wdiff draft-ietf-i2rs-protocol-security-requirements-09.txt draft-ietf-i2rs-protocol-security-requirements-10.txt

I2RS working group S. Hares
Internet-Draft Huawei
Intended status: Informational D. Migault
Expires: February 20, March 12, 2017 J. Halpern
Ericsson
August 19,
September 8, 2016

I2RS Security Related Requirements
draft-ietf-i2rs-protocol-security-requirements-09
draft-ietf-i2rs-protocol-security-requirements-10

Abstract

This presents security-related requirements for the I2RS protocol for
which provides a new interface to the routing system described in the
I2RS architecture document (RFC7921). The I2RS protocol is a re-use
protocol implemented by re-using portions of existing IETF protocols
and adding new features to these protocols. The I2RS protocol re-
uses security features of a secure transport (E.g. TLS, SSH, DTLS)
such as encryption, message integrity, mutual peer authentication, transport protocols, data transfer
and
transactions. replay protection. The new security features I2RS adds are: a
priority mechanism to handle multi-headed write transactions, an
opaque secondary identifier which identifies an application using the
I2RS client, and an extremely constrained read-only non-secure
transport. This document provides the detailed requirements for
these security features.

Status of This Memo

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provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on February 20, March 12, 2017.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language 3
2. Definitions . . . . . . . . . . . . . . . . . . 3
2. Definitions . . . . . . . 4
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2.1. 4
2.2. Security Definitions . . . . . . . . . . . . . . . . . . 3
2.2. 5
2.3. I2RS Specific Definitions . . . . . . . . . . . . . . . . 3 5
3. Security-Related Requirements Security Features and Protocols: Re-used and New . . . . . . 7
3.1. Security Protocols Re-Used by the I2RS Protocol . . . . . 7
3.2. New Security Features . . . . . . . . . . . . 5
3.1. Mutual authentication of an I2RS client and an I2RS Agent 5
3.2. Transport Requirements Based on Mutual Authentication . . 6 . . . . 8
3.3. Data Confidentiality I2RS Protocol Security Requirements vs. IETF Management
Protocols . . . . . . . . . . . . 7
3.4. Data Integrity . . . . . . . . . . . . 9
4. Security-Related Requirements . . . . . . . . . . . . . . . 8
3.5. . 10
4.1. I2RS Peers(agent and client) Identity Authentication . . 11
4.2. Identity Validation Before Role-Based Data Model Security Message Actions . . 12
4.3. Peer Identity, Priority, and Client Redundancy . . . . . 12
4.4. Multi-Channel Transport: Secure Transport and Insecure
Transport . . . . . . . . 8
3.6. . . . . . . . . . . . . . . . . 14
4.5. Management Protocol Security of the environment . . . . . . . . . . . . . . 16
4.6. Role-Based Data Model Security . . . 9
4. Acknowledgement . . . . . . . . . . 17
4.7. Security of the environment . . . . . . . . . . . . . 9
5. IANA Considerations . . 18
5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 18
6. Security IANA Considerations . . . . . . . . . . . . . . . . . . . 9
7. References . . 18
7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 10
7.1. Normative 18
8. References . . . . . . . . . . . . . . . . . . 10
7.2. Informative References . . . . . . . 18
8.1. Normative References . . . . . . . . . . 10
Authors' Addresses . . . . . . . . 18
8.2. Informative References . . . . . . . . . . . . . . . 11 . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21

1. Introduction

The Interface to the Routing System (I2RS) provides read and write
access to information and state within the routing process. An I2RS
client interacts with one or more I2RS agents to collect information
from network routing systems.

This document [RFC7921] describes the requirements for the I2RS protocol in the
security-related areas architecture
of mutual authentication this interface, and this documents assumes the reader is familiar
with this architecture and its definitions. Section 2 highlights
some of the references the reader is required to be familiar with.

The I2RS interface is instantiated by the I2RS protocol connecting an
I2RS client and agent, the transport an I2RS agent associated with a routing system. The
I2RS protocol is a re-use protocol implemented by re-using portions
of existing IETF protocols, and adding new features to these
protocols. As a re-use protocol, it can be considered a higher-level
protocol carrying since it can be instantiated in multiple management
protocols (e.g. NETCONF [RFC6241] or RESTCONF
[I-D.ietf-netconf-restconf]) operating over a secure transport. The
security for the I2RS protocol
messages, and comes from the atomicity managmenet protocols
operating over a a secure transport which carries traffic over
multiple links.

This document is part of the transactions. These requirements
align with the description of the for I2RS architecture found in
[RFC7921] document protocol which solves the problem described in [RFC7920].

