1. New Security Services Based on PKI
Antonio F. Gómez Skarmeta
University of Murcia
SPAIN

2. Agenda Introduction The UMU IPv6 PKI (UMU-PKIv6)
Distributed Security Policy Management architecture (DSPM)
Distributed Credential Management System (DCMS)
Conclusions
I’m going to expose the contents of this speech.
First, I will start identifying some scenarios that we used as starting points to design DCMS.
Second, I’m going to introduce the main elements of our proposal […] and I will show how DCMS can be used to manage some access control scenarios
Then, some details about the implementation will be analyzed,
And finally, I draw some conclusions about our system and I depict our work in progress and the future lines.

3. Introduction
PKIs ... key element for providing security to distributed and dynamic networks and services
Our experience ... based on our own designs and implementations:
An IPv6 PKI (UMU-PKIv6)
Two innovative secure distributed services built over this PKI
Distributed Security Policy Management architecture (DSPM)
Based on the concept of policy (set of rules governing choices in the behaviour of one system)
Modifying a policy we can change the behaviour of one system
It defines a new network paradigm, based on flexible and programmable networks
Distributed Credential Management System (DCMS)
Difference between the concepts of certificate and identity certificate
Based on SPKI/SDSI infrastructure
More suitable for complex and distributed environments
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

4. The UMU IPv6 PKI (UMU-PKIv6)

5. UMU-PKIv6 Description
Main Objective ... to establish a high security infrastructure for distributed systems
Main Features:
First PKI supporting the IPv6 protocol
Developed in Java  running on every Operating System
Issue, renew and revoke certificates for every entity belonging to one organisation
Final users can use either RAs or Web browsers to make their own certification operations
LDAPv6 directory support
Use of smart cards (file system, RSA or Java Cards) ... allowing user mobility and increasing security
PKI Certification Policy support
VPN devices certification support (using the SCEP protocol)
Support for the OCSP protocol and Time Stamp
Web administration
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

6. UMU-PKIv6 Architecture
WWW Secure
Request Server
Data Base
LDAP
Server
End
User
Certification
Authority
Registration
Administrator
IPv6 SSL connection
IPv6 Plain connection
SCEP
VPN Device
SCEP over IPv6
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

7. Distributed Security Policy Management architecture (DSPM)

8. Security Policies There is ...
high interest in policy-based networking, but
no complete systems supporting the specification and deployment of these policies
Policies used to manage distributed communication systems ... “IF certain conditions are present, THEN specific actions are taken”
Security is vital  we sign every policy (using X.509 certificates issued by our own PKIv6)
We use policies for managing
The UMU-PKIv6 itself
Secure IPv6 VPNs
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

9. Security Policies for PKIs
UMU-PKIv6 policies
Drive the way the PKIv6 itself works
Digital implementation of a Certification Practice Statement (CPS) ... they specify which rules must be applied to requested or existing certificates
Digitally signed (integrity and authentication) normally by the CA private key
Centralised creation process driven by the PKI admin
Distributed use by RAs and other PKI components
Categories:
Certification rules
Re-issuance rules
Revocation rules
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

10. Security Policies for PKIs (II)
Information about a Policy
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

11. Security Policies for VPNs
IPsec
Receiving widespread deployment for implementing VPN
Typical policy-enabled networking service
But ...
IPsec policy databases are normally manually-configured
Growing number of Internet applications using VPNs
Therefore, a IPsec Policy-Based Network Management system (PBNM) is clearly needed
Our designed and implemented PBNM is divided in two different components:
Policy Definition Process
Policy Recovery Process
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

12. Security Policies for VPNs (II)
Policy Definition Process
IPsec Policy ... “IF conditions include a type of traffic, IP address, and/or TCP/UDP port, THEN actions should include setting certain level of authentication and encryption of traffic”
Provides a common means of specifying IPsec policies
Vendor and platform independent
Defined in XML and mapping, using XML style-sheets, onto every IPsec and IKE (freeware or commercial) implementations
Enables a coordinated control of IP-level security services in every administrative domain
Based on the CIM model (from the IETF/DMTF) ... common data schema for describing management information
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

13. Security Policies for VPNs (III)
Policy Definition Process Schema
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

14. Security Policies for VPNs (IV)
Policy Recovery Process
It makes use of two kind of entities
Policy Decision Points (PDPs)
Policy Enforcement Points (PEPs)
and one IETF-defined integrated framework of standards based on COPS (Common Open Policy Service)
Three scenarios are currently defined
COPS IPsec node
Non-COPS IPsec node
With SMTP
Without SMTP
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

15. Security Policies for VPNs (V)
Policy Recovery Process Schema
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

16. Distributed Credential Management System (DCMS)

17. DCMS  Motivation Most of those SPKI scenarios are based on delegation
Resource controllers have small ACLs delegating access to some particular public keys (authorities)
Application-dependent approaches try to answer:
How do I encode a certification request?
How do I submit the certification request?
How do the authorities specify and enforce the authorization policies? (i.e. who is able to obtain a particular authorization?)
In complex environments, simple command-line (and off-line) applications do not seem to be the right approach
[1st =]
Usually, those proposals don’t explain how certificates are issued by the authorities (it is usually application-dependent)
[2nd =]
In complex environments, a structured and distributed system must be provided (and application independent)

18. DCMS  Motivation (II)
It is necessary to address the problems related to scalability and interoperability.
DCMS (Distributed Credential Management System)
DCMS defines: requests, policies, and entities
DCMS is divided into:
NMS: SPKI ID Certificates
AMS: SPKI Attribute and Authorization Certificates
Entities exchange authorization information using the AMBAR Protocol (similar protocols are valid too)
Main goal of DCMS: to be application-independent
When the number of principals is high, we need to provide a mechanisms able to address the problems derived from scalability and interoperability
In this work, we present DCMS (DCMS stands for…)
DCMS defines how requests and policies must be encoded, and which are the entities involved
We have divided DCMS into …
[rest =]

