Requirements for Client-Facing Interface to Security Controller
draft-ietf-i2nsf-client-facing-interface-req-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Expired".
|
|
|---|---|---|---|
| Authors | Rakesh Kumar , Anil Lohiya , Dave Qi , Nabil Bitar , Senad Palislamovic , Liang Xia | ||
| Last updated | 2017-04-28 | ||
| Replaces | draft-kumar-i2nsf-client-facing-interface-req | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
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| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-i2nsf-client-facing-interface-req-01
I2NSF Working Group R. Kumar
Internet-Draft A. Lohiya
Intended status: Informational Juniper Networks
Expires: October 28, 2017 D. Qi
Bloomberg
N. Bitar
S. Palislamovic
Nokia
L. Xia
Huawei
April 26, 2017
Requirements for Client-Facing Interface to Security Controller
draft-ietf-i2nsf-client-facing-interface-req-01
Abstract
This document captures requirements for Client-Facing interface to
Security Controller. The interface is expressed using objects and
constructs understood by Security Admin as opposed to vendor or
device specific expressions associated with individual product and
feature. This document identifies a broad set of requirements needed
to express security policies based on User-constructs which are well
understood by User Community. This gives ability to decouple policy
definition from policy enforcement on a specific element, be it a
physical or virtual.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 28, 2017.
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Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in this Document . . . . . . . . . . . . . . 4
3. Guiding principle for Client-Facing Interface defintion . . . 5
3.1. User-construct based modeling . . . . . . . . . . . . . . 5
3.2. Basic rules for Client-Facing Interface definition . . . 6
3.3. Deployment Models for Implementing Security Policies . . 7
4. Functional Requirements for the Client-Facing Interface . . . 10
4.1. Requirement for Multi-Tenancy in client interface . . . . 11
4.2. Requirement for Authentication and Authorization of
client interface . . . . . . . . . . . . . . . . . . . . 12
4.3. Requirement for Role-Based Access Control (RBAC) in
client interface . . . . . . . . . . . . . . . . . . . . 12
4.4. Requirement to protect client interface from attacks . . 12
4.5. Requirement to protect client interface from
misconfiguration . . . . . . . . . . . . . . . . . . . . 12
4.6. Requirement to manage policy lifecycle with diverse needs 13
4.7. Requirement to define dynamic policy Endpoint group . . . 14
4.8. Requirement to express rich set of policy rules . . . . . 15
4.9. Requirement to express rich set of policy actions . . . . 16
4.10. Requirement to express policy in a generic model . . . . 18
4.11. Requirement to detect and correct policy conflicts . . . 18
4.12. Requirement for backward compatibility . . . . . . . . . 18
4.13. Requirement for Third-Party integration . . . . . . . . . 18
4.14. Requirement to collect telemetry data . . . . . . . . . . 19
5. Operational Requirements for the Client-Facing Interface . . 19
5.1. API Versioning . . . . . . . . . . . . . . . . . . . . . 19
5.2. API Extensiblity . . . . . . . . . . . . . . . . . . . . 19
5.3. APIs and Data Model Transport . . . . . . . . . . . . . . 20
5.4. Notification . . . . . . . . . . . . . . . . . . . . . . 20
5.5. Affinity . . . . . . . . . . . . . . . . . . . . . . . . 20
5.6. Test Interface . . . . . . . . . . . . . . . . . . . . . 20
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6. Security Considerations . . . . . . . . . . . . . . . . . . . 20
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
9. Normative References . . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
Programming security policies in a network has been a fairly complex
task that often requires very deep knowledge of vendor specific
device and features. This has been the biggest challenge for both
Service Provider and Enterprise, henceforth named as Security Admin
in this document. This challenge is further amplified due to network
virtualization with security functions deployed in physical and
virtual form factor, henceforth named as network security function
(NSF) in this document, from multiple vendors with proprietary
interface.