[I-D.ietf-i2rs-ephemeral-state] discusses
also include:

o I2RS architecture [RFC7921],

o I2RS role-based access
control that provides write conflict resolution in the ephemeral data
store using state requirements [I-D.ietf-i2rs-ephemeral-state],

o publication/subscription requirements [RFC7922], and

o traceability [RFC7923].

Since the I2RS Client Identity, I2RS Secondary Identity and
priority. The draft [RFC7922] describes "higher-level" protocol changes the traceability framework
and its interface to the
routing systems, it is important that implementers understand the new
security requirements for I2RS. The draft [RFC7923] describes the environment the I2RS protocol operates
in. These secuirty requirements for the I2RS to be able to publish information or have a
remote client subscribe to an information data stream.

1.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document environment are to be interpreted as
specified in [I-D.ietf-i2rs-security-environment-reqs], and the
summary of the I2RS protocol security environment found in the I2RS
Architecture [RFC7920].

I2RS reuses the secure transport protocols (TLS, SSH, DTLS) which
support encryption, message integrity, peer authentication, and key
distribution protocols. Optionally, implementers may utilize AAA
protocols (Radius over TLS or Diameter over TLS) to securely
distribute identity information.

Section 3 provides an overview of security features and protocols
being re-used (section 3.1) and the new security features being
required (section 3.2). Section 3 also explores how existing and new
security features and protocols would be paired with existing IETF
management protocols (section 3.3).

The new features I2RS extends to these protocols are a priority
mechanism to handle multi-headed reads, an opaque secondary
identifier to allow traceability of an application utilizing a
specific I2RS client to communicate with an I2RS agent, and insecure
transport constrained to be utilized only for read-only data which
publically available data (e.g. public BGP Events, public telemetry
information, web service available) and some legacy data.

Section 4 provides the I2RS protocol security requirements by the
following security features:

o peer identity authentication (section 4.1),

o peer identity validation before role-based message actions
(section 4.2)

o peer identity and client redundancy (section 4.3),

o multi-channel transport requirements: Secure transport and
insecure Transport (section 4.4),

o management protocol security requirements (section 4.5),

o role-based security (section 4.6),

o security environment (section 4.7)

Protocols designed to be I2RS higher-layer protocols need to fulfill
these security requirements.

2. Definitions

2.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].

2. Definitions

2.1.

2.2. Security Definitions

This document utilizes the definitions found in the following
documents: [RFC4949] and [RFC7921]

Specifically, this document utilizes the following definitions from
[RFC4949]:

o access control,

o Authentication, authentication,

o Data Confidentiality, data confidentiality,

o Data Integrity, data integrity,

o Data Privacy, data privacy,

o Identity, identity,

o Identifier, identifier,

o Mutual Authentication, mutual authentication,

o role,

o role-based access control,

o security audit trail, and

o trust.

[RFC7922] describes traceability for I2RS interface and the I2RS
protocol. Traceability is not equivalent to a security audit trail.

2.2. trail
or simple logging of information. A security audit trail may utilize
traceability information.

This document also requires that the user is familiar with the
pervasive security requirements in [RFC7258].

2.3. I2RS Specific Definitions

I2RS component protocols

Protocols which are combined to create

The document utilizes the following concepts from the I2RS protocol.
architecture: [RFC7921]:

o I2RS Higher-level protocol

The client, I2RS agent, and I2RS protocol exists as a higher-level (section 2),

o I2RS higher-layer protocol which may
combine other protocols (NETCONF, RESTCONF, IPFIX (section 7.2)
o scope: read scope, notification scope, and others)
within a specific I2RS client-agent relationship with a specific
trust for ephemeral configurations, event, tracing, actions, write scope (section
2),

o identity and
data flow interactions. The protocols included in scope of the identity (section 2),

o roles or security rules (section 2),

o identity and scope, and secondary identity (section 2),

o routing system/subsytem (section 2),

o I2RS
protocol protocol are defined as assumed security environment (section 4),

o I2RS component protocols. (Note:
Version 1 identity and authorization (section 4.1),

o I2RS authorization, scope of the Authorization in I2RS protocol will combine only NETCONF client and
RESTCONF. Experiments with other protocols such as IPFIX have
shown these are useful to combine
agent (section 4.2),

o client redundancy with NETCONF and RESTCONF
features.)

I2RS message

is a complete data message of one of the single client identity (section 4.3),

o restrictions on I2RS component protocols.
The in personal devices (section 4.4),

o communication channels and I2RS component protocols may require multiple IP-packets to
send one high-layer protocol message.

I2RS (section 7.2),

o active communication versus connectivity (section 7.5),

o multi-headed control (section 7.8), and

o transaction, message, multi-message atomicity

An I2RS operation (read, write, event, action) must be contained
within one I2RS message. Each I2RS operation must be atomic.
While it is possible to have an I2RS operation which is contained
in multiple I2RS (E.g. write in multiple messages), this (section 7.9).

