Grid certificates

< Getting started with SweGrid
< Swestore

Introduction

In order to access to Swestore using certificate authentication or grid resources a valid eScience client certificate is required. A certificate is similar to an electronic key card in real-life, in the same manner that you must swipe a key card in the lock/reader, the application you are using) must present a certificate. Not having a certificate is similar to not having a key-card, just entering the PIN code is usually not enough.

Keep your certificate safe, just like a physical key or key card. Store them in a safe place, utilizing secure credential store, browser master password, private directories and file permissions as appropriate.

Most importantly, always use a unique passphrase to protect certificates whenever possible.

Requesting a certificate

In order to use certificate authentication you need a valid certificate.

Certificates are issued by a Certificate Authority or CA. The certificate needed for accessing the Swestore or other grid resources should have the IGTF, eScience or Grid type, not all CA:s are certified by The International Grid Trust Federation to issue these.

For users residing in the Nordics there are two relevant CA:s that can issue grid/eScience/e-Science certificates: Sectigo and Nordugrid. The Sectigo CA is preferred if it is available for your university or research group, but some institutions has not enabled this service yet. The Nordugrid CA can also be used but requires more manual labor by all parties.

Instructions for the Sectigo CA

Instructions for the NorduGrid CA (use this only if Sectigo isn't available at your site)

An eScience certificate is valid for 13 months and thus needs to be renewed yearly.

If you have acquired a certificate as part of new-user setup, return to the documentation that referred you here.

Proxy certificates

Authentication to Swestore can by done using your client certificate directly (as done with your web browser). But on the command line it's usually good practice to use a special short lived proxy certificate. When using other grid resources you must use proxy certificates or other similar mechanisms.

A proxy certificate is bascially a new short lived certificate you issue yourself and then sign using your reglar certificate (or rather your secret key). If you lose this proxy certificate it will shortly expire and then be useless for bad guys. In many grid applications you upload your proxy certificate to the grid resource (the compute element might need your credentials for accessing a storage element as you) and if stolen it can be used to authenticate as you on alla resources you have access to.

There are several tools available for creating, checking and destroying these proxy certificates. The examples below demonstrates the arcproxy command from the ARC software suite. Another common tool is the grid-proxy-init from the globus packages.

Creating a proxy certificate

This example requires that the certificate is available for use with grid tools. This is the default with Nordugrid certificates, although you might need to transfer the certificate to the resource where you are using the grid tools.

For Digicert certificates you must first export the certificate, transfer it to the resource where you are using the grid tools if needed and prepare it for use with grid tools. ARC can use the Firefox certificate store directly, as described in the next section.

To create a short lived proxy that can be used for authentication with grid services, the arcproxy command can be used. A 12 hour (default) proxy is created in the following example:

$ arcproxy
Your identity: /O=Grid/O=NorduGrid/OU=lunarc.lu.se/CN=Kalle Kula
Enter pass phrase for /home/kalle/.globus/userkey.pem:
.++++++
.....++++++
Proxy generation succeeded
Your proxy is valid until: 2016-03-11 03:00:14

The proxy file itself will be created in the /tmp directory with the format x509up_uid, where uid is the user id number for your account.

In some cases a longer lived proxy will be needed. This is achieved using the --constraint switch. A 24-hour can be created by issuing the following command:

$ arcproxy --constraint="validityPeriod=24H"
Your identity: /O=Grid/O=NorduGrid/OU=lunarc.lu.se/CN=Kalle Kula
Enter pass phrase for /home/kalle/.globus/userkey.pem:
....++++++
.....++++++
Proxy generation succeeded
Your proxy is valid until: 2011-03-11 15:03:19

Creating a proxy certificate using the Firefox/Thunderbird credential store

Using the ARC client tools it is possible to generate a proxy certificate directly from the Firefox or Thunderbird credential stores. To do this the -F flag is used as shown in the following example:

$ arcproxy -F
There are 2 NSS base directories where the certificate, key, and module datbases live
Number 1 is: /Users/lindemann/Library/Application Support/Firefox/Profiles/t22f3aj2.default
Number 2 is: /Users/lindemann/Library/Thunderbird/Profiles/7abb733v.default
Please choose the NSS database you would use (1-2): 1

Here ARC finds the available Firefox and Thunderbird profile in which the credential stores are stored. Next the passphrase for the credential store is used to unlock the stored credentials:

NSS database to be accessed: /Users/lindemann/Library/Application Support/Firefox/Profiles/t22f3aj2.default
Enter Password or Pin for "internal (software)":

If the passphrase was correct, ARC will list the available certificates in the credential store and ask you for which you would like to use.