Even if a Security Admin deploys a single vendor solution with one or
more security appliances across its entire network, it is still very
difficult to manage security policies due to complexity of security
features, and mapping of business requirements to vendor specific
configuration. The Security Admin may use vendor provided management
systems to provision and manage security policies. But, the single
vendor approach is highly restrictive in today's network for
following reasons:
o An organization may not be able to rely on a single vendor because
the changing security requirements may not align with vendor's
release cycle.
o A large organization may have a presence across different sites
and regions; which means, it may not be possible to deploy same
solution from the same vendor because of regional regulatory and
compliance policy.
o If and when an organization migrates from one vendor to another,
it is almost impossible to migrate security policies from one
vendor to another without complex and time consuming manual
workflows.
o An organization may deploy multiple network security functions in
virtual and physical forms to attain the flexibility, elasticity,
performance scale, and operational efficiency they require.
Practically, that often requires different sources (vendor, open
source) to get the best of breed for any such security function.
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o An organization may choose all or part of their assets such as
routers, switches, firewalls, and overlay-networks as policy
enforcement points for operational and cost efficiency. It would
be highly complex to manage policy enforcement with different tool
set for each type of device.
In order to facilitate deployment of security policies across
different vendor provided NSFs, the Interface to Network Security
Functions (I2NSF) working group in the IETF is defining a Client-
Facing interface to Security Controller [I-D. ietf-i2nsf-framework]
[I-D. ietf-i2nsf-terminology]. Deployment facilitation should be
agnostic to the type of device, be it physical or virtual, or type of
enforcement point. Using these interfaces, it becomes possible to
write different kinds of security management applications (e.g. GUI
portal, template engine, etc.) allowing Security Admin to express
security policies in an abstract form with choice of wide variety of
NSF for policy enforcement. The implementation of security
management applications or controller is completely out of the scope
of the I2NSF working group, which is only focused on interface
definition.
This document captures the requirements for Client-Facing interface
that can be easily used by Security Admin without a need for
expertise in vendor and device specific feature set. We refer to
this as "User-construct" based interfaces. To further clarify, in
the scope of this document, the "User-construct" here does not mean
some free-from natural language input or an abstract intent such as
"I want my traffic secure" or "I don't want DDoS attacks in my
network"; rather the User-construct here means that policies are
described using expressions such as application names, application
groups, device groups, user groups etc. with a vocabulary of verbs
(e.g., drop, tap, throttle), prepositions, conjunctions,
conditionals, adjectives, and nouns instead of using standard
n-tuples from the packet header.
2. Conventions Used in this Document
BSS: Business Support System
CLI: Command Line Interface
CMDB: Configuration Management Database
Controller: Used interchangeably with Security Controller or
management system throughout this document
CRUD: Create, Retrieve, Update, Delete
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FW: Firewall
GUI: Graphical User Interface
IDS: Intrusion Detection System
IPS: Intrusion Protection System
LDAP: Lightweight Directory Access Protocol
NSF: Network Security Function, defined by
[I-D.ietf-i2nsf-problem-and-use-cases]
OSS: Operation Support System
RBAC: Role Based Access Control
SIEM: Security Information and Event Management
URL: Universal Resource Locator
vNSF: Refers to NSF being instantiated on Virtual Machines
3. Guiding principle for Client-Facing Interface defintion
Client-Facing Interface must ensure that a Security Admin can deploy
any NSF from any vendor and should still be able to use the same
consistent interface. In essence, this interface must allow a
Security Admin to express security policies independent of how NSFs
are implemented in their deployment. Henceforth, in this document,
we use "security policy management interface" interchangeably when we
refer to Client-Facing interface.
3.1. User-construct based modeling
Traditionally, security policies have been expressed using
proprietary interface. The interface is defined by a vendor based on
proprietary command line text or a GUI based system with
implementation specific constructs such IP address, protocol and
L4-L7 information. This requires Security Admin to translate their
business objectives into vendor provided constructs in order to
express a security policy. But, this alone is not sufficient to
render a policy in the network; the admin must also understand
network and application design to locate a specific policy
enforcement point to make sure policy is effective. This may be
highly manual task based on specific network design and may become
unmanageable in virtualized networks.
