Convert certificates formats (PEM/P7B/PFX/DER)

You can change certificate format using OpenSSL commands or SSL Converter tool. The most common are listed below:

I. Convert PEM files
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 to PFX
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt

II. Convert P7B files
P7B to PEM openssl pkcs7 -print_certs -in certificate.p7b -out certificate.cer
P7B to PFX
openssl pkcs7 -print_certs -in certificate.p7b -out certificate.cer openssl pkcs12 -export -in certificate.cer -inkey privateKey.key -out certificate.pfx -certfile CACert.cer

III. Convert PFX files
PFX to PEM
openssl pkcs12 -in certificate.pfx -out certificate.cer -nodes konwersja poprze OpenSSL

IV. Convert DER files
DER to PEM
openssl x509 -inform der -in certificate.cer -out certificate.pem