I2NSF Working Group R. Kumar
Internet-Draft A. Lohiya
Intended status: Informational Juniper Networks
Expires: April 12, 2017 D. Qi
Bloomberg
N. Bitar
S. Palislamovic
Nokia
L. Xia
Huawei
October 9, 2016
Requirements for Client-Facing Interface to Security Controller
draft-kumar-i2nsf-client-facing-interface-req-01
Abstract
This document captures the requirements for the client-facing
interface to security controller. The interfaces are based on user-
intent instead of developer-specific or device-centric approaches
that would require deep knowledge of specific products and their
security features. The document identifies the requirements needed
to enforce the user-intent based policies onto network security
functions (NSFs) irrespective of how those functions are realized.
The function may be physical or virtual in nature and may be
implemented in networking or dedicated appliances.
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 April 12, 2017.
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Copyright Notice
Copyright (c) 2016 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 principles for definition of Client-Facing Interfaces 5
3.1. User-intent based modeling . . . . . . . . . . . . . . . 5
3.2. Basic rules for interface definition . . . . . . . . . . 6
3.3. Independent of deployment models . . . . . . . . . . . . 6
4. Functional Requirements for the Client-Facing Interface . . . 10
4.1. Requirement for Multi-Tenancy . . . . . . . . . . . . . . 11
4.2. Requirement for Authentication and Authorization . . . . 12
4.3. Requirement for Role-Based Access Control (RBAC) . . . . 12
4.4. Requirement for Protection from Attacks . . . . . . . . . 12
4.5. Requirement for Protection from Misconfiguration . . . . 13
4.6. Requirement for Policy Lifecycle Management . . . . . . . 13
4.7. Requirement for Dynamic Policy Endpoint Groups . . . . . 14
4.8. Requirement for Policy Rules . . . . . . . . . . . . . . 16
4.9. Requirement for Policy Actions . . . . . . . . . . . . . 16
4.10. Requirement for Generic Policy Models . . . . . . . . . . 18
4.11. Requirement for Policy Conflict Resolution . . . . . . . 18
4.12. Requirement for Backward Compatibility . . . . . . . . . 18
4.13. Requirement for Third-Party Integration . . . . . . . . . 18
4.14. Requirement for 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
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
8. Normative References . . . . . . . . . . . . . . . . . . . . 21
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
Programming security policies in a network has been a fairly complex
task that often requires very deep knowledge of developers' specific
devices. This has been the biggest challenge for both service
providers and enterprises, henceforth named as security administrator
in this document. The challenge is amplified due to virtualization
because security appliances come in both physical and virtual forms
and are supplied by a variety of developers who have their own
proprietary interfaces to manage and implement the security policies
on their devices.
Even if a security administrator deploys a single developer solution
with a set of one or more security functions across its entire
network, it is difficult to manage security policies due to the
complexity of network security features available in the developer
devices, and the difficulty in mapping the user intent to developer-
specific configurations. The security administrator may use asset of
developer-specific APIs or a developer-provided management system
that gives some abstraction in the form of GUI to help provision and
manage security policies. However, the single developer approach is
highly restrictive in today's network for the following reasons:
o The security administrator cannot rely on a single developer
because one developer may not be able keep up to date with the
customer security needs or specific deployment models.
o A large organization may have a presence across different sites
and regions; which means, it is not possible to have a complete
solution from a single developer due to technical, regulatory or
business reasons.
o If and when the security administrator migrates from one developer
to another, it is almost impossible to migrate security policies
from one management system to another without complex manual work.
o Security administrators are implementing various security
functions in virtual forms or physical forms to attain the
flexibility, elasticity, performance, and operational efficiency
they require. Practically, that often requires different sources
(developers and open source) that provide the best of breed for
any such security function.
o The security administrator might choose various devices or network
services (such as routers, switches, firewall devices, and
overlay-networks) as enforcement points for security policies for
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any reason (such as network design simplicity, cost, most-
effective place, scale and performance).
In order to ease the deployment of security policies across different
developers and devices, the Interface to Network Security Functions
(I2NSF) working group in the IETF is defining a client-facing
interface from the security controller to clients [I-D. ietf-i2nsf-
framework] [I-D. ietf-i2nsf-terminology]. The easiness of deployment
should be agnostic to type of device, be it physical or virtual, or
type of the policy, be it dynamic or static. Using these interfaces,
a user can write any application (e.g. GUI portal, template engine,
etc.) to control the implementation of security policies on security
functional elements, but this is completely out of scope for the
I2NSF working group.
