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Grid Security Infrastructure : 

Grid Security Infrastructure Original Source: The Globus Project Argonne National LaboratoryUSC Information Sciences Institute Some slides are being added and/or localised by: Rajkumar Buyya

Grid Security: Authentication Infrastructure : 

Grid Security: Authentication Infrastructure Based on PKI (Public Key Infrastructure)

Security : 

Security As Grid Resources and Users are Distributed and Owned by different organizations, only authorized users should be allowed to access them. A simple authentication infrastructure is needed. Also, both users and owners should be protected from each other. The Users need be assured about security of their: Data Code Message

Globus/Grid Security Infrastructure (GSI) based on PKI : 

Globus/Grid Security Infrastructure (GSI) based on PKI GSI is: PKI (CAs and Certificates) SSL/ TLS Proxies and Delegation PKI for credentials SSL for Authentication And message protection Proxies and delegation (GSI Extensions) for secure single Sign-on PKI: Public Key Infrastructure, SSH: Secure Socket Layer TLS: Transport Level Security

Public Key Infrastructure (PKI) : 

Public Key Infrastructure (PKI) PKI allows you to know that a given public key belongs to a given user PKI builds off of asymmetric encryption: Each entity has two keys: public and private Data encrypted with one key can only be decrypted with other. The private key is known only to the entity The public key is given to the world encapsulated in a X.509 certificate

Public Key Infrastructure (PKI) Overview : 

Public Key Infrastructure (PKI) Overview X.509 Certificates Certificate Authorities (CAs) Certificate Policies Namespaces Requesting a certificate Certificate Request Registration Authority

Certificates : 

Certificates A X.509 certificate binds a public key to a name It includes a name and a public key (among other things) bundled together and signed by a trusted party (Issuer)

Certificates : 

Certificates Similar to passport or driver’s license

Certificates : 

Certificates By checking the signature, one can determine that a public key belongs to a given user. Hash Hash Hash =? Decrypt Public Key from Issuer

Certificate Authorities (CAs) : 

Certificate Authorities (CAs) A small set of trusted entities known as Certificate Authorities (CAs) are established to sign certificates A Certificate Authority is an entity that exists only to sign user certificates The CA signs it’s own certificate which is distributed in a trusted manner

Certificate Authorities (CAs) : 

Certificate Authorities (CAs) The public key from the CA certificate can then be used to verify other certificates Hash Hash Hash =? Decrypt

Requesting a Certificate : 

Requesting a Certificate To request a certificate a user starts by generating a key pair The private key is stored encrypted with a pass phrase the user gives The public key is put into a certificate request Certificate Request Public Key Encrypted On local disk

Certificate Issuance : 

Certificate Issuance The user then takes the certificate to the CA The CA usually includes a Registration Authority (RA) which verifies the request: The name is unique with respect to the CA It is the real name of the user Etc. Certificate Request Public Key State of Victoria ID Certificate Authority

Certificate Issuance : 

Certificate Issuance The CA then signs the certificate request and issues a certificate for the user Certificate Authority Certificate Request Public Key Sign

Secure Socket Layer (SSL) : 

Secure Socket Layer (SSL) Also known as TLS (Transport Layer Security) Uses certificates and TCP sockets to provide a secured connection Authentication of one or both parties using the certificates Message protection Confidentiality (encryption) Integrity Certificates TCP Sockets SSL/TLS

Mutual Authentication : 

Mutual Authentication A and B are two parties: Both need to trust each others’ CA. A  B (A establishes connection to B and gives his certificate (name,pub. Key) to B). B makes sure that it can trust CA of A. B generates random message A and asks it encrypt it. A encrypts it and send to B B decrypts using A’s public key. If the msg. is same as what B has sent, then A is who it is claiming to be.

Globus Security Review : 

Globus Security Review GSI extends existing standard protocols & APIs Based on standards: SSL/TLS, X.509, GSS-API Extensions for single sign-on and delegation The Globus Toolkit provides: Generic Security Services API (GSS-API) on GSI protocols The GSS-API is the IETF standard for adding authentication, delegation, message integrity, and message confidentiality to applications. Various tools for credential management, login/logout, etc.