This document assumes the reader is not
supported in order to simplify familar with these terms.

This document discusses the first version of I2RS.
Multiple-message atomicity of I2RS operations would be used in a
roll-back of a grouping security of commands (e.g. the multiple writes).

I2RS transaction

is a unit of I2RS functionality. Some examples of
communication channels which operate over the higher-layer I2RS
transactions are:

*
protocol. The higher-layer I2RS client issues a read request to protocol combines a secure transport
and I2RS agent, contextual information, and re-uses IETF protocols and data
models to create the secure transport and the I2RS Agent responding to data-model driven
contextual information. To describe how the read request

* The I2RS client issues a write of ephemeral configuration
values high-layer protocol
combines other protocols into an I2RS agent's data model, followed by the I2RS
agent response to the write.

* An I2RS client may issue an action request, the I2RS agent
responds to higher-layer protocol, the action-request, and then responds when action
is complete. Actions can be single step processes or multiple
step process.

* An
following terms are used:

I2RS client requests to receive an event notification, component protocols

Protocols which are re-used and
the I2RS Agent sets up combined to send create the events.

* An I2RS agent sends events to an
protocol.

I2RS Client on an existing
connection.

An secure-transport component protocols
The I2RS action may require multiple secure transport protocols that support the I2RS messages in order to
complete a transation. higher-
layer protocol.

I2RS secondary identifier management component protocols

The I2RS architecture document [RFC7921] defines a secondary
identity as the entity of some non-I2RS entity (e.g. application) management protocol which has requested a particular provide the management
information context.

I2RS client perform an operation. AAA component protocols

The I2RS secondary identifier represents this identity so it may
be distinguished from all others.

I2RS routing system

Layer three (L3) routing systems which include physical routers,
virtual routers (in hypervisors or load splitters), and other
devices AAA protocols supporting L3 routing in order to forward packets based on
L3 headers.

3. Security-Related Requirements

The security for the I2RS higher-layer protocol.

The I2RS higher-layer protocol requires mutually authenticated implementation of a I2RS clients
secure-transport component protocol and the I2RS agents communicating over a secure transport. management component
protocol. The I2RS AAA component protocol MUST be able to provide atomicity of an I2RS
transaction, but it is not required to have multi-message atomicity optional.

3. Security Features and roll-back mechanism transactions. Multiple messages transactions
may be impacted Protocols: Re-used and New

3.1. Security Protocols Re-Used by the interdependency of data. This section
discusses the details of these security requirements.

There I2RS Protocol

I2RS also requires a secure transport protocol and key distribution
protocols. The secure transport features required by I2RS are dependencies in some of the requirements below. For
confidentiality (section 3.3) peer
authentication, confidentiality, data integrity, and integrity (section 3.4) replay
protection for I2RS messages. According to be
achieved,
[I-D.ietf-taps-transports], the client-agent must have mutual authentication (section
3.1) and secure transport (section 3.2). Since I2RS does not itself
provide confidentiality protocols which
support peer authentication, confidentiality, data integrity, and
replay protection are the following:

1. TLS [RFC5246] over TCP or SCTP,

2. DTLS over UDP with replay detection and anti-DoS stateless cookie
mechanism required for the I2RS protocol, and the I2RS protocol
allow DTLS options of record size negotiation and and conveyance
of "don't" fragment bits to be optional in deployments.

3. HTTP over TLS (over TCP or SCTP), and

4. HTTP over DTLS (with the requirements and optional features
specified above in item 2).

The following protocols will need to be extended to provide
confidentiality, data integrity, it peer authentication, and key
distribution protocols: SSH, SCTP, or the ForCES TML layer over SCTP.

The specific type of key management protocols an I2RS secure
transport uses depends on running the transport. Key management protocols
utilized for the I2RS protocols SHOULD support automatic rotation.

An I2RS implementer may use AAA protocols over secure transport to
distribute the identities for I2RS client and I2RS agent and role
authorization information. Two AAA protocols are: Diameter [RFC6733]
and Radius [RFC2865]. To provide the best security I2RS peer
identities, the AAA protocols MUST be run over a secure Transport that provides these features.

3.1. Mutual authentication of transport
(Diameter over secure transport (TLS over TCP) [RFC6733]), Radius
over a secure transport (TLS) [RFC6614]).