This document captures the requirements for the client-facing
interface that can be easily used by security administrators without
knowledge of specific security devices or features. We refer to this
as "user-intent" based interfaces. To further clarify, in the scope
of this document, the "user-intent" 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-intent here means that policies are described using client-
oriented 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 Service Provider Security
Controller or management system throughout this document
CRUD: Create, Retrieve, Update, Delete
FW: Firewall
GUI: Graphical User Interface
IDS: Intrusion Detection System
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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 principles for definition of Client-Facing Interfaces
The "Client-Facing Interface" ensures that a security administrator
can deploy any device from any developer and still be able to use
same consistent interface. In essence, these interfaces provide a
management framework to manage security administrator's security
policies. Henceforth in this document, we use "security policy
management interface" interchangeably when we refer to the client-
facing interface.
3.1. User-intent based modeling
Traditionally, security policies have been expressed using
proprietary interfaces. These interfaces are defined by a developer
either based on CLI or a GUI system; but more often these interfaces
are built using developer specific networking construct such IP
address, protocol and application constructs with L4-L7 information.
This requires security operators to translate their oragnzational
business objectives into actionable security policies on security
device using developers policy constructs. But, this alone is not
sufficient to render policies in the network as operator also need to
identify the device where the policy need to be applied in a complex
network environment with multiple policy enforcement points.
The User-intent based framework defines constructs such as user-
group, application-group, device-group and location group. The
security operator would use these constructs to express a security
policy instead of proprietary constructs. The policy defined in such
a manner is referred to user-intent based policies in this draft.
The idea is to enable security operator to use constructs they knows
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best in expressing security policies; which simplify their tasks and
help in avoiding human errors in complex security provisioing.
3.2. Basic rules for interface definition
The basic rules in defining the client-facing interfaces are as
following:
o Agnostic of network topology and NSF location in the network.
o Agnostic to the features and capabilities supported in NSFs.
o Agnostic to the resources available in NSFs or resources available
for various features/capabilities.
o Agnostic to the network function type, be it stateful firewall,
IDP, IDS, Router, Switch.
o Declarative/Descriptive model instead of Imperative/Prescriptive
model - What security policies need to enforce (declarative)
instead of how they would be actually implemented (imperative).
o Agnostic of developer, implementation and form-factor (physical,
virtual).
o Agnostic to how NSF is implemented and its hosting environment.
o Agnostic to how NSF becomes operational - Network connectivity and
other hosting requirements
o Agnostic to NSF control plane implementation (if there is one)
E.g., cluster of NSF active as one unified service for scale and/
or resilience.
o Agnostic to NSF data plane implementation i.e. Encapsulation,
Service function chains.
3.3. Independent of deployment models
This document does not describe requirements for NSF-facing
interface; they are expected to be defined in a separate draft. This
draft does not mandate a specific deployment model but rather shows
how client interfaces remain the same and interact with the overall
security framework from security administrator's perspective.
Traditionally, medium and larger operators deploy management systems
to manage their statically-defined security policies. This approach
may not be suitable nor sufficient for modern automated and dynamic
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data centers that are largely virtualized and rely on various
management systems and controllers to dynamically implement security
policies over any types of resources.
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 the various processing functions reside. These models are:
a. Management without an explicit management system for control of
devices and NSFs. In this deployment, the security controller
acts as a NSF policy management system that takes information
passed over the client security policy interface and translates
into data on the I2NSF southbound interface. The I2NSF
interfaces are implemented by security device/function
developers. This would usually be done by having an I2NSF agent
embedded in the security device or NSF. This deployment model is
shown in Figure 1.
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RESTful API
SUPA or I2NSF Policy Management
^
Client-facing |
Security Policy Interface |
(Independent of individual |
NSFs, devices,and developers)|
|
------------------------------
| |
| Security Controller |
| |
------------------------------
| ^
Southbound Security | I2NSF |
Capability 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. Management with an explicit management system for control of
devices and NSFs. This model is similar to the model above
except that security controller interacts with a dedicated
management system which could either proxy I2NSF southbound
interfaces or could provide a layer where security devices or
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NSFs do not support an I2NSF agent to process I2NSF southbound
interfaces. This deployment model is shown in Figure 2.
RESTful API
SUPA or I2NSF Policy Management
^
Client-facing |
Security Policy Interface |
(Independent of individual |
NSFs,devices,and developers) |
|
------------------------------
| |
| Security Controller |
| |
------------------------------
| ^
Southbound Security | I2NSF |
Capability 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 client security policy 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 principles for defining I2NSF client-facing
interface, the security policies and the client-facing interface
shall be defined from a user/client perspective and abstracted away
from the type of NSF, NSF specific implementation, controller
implementation, NSF topology, NSF interfaces, controller southbound
interfaces. Thus, the security policy definition shall be
declarative, expressing the user/client intent, and driven by how
security administrators view security policies from the definition,
communication and deployment perspective.
