cryptest: 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/cryptest - from package: cryptopp-progs

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

On Debian possible default full paths are:

/usr/bin/cryptest - from package: libcrypto++-utils

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

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