generate PEM (1) client cert (2) ca cert (3) private key file from PKCS12 client cert, to be used by wget and other commandline http client.

p12topem

#!/bin/sh

yourp12="$1"
clcert="${yourp12}-clcert.pem"
cacert="${yourp12}-cacert.pem"
keyfile="${yourp12}-key.pem"

echo -n "Type passphrase: "
read -s passwd

openssl pkcs12 -in "$1" -clcerts -nokeys -out "$clcert" -passin pass:"$passwd"
openssl pkcs12 -in "$1" -cacerts -nokeys -out "$cacert" -passin pass:"$passwd"
openssl pkcs12 -in "$1" -nocerts -nodes -out "$keyfile" -passin pass:"$passwd"

# wget --certificate="$clcert" --private-key="$keyfile" --ca-certificate="$cacert" https://example.com/secret/