3.2. New Security Features

The new features are priority, an opaque secondary identifier, and an
insecure protocol for read-only data constrained to specific standard
usages. The I2RS client protocol allows multi-headed control by several
I2RS clients. This multi-headed control is based on the assumption
that the operator deploying the I2RS clients, I2RS agents, and the
I2rs protocol will coordinate the read, write, and notification scope
so the I2RS clients will not contend for the same write scope.
However, just in case there is an unforseen overlap of I2RS Agent

The clients
attempting to write a particular piece of data, the I2RS architecture
[RFC7921] sets provides the following requirements:

o SEC-REQ-01: All concept of each I2RS clients and client having a priority.
The I2RS agents MUST client with the highest priority will have an
identity, and at least one unique its write
succeed. This document specifies requirements for this new concept
of priority.

The opaque secondary identifier identifies an application which is
using the I2RS client to I2RS agent communication to manage the
routing system. The secondary identifier is opaque to the I2RS
protocol. In order to protect personal privacy, the secondary
identifier should not contain personal identifiable information.

The last new security feature is the ability to allow non-
confidential data to be transfered over a non-secure transport. It
is expected that most I2RS data models will describe information that
will be transferred with confidentiality. Therefore, any model which
transfers data over a non-secure transport is marked. The use of a
non-secure transport is optional, and an implementer SHOULD create
knobs that allow data marked as non-confidential to be sent over a
secure transport.

Non-confidential data can only be read or notification scope
transmission of events. Non-confidential data cannot be write scope
or notification scope configuration. An example of non-confidential
data is the telemetry information that is publically known (e.g. BGP
route-views data or web site status data) or some legacy data (e.g.
interface) which cannot be transported in secure transport. The IETF
I2RS Data models MUST indicate in the data model the specific data
which is non-confidential.

Most I2RS data models will expect that the information described in
the model will be transferred with confidentiality. Therefore, it is

3.3. I2RS Protocol Security Requirements vs. IETF Management Protocols

Table 1 below provides a partial list of the candidate management
protocols and the secure transports each one of the support. One
column in the table indicates the transport protocol will need I2RS
security extensions.

Mangement
Protocol Transport Protocol I2RS Extensions
========= ===================== =================
NETCONF TLS over TCP (*1) None required (*2)

RESTCONF HTTP over TLS with None required (*2)
X.509v3 certificates,
certificate validation,
mutual authentication:
1) authenticated
server identity,
2) authenticated
client identity
(*1)

FORCES TML overs SCTP Needs extension to
(*1) TML to run TML
over TLS over SCTP,
or DTLS described
above. The
IPSEC mechanism is
not sufficient for
I2RS traveling over
multiple hops
(router + link)
(*2)

IPFIX SCTP, TCP, UDP Needs to extension
TLS or DTLS for to support TLS or
secure client (*1) DTLS with options
described above. (*2)

*1 - Key management protocols
MUST support appropriate key rotation.

*2 - Identity and Role authorization distributed
by Diameter or Radius MUST use Diameter over TLS
or Radius over TLS.

4. Security-Related Requirements

This section discusses security requirements based on the following
security functions:

o peer identity authentication (section 4.1),
o Peer Identity validation before Role-based Message Actions
(section 4.2)

o peer identity and client redundancy (section 4.3),

o multi-channel transport requirements: Secure transport and
insecure Transport (section 4.4),

o management protocol security requirements (section 4.5),

o role-based security (section 4.6),

o security environment (section 4.7)

The I2RS Protocol depends upon a secure transport layer for peer
authentication, data integrity, confidentiality, and replay
protection. The optional insecure transport can only be used
restricted set of publically data available (events or information)
or a select set of legacy data. Data passed over the insecure
transport channel MUST not contain any data which identifies a person
or any "write" transactions.

4.1. I2RS Peers(agent and client) Identity Authentication

The following requirements specify the security requirements for Peer
Identity Authentication for the I2RS protocol:

o SEC-REQ-01: All I2RS clients and I2RS agents MUST have an
identity, and at least one unique identifier that uniquely
identifies each party in the I2RS protocol context.

o SEC-REQ-02: The I2RS protocol MUST utilize these identifiers for
mutual identification of the I2RS client and I2RS agent.

o SEC-REQ-03: Identifier distribution and the loading of these
identifiers into I2RS agent and I2RS client SHOULD occur outside
the I2RS protocol prior to the I2RS protocol establishing a
connection between I2RS client and I2RS agent. AAA protocols MAY
be used to distribute these identifiers, but other mechanism can
be used.

Explanation:

These requirements specify the requirements for I2RS peer (I2RS agent
and I2RS client) authentication. A secure transport (E.g. TLS) will
authenticate based on these identities. The AAA protocol
distributing I2RS identity information SHOULD transport its
information over a secure transport.

4.2. Identity Validation Before Role-Based Message Actions

The requirements for I2RS clients with Secure Connections are the
following:

SEC-REQ-04: An I2RS agent receiving a request from an I2RS client
MUST confirm that the I2RS client has a valid identity.

SEC-REQ-05: An I2RS client receiving an I2RS message over a secure
transport MUST confirm that the I2RS agent has a valid identifier.