Kerberos Security : 

Kerberos Security Some Grids use a Kerberos GSS-API. As far as tools and APIs go, this is not visible. (That’s the point of GSS-API!) However, it is NOT interoperable with GSI based versions of the Globus Toolkit Various differences of Kerberos vs GSI: The security files created “under the covers” are different Different commands to login, logout, etc. We will discuss security using GSI (PKI).

Obtaining a Certificate : 

Obtaining a Certificate The program grid-cert-request is used to create a public/private key pair and unsigned certificate in ~/.globus/: usercert_request.pem: Unsigned certificate file userkey.pem: Encrypted private key file Must be readable only by the owner Mail usercert_request.pem to Receive a Globus-signed certificate Place in ~/.globus/usercert.pem Other organizations use different approaches NCSA, NPACI, NASA, etc. have their own CA

Your New Certificate : 

Your New Certificate Certificate: Data: Version: 3 (0x2) Serial Number: 28 (0x1c) Signature Algorithm: md5WithRSAEncryption Issuer: C=US, O=Globus, CN=Globus Certification Authority Validity Not Before: Apr 22 19:21:50 1998 GMT Not After : Apr 22 19:21:50 1999 GMT Subject: C=US, O=Globus, O=NACI, OU=SDSC, CN=Richard Frost Subject Public Key Info: Public Key Algorithm: rsaEncryption RSA Public Key: (1024 bit) Modulus (1024 bit): 00:bf:4c:9b:ae:51:e5:ad:ac:54:4f:12:52:3a:69: <snip> b4:e1:54:e7:87:57:b7:d0:61 Exponent: 65537 (0x10001) Signature Algorithm: md5WithRSAEncryption 59:86:6e:df:dd:94:5d:26:f5:23:c1:89:83:8e:3c:97:fc:d8: <snip> 8d:cd:7c:7e:49:68:15:7e:5f:24:23:54:ca:a2:27:f1:35:17:

Certificate and Key Data : 

Certificate and Key Data

Certificate Information : 

Certificate Information To get cert information run grid-cert-info % grid-cert-info -subject /O=Grid/O=Globus/ Buyya Options for printing cert information-all -startdate-subject -enddate-issuer -help

“Logging on” to the Grid : 

“Logging on” to the Grid To run programs, authenticate to Globus: % grid-proxy-init Enter PEM pass phrase: ****** Creates a temporary, local, short-lived proxy credential for use by our computations Options for grid-proxy-init: -hours <lifetime of credential> -bits <length of key> -help

grid-proxy-init Details : 

grid-proxy-init Details grid-proxy-init creates the local proxy file. User enters pass phrase, which is used to decrypt private key. Private key is used to sign a proxy certificate with its own, new public/private key pair. User’s private key not exposed after proxy has been signed Proxy placed in /tmp, read-only by user NOTE: No network traffic! grid-proxy-info displays proxy details

Grid Sign-On With grid-proxy-init : 

Grid Sign-On With grid-proxy-init User certificate file Private Key (Encrypted) Pass Phrase User Proxy certificate file

Destroying Your Proxy (logout) : 

Destroying Your Proxy (logout) To destroy your local proxy that was created by grid-proxy-init: % grid-proxy-destroy This does NOT destroy any proxies that were delegated from this proxy. You cannot revoke a remote proxy Usually create proxies with short lifetimes

Proxy Information : 

Proxy Information To get proxy information run grid-proxy-info % grid-proxy-info -subject /O=Grid/O=Globus/ Buyya Options for printing proxy information-subject -issuer-type -timeleft-strength -help Options for scripting proxy queries-exists -hours <lifetime of credential>-exists -bits <length of key> Returns 0 status for true, 1 for false:

Important Files : 

Important Files /etc/grid-security hostcert.pem: certificate used by the server in mutual authentication hostkey.pem: private key corresponding to the server’s certificate (read-only by root) grid-mapfile: maps grid subject names to local user accounts (really part of gatekeeper) /etc/grid-security/certificates CA certificates: certs that are trusted when validating certs, and thus needn’t be verified ca-signing-policy.conf: defines the subject names that can be signed by each CA

Important Files : 

Important Files $HOME/.globus usercert.pem: User’s certificate (subject name, public key, CA signature) userkey.pem: User’s private key (encrypted using the user’s pass phrase) /tmp Proxy file(s): Temporary file(s) containing unencrypted proxy private key and certificate (readable only by user’s account) Same approach Kerberos uses for protecting tickets

