GenExtKeyUsage: 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/GenExtKeyUsage - from package: pki-java-tools

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

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