Convert my certificate file with OpenSSL
.PEM to .DER
openssl x509 -outform der -in certificate.pem -out certificate.der
.PEM to .P7B
openssl crl2pkcs7 -nocrl -certfile certificate.cer -out certificate.p7b -certfile CACert.cer
.PEM tp .PFX
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt
.DER to .PEM
openssl x509 -inform der -in certificate.cer -out certificate.pem
.PEM to .PFX
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt
.DER to .PEM
openssl x509 -inform der -in certificate.cer -out certificate.pem
.P7B to .PEM
openssl pkcs7 -print_certs -in certificate.p7b -out certificate.cer
.P7B to .PFX
openssl pkcs7 -print_certs -in certificat.p7b -out certificate.cer
openssl pkcs12 -export -in certificate.cer -inkey privateKey.key -out certificate.pfx -certfile CACert.cer
.PFX to .PEM
openssl pkcs12 -in certificate.pfx -out certificate.cer -nodes