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The User-construct based framework does not rely on lower level
semantics due to problem explained above, but rather uses higher
level constructs such as User-group, Application-group, Device-group,
Location-group, etcetera. A Security Admin would use these
constructs to express a security policy instead of proprietary
implementation or feature specific constructs. The policy defined in
such a manner is referred to User-construct based policies in this
draft. The idea is to enable Security Admin to use constructs they
understand best in expressing security policies which simplify their
tasks and help avoiding human errors in complex security
provisioning.
3.2. Basic rules for Client-Facing Interface definition
The basic rules in defining the Client-Facing interfaces are as
follows:
o Not dependent on particular Network topology or the NSF location
in the network
o Not requiring deep knowledge of proprietary features and
capabilities supported in the deployed NSFsa€
o Independent of NSF type that will implement the user security
policy be it a stateful firewall,IDP, IDS, Router, Switch
o Declarative/Descriptive model instead of Imperative/Prescriptive
model - What security policy need to be enforced (declarative)
instead of how it is implemented (imperative)
o Not dependent on any specific vendor implementation or form-factor
(physical, virtual) of the NSF
o Not dependent on how a NSF becomes operational - Network
connectivity and other hosting requirements.
o Not dependent on NSF control plane implementation (if there is
one) E.g., cluster of NSFs active as one unified service for scale
and/ or resilience.
o Not depending on specific data plane implementation of NSF i.e.
Encapsulation, Service function chains.
Note that the rules stated above only apply to the Client-Facing
interface, which a user would use to express a high level policy.
These rules do not apply to the lower layers e.g. Security
Controller that convert higher level policies into lower level
constructs. The lower layers may still need some intelligence such
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as topology awareness, capability of the NSF and its functions,
supported encapsulations etc. to convert and apply the policies
accurately on the NSF.
3.3. Deployment Models for Implementing Security Policies
Traditionally, medium and large Enterprise deploy management systems
to manage their statically defined security policies. This approach
may not be suitable nor sufficient for modern automated and dynamic
data centers that are largely virtualized and rely on various
management systems and controllers to dynamically implement security
policies over any types of NSF.
There are two different deployment models in which the Client-Facing
interface referred to in this document could be implemented. These
models have no direct impact on the Client-Facing interface, but
illustrate the overall security policy and management framework and
where various processing functions reside. These models are:
a. Policy management without an explicit management system for
control of NSFs. In this deployment, Security Controller acts as
a NSF management system; it takes information passed over Client-
Facing interface and translates into data on I2NSF NSF-facing
interface. The NSF-Facing interface is implemented by NSF
vendors; this would usually be done by having an I2NSF agent
embedded in the NSF. This deployment model is shown in Figure 1.
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RESTful API
SUPA or I2NSF Policy Management
^
|
Client-Facing Interface |
(Independent of individual |
NSFs, devices,and vendors)|
|
------------------------------
| |
| Security Controller |
| |
------------------------------
| ^
| I2NSF |
NSF Interface | NSF-facing |
(Specific to NSFs) | Interface |
..............................
| |
v |
------------- -------------
| I2NSF Agent | | I2NSF Agent |
|-------------| |-------------|
| |---| |
| NSF | | NSF |
NSFs | | | |
(virtual -------------\ /-------------
and | \ / |
physical) | X |
| / \ |
-------------/ \-------------
| I2NSF Agent | | I2NSF Agent |
|-------------| |-------------|
| |---| |
| NSF | | NSF |
| | | |
------------- -------------
Figure 1: Deployment without Management System
b. Policy management with an explicit management system for control
of NSFs. This model is similar to the model above except that
Security Controller interacts with a vendor's dedicated
management system that proxy I2NSF NSF-Facing interfaces as NSF
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may not support NSF-Facing interface. This is a useful model to
support legacy NSF. This deployment model is shown in Figure 2.
