Help needed in Kernel Crypto Example

[Aravindhan K]

Hi,

I am working on  implementation of SegmentRouting IPv6 for learning
purposes.
I were stuck on implementing HMAC-TLV. I was not able to find simple
example using crypto framework.
Here is my attempt to utilize crypto(9),
https://pastebin.com/dPYKT0tx
where crp->crp_olen returns 0.

Kindly help me to resolve the problem

Thanks & Regards,
Aravindhan K