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DigiCert IGTF Host Certificates


This document describes how to get host certificates. For instructions on how to get user certificates, see the User Certificates document.

This document describes how to purchase individual IGTF-accredited host certificates from DigiCert. Before purchasing individual certificates, consider the following alternatives:

  1. Request a Let's Encrypt certificate if you don't support any VOs that require IGTF-accredited certificates (e.g. ATLAS or CMS).
  2. Request an InCommon certificate if your institution has an InCommon subscription.

Before Starting

Before requesting a new host certificate, use openssl to check if your host already has a valid certificate, i.e. the present is between notBefore and notAfter dates and times. If so, you may safely skip this document:

[email protected] $ openssl x509 -in /etc/grid-security/hostcert.pem -subject -issuer -dates -noout
subject= /DC=org/DC=opensciencegrid/O=Open Science Grid/OU=Services/
issuer=/DC=org/DC=cilogon/C=US/O=CILogon/CN=CILogon OSG CA 1
notBefore=Jan  4 21:08:09 2010 GMT
notAfter=Jan  4 21:08:09 2011 GMT

If you do not have a valid certificate, the OSG offers a command-line tool to generate certificate signing requests (CSR) to assist in acquiring a grid host certificate. As with all OSG software installations, there are some one-time (per host) steps to prepare in advance:

Create a DigiCert Account

Before requesting a certificate, you must create a DigiCert account with permission to request grid certificates:

  1. Navigate to the DigiCert sign up page and create an account


    It is very important to use your institution's main address and other contact information. Departmental addresses will not pass DigiCert's verification process.

  2. Submit a support request to allow you to order grid host certificates, referencing support ticket #01336672

  3. After your request has been approved, verify that the Grid Host SSL option is available to you from your account's order page:

DigiCert Order Menu

Requesting DigiCert IGTF Host Certificates

  1. Install the osg-pki-tools:

    [email protected] # yum install osg-pki-tools
  2. Generate a CSR and private key using the osg-cert-request tool:

    [email protected] $ osg-cert-request --hostname <HOSTNAME> \
                 --country <COUNTRY> \
                 --state <STATE> \
                 --locality <LOCALITY> \
                 --organization <ORGANIZATION>

    You may also add DNS Subject Alternative Names (SAN) to the request by specifying any number of --altname <SAN>. For example, the following generates a CSR for with and as SANs:

    [email protected] $ osg-cert-request --hostname \
                 --country US \
                 --state Wisconsin \
                 --locality Madison \
                 --organization 'University of Wisconsin-Madison' \
                 --altname \

    If successful, the CSR will be named <HOSTNAME>.req and the private key will be named <HOSTNAME>-key.pem. Additional options and descriptions can be found here.

  3. Submit an order using DigiCert's grid certificate order page:

    1. Login to your DigiCert account

    2. Attach the CSR that you generated above

    3. Pay for your certificate and await approval

  4. After the certificate has been issued by DigiCert, download the host certificate only (not the full chain) to its intended host and copy over the key you generated above.

  5. Verify that the issuer CN field is DigiCert Grid Trust CA G2:

    $ openssl x509 -in <PATH TO CERTIFICATE> -noout -issuer
    issuer= /C=US/O=DigiCert Grid/ Grid Trust CA G2

    Where <PATH TO CERTIFICATE> is the file you downloaded in the previous step

  6. Install the host certificate and key:

    [email protected] # cp <PATH TO CERTIFICATE> /etc/grid-security/hostcert.pem
    [email protected] # chmod 444 /etc/grid-security/hostcert.pem
    [email protected] # cp <PATH TO KEY> /etc/grid-security/hostkey.pem
    [email protected] # chmod 400 /etc/grid-security/hostkey.pem

    Where <PATH TO KEY> is the ".key" file you created in the first step