SEC-REQ-06: An I2RS agent receiving an I2RS message over an
insecure transport MUST confirm that the content is suitable for
transfer over such a transport.

Explanation:

Each I2RS client has a scope based on its identity and the security
roles (read, write, or events) associated with that identity, and
that scope must be considered in processing an I2RS messages sent on
a communication channel. An I2RS communication channel may utilize
multiple transport sessions, or establish a transport session and
then close the transport session. Therefore, it is important that
the I2RS peers are operating utilizing valid peer identities when a
message is processed rather than checking if a transport session
exists.

4.3. Peer Identity, Priority, and Client Redundancy

Requirements:

SEC-REQ-07: Each I2RS Identifier MUST be associated with just one
priority.

SEC-REQ-08: Each Identifier is associated with one secondary
identifier during a particular I2RS transaction (e.g. read/write
sequence), but the secondary identifier may vary during the time a
connection between the I2RS client and I2RS agent is active.

Explanation:

The I2RS architecture also allows multiple I2RS clients with unique
identities to connect to an I2RS agent (section 7.8). The I2RS
deployment using multiple clients SHOULD coordinate this multi-headed
control of I2RS agents by I2RS clients so no conflict occurs in the
write scope. However, in the case of conflict on a write scope
variable, the error resolution mechanisms defined by the I2RS
architecture multi-headed control ([RFC7921], section 7.8) allow the
I2RS agent to deterministically choose one I2RS client. The I2RS
client with highest priority is given permission to write the
variable, and the second client receives an error message.

A single I2RS client may be associated with multiple applications
with different tasks (e.g. weekly configurations or emergency
configurations). The secondary identity is an opaque value that the
I2RS client passes to the I2RS agent so that this opaque value can be
placed in the tracing file or event stream to identify the
application using the I2RS client to I2RS agent communication.

One example of the use of the secondary identity is the situation
where an operator of a network has two applications that use an I2RS
client. The first application is a weekly configuration application
that uniquely
identifies each party in uses the I2RS protocol context.

o SEC-REQ-02: to change configurations. The I2RS protocol MUST utilize these identifiers for
mutual identification second
application is an application that allows operators to makes
emergency changes to routers in the network. Both of these
applications use the same I2RS client and I2RS agent.

o SEC-REQ-03: An I2RS agent, upon receiving to write to an I2RS message from agent. In
order for traceability to determine which application (weekly
configuration or emergency) wrote some configuration changes to a
I2RS client, MUST confirm that
router, the I2RS client has sends a valid
identifier.

o SEC-REQ-04: different opaque value for each of
the applications. The I2RS client, upon receiving an I2RS message from
an I2RS agent, MUST confirm weekly configuration secondary opaque value
could be "xzzy-splot" and the emergency secondary opaque value could
be "splish-splash".

A second example is if the I2RS agent has client is used for monitoring of
critical infrastructure. The operator of a valid identifier.

o SEC-REQ-05: Identifier distribution and network using the loading of these
identifiers into I2RS agent and
client may desire I2RS Client SHOULD occur outside client redundancy where the I2RS protocol prior to monitoring
application wth the I2RS protocol establishing a
connection between I2RS client and I2RS agent. (One mechanism
such mechanism is AAA protocols.)

o SEC-REQ-06: Each Identifier MUST have just one priority.

o SEC-REQ-07: Each Identifier is associated deployed on two different boxes
with one secondary
identifier during a particular the same I2RS transaction (e.g. read/write
sequence), but client identity (see [RFC7921] section 4.3) These
two monitoring applications pass to the secondary identifier may vary during I2RS client whether the time a
connection between
application is the primary or back up application, and the I2RS
client and passes this information in the I2RS agent secondary identitifier as
the figure below shows. The primary applications secondary
identifier is active.
Since a single "primary-monitoring", and the backup application
secondary identifier is "backup-monitoring". The I2RS client may be use by multiple applications, tracing
information will include the secondary identifier may vary as information along
with the transport information in the tracing file in the I2RS client is utilize by
different application each of whom have a unique agent.

Example 2: Primary and Backup Application for Monitoring
Identification sent to agent

Application A--I2RS client--Secure transport(#1)
[I2RS identity 1, secondary identifier: "primary-monitoring"]-->

Application B--I2RS client--Secure transport(#2)
[I2RS identity 1, secondary identifier: "backup-monitoring"]-->

Figure 1

4.4. Multi-Channel Transport: Secure Transport and identifier.

3.2. Insecure Transport Requirements Based on Mutual Authentication

SEC-REQ-08:

Requirements:

SEC-REQ-09: The I2RS protocol MUST be able to transfer data over a
secure transport and optionally MAY be able to transfer data over
a non-secure transport. A The default transport is a secure
transport, and this means it is mandatory to implement (MTI) in
all I2RS agents, and in any I2RS client which: a) performs a Write
scope transaction which is sent to the I2RS agent or b):
configures an Event Scope transaction. It is mandatory to use
(MTU) on any I2RS client's Write transaction or the configuration
of an Event Scope transaction.