There are 2 user certificates existing in the NSS database
Number 1 is with nickname: Jonas Lindemann xxxxx@lu.se's TERENA ID (Jonas Lindemann xxxxx@lu.se)
    expiration time: 2013-06-04 01:59:59
Number 2 is with nickname: Imported Certificate (Jonas Lindemann)
    expiration time: 2014-01-18 16:55:52
Please choose the one you would use (1-2): 1
Certificate to use is: Jonas Lindemann xxxxxx@lu.se's TERENA ID
Proxy generation succeeded
Your proxy is valid until: 2013-05-01 04:11:37

Checking proxy lifetime

The remaining lifetime of a proxy certificate can be checked using the arcproxy command with the --info switch.

$ arcproxy --info
Subject: /O=Grid/O=NorduGrid/OU=lunarc.lu.se/CN=Kalle Kula/CN=1567862803
Identity: /O=Grid/O=NorduGrid/OU=lunarc.lu.se/CN=Kalle Kula
Time left for proxy: 11 hours 55 minutes
Proxy path: /tmp/x509up_u500
Proxy type: X.509 Proxy Certificate Profile RFC compliant restricted proxy

In this example the proxy certificate is valid for 11 hours 55 minutes more.

Destroying a proxy certificate

A proxy can be destroyed with the -r or --remove switch.

$ arcproxy -r

or

$ arcproxy --remove

Requesting membership in the SweGrid VO

This was previously needed for Swestore, but Swestore users are now managed in the SUPR portal.

Introduction

SweGrid resources are allocated for VO:s, virtual organizations, rather than individual users. A VO is basically just a list of users. To be able to use a SweGrid resource a membership in the SweGrid VO (virtual organization) and a corresponding subgroup is required.

Preparations

To apply for membership, make sure that the NorduGrid root CA 2015 certificate and your personal certificate is installed in the browser.

The NorduGrid CA certificate can be installed by clicking on the following link:

http://ca.nordugrid.org/NorduGrid-2015.crt

Make sure you check the "Trust this CA to identify web sites." boxes in the dialog shown.

File:Certinstall.png

Step 1 - Apply for VO membership

When the NorduGrid CA certificate have been installed in the browser go to the following URL:

https://voms.ndgf.org:8443/voms/swegrid.se

and follow the instructions. After a manual review, normally within a couple of hours, you will be added to the SweGrid VO.

Step 2 - Request group membership

After being added to the Swegrid VO you need to be added to the correct project/allocation group to use that allocation. Use the Request membership function in the Your groups and roles section of your VOMS homepage at https://voms.ndgf.org:8443/voms/swegrid.se/user/home.action as shown in the following screenshot, selecting the project in the dropdown box and clicking the Request membership button. No further actions need to be taken on that page after requesting the membership.

The request is handled manually, usually within a few hours. Allow for a couple more hours for the membership to propagate to Swestore.

If it doesn't work

If things doesn't work for some reason, contact SweGrid support at support@swegrid.se or Swestore support at support@swestore.se as appropriate.

More information

A certificate consist of a public key, some user information and the signature of the CA. In addition to the certificate you have a corresponding private key. The private key is secret and should be kept as secure as possible.

The grid certificate and private key is stored in your web browser and/or in your home directory on the host where you will be accessing the resource. Standard file names are:

     ~/.globus/usercert.pem
     ~/.globus/userkey.pem

The certificate contains your public key, your name and organization and a signature by the CA. It is does not contain any username.

The private key should be handled with great care. It should only be readable by you and not by the group or others (i.e. ``chmod 400 userkey.pem). Store the key on trusted computers and transfer the key between computers using encryption (using for example scp).

On shared file systems make sure that ~/.globus is not readable by everybody:

chmod 700 ~/.globus

and on AFS:

fs sa ~/.globus system:anyuser none

The private key should be encrypted using a passphrase. Anyone that can decrypt the private key will be able to authenticate as you to grid resources. This is similar to the private key in SSH. You must choose a strong passphrase for the private key. This passphrase must not be used anywhere else. You must never ever give away or share the certificate, passphrase or the unencrypted key to someone else.