19. DCMS-NMS (Naming Management System)
NMS is responsible for certification operations related to SPKI ID certificates
This type of certificates can be used to:
link a name to a particular public key (principal)
define group membership
NMS can be especially useful when authorization is based on groups of principals
NMS can be used by the principals in order to obtain an ID certificate for group G
ID certificates are issued by naming authorities (NA)
As I previously said, DCMS is composed by two subsystems: NMS and AMS
[rest =]
Naming is not a requirement of distributed systems, but I would like to note that large-scale delegation-based systems can be simplified using roles (or groups), and role membership can be implemented using SPKI ID certificates.

20. DCMS-NMS Entities Requestors: They create certification requests
Additional certificates can be also attached to the requests
Two types of requestors:
Demanding an ID certificate for a name (subgroups)
Demanding an ID certificate for a public key
This figure shows the three types of entities involved in NMS: requestors, service access points and naming authorities
A requestor is a principal demanding the generation of a new ID certificate
[1st =]
We are going to see how those requests are encoded
[2nd =]

21. DCMS-NMS Entities Service Access Points (SAP):
Requestors use SAPs to submit the certification requests
Several advantages:
Naming authorities can be protected
They “know” the appropriate naming authorities
Public terminals placed at buildings or departments
Requestors can make use of access points to submit their certification requests to the appropriate naming authorities
These access points provide several advantages: [=]
Communication between requestors and access points is system-dependent. SAPs can be public terminals placed at buildings or departments.

22. DCMS-NMS Entities Naming Authorities (NA):
NAs are controlled by authorization policies
In DCMS, those policies are implemented using SPKI ACLs
Use of certificate chain discovery methods
Input: request, additional certificates, ACL
Output: data used to generate the new certificate
Naming authorities are the certificate issuers
[=]
Discovery methods: in order to determine whether the certification request must be granted or denied.
Communication with NAs is performed using AMBAR.

23. DCMS-NMS Requests and ACL Entries
(cert
(issuer (name NA-pk N))
(subject P)
(valid …) )
(tag
(cert-request
NMS s-expressions:
There is no need for a new syntax (we use the certificate struct)
Main differences:
N can be a (* prefix) form or a (* set) form
P can make reference to several principals (* set Q S T)
valid is making reference to the intended validity period
The request is signed by the requestor, not by the issuer
Certification requests for ID certificates must contain information about the issuer defining the name, the name itself, the intended subject, and validity dates.
Those fields are also contained in the SPKI structure for ID certificates, so… [=]

24. DCMS-NMS example Request and additional certificate ACL (sequence (tag
(cert-request
(issuer
(name morpheus-pk Nebuchadnezzar))
(subject neo-pk) )
(signature …)
Request and additional certificate
(cert
(issuer
(name morpheus-pk Nebuchadnezzar))
(subject trinity-pk) )
(acl
(entry
(subject
(name morpheus-pk Nebuchadnezzar))
(tag
(cert-request
(issuer
(* set neo-pk trinity-pk switch-pk)) )
ACL
Improvisar

25. DCMS-AMS (Authorization Management System)
AMS is responsible for the certification operations related to SPKI Attribute and Authorization certificates
NMS and AMS are based on similar entities:
Requestors and SAPs are also part of AMS
NAs are replaced by AAs (Authorization Authorities)
S-expressions for requests and ACLs are similar to those defined for NMS (including propagation and tags)
There are also two types of requestors:
Requestors of authorization certificates
Requestors of attribute certificates
[1st =]
In fact, the tag field is especially useful since I we will see we can specify sets of certificates that will be issued on demand (using *-forms)
The tag contains information about the particular authorization being requested (when it is contained in a certification request) or granted (when it is part of an ACL entry)
[2nd =]
I’m going to pay special attention to attribute certificates

26. DCMS-AMS  Role Managers
We need to encode statements like:
Psion-AA authorizes the Role Manager RM to request attribute certificates granting the set of permissions tag-A for group Nebuchadnezzar defined by Morpheus
(acl
(entry
(subject RM-pk)
(tag
(cert-request
(issuer psion-pk)
(subject (name morpheus-pk Nebuchadnezzar))
(tag tag-A) )
Improvisar

27. DCMS  Implementation AMBAR was implemented using Intel CDSA 3.14
DCMS is being implemented also using CDSA
Graphical User Interface (QT libraries)
Red Hat Linux 7.1
Several applications:
DCMS tag constructors
ACL Management
Authorities
Service Access Points

28. DCMS  Implementation

29. Conclusions

30. Conclusions
UMU-PKIv6 ... provides a common trustworthy point for new distributed services, like:
DSPM that provides:
New active network management paradigm based on policies (for several scenarios: UMU-PKIv6 and VPNs)
Expressed in XML
Based on IETF/DMTF standards: CIM and COPS
DCMS that provides:
Certification requests (s-expressions)
Authorization policies (SPKI ACLs)
Architectural elements
It’s known that questions about digital identity have been solved (well, more or less) by the X.509 standard, but sometimes it is necessary to determine what the identities should be allowed to do
As you know, certificates are digitally-signed statements containing information about anything (for example authorization). Some well-known specifications for authorization are […]
In fact, [3rd =]

31. New Security Services Based on PKI
Antonio F. Gómez Skarmeta
University of Murcia
SPAIN