To help you generate p12 file to import to another mac.

GenCert.sh

#!/bin/bash

read -p "Please enter passphrase to decrypt certifications: " passphrase
outputPath="./output"
mkdir -p ${outputPath}

read -p "Pleas enter password to decrypt output p12 file: " outputPassword

for entry in ./certs/*/*.cer
do
  cerID=${entry: -14:10}

  OIFS="$IFS"
  IFS='/'
  read -a new_string <<< "${entry}"
  IFS="$OIFS"
  type=${new_string[2]}

  echo "certificatoin type ${type}: ${cerID} found!"

  mkdir -p "${outputPath}/${type}"

  outCertDer="${outputPath}/${type}/${cerID}.der"
  certPem="${outputPath}/${type}/${cerID}-cert.pem"
  keyPem="${outputPath}/${type}/${cerID}-key.pem"
  openssl aes-256-cbc -k "${passphrase}" -in "certs/${type}/${cerID}.cer" -out ${outCertDer} -a -d
  openssl x509 -inform der -in "${outCertDer}" -out "${certPem}"

  openssl aes-256-cbc -k "${passphrase}" -in "certs/${type}/${cerID}.p12" -out "${keyPem}" -a -d

  openssl pkcs12 -export -out "${outputPath}/${type}/${cerID}-cert.p12" -inkey "${keyPem}" -in "${certPem}" -password pass:"${outputPassword}"
done

echo "Generate done! You can find p12 files under ${outputPath} folder!"

read -n 1 -s -r -p "Would you like to keep der, key.pem, cert.pem files? [y/n]" keep
if [ "$keep" = "n" ]
then
  rm -rf ${outputPath}/*/*.pem
  rm -rf ${outputPath}/*/*.der
fi