# iwctl
[iwd]# station wlan0 connect foo
Not configured

src/network.c:network_connect()
src/network.c:network_connect_8021x()
Failed to load /var/lib/wireless/skybert.pem

# uname -r
5.2.1
# lsmod | grep pkcs8_key_parser
pkcs8_key_parser       16384  0

# /usr/libexec/iwd --version
0.18
# export IWD_TLS_DEBUG=1
# /usr/libexec/iwd -d
[..]
src/network.c:network_connect()
src/network.c:network_connect_8021x()
Failed to load /var/lib/wireless/skybert.pem

[Security]
EAP-Method=TLS
EAP-TLS-ClientCert=/var/lib/wirelss/skybert.pem
EAP-TLS-ClientKey=/var/lib/wireless/skybert.des3.key
EAP-TLS-ClientKeyPassphrase=youwish
EAP-Identity=skybert

network={
   ssid="foo"
   key_mgmt=WPA-EAP
   proto=WPA2
   eap=TLS
   identity="skybert"
   client_cert="/var/lib/wireless/skybert.pem"
   private_key="/var/lib/wireless/skybert.des3.key"
   private_key_passwd="youwish"
}

❯ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 10 (buster)
Release:        10
Codename:       buster