Secure Services : 

Secure Services On most unix machines, inetd listens for incoming service connections and passes connections to daemons for processing. On Grid servers, the gatekeeper securely performs the same function for many services It handles mutual authentication using files in /etc/grid-security It maps to local users via the gridmap file

Sample Gridmap File : 

Sample Gridmap File # Distinguished name Local # username /O=Grid/O=Globus/ Buyya raj "/C=US/O=Globus/O=NPACI/OU=SDSC/CN=Richard Frost” frost "/C=US/O=Globus/O=USC/OU=ISI/CN=Carl Kesselman” u14543 "/C=US/O=Globus/O=ANL/OU=MCS/CN=Ian Foster” itf Gridmap file maintained by Globus administrator Entry maps Grid-id into local user name(s)

ExampleSecure Remote Startup : 

ExampleSecure Remote Startup gatekeeper client 1. Exchange certificates, authenticate, delegate 2. Check gridmap file 3. Lookup service 4. Run service program (e.g. jobmanager) 1. 2. 4. 3.

Simple job submission : 

Simple job submission globus-job-run provides a simple RSH compatible interface% grid-proxy-init Enter PEM pass phrase: *****% globus-job-run host program [args] Job submission will be covered in more detail later

Delegation : 

Delegation Delegation = remote creation of a (second level) proxy credential New key pair generated remotely on server Proxy cert and public key sent to client Clients signs proxy cert and returns it Server (usually) puts proxy in /tmp Allows remote process to authenticate on behalf of the user Remote process “impersonates” the user

Limited Proxy : 

Limited Proxy During delegation, the client can elect to delegate only a “limited proxy”, rather than a “full” proxy GRAM (job submission) client does this Each service decides whether it will allow authentication with a limited proxy Job manager service requires a full proxy GridFTP server allows either full or limited proxy to be used

Restricted Proxies : 

Restricted Proxies A generalization of the simple limited proxies Desirable to have fine-grained restrictions Reduces exposure from compromised proxies Embed restriction policy in proxy cert Policy is evaluated by resource upon proxy use Reduces rights available to the proxy to a subset of those held by the user A proxy no longer grants full impersonation rights Extensible to support any policy language Will be in future version > GT 2.0

ExerciseSign-On & Remote Process Creation : 

ExerciseSign-On & Remote Process Creation Use grid-cert-info to examine your cert: % grid-cert-info -all Use grid-proxy-init to create a proxy certificate: % grid-proxy-init Enter PEM pass phrase: ......................................+++++ .....+++++ Use grid-proxy-info to query proxy: % grid-proxy-info -subject Use globus-job-run to start remote programs: % globus-job-run /usr/bin/ls -l /tmp

Generic Security Service API : 

Generic Security Service API The GSS-API is the IETF draft standard for adding authentication, delegation, message integrity, and message confidentiality to apps For secure communication between two parties over a reliable channel (e.g. TCP) GSS-API separates security from communication, which allows security to be easily added to existing communication code. Filters on each end of the communications link GSS-API Extensions defined in GGF draft Globus Toolkit components all use GSS-API

Building Secure Applications : 

Building Secure Applications Embed Security Code into Application: -- including (A) authentication logic (B) Use Globus IO calls (instead of plain socket I/O). Use Cryptography for secure communication

gss_acquire_cred() : 

gss_acquire_cred() Loads security credentials into program User proxy certificate and private key are loaded at this point gss_release_cred() Removes security credentials into program User proxy certificate and private key remain on disk for later use

gss_inquire_cred() : 

gss_inquire_cred() Extract information (e.g. the subject name) from a credential gss_inquire_cred_by_oid() Extract information associated with a OID from a credential (e.g. information in certificate extensions) Will be in future version > GT 2.0

gss_export_cred() : 

gss_export_cred() Export a credential either to a opaque buffer or to a file New in GT 2.0 gss_import_cred() Import a credential in either one of the formats used by gss_export_cred New in GT 2.0

gss_init_sec_context()gss_accept_sec_context() : 

gss_init_sec_context()gss_accept_sec_context() Establish a security context between two processes Tokens are fed into and out of these routine Application can pass tokens between processes in any way desired One side calls init, the other accept while (!done) gss_init_sec_context( in_t, &out_t, &done); if (out_t) send(out_t); if (!done) receive(&in_t); while (!done) receive(&in_t); gss_accept_sec_context( in_t, &out_t, &done); if (out_t) send(out_t);

