You can convert a PKCS12 file to PEM format using OpenSSL.
The following command will put the certificate and private key into newfile.pem
:
openssl pkcs12 -in certificate.p12 -out somefile.pem -clcerts -nodes
The following command will put the certificate only into somefile.crt.pem
:
openssl pkcs12 -in certificate.p12 -out somefile.crt.pem -clcerts -nokeys
Note: You may be asked to enter your passphrase when running the above commands.