Donkey Project Introduction and ideas around February 21, 2003 Yuri Demchenko

Donkey Project

Introduction and ideas around

February 21, 2003Yuri Demchenko <[email protected]>

©February 21, 2003. Amsterdam. Donkey Project Slide2_2

Outlines

Problems in traditional PKI and Identity Management Donkey goals Donkey Functionality Design issues Timetable Next steps Discussion:

Where the Donkey can be of use for RIPE NCC


Problems in PKI and Identity Management

X.509 PKI is a heavy-weight solution and usually enterprise oriented: Requires Certificate Authority (CA) to create and trust a certificate (PKC) Certificate creation/revocation mechanism is complex, slow and expensive LDAP as a standard mechanism to publish X.509 Certs is not easily extensible

and (generically) not globally scaled

Distributed applications and mobile users require secure remote access to electronic credentials and identity information

P2P networks normally (based on DHT) require non-hierarchical (non-PKI) security infrastructure

Advent of XML/SOAP based standards for SSO/Identity management creates technological alternative for traditional PKI and PMI


Donkey and DNSSEC

DNSSEC can be a source of public keys for zones/nodes but it's not intended to provide this service for other applications: Intended for host names, not arbitrary names Updates are slow (propagation through caches, administrative overhead) Requires DNSSEC protocol for public key access/request (standard request for

KEY and SIG RRs)

Donkey can provide (shadow/alternative) key distribution infrastructure using application specific protocols to off-load DNSSEC


Donkey Goal(s)

Open extendable system for public key and Identity management

Initial stage

Open global distributed system for publishing and retrieving named, signed public keys

Intended development

Identity management for federated cross-domain AuthN and AuthZ

Donkey website: http://www.nlnetlabs.nl/donkey/


What is Donkey: Donkey functionality

Donkey allows anyone to publish a named key, together with optional data (Donkey package)

Multiple parties are allowed to publish a key with the same name. Applications must select the correct key when multiple keys match

Donkey is NOT a permanent storage: key must be republished to remain available

Donkey does NOT define a policy for key/payload usage – This is an application specific function

Donkey allows anyone to query for a published key, based on the key's name (required) and signers (optional)

Donkey allows anyone to sign a published key


Design issues: Package structure

(Proprietary) Internal format (Python data object) but XML based exchange format Package ID Content

Header– Flags– Names

Owner Public Key– <Name, Owner Key> must be unique

Body– Payload

• Application dependent content and format• Intended for AA and Identity management • May include specific format definition (e.g., embedded XML Schema)

Signatures


Design considerations

Build upon existing solutions and standards But still capable to do a low start

Gradual development Build up upon key storage/management engine

XML for package extensibility and exchange Including prospective use of the XML Protocol


Existing OpenSource solutions for AA and PMI

Donkey will be built upon existing PKI and AA applications:

• PGP Key Server

• Internet2 PubCookie/WebISO and Shibboleth/AA

• PAPI (AuthZ and Web SSO)

• A-Select (AuthZ and Web SSO)

• PERMIS (PrivilEge and Role Management Infrastructure Standards Validation Project)

• Akenti (cross-domain AA for Grid applications)


Standards for security assertions

• PGP

• X.509 Public Key Certificate (PKC)

• X.509 Attribute Certificate (AC) for Privilege Management

• SAML (Security Assertion Mark-up Language)

• Liberty Alliance Network Identity (XML and SAML based)

• Web Services Security (SOAP Extensions)


PKC vs AC: Purposes

X.509 PKC binds an identity and a public key AC is a component of X.509 Role-based PMI

AC contains no public key AC may contain attributes that specify group membership, role, security clearance,

or other authorisation information associated with the AC holder Analogy: PKC is like passport, and AC is like entry visa

PKC is used for Authentication and AC is used for Authorisation– AC may be included into Authentication message

PKC relies on Certification Authority and AC requires Attribute Authority (AA)


X.509 PKC Fields and Extensions – check with RFC 3280

X.509 PKC Fields Serial Number Subject Subject Public Key Issuer Unique ID Subject Unique ID

X.509 PKC Extensions Standard Extensions

Authority Key Identifier Subject Key Identifier Key Usage Extended Key Usage CRL Distribution List Private Key Usage Period Certificate Policies Policy Mappings Subject Alternative Name Issuer Alternative Name Subject Directory Attributes Basic Constraints Name Constraints

X.509 PKC Fields Private Extensions

Authority Information Access Subject Information Access

Custom Extensions


X.509 PKC Extensions format

Identifier: Key Usage: - 2.5.29.15 Critical: yes Key Usage:

Digital Signature Key CertSign Crl Sign


AC vs PKC: Certificates structure

X.509 PKC Version Serial number Signature Issuer Validity Subject Subject Public key info Issuer unique identifier Extensions

AC Version Holder Issuer Signature Serial number Validity Attributes Issuer unique ID Extensions


AC Attribute Types and AC Extensions

AC Attribute Types Service Authentication Informaion Access Identity Charging Identity Group Role Clearance Profile of AC

AC Extensions Audit Identity

To protect privacy and provide anonymity

May be traceable via AC issuer

AC Targeting Authority Key Identifier Authority Information Access CRL Distribution Points


Donkey Project milestones

Overview and inventory/planning - current stage Selected basic technologies and development environment Overview document

March-April: Prospective applications area overview Requirements (common and specific for applications) Draft Package and Protocol description/definition

April-May: API(s) definition and Donkey prototyping API requirements

June-August: Development and pilot implementation for 1-2 applications


Donkey current status

Just started work on Donkey prototype Key generation (DSA or RSA keys) Creating a new Donkey package Add and verify signature to/of an existing Donkey package Data model and XML DTD/Schema for Donkey packages

Goal: Create a base for experiments with application specific payloads


Some specific next tasks

Overview of existing solutions for AA and Identity management Analysis of applications specific requirements Scalability analysis Trust analysis Threats analysis

Documents

Donkey Project Introduction and ideas around February 21, 2003 Yuri Demchenko