RHEL4 has no kernel-source rpm?????

[Robert Canary]

I donwloaded the strongswan and was attempting build the rpm file from 
the bz2 file. rpmbuild -tb strongswan.bz2

However, the build is looking for the kernel build files.  I did a scan 
for the kernel-source (rpm -qa | egrep"kernel") but is wasn't installed. 
  I did a "up2date kernel-source" on my RHEL4.1 and dosen't exist.

Were dose one get the kernel-source for the RHEL4 kernels if one needs 
to recompile it and repackage it?

--
robert