PKI: A High Level View from the

TrenchesKen Klingenstein,

Project Director, Internet2 Middleware Initiative

Chief Technologist, University of Colorado at Boulder

Agenda

Fundamentals - Components and Contexts The missing pieces - in the technology and in the

community Current Activities - feds, chime, anx, overseas,

pkiforum, etc. Higher Ed Activities (CREN, HEPKI-TAG, HEPKI-PAG,

Net@edu, PKIlabs)

PKI : A few observations

Think of it as wall jack connectivity, except it’s connectivity for individuals, not for machines, and there’s no wall or jack…But it is that ubiquitous and important

Does it need to be a single infrastructure? What are the costs of multiple solutions? Subnets and ITP’s...

Options breed complexity; managing complexity is essential

A few more...

IP connectivity was a field of dreams. We built it and then the applications came. . Unfortunately, here the applications have arrived before the infrastructure, making its development much harder.

Noone seems to be working on the solutions for the agora.

Uses for PKI and Certificates

authentication and pseudo-authentication signing docs encrypting docs and mail non-repudiation secure channels across a network authorization and attributes and more...

A framework

PKI Components - hardware, software, processes, policies

Contexts for usage - community of interests Implementation options (in-source, out-source, roll-

your-own,etc.) Note changes over time...

PKI Components

X.509 v3 certs - profiles and uses Validation - Certificate Revocation Lists, OCSP, path

construction Cert management - generating certs, using keys,

archiving and escrow, mobility, etc. Directories - to store certs, and public keys and

maybe private keys Trust models and I/A Cert-enabled apps

PKI Contexts for Usage

Intracampus Within the Higher Ed community of interest In the Broader World

PKI Implementation Options

In-source - with public domain or campus unique In-source - with commercial product Bring-in-source - with commercial services Out-source - a spectrum of services and issues what you do depends on when you do it...

Cert-enabled applications

Browsers Authentication S/MIME email IPsec and VPN Globus Secure multicast

X.509 certs

purpose - bind a public key to a subject standard fields extended fields profiles client and server cert distinctions

Standard fields in certs

cert serial number the subject, as x.500 DN or … the subject’s public key the validity field the issuer, as id and common name signing algorithm signature info for the cert, in the issuer’s private key

Extension fields

Examples - auth/subject subcodes, key usage, LDAP URL, CRL distribution points, etc

Key usage is very important - for digsig, non-rep, key or data encipherment, etc.

Certain extensions can be marked critical - if an app can’t understand it, then don’t use the cert

Requires profiles to document, and great care...

Cert Management

Certificate Management Protocol - for the creation and management of certs

Revocation Options - CRL, OCSP Storage - where (device, directory, private cache,

etc.) and how - format escrow and archive - when, how, and what else

needs to be kept Cert Authority Software or outsource options Authority and policies

Certificate Management Systems

Homebrews OpenSSL and OpenCA Baltimore, Entrust, etc. W2K, Netscape, etc.

Directories

to store certs to store CRL to store private keys, for the time being to store attributes implement with border directories, or acls within the

enterprise directory, or proprietary directories

Inter-organizational trust model components

Certificate Policy- uses of particular certs, assurance levels for I/A, audit and archival requirements

Certificate Practices Statement- the nitty gritty operational issues

Hierarchies vs Bridges• a philosopy and an implementation issue• the concerns are transitivity and delegation• hierarchies assert a common trust model• bridges pairwise agree on trust models and policy

mappings

Certificate Policies Address (CP)

Legal responsibilities and liabilities (indemnification issues)

Operations of Certificate Management systems Best practices for core middleware Assurance levels - varies according to I/A processes

and other operational factors

Certificate Practice Statements (CPS)

Site specific details of operational compliance with a Cert Policy

A single practice statement can support several policies (Chime)

A Policy Management Authority (PMA) determines if a CPS is adequate for a given CP.

Trust chains

Path construction• to determine a path from the issuing CA to a trusted

CA• heuristics to handle branching that occurs at

bridges Path validation

• uses the path to determine if trust is appropriate• should address revocation, key usage, basic

constraints, policy mappings

Trust chains

When and where to validate• off-line on a server at the discretion of the

application• depth of chain

some revocations better than others - major (disaffiliation, key compromise, etc.) and minor (name change, attribute change)

sometimes the CRL can’t be found or hasn’t been updated

Mobility Options

smart cards usb dongles passwords to download from a store or directory proprietary roaming schemes abound - Netscape,

Verisign, etc SACRED within IETF recently formed for standards integration of certificates from multiple stores

More current activities

HEPKI the Grid

Current Activities

PKIX (http://www.ietf.org/html.charters/pkix-charter.html)

Federal PKI work (http://csrc.nist.gov/pki/twg/) State Govs (http://www.ec3.org/) Medical community (Tunitas, CHIME, HIPAA) Automobile community (ANX) Overseas

• Euro government - qualifying certs• EuroPKI for Higher Ed

(http://www.europki.org/ca/root/cps/en_index.html)

All the stuff we don’t know…

Revocation approaches Policy languages Standard profiles Mobility Path math User interface

PKI and Higher Ed

ah, the public sector life… Key issues Current activities

ah, the public sector…

almost universal community of interests cross-agency relationships complex privacy and security issues limited budgets and implementation options sometimes ahead of the crowd and the obligation to

build a marketplace

Key issues

trust relationships among autonomous organizations interoperability of profiles and policies interactions with J.Q. Public international governance issues