gss_delete_sec_context() : 

gss_delete_sec_context() Discard a security context gss_context_time() Determine how long a context will remain valid

gss_inquire_context() : 

gss_inquire_context() Extract information (e.g. the target subject name) from a security context gss_inquire_sec_context_by_oid() Extract information associated with a OID from a security context (e.g. information in certificate extensions) Will be in future version > GT 2.0

gss_export_context() : 

gss_export_context() Export a security context to a opaque buffer gss_import_context() Import a opaque buffer containing a security context exported by gss_export_context

gss_set_sec_context_option() : 

gss_set_sec_context_option() Set options on a security context prior to establishing it Will be in future version > GT 2.0 gss_wrap_size_limit() Returns the maximum token size gss_wrap can deal with

gss_wrap()gss_unwrap() : 

gss_wrap()gss_unwrap() gss_wrap() consumes an user input buffer performs cryptographic checksum and/or encryption on it produces a token, which application sends gss_unwrap() consumes a token produced by gss_wrap() decrypts and/or verifies the checksum produces a user output buffer

gss_get_mic()gss_verify_mic() : 

gss_get_mic()gss_verify_mic() gss_get_mic() Produces a cryptographic checksum on a user input buffer gss_verify_mic() Verifies a cryptographic checksum on a user buffer

gss_import_name() : 

gss_import_name() Import a subject name into GSS gss_export_name() Export a GSS name into a buffer

gss_display_name() : 

gss_display_name() Convert GSS name to text gss_compare_name() Compare two GSS names

gss_release_name() : 

gss_release_name() Discard a GSS name

gss_add_oid_set_member() : 

gss_add_oid_set_member() Add a OID to a OID set gss_test_oid_set_member() Checks whether a OID is in a OID set gss_create_empty_oid_set() Creates a empty OID set gss_release_oid_set() Discard a OID set

gss_indicate_mech() : 

gss_indicate_mech() Determine available underlying security mechanisms

gss_release_buffer() : 

gss_release_buffer() Discard a GSS buffer gss_release_buffer_set() Discard a GSS buffer set Will be in future version > GT 2.0

gss_init_delegation()gss_accept_delegation() : 

gss_init_delegation()gss_accept_delegation() Delegate a credential and optionally add restrictions to the delegated credential One side calls init, the other accept Can be in either direction, relative to gss_{init,accept}_sec_context() Tokens are fed into and come out of these routines Similar use to gss_{init,accept}_sec_context() It is up to the application to pass the tokens from one function to the other Will be in future version > GT 2.0

GSSAPI exercises : 

GSSAPI exercises Go to the “gssapi” subdirectory Documentation Follow instructions in the file README

What’s Wrong with GSS-API : 

What’s Wrong with GSS-API The GSS-API works, but it is not pretty! GSS-API accomplishes its goal of providing an API that is independent of any specific security implementation, or communication mechanism Same application can use either Globus Toolkit GSS-API or Kerberos 5 GSS-API with almost no change It has rich feature support But it is not easy to use

globus_gss_assist : 

globus_gss_assist The globus_gss_assist module is a Globus Toolkit specific wrapper around GSS-API which makes it easier to use Hides some of the gross details of GSS-API Conforms to Globus Toolkit conventions Still maintains separation from communication method

globus_io and security : 

globus_io and security For even easier security integration with socket code, use the globus_io module Simple to add authentication and authorization to TCP socket code But looses separation of security from communication method Will be discussed more later...

Authorization : 

Authorization GSI handles authentication, but authorization is a separate issue Authorization issues: Management of authorization on a multi-organization grid is still an interesting problem. The grid-mapfile doesn’t scale well, and works only at the resource level, not the collective level. Large communities that share resources exacerbates authorization issues, which has led us to CAS…

Security Summary : 

Security Summary Programs for credential management grid-cert-info, grid-proxy-init, grid-proxy-destroy, grid-proxy-info GSS-API: The Globus Toolkit Grid Security Infrastructure (GSI) uses this API, which allows programs to easily add security globus_gss_assist: This is a simple wrapper around GSS-API, making it easier to use

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