From Fedora Project Wiki

The following ECC curves are currently permitted in Fedora:

Curve Description
Curve 448 224 bit curve designed for use with the elliptic curve Diffie–Hellman (ECDH) key agreement scheme
Curve 25519 128 bit curve designed for use with the elliptic curve Diffie–Hellman (ECDH) key agreement scheme
secp224r1 NIST/SECG curve over a 224 bit prime field
secp256k1 SECG curve over a 256 bit prime field
secp256r1/prime256v1 X9.62/SECG curve over a 256 bit prime field
secp384r1 NIST/SECG curve over a 384 bit prime field
secp521r1 NIST/SECG curve over a 521 bit prime field