RESTful API
SUPA or I2NSF Policy Management
^
|
Client-facing Interface |
(Independent of individual |
NSFs,devices,and vendors) |
|
------------------------------
| |
| Security Controller |
| |
------------------------------
| ^
| I2NSF |
NSF Interface | NSF-facing |
(Specific to NSFs) | Interface |
..............................
| |
v |
------------------------------
| |
| I2NSF Proxy Agent / |
| Management System |
| |
------------------------------
| ^
| Proprietary |
| Functional |
| Interface |
..............................
| |
v |
------------- -------------
| |---| |
| NSF | | NSF |
NSFs | | | |
(virtual -------------\ /-------------
and | \ / |
physical) | X |
| / \ |
-------------/ \-------------
| |---| |
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| NSF | | NSF |
| | | |
------------- -------------
Figure 2: Deployment with Management System or I2NSF Proxy Agent
Although the deployment models discussed here don't necessarily
affect the definition of Client-Facing interface, they do give an
overall context for defining a security policy interface based on
abstraction.
4. Functional Requirements for the Client-Facing Interface
As stated in the guiding principle for defining the I2NSF Client-
Facing interface, the security policies and the Client-Facing
interface shall be defined from user's or client's perspective and
abstracted away from type of NSF, NSF specific implementation,
controller implementation, network topology, controller NSF-Facing
interface. Thus, the security policy definition shall be
declarative, expressed using User-construct, and driven by how
Security Admin view security policies from definition, communication
and deployment perspective.
Security Controller's' implementation is outside the scope of this
document and the I2NSF working group.
In order to express and build security policies, high level
requirement for Client-Facing interface is as follows:
o Multi-Tenancy
o Authentication and Authorization
o Role-Based Access Control (RBAC)
o Protection from Attacks
o Protection from Misconfiguration
o Policy Lifecycle Management
o Dynamic Policy Endpoint Groups
o Policy Rules
o Policy Actions
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o Generic Policy Model
o Policy Conflict Resolution
o Backward Compatibility
o Third-Party Integration
o Telemetry Data
The above requirements are by no means a complete list and may not be
sufficient for all use-cases and all Security Admins, but should be a
good starting point for a wide variety of use-cases in Service
Provider and Enterprise networks.
4.1. Requirement for Multi-Tenancy in client interface
A Security Admin may have internal tenants and might want a framework
wherein each tenant manages its own security policies with isolation
from other tenants.
A Security Admin may be a cloud service provider with multi-tenant
deployment, where each tenant is a different customer. Each tenant
or customer must be allowed to manage its own security policies.
It should be noted that tenants may have their own tenants, so a
recursive relation may exist. For instance, a tenant in a Cloud
Service Provider may have multiple departments or organizations that
need to manage their own security rules for compliance.
Some key concepts are listed below and used throughout the document
hereafter:
Policy-Tenant: An entity that owns and manages the security policies
applied on its resources.
Policy-Administrator: A user authorized to manage the security
policies for a Policy-Tenant.
Policy-User: A user within a Policy-Tenant who is authorized to
access certain resources of that tenant according to the
privileges assigned to it.
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4.2. Requirement for Authentication and Authorization of client
interface
Security Admin MUST authenticate to and be authorized by Security
Controller before they are able to issue control commands and any
policy data exchange commands.
There must be methods defined for Policy-Administrator to be
authenticated and authorized to use Security Controller. There are
several authentication methods available such as OAuth, XAuth and
X.509 certificate based; the authentication may be mutual or single-
sided based on business needs and outside the scope of I2NSF. In
addition, there must be a method o authorize the Policy-Administrator
to perform certain action. It should be noted that, Policy-
Administrator authentication and authorization to perform actions
could be part of Security Controller or outside; this document does
not mandate any specific implementation but requires that such a
scheme must be implemented.
4.3. Requirement for Role-Based Access Control (RBAC) in client
interface
Policy-Authorization-Role represents a role assigned to a Policy-User
that determines whether a user has read-write access, read-only
access, or no access for certain resources. A User can be mapped to
a Policy-Authorization-Role using an internal or external identity
provider or mapped statically.