The security controller's implementation is outside the scope of this
document and the I2NSF working group.
At a high level, the requirements for the client-facing interface in
order to express and build security policies are 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 constructs are by no means a complete list and may not be
sufficient for all use-cases and all operators, but should be a good
start for a wide variety of use-cases in both Service Provider
networks and Enterprise networks.
4.1. Requirement for Multi-Tenancy
A security administrator that uses security policies may have
internal tenants and would like to have a framework wherein each
tenant manages its own security policies to provide isolation across
different tenants.
An operator may be a cloud service provider with multi-tenant
deployments where each tenant is a different organization and must
allow complete isolation across different tenants.
It should be noted that tenants in turn can have their own tenants,
so a recursive relation exists. For instance, a tenant in a cloud
service provider may have multiple departments or organizations that
need to manage their own security rules.
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 itself.
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 security
policies of the Policy-Tenant.
Policy-User-Group: A collection of Policy-Users. This group
identifies a set of users based on a policy tag or on static
information. The tag to identify the user is dynamically derived
from systems such as Active Directory or LDAP. For example, an
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operator may have different user-groups, such as HR-users,
Finance-users, Engineering-users, to classify a set of users in
each department.
4.2. Requirement for Authentication and Authorization
Security administrators MUST authenticate to and be authorized by
security controller before they are able to issue control commands
and any policy data exchange commences.
There must be methods defined for Policy-Administrator be
authenticated and authorized to use the security controller. There
are several authentication methods available such as OAuth, XAuth and
X.509 certificate based. The authentication scheme between Policy-
Administrator and security controller may also be mutual instead of
one-way. Any specific method may be determined based on
organizational and deployment needs and outside the scope of I2NSF.
In addition, there must be a method to authorize the Policy-
Administrator for performing certain action. It should be noted
that, depending on the deployment model, Policy-Administrator
authentication and authorization to perform actions communicated to
the controller could be performed as part of a portal or another
system prior to communication the action to the controller.
4.3. Requirement for Role-Based Access Control (RBAC)
Policy-Authorization-Role represents a role assigned to a Policy-User
or Policy-User Group that determines whether the user or the user-
group has read-write access, read-only access, or no access for
certain resources. A User or a User-Group can be mapped to a Policy-
Authorization- Role using an internal or external identity provider
or mapped statically.
4.4. Requirement for Protection from Attacks
There Must be protections from attacks, malicious or otherwise, from
clients or a client impersonator. Potential attacks could come from
a botnet or a host or hosts infected with virus or some unauthorized
entity. It is recommended that security controller use adedicated 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
controllers be encrypted. Furthermore, some straightforward traffic/
session control mechanisms (i.e., Rate-limit, ACL, White/Black list)
can be employed on the security controller to defend against DDoS
flooding attacks.
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4.5. Requirement for Protection from Misconfiguration
There Must be protections from mis-configured clients, unintentional
or otherwise. System and policy validations should be implemented.
Validation may be based on a set of default parameters or custom
tuned thresholds such as # of policy changes submitted; # of objects
requested in given time interval, etc.
4.6. Requirement for Policy Lifecycle Management
In order to provide more sophisticated security framework, there
should be a mechanism to express that a policy becomes dynamically
active/enforced or inactive based on either security administrator
intervention or an event.
One example of dynamic policy management is when the security
administrator pre-configures all the security policies, but the
policies get activated/enforced or deactivated based on dynamic
threats faced by the security administrator. 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 four models for dynamically activating policies:
o The policy may be dynamically activated by the I2NSF client or
associated management entity, and dynamically communicated over the
I2NSF client-facing interface to the controller to program I2NSF
functions using the I2NSF NSF-facing interface
o The policy may be pulled dynamically by the controller upon
detecting an event over the I2NSF monitoring interface
o The policy may be statically pushed to the controller and
dynamically programmed on the NSFs upon potentially detecting another
event
o The policy can be programmed in the N2SFs functions, and activated/
deactivated upon policy attributes, like time or admin enforced.
The client-facing interface should support the following policy
attributes for policy enforcement:
Admin-Enforced: The policy, once configured, remains active/enforced
until removed by the security administrator.
