How to Convert .CER to .P12

A computer keyboard
Image Credit: Devonyu/iStock/Getty Images

CER and P12 are both types of digital security certificates created with the OpenSSL program. P12 is a type of encryption within the more well-known PFX family (it shares the extension). To convert a CER certificate to a P12, simply run one command in OpenSSL. The security data will be the same, retaining your access key embedded within the file itself.

Step 1

Open OpenSSL.

Step 2

Copy and paste the following into the command window: openssl pkcs12 -export -out OUTPUTNAME.pfx -inkey KEY.key -in FILENAME.cer -certfile CACert.crt

Step 3

Replace "OUTPUTNAME" with the desired name of your P12 PFX file.

Step 4

Replace KEY with the access key of the CER (which will be transferred to the P12).

Step 5

Replace "FILENAME" with the name of the existing CER file.

Step 6

Hit Enter. This will perform the conversion, saving the P12 in the same folder as the CER.