scepclient is a client implementation of the Simple Certificate Enrollment Protocol (SCEP, RFC 8894).
Note: This tool was written in 2005 and only got marginal updates since then. Hence, it implements an old version of the SCEP Internet Draft (version 10/11 of draft-nourse-scep). RFC 8894 was released in September 2020, so the tool might not be compatible with newer SCEP servers. It also uses default algorithms that are really not state-of-the-art anymore (MD5 to hash/sign and single DES to encrypt).