pk12util: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/pk12util - from package: nss-tools

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pk12util - from package: libnss3-tools

You may install the required package with command apt-get install {package}

Error in other languages:
pk12util: bevel nie gevind nie
pk12util: comandă negăsită
pk12util: comando não encontrado
pk12util: commande introuvable
pk12util: command not found
pk12util: käsku ei ole
pk12util: không tìm thấy lệnh
pk12util: komanda nerasta
pk12util: Kommando nicht gefunden.
pk12util: kommandot finns inte
pk12util: komut yok
pk12util: nie znaleziono polecenia
pk12util: níor aimsíodh an t-ordú
pk12util: no se encontró la orden
pk12util: no s'ha trobat l'ordre
pk12util: opdracht niet gevonden
pk12util: parancs nem található
pk12util: perintah tidak ditemukan
pk12util: príkaz nenájdený
pk12util: příkaz nenalezen
pk12util: команда не найдена
pk12util: командата не е открита
pk12util: 命令找不到
pk12util: コマンドが見つかりません