Difference between revisions of "Grid certificates"

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[[Category:Grid computing]]
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#REDIRECT[[Swestore Documentation Moved]]
[[Category:SweGrid user guide]]
 
[[Category:SweStore]]
 
[[Category:SweStore user guide]]
 
[[Getting started with SweGrid|< Getting started with SweGrid]]
 
 
 
 
 
=Introduction to certificates=
 
 
 
In order to get access to computer and storage resources on the grid or [[SweStore]] you must have a valid (grid) certificate. This certificate is used instead of a username and password when accessing the resource. The resource have a certificate that tells you that you have contacted the right resource. This is exactly the same mechanism used when you use a web browser to contact your bank.
 
 
 
A certificate is the similar to a passport in real-life. In the same way you have prove your credentials when you acquire a passport the same is true for a certificate. A third party, the Certificate Authority or CA, that both you and the resource trust has to vouch for your identity and sign your certificate.
 
 
 
A certificate consist of a public key, some user information and a signature of the CA. In addition to the certificate you have a private key. The private key is secret and should be kept as secure as possible.
 
 
 
For more information regarding certificates and public key cryptography:
 
 
 
[http://en.wikipedia.org/wiki/Public-key_cryptography http://en.wikipedia.org/wiki/Public-key_cryptography]
 
 
 
[http://en.wikipedia.org/wiki/Public_key_certificate http://en.wikipedia.org/wiki/Public_key_certificate]
 
 
 
[http://www.nordugrid.org/documents/certificate_howto.html http://www.nordugrid.org/documents/certificate_howto.html]
 
 
 
* The grid certificate and the private key are stored in your web browser and/or located in ~/.globus at the host(s) from where you will be accessing the resource:
 
      usercert.pem
 
      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 certificate is valid for 13 month and should be renewed yearly.
 
* The private key should be handled with great care. It should only be readable by you (i.e. ``chmod 400 userkey.pem''). Store the key on trusted computers and transfer the key between computers using encryption (using for example scp).
 
* The private key is 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 the passphrase to somebody else.
 
* You should not share the certificate with someone. It's personal.
 
 
 
For more information regarding certificates and public key cryptography:
 
 
 
[http://en.wikipedia.org/wiki/Public-key_cryptography http://en.wikipedia.org/wiki/Public-key_cryptography]
 
[http://en.wikipedia.org/wiki/Public_key_certificate http://en.wikipedia.org/wiki/Public_key_certificate]
 
 
 
= Requesting a certificate =
 
 
 
Certificates are issued by a Certificate Authority or CA. For swedish users there are two CA:s that can issue certificates, Terena and Nordugrid. The Terena CA is preferred if it is available for your university or research group, but many sites has not enabled this service yet. The Nordugrid CA can also be used but requires more manual work by all parties.
 
 
 
== [[Requesting a grid certificate using the Terena eScience Portal]] ==
 
 
 
== [[Requesting a grid_certificate from the Nordugrid CA]] ==
 
 
 
= Requesting membership in the SweGrid VO =
 
 
 
To be able to use the SweGrid or Swestore resources a membership in the SweGrid VO and a corresponding group is required. To apply for membership, make sure that the Nordugrid CA and your certificate is installed in the browser.
 
 
 
The NorduGrid CA can be installed by clicking on the following [http://ca.nordugrid.org/cacrt.crt link]
 
 
 
When certifcates have been installed in the browser go to the following URL:
 
 
 
[https://voms.ndgf.org:8443/voms/swegrid.se https://voms.ndgf.org:8443/voms/swegrid.se]
 
 
 
and follow the instructions. In a couple of hours you will be added to the SweGrid VO.
 
 
 
To be added to the correct SNIC project send a mail to [mailto:support@swegrid.se support@swegrid.se] and specify your DN as shown in the Terena portal or from the '''arproxy --info''' command and which SNIC-project to be added to.
 
 
 
To be added to the correct Swestore allocation send a mail to [mailto:swestore-support@snic.vr.se swestore-support@snic.vr.se] and specify your DN as shown in the Terena portal or from the '''arproxy --info''' command and which Swestore allocation to be added to.
 
 
 
= Proxy certificates =
 
 
 
Authentication on the grid is done using special short lived ''proxy'' certificates. There are several tools available for creating, checking and destroying these proxy certificates.
 
 
== Creating a proxy certificate ==
 
 
 
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: 2011-03-11 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
 
 
 
== 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
 
 
 
= VOMS certificates =
 
 
 
To use the SweStore national storage resources a membership in a virtual organisation, VO, is required. When accessing the storage resources a special grid proxy certificate is required which indicates VO membership. The special proxy certificate requires that it is signed by the virtual organisation management server, VOMS. To enable this signing process, configuration files have to be added to the system. First a '''$HOME/.voms/vomses''' file with the following contents must be added:
 
 
 
<pre>"swegrid.se" "voms.ndgf.org" "15009" "/O=Grid/O=NorduGrid/CN=host/voms.ndgf.org" "swegrid.se"</pre>
 
 
 
Next the file '''/etc/grid-security/vomsdir/swegrid.se/voms.ndgf.org.lsc''' with the following contents:
 
 
 
<pre>/O=Grid/O=NorduGrid/CN=host/voms.ndgf.org
 
/O=Grid/O=NorduGrid/CN=NorduGrid Certification Authority</pre>
 
 
 
== 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:
 
 
 
$ 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: 2011-03-10 23:33:06
 

Latest revision as of 10:00, 8 February 2023