how to generate RSA CSR using SHA-1 algorithm in sap netweaver portal

Hi experts,

I got a requirement to generate RSA CSR from sap netwevaer portal 7.3  eph1

I generated  a CSR but  while trying to renew the https certificate it is showing

Your CSR uses an unsupported signature digest algorithm.

please generate the CSR in the below formats

DSA CSR using SHA-256 or your RSA CSR using SHA-1, SHA-224, SHA-256, SHA-384, or SHA-512 or ECC CSR using SHA-256.

please help me!

Regards,

pandu.