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Lezione 7a - 9 Dicembre 2009

Lezione 7a - 9 Dicembre 2009.

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Lezione 7a - 9 Dicembre 2009

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  1. Lezione 7a - 9 Dicembre 2009 Il materiale didattico usato in questo corso è stato mutuato da quello utilizzato da Paolo Veronesi per il corso di Griglie Computazionali per la Laurea Specialistica in Informatica tenutonell’anno accademico 2008/09 presso l’Università degli Studi di Ferrara. Paolo Veronesi paolo.veronesi@cnaf.infn.it, pveronesi@unife.it http://www.cnaf.infn.it/~pveronesi/unife/ Università degli Studi di Bari – Corso di Laurea Specialistica in Informatica “Tecnologia dei Servizi “Grid e cloud computing” A.A. 2009/2010 Giorgio Pietro Maggigiorgio.maggi@ba.infn.it, http://www.ba.infn.it/~maggi

  2. Referenze gLite doc http://glite.web.cern.ch/glite/documentation/default.asp gLite userGuide https://edms.cern.ch/file/722398//gLite-3-UserGuide.pdf VOMS Guide https://edms.cern.ch/file/973684/1/voms-guide.pdf VOMS Admin User Guide https://edms.cern.ch/file/974094/1/voms-admin-user-guide.pdf

  3. Make a proxy Inspecting personal certificate (grid-cert-info). Creation of a proxy without voms extensions and check your proxy (grid-proxy-init) Creation of a proxy with voms extensions and check your proxy (voms-proxy-init) Use <command> -help to check how to use them

  4. grid-cert-info Ispeziona il certificato pubblico in $HOME/.globus Nessuna communicazione di rete Stesso risultato che si ottiene ispezionando con I comandi openssl o verificando il certificato nel sito della Certification Authority

  5. grid-proxy-init Crea un proxy senza estensioni voms (password richiesta perchè si usa la chiave privata) Durata predefinita: 12 ore Si possono creare proxy di durata superiore alla validità del certificato! Verifica del proxy: grid-proxy-info –all Posso solo autenticarmi, le autorizzazioni sono basate sulle estensioni VOMS $ grid-proxy-info -all subject : /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi/CN=1777588616 issuer : /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi identity : /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi type : Proxy draft (pre-RFC) compliant impersonation proxy strength : 512 bits path : /tmp/x509up_u11397 timeleft : 1513:49:55 (63.0 days)

  6. voms-proxy-init Equivalente a grid-proxy-init se non si specifica la VO; Viene contattato il voms server per recuperare le estensioni; • Verifica con voms-proxy-info –all (da notare i due campi timeleft distinti, cosa succede quando uno dei due scade?) $ voms-proxy-info -all subject : /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi/CN=proxy issuer : /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi identity : /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi type : proxy strength : 512 bits path : /tmp/x509up_u11397 timeleft : 11:58:17 === VO gilda extension information === VO : gilda subject : /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi issuer : /C=IT/O=INFN/OU=Host/L=Catania/CN=voms.ct.infn.it attribute : /gilda/Role=NULL/Capability=NULL timeleft : 11:58:17

  7. Requesting Voms Group/Role in Proxy One of the main features of VOMS is its capability to create groups and roles which allows VO administrator to differentiate users' privileges and right. Users, if already belonging to a group, or already assigned to a Role, can apply the request while creating the proxy with voms-proxy-init command. In this way, the information will be signed by the VOMS server and inserted in the proxy AC; resources will be able to parse them assigning to the user the expected rights. Syntax The group/role request is done by users appending a request command to the --voms option of voms-proxy-init voms-proxy-init --voms YourVO:/YourVO/Desired-Group in case of group request; voms-proxy-init --voms YourVO:/YourVO/Role=Desired-Role in case of role request; voms-proxy-init --voms YourVO:/YourVO/Desired-Group/Role=Desired-Role in case of mixed (group + role) request. Let's make it plain by some examples