SEC-REQ-10: The secure transport MUST provide data
confidentiality, data integrity, and practical replay prevention.

SEC-REQ-11: The default I2RS client and I2RS agent protocol SHOULD
implement mechanisms that mitigate DoS attacks. For the secure
transport, this means the secure transport must support DoS
prevention. For the insecure transport protocol, the I2RS higher-
layer protocol MUST contain a transport is management layer that
considers the detection of DoS attacks and provides a secure transport. warning over
a secure-transport channel.

SEC-REQ-12: A non-secure secure transport can MUST be used for publishing telemetry data or
other operational state associated with a key
management solution that was specifically indicated to non-
confidential in can guarantee that only the data model in entities
having sufficient privileges can get the Yang syntax. Since keys to encrypt/decrypt
the sensitive data.

SEC-REQ-13: A machine-readable mechanism to indicate that a data-
model contains non-confidential data MUST be provided. A non-
secure transport is optional, MAY be used to publish only read scope or
notification scope data if the operator may transmit this associated data model indicates
that that data is non-confidential.

SEC-REQ-14: The I2RS protocol MUST be able to support multiple
secure transport sessions providing protocol and data
communication between an I2RS agent and an I2RS client. However,
a single I2RS agent to I2RS client connection MAY elect to use a
single secure transport session or a single non-secure transport
session conforming the requirements above.

SEC-REQ-15: Deployment configuration knobs SHOULD be created to
allow operators to send "non-confidential" Read scope (data or
Event streams) over a secure transport.

Explanation:

The following are further restrictions on
the non-secure transport:

o I2RS architecture defines three scopes: read, write, and
notification scope. Insecure data can only be used for read scope
and notification scope of "non-confidential data". The configuration
of ephemeral data in the I2RS Agent by agent uses either write scope for data
or write scope for configuration of event notification streams. The
requirement to use secure transport for configuration prevents
accidental or malevolent entities from altering the I2RS
client SHOULD be done over a secure transport.

o routing
system through the I2RS agent.

It is anticipated that the passing of most I2RS ephemeral state
operational status SHOULD be done over a secure transport.

o As [I-D.ietf-i2rs-ephemeral-state] notes, each data model SHOULD
indicate whether the transport exchanging

In most circumstances the data between I2RS
client and I2RS agent is secure or insecure.

SEC-REQ-09: A secure transport MUST protocol will be
associated with a key management solution that can guarantee that only the entities having
sufficient privileges can get the keys to encrypt/decrypt the
sensitive data. Per BCP107 [RFC4107] this key management system
SHOULD be automatic, but MAY be manual in the following scenarios:

a) The environment has limited bandwidth or high round-trip times.

b) The information being protected has low value.

c) The total volume of traffic over the entire lifetime of the
long-term session key will be very low.

d) The scale system. Most deployments of the deployment is limited.

Most
I2RS environments (Clients and Agents) protocol will not have allow for automatic key management systems. Since
the
environment described by BCP107 [RFC4107] but a few I2RS use cases
required limited non-secure light-weight telemetry messages that have
these requirements. An I2RS data model must indicate which portions
can be served by manual key management.

SEC-REQ-10: The models for the I2RS protocol MUST be able to support multiple secure
transport sessions providing protocol and data communication between
an I2RS Agent and an I2RS client. However, a single I2RS Agent to will control key routing
functions, it is important that deployments of I2RS client connection MAY elect to use a single secure transport
session automatic key
management systems.

Per BCP107 [RFC4107] while key management system SHOULD be automatic,
the systems MAY be manual in the following scenarios:

a) The environment has limited bandwidth or a single non-secure transport session.

SEC-REQ-11: high round-trip times.

b) The information being protected has low value.

c) The total volume of traffic over the entire lifetime of the
long-term session key will be very low.

d) The scale of the deployment is limited.

Operators deploying the I2RS Client and I2RS Agent protocol selecting manual key management
SHOULD implement
mechanisms that mitigate DoS attacks.

3.3. Data Confidentiality Requirements

SEC-REQ-12: consider both short and medium term plans. Deploying
automatic systems initially may save effort over the long-term.

4.5. Management Protocol Security

Requirements:

SEC-REQ-16: In a critical infrastructure, certain data within
routing elements is sensitive and read/write operations on such
data SHOULD be controlled in order to protect its confidentiality. For example,
most
To achieve this, higher-layer protocols MUST utilize a secure
transport, and SHOULD provide access control functions to protect
confidentiality of the data.

