Configuring OpenSSL for installation and configuration of CA signed certificates in the vSphere environment
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Configuring OpenSSL for installation and configuration of CA signed certificates in the vSphere environment


Article ID: 344117


Updated On:


VMware vCenter Server VMware vSphere ESXi


This article guides you through the installation and configuration of OpenSSL. You may want to install and configure OpenSSL to be able to create custom certificates for vSphere environments. It also helps to eliminate common causes for problems and ensure that the requests generated are appropriate for vSphere environments.


VMware ESXi 4.1.x Embedded
VMware vSphere ESXi 5.0
VMware vCenter Server 5.1.x
VMware vSphere ESXi 5.5
VMware ESXi 4.1.x Installable
VMware vCenter Update Manager 5.0.x
VMware vCenter Server Appliance 5.1.x
VMware vCenter Server 4.1.x
VMware ESX 4.1.x
VMware vCenter Update Manager 4.1.x
VMware vSphere ESXi 5.1
VMware vCenter Server 5.0.x



OpenSSL can be used for creating certificate requests and also as a certificate authority. Although the steps that are used to generate the certificate are different, the setup and configuration steps are the same as the certificates that vSphere uses are X.509 v3 SSL certificates. Only the way in which the actual certificate is generated is different.


Important: Ensure that you are using OpenSSL version 0.9.8 or newer. If you do not use this version, the SSL implementation will fail.

To setup OpenSSL:
  1. Ensure that the Microsoft Visual C++ 2008 Redistributable Package (x86) is installed on the system on which you want to generate the requests. To download the package, see the Microsoft Download Center.
  2. Download the Shining Light Productions installer for OpenSSL x86 selecting the current version of 0.98, available at Shining Light Productions. This is a software developed from the OpenSSL Project.
  3. Launch the installer and proceed through the installation and note the appropriate directory for later use. By default, it is located at c:\OpenSSL-Win32.

    After this program is installed, you must configure it to issue vSphere certificates.

    Note: The preceding links were correct as of July 25, 2014. If you find a link is broken, provide feedback and a VMware employee will update the link.


To configure OpenSSL follow these steps:
  1. Take a backup of the openssl.cfg file. By default, this file is located at the c:\OpenSSL-Win32\bin directory.
  2. Delete the contents of the file and replace with:

    Note: Replace the code in Red with the details of the server that you are configuring.

    [ req ]
    default_bits = 2048
    default_keyfile = rui.key
    distinguished_name = req_distinguished_name
    encrypt_key = no
    prompt = no
    string_mask = nombstr
    req_extensions = v3_req

    [ v3_req ]
    basicConstraints = CA:FALSE
    keyUsage = digitalSignature, keyEncipherment, dataEncipherment
    extendedKeyUsage = serverAuth, clientAuth
    subjectAltName = DNS:vc50, IP:,

    [ req_distinguished_name ]
    countryName = US
    stateOrProvinceName = NY
    localityName = New York
    0.organizationName = VMWare
    organizationalUnitName = vCenterInventoryService
    commonName =

  3. Save and close the file.

    The installation is now set to configure a certificate for the server that you have entered in the file. You can repeat this configuration by creating separate files for each server request or by not specifying a value. If you do not specify a value, OpenSSL prompts you for the information.

    Note: The preceding modified file will not prompt you for information because all information is configured within the file.

Additional Information

For more information on configuring CA signed certificates, see:
Implementing CA signed SSL certificates with vSphere 5.0
Configuring CA signed certificates for ESXi 5.x hosts
Implementing CA signed SSL certificates with vSphere 5.x
vSphere 環境に CA 署名証明書をインストールして構成するための OpenSSL の構成
在 vSphere 环境中为 CA 签名证书的安装和配置配置 OpenSSL