4.4. Requirement to protect client interface from attacks
The interface must be protections from attacks, malicious or
otherwise, from clients or a client impersonator. Potential attacks
could come from Botnets, hosts infected with virus or some
unauthorized entity. It is recommended that Security Controller use
a dedicated IP interface for Client-Facing communications and those
communications should be carried over an isolated out-of-band
network. In addition, it is recommended that traffic between clients
and Security controller be encrypted. Furthermore, some
straightforward traffic/session control mechanisms (i.e., Rate-limit,
ACL, White/Black list) can be employed on Security Controller to
defend against DDoS flooding attacks.
4.5. Requirement to protect client interface from misconfiguration
There must be protections from mis-configured clients. System and
policy validations should be implemented to detect this. Validation
may be based on a set of default parameters or custom tuned
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thresholds such as the number of policy changes submitted, number of
objects requested in a given time interval, etc.
4.6. Requirement to manage policy lifecycle with diverse needs
In order to provide more sophisticated security framework, there
should be a mechanism so that a policy becomes dynamically active/
enforced or inactive based on Security Admin's manual intervention or
some external event.
One example of dynamic policy management is when Security Admin pre-
configures all the security policies, but the policies get activated
or deactivated based on dynamic threats. Basically, a threat event
may activate certain inactive policies, and once a new event
indicates that the threat has gone away, the policies become inactive
again.
There are following ways for dynamically activating policies:
o The policy may be dynamically activated by Security Admin or
associated management entity
o The policy may be dynamically activated by Security Controller upon
detecting an external event or an event from I2NSF monitoring
interface
o The policy can be statically configured but activated or
deactivated upon policy attributes, such as timing calendar
Client-Facing interface should support the following policy
attributes for policy enforcement:
Admin-Enforced: A policy, once configured, remains active/enforced
until removed by Security Admin.
Time-Enforced: A policy configuration specifies the time profile
that determines when the policy is to be activated/enforced.
Otherwise, it is de-activated.
Event-Enforced: A policy configuration specifies the event profile
that determines when the policy is to be activated/enforced. It
also specifies the duration attribute of that policy once
activated based on event. For instance, if the policy is
activated upon detecting an application flow, the policy could be
de-activated when the corresponding session is closed or the flow
becomes inactive for certain time.
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A policy could be a composite policy, that is composed of many rules,
and subject to updates and modification. For the policy maintenance,
enforcement, and audit-ability purposes, it becomes important to name
and version Security Policy. Thus, the policy definition SHALL
support policy naming and versioning. In addition, the i2NSF Client-
Facing interface SHALL support the activation, deactivation,
programmability, and deletion of policies based on name and version.
In addition, it should support reporting operational state of
policies by name and version. For instance, a client may probe
Security Controller whether a Security Policy is enforced for a
tenant and/or a sub-tenant (organization) for audit-ability or
verification purposes.
4.7. Requirement to define dynamic policy Endpoint group
When Security Admin configures a Security Policy, it may have
requirement to apply this policy to certain subsets of the network.
The subsets may be identified based on criteria such as Users,
Devices, and Applications. We refer to such a subset of the network
as a "Policy Endpoint Group".
One of the biggest challenges for a Security Admin is how to make
sure that a Security Policy remain effective while constant changes
are happening to the "Policy Endpoint Group" for various reasons
(e.g., organizational, network and application changes). If a policy
is created based on static information such as user names,
application, or network subnets; then every time this static
information change, policies need to be updated. For example, if a
policy is created that allows access to an application only from the
group of Human Resource users (HR-users group), then each time the
HR-users group changes, the policy needs to be updated.
We call these dynamic Policy Endpoint Groups "Meta-data Driven
Groups". The meta-data is a tag associated with endpoint information
such as User, Application, or Device. The mapping from meta-data to
dynamic content could come from a standards-based or proprietary
tools. Security Controller could use any available mechanisms to
derive this mapping and to make automatic updates to policy content
if the mapping information changes. The system SHOULD allow for
multiple, or sets of tags to be applied to a single network object.