For more information regarding certificates and public key cryptography:

• http://en.wikipedia.org/wiki/Public-key_cryptography
• http://en.wikipedia.org/wiki/Public_key_certificate
• http://www.nordugrid.org/documents/certificate_howto.html

VOMS proxy certificates

As long as you are a member of only one VO or VO group, you can authenticate to a grid service with the regular grid proxy certificate as defined in the previous section. If you are a member of more than one VO or VO group you may want to select which membership you want to be authenticated as. For example, if you are a member of swegrid.se:/swegrid.se/ops (operations staff) and swegrid.se:/swegrid.se/bils and want to write a file, who should be the owner? Ops or bils? You need to provide some additional information. In the grid world this is done with a voms proxy certificate which basically is a regular proxy certificate but with a so called voms extension that contains a list of your VO group memberships (and roles and attributes, which we don't use in Swegrid/Swestore at the moment).

Please note, if you only have one membership you can skip this section!

The voms extension of the certificate is signed by the virtual organization management server, or VOMS server. The very same VOMS server you used when applying for the swegrid.se VO membership in the first place. To enable this signing process you need to add a few configuration files to your system. First add this to the file ~/.arc/vomses or /etc/vomses:

  "swegrid.se" "voms.ndgf.org" "15009" "/O=Grid/O=NorduGrid/CN=host/voms.ndgf.org" "swegrid.se"

Next create the necessary directories and the file /etc/grid-security/vomsdir/swegrid.se/voms.ndgf.org.lsc with the following contents:

  /O=Grid/O=NorduGrid/CN=host/voms.ndgf.org
  /O=Grid/O=NorduGrid/CN=NorduGrid Certification Authority 2015

Creating a VOMS proxy

VOMS proxies in ARC1 can be created using the arcproxy command and the -S or --voms switches as shown in the following example (if you are a member of the /swegrid.se/ops group. Adjust as necessary):

$ arcproxy -S swegrid.se:/swegrid.se/ops
Your identity: /O=Grid/O=NorduGrid/OU=lunarc.lu.se/CN=Kalle Kula
Enter pass phrase for /home/kalle/.globus/userkey.pem:
.....++++++
............++++++
Contacting VOMS server (named swegrid.se): voms.ndgf.org on port: 15009
Proxy generation succeeded
Your proxy is valid until: 2015-12-10 23:33:06

Signing your e-mail with your certificate

First, you will need your grid certificate in PKCS12 format:

How to transform your certificate from PEM format into PKCS#12 format

This is how you transform your cert into PKCS12 format that can be used within your web browser or email program: You first will have to change directory into where you created and keep the certificate, historically this is often in ~/.globus

openssl pkcs12 -export -in usercert.pem -inkey userkey.pem -out cert+key.p12	 

First you will have to enter the password you used for your private key, then you will be asked for a new password to protect the new file. cert+key.p12 contains your private key, and is therefore as valuable as userkey.pem. See also #More information. Security wise the safest way is to delete the PKCS12 file after having imported it into your mail client or browser. Don't forget this.

Remarks: openssl will either need the variable RANDFILE to be set or that ~/.rnd is writable. So you have to make sure that the current $HOME is yours if you have pagshed away, otherwise the command will fail with unable to write 'random state.

Thunderbird

Mozilla Thunderbird is a graphical email program available for many platforms. More information at https://www.mozilla.org/thunderbird

In Thunderbird, Navigate options->security->digitally sign this message.

If you do this for the first time and haven't defined yet the certificate to sign with, thunderbird will pop up the according preferences [Account settings/Security], where you can choose between your imported certificates in PKCS12 format.

In the beginning, of course, you haven't imported any: Click there on the same preferences tab that popped up on [View Certificates]. In the new window that opens you can import the certificate.

Afterwards you can then choose this certificate to be used for signing and for encryption for this email account.

Don't forget to actually check that you then really sign the corresponding mail.

Mew

Mew is a mail reader for Emacs. More information at https://www.mew.org/

Mew uses gpgsm.

1. Import the nordugrid root cert

1.1. get 1f0e8352.0 from nordugrid web

1.2. gpgsm --import 1f0e8352.0

1.2. Make it trusted:
     gpgsm --list-keys 2>/dev/null | grep fingerprint | awk '{print $2 " S"}' | grep THE-FINGERPRINT-YOU-WANT >> .gnupg/trustlist.txt

2. Add your own key from the cert+key.p12 file in this case

2.1 openssl pkcs12 -in cert+key.p12 -out tmp.pem -nokeys

2.2. gpgsm --import tmp.pem ; rm tmp.pem

2.3. Tell gpgsm not to use revocation lists (bad bad security)
     echo disable-crl-checks >> .gnupg/gpgsm.conf

3. Test
   gpgsm --detach-sign file > sign  # should ask for passphrase and give some kind of sign file

4. Use:
   C-uC-cC-s  then enter your email address (must match email in cert) and passphrase