SEC-REQ-17: An integrity protection mechanism for I2RS MUST be
provided that will be able to ensure the following:

1) the data being protected is not modified without detection
during its transportation,

2) the data is actually from where it is expected to come from,
and

3) the data is not repeated from some earlier interaction the
higher layer protocol (best effort).

The I2RS higher-layer protocol operating over a secure transport
provides this integrity. The I2RS higher-layer protocol operating
over an insecure transport SHOULD provide some way for the client
receiving non-confidential read-scoped or event-scoped data over
the insecure connection to detect when the data integrity is
questionable; and in the event of a questionable data integrity
the I2RS client should disconnect the insecure transport
connection.

SEC-REQ-18: The I2RS higher-layer protocol MUST provide a
mechanism for message traceability (requirements in [RFC7922])
that supports the tracking higher-layer functions run across
secure connection or a non-secure transport.

Explanation:

Most carriers do not want a router's configuration and data flow
statistics known by hackers or their competitors. While carriers may
share peering information, most carriers do not share configuration
and traffic statistics. To achieve this, the I2RS higher-layer
protocol (e.g NETCONF) needs to have access control (NACM [RFC6536])
to sensitive data needs to be provided, and the confidentiality
protection on such data during transportation needs to be enforced.

3.4. Data

Integrity Requirements

SEC-REQ-13: An integrity protection mechanism for I2RS MUST be
provided that will be able to ensure the following:

1) the data being protected is not modified without detection
during its transportation,

2) the data is actually from where it is expected to come from,
and

3) the data is not repeated from some earlier interaction of the
protocol. (That is, when both confidentiality and integrity of data is properly protected, it important even if the I2RS protocol is possible to ensure that
encrypted sending
non-confidential data is not modified or replayed without detection.)

SEC-REQ-14: over an insecure connection. The I2RS client ability to
trace I2RS agent transport protocol MUST
protect against replay attack.

Requirements SEC-REQ-13 and SEC-REQ-14 are requirements for the
secure channel which must be supported as the default by every I2RS
Agent, and by every messages that enact I2RS client communicating over transactions provides a secure
transport. In order to provide some traceability or notification for
the non-secure protocol, SEC-REQ-15 suggests traceability and
notification are important
minimal aid to include for any non-secure protocol.

SEC-REQ-15: The I2RS protocol MUST provide helping operators check how messages enact
transactions on a mechanism for message
traceability and notification requirements requirements found in
[RFC7922] and [RFC7923] that can be supported in communication
channel that is non-secure to trace secure or notify about potential
security issues.

3.5. insecure transport.

4.6. Role-Based Data Model Security

The I2RS Architecture [RFC7921] defines a role or security role as
specifying read, write, or notification access by a I2RS client to
data within an agent's data model.

SEC-REQ-16:

SEC-REQ-19: The rules around what I2RS security role is permitted
to access and manipulate what information plus over a secure transport
(which protects the data in transit) SHOULD ensure that data of
any level of sensitivity is reasonably protected from being
observed by those without permission to view it, so that privacy
requirements are met.

SEC-REQ-17:

SEC-REQ-20: Role security MUST work when multiple transport transport
connections are being used between the I2RS client and I2RS agent
as the I2RS architecture [RFC7921] describes.

Sec-REQ-21: If an I2RS agents or an I2RS client is tightly
correlated with a person, then the I2RS protocol and data models
SHOULD provide additional security that protects the person's
privacy.

Explanation:

I2RS higher-layer uses management protocol E.g. NETCONF, RESTCONF)
to pass messages in order to enact I2RS transactions. Role Security
must secure data (sensitivity and normal data) in a router even when
it is operating over multiple connections are being used between the I2RS client and I2RS agent as
the I2RS architecture [RFC7921] states. These transport message
streams may start/stop without affecting the existence of at the client/
agent data exchange. same time. NETCONF
can run over TLS (over TCP supports or SCTP) or SSH. RESTCONF runs over HTTP
over a single stream of data. secure transport (TLS). SCTP [RFC4960] provides security for
multiple streams plus end-to-end transport of data.

SEC-REQ-18: I2RS clients MAY be used by multiple applications to
configure routing via I2RS agents, receive status reports, turn on
the I2RS audit stream, or turn on I2RS traceability. Application
software using Some I2RS client
functions may host multiple secure
identities, but each connection will use only one identifier with one
priority. Therefore, the security of each I2RS Client wish to I2RS Agent
connection is unique. operate over DTLS which runs over UDP
([RFC6347]), DDCP ([RFC6238]), and SCTP ([RFC5764]).

Please note the security of the application to I2RS client connection
is outside of the I2RS protocol or I2RS interface.

