode security information in security.NTACL

[Ted]

Hi, all

Recently I was developing a client software on Windows for a distributed
network file system.

The server of the distributed network file system is linux. We want to
implement Windows acl for our file system, and our goal is compatible with
samba4 acl. I downloaded the samba code and found that samba store the
security descriptor in the file's xattr. So we made a design that the server
just send the data blob of the file's xattr to the client, and the client
parse the data in the data blob, then convert to the nt security descriptor.

The problem was that I found that samba uses many ndr_xxx functions to
pull/push the datablob/security descriptor. And the ndr lib is a bit
complex. Our system was based on oncrpc. We don't have the ndr lib. I just
wondering is there a simple way to decode the data in xattr?

Thanks.