Client-Facing policy interface must support endpoint groups for
expressing a Security Policy. The following meta-data driven groups
MAY be used for configuring security polices:
User-Group: This group identifies a set of users based on a tag or
on static information. The tag to identify user is dynamically
derived from systems such as Active Directory or LDAP. For
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example, an organization may have different User-groups, such as
HR-users, Finance-users, Engineering-users, to classify a set of
users in each department.
Device-Group: This group identifies a set of devices based on a tag
or on static information. The tag to identify device is
dynamically derived from systems such as configuration management
database (CMDB). For example, a Security Admin may want to
classify all machines running a particular operating system into
one group and machines running a different operating system into
another group.
Application-Group: This group identifies a set of applications based
on a tag or on static information. The tag to identify
application is dynamically derived from systems such as CMDB. For
example, a Security Admin may want to classify all applications
running in the Legal department into one group and all
applications running in the HR department into another group. In
some cases, the application can semantically associated with a VM
or a device. However, in other cases, the application may need to
be associated with a set of identifiers (e.g., transport numbers,
signature in the application packet payload) that identify the
application in the corresponding packets. The mapping of
application names/tags to signatures in the associated application
packets should be defined and communicated to the NSF. The
Client-Facing Interface shall support the communication of this
information.
Location-Group: This group identifies a set of location tags. Tag
may correspond 1:1 to location. The tag to identify location is
either statically defined or dynamically derived from systems such
as CMDB. For example, a Security Admin may want to classify all
sites/locations in a geographic region as one group.
4.8. Requirement to express rich set of policy rules
The security policy rules can be as simple as specifying a match for
the user or application specified through "Policy Endpoint Group" and
take one of the "Policy Actions" or more complicated rules that
specify how two different "Policy Endpoint Groups" interact with each
other. The Client-Facing interface must support mechanisms to allow
the following rule matches.
Policy Endpoint Groups: The rule must allow a way to match either a
single or a member of a list of "Policy Endpoint Groups".
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There must be a way to express a match between two "Policy Endpoint
Groups" so that a policy can be effective for communication between
two groups.
Direction: The rule must allow a way to express whether Security
Admin wants to match the "Policy Endpoint Group" as the source or
destination. The default should be to match both directions, if
the direction rule is not specified in the policy.
Threats: The rule should allow the security administrator to express
a match for threats that come either in the form of feeds (such as
Botnet feeds, GeoIP feeds, URL feeds, or feeds from a SIEM) or
speciality security appliances. Threats could be identified by
Tags/names in policy rules. The tag is a label of one or more
event types that may be detected by a threat detection system.
The threat could be from malware and this requires a way to match for
virus signatures or file hashes.
4.9. Requirement to express rich set of policy actions
Security Admin must be able to configure a variety of actions within
a security policy. Typically, security policy specifies a simple
action of "deny" or "permit" if a particular condition is matched.
Although this may be enough for most of the simple policies, the
I2NSF Client-Facing interface must also provide a more comprehensive
set of actions so that the interface can be used effectively across
various security functions.
Policy action MUST be extensible so that additional policy action
specifications can easily be added.
The following list of actions SHALL be supported:
Permit: This action means continue processing the next rule or allow
the packet to pass if this is the last rule. This is often a
default action.
Deny: This action means stop further packet processing and drop the
packet.
Drop connection: This action means stop further packet processing,
drop the packet, and drop connection (for example, by sending a
TCP reset).
Log: This action means create a log entry whenever a rule is
matched.
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Authenticate connection: This action means that whenever a new
connection is established it should be authenticated.
Quarantine/Redirect: This action may be relevant for event driven
policy where certain events would activate a configured policy
that quarantines or redirects certain packets or flows. The
redirect action must specify whether the packet is to be tunneled
and in that case specify the tunnel or encapsulation method and
destination identifier.
