160 likes | 175 Views
This presentation discusses the Prospero Resource Manager (PRM) and its overall security model, including an extended access control list framework and a generic authorization and access control API. It explores the motivation behind the model, as well as its application to PRM. The current prototype and future work are also presented.
E N D
Authorization for Metacomputing Applications G. Gheorghiu, T. Ryutov and B. C. Neuman University of Southern California Information Sciences Institute July, 1998
Outline of Presentation • The Prospero Resource Manager (PRM) • Motivation • Overall security model - Extended Access Control List framework - Generic Authorization and Access control API • Applying the model to PRM • Status • Summary
The Prospero Resource Manager (PRM) • The System Manager (SM) - allocates resources to jobs • The Job Manager (JM) - requests necessary resources • The Node Manager (NM) - loads and executes tasks
Running a job with PRM NM 1 JM 3 SM . . . 4 2 5 % appl NM 5 NM 1.JM requests resources 2.SM allocates resources to the JM, notifies the NMs 3.SM informs the JM of the assigned resources 4.JM requests task initiation 5.NMs create tasks
Motivation • Need for user Authentication • Security policies: - authorized principals - type of granted access - restrictions on granted access and resources • Customization of the policies • Enforcement of the policies Request to load an application Security Policy Data Base Domain A Domain B
EACL framework EACL for host kot.isi.edu EACL entry Principals Access Rights Conditions . . . Default EACL for domain isi.edu . . . Prospero Directory Service
EACL Management • Goal: enable easy sharing of a default authorization policy among NMs while allowing customization at host level • The Prospero Directory Service API is used to create virtual links to the EACL files and to specify attributes for the links • Example of attributes for the default EACL file: • SYSTEM_MANAGER darkstar.isi.edu • EACL_DEFAULT True • Example of attributes for a local EACL file: • NODE_MANAGER kot.isi.edu • EXTEND_DEFAULT Append
EACL entry structure : Principals TYPE SECURITY MECHANISM ID USER Kerberos.V5 joe@ISI.EDU HOST IPaddress 164.67.21.82 APPLICATION Checksum 0x75AA31 GROUP DCE 8 ANYBODY
EACL entry structure: Access Rights user-level representation tag value HOST load HOST status DEVICE power_up DEVICE power_down
EACL entry structure: Conditions TYPE VALUE location DNS_* _island.com time_window 8AM-6PM time_day Monday-Friday payment $20 CPU_load 30 application_name matlab PRM-SPECIFIC GENERIC
Generic Authorization and Access control API (GAA API) Reference to object Upcall function for EACL retrieval . . . gaa_get_object_eacl Object EACL handle GAA API Security Context [ operations for authorization ] . . . gaa_check_authorization YES / NO / MAYBE [ list of authorized operations and corresponding conditions, if any ] . . .
GAA API Security Context • Identity • Authorization Attributes • Delegated credentials • Evaluation and Retrieval functions for Upcalls
Using the GAA API in PRM GAA API EACL 5a 5 gaa_get_object_eacl SM 6 . . . 1 4 gaa_check_authorization 6b Transport Mechanism 6a 4a GAA API security context 2 3 Kerberos Library (1, 2, 3, 4, 4a) request and verification of principal’s identity (5, 5a) call to gaa_get_object_eacl, retrieval of appropriate EACL (6, 6a, 6b) call to gaa_check_authorization
EACL Evaluation EACL associated with the host kot.isi.edu GAA API security context PRINCIPALS OPERATIONS CONDITIONS Identity: USER kerberos.v5 joe@ISI.EDU Functions for upcall: GROUP kerberos.v5 oper@ISI.EDU * USER kerberos.v5 joe@ISI.EDU load time_w: 6AM-8PM cpu_load : 20 REQUEST This is Joe, load matlab, on the host kot.isi.edu Joe host kot.isi.edu 10:07AM
Status • Current Prototype The prototype is used within our current PRM testbed to check user authorization based on the policies in the EACL file. - implemented PRM-specific conditions: time window, idle time and CPU load - only the default policy per domain is used • IETF drafts - draft-ietf-cat-acc-cntrl-frmw-00.txt - draft-ietf-cat-gaa-cbind-00.txt • Future work - implementing the local EACL policy mechanism - other PRM-specificconditions - refining the EACL evaluation algorithm - requesting additional credentials and evaluation of acquired ones
Summary • Flexible and configurable security policy • Integration of local and distributed policies • Fine-grained access control • Facilitation of authorization decisions • Contact authors at {grig, bcn, tryutov}@isi.edu