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Time-Enforced: The policy configuration specifies the time profile
that determines when policy is activated/enforced. Otherwise, it
is de-activated.
Event-Enforced: The policy configuration specifies the event profile
that determines when policy is 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.
A policy could be a composite policy, that is composed of many rules,
and subject to updates and modification. For policy maintenance
purposes, enforcement, and auditability, it becomes important to name
and version the policies. 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 on the state of policies by
name and version. For instance, a client may probe the controller
about the current policies enforced for a tenant and/or a sub-tenant
(organization) for auditability or verification purposes.
4.7. Requirement for Dynamic Policy Endpoint Groups
When the security administrator configures a security policy, the
intention is 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 administrator is how to
make sure that security policies remain effective while constant
changes are happening to the "Policy Endpoint Group" for various
reasons (e.g., organizational changes). If the policy is created
based on static information such as user names, application, or
network subnets, then every time that this static information changes
policies would 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 (the HR-users group), then each time the HR-
users group changes, the policy needs to be updated.
Changes to policy could be highly taxing to the security
administrator for various operational reasons. The policy management
framework must allow "Policy Endpoint Group" to be dynamic in nature
so that changes to the group (HR-users in our example) automatically
result in updates to its content.
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We call these dynamic Policy Endpoint Groups "Meta-data Driven
Groups". The meta-data is a tag associated with endpoint information
such as users, applications, and devices. The mapping from meta-data
to dynamic content could come either from standards-based or
proprietary tools. The security controller could use any available
mechanisms to derive this mapping and to make automatic updates to
the 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.
The client-facing policy interface must support endpoint groups for
user-intent based policy management. 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
example, an operator 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 mannagement
database (CMDB). For example, a security administrator may want
to classify all machines running one operating system into one
group and machines running another 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 administrator may want to classify all
applications running in the Legal department into one group and
all applications running under a specific operating system 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
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as CMDB. For example, a security administrator may want to
classify all sites/locations in a geographic region as one group.
4.8. Requirement for 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".
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 the security
administrator 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 for Policy Actions
The security administrator 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:
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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.
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: Instantiate a NSF with predefined profile. A NSF
can be any of FW, LB, IPS, IDS, honeypot, or VPN, etc.
WAN-Accelerate: This action optimize packet delivery using a set of
predefined packet optimization methods.
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Load-Balance: This action load balance 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.
4.10. Requirement for Generic Policy Models
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.
4.11. Requirement for Policy Conflict Resolution
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 the security administrator's 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.
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The client-facing interface must allow the security administrator to
configure these threat sources and any other information to provide
integration and fold this into policy management.
4.14. Requirement for Telemetry Data
One of the most important aspect of security is to have visibility
into the networks. As threats become more sophisticated, the
security administrator 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 the security administrator 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 controllers. 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
The client-facing interface must support a version number for each
RESTful API. This is very important because the client application
and the controller application will most likely come from different
developers. Even if the developer 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
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 the client-facing interface is of
tremendous value to security administrators as it gives them the
flexibility of deploying any developers' NSF without needing to
redefine their policies or change the client interface. However this
might also look like as an obstacle to innovation.
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If an NSF developer 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 developer only.
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
The client-facing interface must allow the security administrator to
collect various alarms and events from the NSF in the network. The
events and alarms may be either related to security policy
enforcement or NSF operation. The events and alarms could also be
used as a input to the security policy for autonomous handling.
5.5. Affinity
The client-facing interface must allow the security administrator to
pass any additional metadata that a user may want to provide for a
security policy e.g. certain security policy needs to be applied only
on linux machine or windows machine or that a security policy must be
applied on the device with Trusted Platform Module chip.
5.6. Test Interface
The client-facing interface must allow the security administrator the
ability to test the security policies before the policies are
actually applied e.g. a user may want to verify if a policy creates
potential conflicts with the existing policies or whether a certain
policy can be implemented. The test interface provides such
capabilities without actually applying the policies.
6. IANA Considerations
This document requires no IANA actions. RFC Editor: Please remove
this section before publication.
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7. Acknowledgements
The editors would like to thank Adrian Farrel for helpful discussions
and advice.
8. Normative References
[I-D.ietf-i2nsf-problem-and-use-cases]
Hares, S., Dunbar, L., Lopez, D., Zarny, M., and C.
Jacquenet, "I2NSF Problem Statement and Use cases", draft-
ietf-i2nsf-problem-and-use-cases-02 (work in progress),
October 2016.
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
Dave Qi
Bloomberg
731 Lexington Avenue
New York, NY 10022
US
Email: DQI@bloomberg.net
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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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