I am trying to use a certificate with its public key algorithm is NIST P-384 and its signature algorithm is ED448. 

I am working on ESP board with IDF framework which supports mbedtls. But when I am trying to use that certificate, I got error message about 'MBEDTLS_ERR_X509_UNKOWN_SIG_ALG'.

So, I thought that maybe mbedtls does not support certificates which signed with ED448.