message digests and modulus sizes supported in free radius

[Jagadish]

Hi,

Can anybody please tell me which standard does free radius supports for 
signature generation and signature verification? I mean, there are 
standards like
(1) PKCS1_V1_5
(2) PSS
(3) ANSIX9.31
Which standard does free radius support?

I have one more doubt on type of message digest algorithms and modulus 
sizes supported in free radius.
I generated certificates with sha1 and with modulus size 1024. This is 
working fine. I want to know if it works with other message digests like 
sha224, sha256, sha384, sha512 and modulus sizes like 1536, 2048, 3072, 
4096.

Please help me in this regard.

thanks in advance,
Jagadish