I'm going to go out on a limb and guess that this DBA works with standard databases rather than writing one himself. So, the DBA probably has some level of comfort with some high level software. Similarly, I expect that the DBA expects you to use some standard libraries (e.g., openssl). It would be quite daunting if you were expected to produce a secure reimplementation of TLS.

What you need to discover is where the DBA draws the line between acceptable and unacceptable high level software layers and why that line is drawn. When you discover why, you'll know what objections are reasonable and what objections must be overcome. If possible, I would approach the issue as a negotiation of where the line should be drawn to meet the DBA's requirements.