Netflow: This action creates a Netflow record; Need to define
Netflow server or local file and version of Netflow.
Count: This action counts the packets that meet the rule condition.
Encrypt: This action encrypts the packets on an identified flow.
The flow could be over an IPSEC tunnel, or TLS session for
instance.
Decrypt: This action decrypts the packets on an identified flow.
The flow could be over an IPSEC tunnel, or TLS session for
instance.
Throttle: This action defines shaping a flow or a group of flows
that match the rule condition to a designated traffic profile.
Mark: This action defines traffic that matches the rule condition by
a designated DSCP value and/or VLAN 802.1p Tag value.
Instantiate-NSF: This action instantiates an NSF with a predefined
profile. An NSF can be any of the FW, LB, IPS, IDS, honeypot, or
VPN, etc.
WAN-Accelerate: This action optimizes packet delivery using a set of
predefined packet optimization methods.
Load-Balance: This action load balances connections based on
predefined LB schemes or profiles.
The policy actions should support combination of terminating actions
and non-terminating actions. For example, Syslog and then Permit;
Count and then Redirect.
Policy actions SHALL support any L2, L3, L4-L7 policy actions.
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4.10. Requirement to express policy in a generic model
Client-Facing interface SHALL provide a generic metadata model that
defines once and then be used by appropriate model elements any
times, regardless of where they are located in the class hierarchy,
as necessary.
Client-Facing interface SHALL provide a generic context model that
enables the context of an entity, and its surrounding environment, to
be measured, calculated, and/or inferred.
Client-Facing interface SHALL provide a generic policy model that
enables context-aware policy rules to be defined to change the
configuration and monitoring of resources and services as context
changes.
Client-Facing interface SHALL provide the ability to apply policy or
multiple sets of policies to any given object. Policy application
process SHALL allow for nesting capabilities of given policies or set
of policies. For example, an object or any given set of objects
could have application team applying certain set of policy rules,
while network team would apply different set of their policy rules.
Lastly, security team would have an ability to apply its set of
policy rules, being the last policy to be evaluated against.
4.11. Requirement to detect and correct policy conflicts
Client-Facing interface SHALL be able to detect policy "conflicts",
and SHALL specify methods on how to resolve these "conflicts"
For example: two clients issues conflicting set of security policies
to be applied to the same Policy Endpoint Group.
4.12. Requirement for backward compatibility
It MUST be possible to add new capabilities to Client-Facing
interface in a backward compatible fashion.
4.13. Requirement for Third-Party integration
The security policies in a network may require the use of specialty
devices such as honeypots, behavioral analytics, or SIEM in the
network, and may also involve threat feeds,virus signatures, and
malicious file hashes as part of comprehensive security policies.
The Client-Facing interface must allow Security Admin to configure
these threat sources and any other information to provide integration
and fold this into policy management.
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4.14. Requirement to collect telemetry data
One of the most important aspect of security is to have visibility
into the networks. As threats become more sophisticated, Security
Admin must be able to gather different types of telemetry data from
various devices in the network. The collected data could simply be
logged or sent to security analysis engines for behavioral analysis,
policy violations, and for threat detection.
The Client-Facing interface MUST allow Security Admin to collect
various kinds of data from NSFs. The data source could be syslog,
flow records, policy violation records, and other available data.
Detailed Client-Facing interface telemetry data should be available
between clients and Security Controller. Clients should be able to
subscribe and receive these telemetry data.
client should be able to receive notifications when a policy is
dynamically updated.
5. Operational Requirements for the Client-Facing Interface
5.1. API Versioning
Client-Facing interface must support a version number for each
RESTful API. This is very important because the client application
and the controller application may come from different vendors. Even
if the vendor is same, it is hard to imagine that two different
applications would be released in lock step.
Without API versioning, it is hard to debug and figure out issues if
an application breaks. Although API versioning does not guarantee
that applications will always work, it helps in debugging if the
problem is caused by an API mismatch.