  8. Group request Suppose you want to create a voms proxy for the gilda VO, requesting the membership of generic-users group. Then you have to just to run voms-proxy-init --voms gilda:/gilda/generic-users Of course this wouldn't work if you don't belong to the gilda VO or either you don't belong to the generic-users group. You can verify that the command has run successfully with voms-proxy-info command : === VO gilda extension information === VO : gilda subject : /C=IT/O=GILDA/OU=Personal Certificate/L=CATANIA/CN=CATANIA49/Email=tony.calanducci@ct.infn.it issuer : /C=IT/O=INFN/OU=Host/L=Catania/CN=voms.ct.infn.it attribute : /gilda/generic-users/Role=NULL/Capability=NULL attribute : /gilda/Role=NULL/Capability=NULL timeleft : 11:59:37

  9. Role request If you belong to gilda VO and want to get the Role GenericRole within your proxy, you have to run just voms-proxy-init --voms gilda:/gilda/Role=GenericRole You can verify then with voms-proxy-info –all === VO gilda extension information === VO : gilda subject : /C=IT/O=GILDA/OU=Personal Certificate/L=CATANIA/CN=CATANIA49/Email=tony.calanducci@ct.infn.it issuer : /C=IT/O=INFN/OU=Host/L=Catania/CN=voms.ct.infn.it attribute : /gilda/Role=GenericRole/Capability=NULL attribute : /gilda/Role=NULL/Capability=NULL attribute : /gilda/generic-users/Role=NULL/Capability=NULL timeleft : 11:57:56

  10. Group + Role (1/2) You may have noticed that both when requesting a Role or a VO membership, the first part of the command you append starts always with /gilda : that's because the group with the VO name is the default group where all the VO members belong; even if it's a default, it is to be always specified. As a consequence, the request :/gilda/Role=GenericRole and /gilda/generic-users/Role=GenericRole are different, as you can verify by executing them and confronting the first attribute inserted in the created voms proxies. In the former you are requesting the Role within the default group, while in the latter you're requesting the Role within the group generic-users. By the way, you will notice that the syntax is /group/subgroup1/..../Role Of course, to be working, the request has to be consistent with the privileges that the VO-Admin has given you.

  11. Group + Role (2/2) Here an example of a Role requested within a subgroup : you can compare the output of a successive voms-proxy-info and see the differences with the one obtained in the paragraph before. $voms-proxy-init --voms gilda:/gilda/generic-users/Role=GenericRole […] === VO gilda extension information === VO : gilda subject : /C=IT/O=GILDA/OU=Personal Certificate/L=CATANIA/CN=CATANIA49/Email=tony.calanducci@ct.infn.it issuer : /C=IT/O=INFN/OU=Host/L=Catania/CN=voms.ct.infn.it attribute : /gilda/generic-users/Role=GenericRole/Capability=NULL attribute : /gilda/Role=NULL/Capability=NULL attribute : /gilda/generic-users/Role=NULL/Capability=NULL timeleft : 11:59:36

  12. Credential Storage MyProxy

  13. What is MyProxy? An Online Certificate Authority Issues short-lived X.509 End Entity Certificates Avoid need for long-lived user keys An Online Credential Repository Issues short-lived X.509 Proxy Certificates Long-lived private keys never leave the server Supporting multiple authentication methods Open Source Software

  14. MyProxy Logon Authenticate to retrieve PKI credentials End Entity or Proxy Certificate Trusted CA Certificates Certificate Revocation Lists (CRLs) MyProxy maintains the user’s PKI context Users don’t need to manage long-lived credentials Enables server-side monitoring and policy enforcement (ex. passphrase quality checks) CA certificates & CRLs updated automatically at login MyProxy integrates with existing authentication systems Providing a gateway to grid authentication

  15. Scenario 1: Users already have PKI credentials MyProxy repository can help users manage the credentials by: Securing private keys in a professionally managed server Obtaining credentials when/where needed Using credentials with MyProxy-enabled applications

  16. Scenario 2: Users have site logons but no PKI credentials Users have site logons but no PKI credentials MyProxy CA can provide the bridge

