hmaccalc dependency for kernel-2.6.18-164.6.1.el5.x86_64

[Ron Rechenmacher]

Hi,

I'm trying to
   rpmbuild -bp kernel-2.6.spec
the spec from kernel-2.6.18-164.6.1.el5.src.rpm.
I get a dependency error:
error: Failed build dependencies:
        hmaccalc is needed by kernel-2.6.18-164.6.1.el5.x86_64

I can't seem to easily find this hmaccalc package via yum.
Does anyone know where/how I can get the package?

Thanks,
Ron