5.2. API Extensiblity
Abstraction and standardization of Client-Facing interface is of
tremendous value to Security Admin as it gives them the flexibility
of deploying any vendor's NSF without need to redefine their policies
if or when a NSF is changed.
If a vendor comes up with new feature or functionality that can't be
expressed through the currently defined Client-Facing interface,
there must be a way to extend existing APIs or to create a new API
that is relevant for that NSF vendor only.
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5.3. APIs and Data Model Transport
The APIs for client interface must be derived from the YANG based
data model. The YANG data model for client interface must capture
all the requirements as defined in this document to express a
security policy. The interface between a client and controller must
be reliable to ensure robust policy enforcement. One such transport
mechanism is RESTCONF that uses HTTP operations to provide necessary
CRUD operations for YANG data objects, but any other mechanism can be
used.
5.4. Notification
Client-Facing interface must allow Security Admin to collect various
alarms and events from the NSF in the network. The events and alarms
may be either related to security policy itself or related to NSF
where the policy is implemented. The events and alarms could also be
used as an input to the security policy for autonomous handling as
specified in a given security policy.
5.5. Affinity
Client-Facing interface must allow Security Admin to pass any
additional metadata that a user may want to provide for a security
policy e.g. certain security policy needs to be implemented only on a
very highly secure NSF with Trusted Platform Module (TPM) chip. A
user may require Security Controller not to share the NSF with other
tenant, this must be expressed through the interface API.
5.6. Test Interface
Client-Facing interface must allow Security Admin ability to test a
security policy before it is enforced e.g. a user may want to verify
whether the policy creates any potential conflicts with the existing
policies or if there are even resources to enforce the policy. The
test policy would provide such a capability without actually applying
the policies.
6. Security Considerations
Client-Facing interface to Security controller must be protected to
ensure that entire security posture is not compromised. This draft
mandates that interface must have proper authentication and
authorization with Role Based Access Controls to address multi-
tenancy requirement. The draft does not specify a particular
mechanism as different organization may have different needs based on
their deployment. This has been discussed extensively in this draft.
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Authentication and authorization alone may not be sufficient for
Client-Facing interface; the interface API must be validated for
proper inputs to guard against attacks. The type of checks and
verification may be specific to each interface API, but a careful
consideration must be made to ensure that Security Controller is not
compromised.
7. IANA Considerations
This document requires no IANA actions. RFC Editor: Please remove
this section before publication.
8. Acknowledgements
The authors would like to thank Adrian Farrel, Linda Dunbar and Diego
R.Lopez from IETF I2NSF WG for helpful discussions and advice.
The authors would also like to thank Kunal Modasiya, Prakash T.
Sehsadri and Srinivas Nimmagadda from Juniper networks for helpful
discussions.
9. Normative References
[I-D.ietf-i2nsf-problem-and-use-cases]
Hares, S., Lopez, D., Zarny, M., Jacquenet, C., Kumar, R.,
and J. Jeong, "I2NSF Problem Statement and Use cases",
draft-ietf-i2nsf-problem-and-use-cases-15 (work in
progress), April 2017.
Authors' Addresses
Rakesh Kumar
Juniper Networks
1133 Innovation Way
Sunnyvale, CA 94089
US
Email: rkkumar@juniper.net
Anil Lohiya
Juniper Networks
1133 Innovation Way
Sunnyvale, CA 94089
US
Email: alohiya@juniper.net
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Dave Qi
Bloomberg
731 Lexington Avenue
New York, NY 10022
US
Email: DQI@bloomberg.net
Nabil Bitar
Nokia
755 Ravendale Drive
Mountain View, CA 94043
US
Email: nabil.bitar@nokia.com
Senad Palislamovic
Nokia
755 Ravendale Drive
Mountain View, CA 94043
US
Email: senad.palislamovic@nokia.com
Liang Xia
Huawei
101 Software Avenue
Nanjing, Jiangsu 210012
China
Email: Frank.Xialiang@huawei.com
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