PEM (.pem, .crt, .cer) to PFX

openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile more.crt

Breaking down the command:

• openssl – the command for executing OpenSSL
• pkcs12 – the file utility for PKCS#12 files in OpenSSL
• -export -out certificate.pfx – export and save the PFX file as certificate.pfx
• -inkey privateKey.key – use the private key file privateKey.key as the private key to combine with the certificate.
• -in certificate.crt – use certificate.crt as the certificate the private key will be combined with.
• -certfile more.crt – This is optional, this is if you have any additional certificates you would like to include in the PFX file.

PKCS#7/P7B (.p7b, .p7c) to PFX

P7B files cannot be used to directly create a PFX file. P7B files must be converted to PEM. Once converted to PEM, follow the above steps to create a PFX file from a PEM file.

openssl pkcs7 -print_certs -in certificate.p7b -out certificate.crt

Breaking down the command:

• openssl – the command for executing OpenSSL
• pkcs7 – the file utility for PKCS#7 files in OpenSSL
• -print_certs -in certificate.p7b – prints out any certificates or CRLs contained in the file.
• -out certificate.crt – output the file as certificate.crt

Sources