  17. Scenario 3: Users need to register to obtain PKI credentials User registration portals provide a MyProxy interface

  18. Scenario 4: Users need run Grid jobs longer than the typical proxy life A myproxy server is used to create and store a long term proxy which is used to renew short term proxies when they are going to expire

  19. MyProxy Repository Policies Who can store credentials? Restrict to specific users or CAs Restrict to administrator only Who can retrieve credentials? Allow anyone with correct password Allow only trusted services / portals Maximum lifetime of retrieved credentials server-wide and per-credential

  20. MyProxy in EGEE EGEE security based on proxy certificates often carrying VOMS attribute certificates MyProxy used for several purposes: Solution for portals (P-GRADE, Genius) a common way of using MyProxy Long-running jobs and data transfers credential renewal t-Infrastructure CA formalized on-line CA based on MyProxy

  21. Long-running Jobs Jobs require valid credentials e.g. to access GridFTP data repositories on the user‘s behalf these operations must be secured, using the users‘ credentials Job's lifetime can easily exceed the lifetime of a proxy consider waiting in the queues, possible resubmissions, computation time, data transfers, etc. also VOMS certificates have limited lifetime Impossible to submit a job with sufficiently long credentials the overall job lifetime not known in advance violation of the meaning of short-time proxies increased risk when the credential is stolen might be unacceptable for the end resources How to provide jobs with a valid short-lived credential throughout their run?

  22. Proxy Renewal Service Periodical renewal of credentials maintains a list of jobs' proxy certificates to be kept valid using MyProxy repository server specified by user in the job description uses the renewal mode authenticates using the WMS credential AND authorizes using the proxy being renewed Support for renewal of VOMS attributes Part of the broker node (WMS) A proxy of a job is registered upon submission It is renewed whenever it is going to expire several attempts done until renewal succeeds After renewal a new proxy is pushed to the computing resource, where the job is running After the job completion the proxy is unregistered

  23. Proxy Renewal Service

  24. Proxy Renewal Service Ensures that jobs always have a valid short-time proxy Users have full control over their proxies and renewal Using the MyProxy repository Support for VOMS All operations are logged allows an audit Stolen credentials can't be renewed easily the WMS credential are necessary for renewal An older (still valid) proxy must be available for renewal reduces the risk when services are compromised Developed in EU Datagrid, in production use in EGEE

  25. Long-term Data Transfers EGEE applications often need to move large amount of data The File Transfer Service (FTS) is used to handle such file movement requests Similar problem as in the case of jobs the transfer can last long time, can be rescheduled etc. FTS currently uses a password based retrieval from MyProxy Support for renewal is currently being added based on routines from the renewal service

  26. Credential Delegation through MyProxy MyProxyUse Register a long living proxy in the MyProxy server grid001.ct.infn.it (myproxy-init) Gather information about the proxy in the MyProxy server (myproxy-info) Get a delegated proxy from the Myproxy server (myproxy-get-delegation) Destroy remote proxy (myproxy-get-destroy) Use <command> -help to check how to use them

  27. myproxy-init Crea archivia un proxy senza estensioni voms sul server myproxy (il proxy è protetto da password diversa da quella della chiave privata); Durata di default: 7 giorni Verifico con myproxy-info $ myproxy-init Your identity: /C=IT/O=GILDA/OU=Personal Certificate/L=unife/CN=Paolo Veronesi Enter GRID pass phrase for this identity: Creating proxy .................................................... Done Proxy Verify OK Your proxy is valid until: Tue May 12 14:03:12 2009 Enter MyProxy pass phrase: Verifying - Enter MyProxy pass phrase: A proxy valid for 168 hours (7.0 days) for user veronesi now exists on myproxy.ct.infn.it.

  28. myproxy-get-delegation Recupero un proxy precedentemente salvato su un server myproxy voms-proxy-init -noregen --voms gilda -cert /tmp/x509up_u11397 Aggiungo le estensioni voms ad un proxy senza rigenerare il proxy stesso => rinnovo delle estensioni VOMS

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