Sec-REQ-19: If an I2RS agents or an I2RS client is tightly correlated
with a person, then the I2RS protocol and data models SHOULD provide
additional security that protects the person's privacy. An

One example of an I2RS agent correlated with privacy concerns related to a person is a if I2RS
agent is running on someone's phone to control tethering, and an example of a the
I2RS client might be the client tracking such tethering. This
protection MAY
require a of the privacy of the person involves the I2RS client and
the I2RS agent communication anonymizing the any data related to the
person's identity or locatino.

A variety of forms including: "operator-applied of managemen may set policy on roles: "operator-
applied knobs", roles that restrict personal access, data-models with
specific "privacy roles", and access filters.

3.6.

4.7. Security of the environment

The security for the implementation of a protocol also considers the
protocol environment. The environmental security requirements are
found in: [I-D.ietf-i2rs-security-environment-reqs].

5. Security Considerations

This is a document about security requirements for the I2RS protocol
and data modules. Security considerations for the I2RS protocol
include both the protocol and the security environment.

6. IANA Considerations

This draft is requirements, and does not request anything of IANA.

7. Acknowledgement

The authors would like to thank Wes George, Ahmed Abro, Qin Wu, Eric
Yu, Joel Halpern, Scott Brim, Nancy Cam-Winget, DaCheng Zhang, Alia
Atlas, and Jeff Haas for their contributions to the I2RS security
requirements discussion and this document. The authors would like to
thank Bob Moskowitz for his review of the requirements.

5. IANA Considerations

This draft includes no request to IANA.

6. Security Considerations

This is a document about security requirements for the I2RS protocol
and data modules. The whole document is security considerations.

7. would like to
thank Bob Moskowitz, Kathleen Moriarty, Stephen Farrell, Alvaro
Retana, Ben Campbell, and Alissa Cooper for their review of these
requirements.

8. References

7.1.

8.1. Normative References

[I-D.ietf-i2rs-security-environment-reqs]
Migault, D., Halpern, J., and S. Hares, "I2RS Environment
Security Requirements", draft-ietf-i2rs-security-
environment-reqs-01 (work in progress), April 2016.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.

[RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic
Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107,
June 2005, <http://www.rfc-editor.org/info/rfc4107>.

[RFC4949] Shirey, R., "Internet Security Glossary, Version 2",
FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
<http://www.rfc-editor.org/info/rfc4949>.

[RFC7920] Atlas, A., Ed., Nadeau, T., Ed.,

[RFC7258] Farrell, S. and D. Ward, "Problem
Statement for the Interface to the Routing System", H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7920, 7258, DOI 10.17487/RFC7920, June 2016,
<http://www.rfc-editor.org/info/rfc7920>. 10.17487/RFC7258, May
2014, <http://www.rfc-editor.org/info/rfc7258>.

[RFC7921] Atlas, A., Halpern, J., Hares, S., Ward, D., and T.
Nadeau, "An Architecture for the Interface to the Routing
System", RFC 7921, DOI 10.17487/RFC7921, June 2016,
<http://www.rfc-editor.org/info/rfc7921>.

7.2.

[RFC7922] Clarke, J., Salgueiro, G., and C. Pignataro, "Interface to
the Routing System (I2RS) Traceability: Framework and
Information Model", RFC 7922, DOI 10.17487/RFC7922, June
2016, <http://www.rfc-editor.org/info/rfc7922>.

[RFC7923] Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements
for Subscription to YANG Datastores", RFC 7923,
DOI 10.17487/RFC7923, June 2016,
<http://www.rfc-editor.org/info/rfc7923>.

8.2. Informative References

[I-D.ietf-i2rs-ephemeral-state]
Haas, J. and S. Hares, "I2RS Ephemeral State
Requirements", draft-ietf-i2rs-ephemeral-state-15 draft-ietf-i2rs-ephemeral-state-16 (work in
progress), July August 2016.

[I-D.ietf-i2rs-security-environment-reqs]
Migault, D., Halpern, J.,

[I-D.ietf-netconf-restconf]
Bierman, A., Bjorklund, M., and S. Hares, "I2RS Environment
Security Requirements", draft-ietf-i2rs-security-
environment-reqs-01 K. Watsen, "RESTCONF
Protocol", draft-ietf-netconf-restconf-16 (work in
progress), April August 2016.

[I-D.ietf-taps-transports]
Fairhurst, G., Trammell, B., and M. Kuehlewind, "Services
provided by IETF transport protocols and congestion
control mechanisms", draft-ietf-taps-transports-11 (work
in progress), July 2016.

[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)",
RFC 2865, DOI 10.17487/RFC2865, June 2000,
<http://www.rfc-editor.org/info/rfc2865>.

[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
RFC 4960, DOI 10.17487/RFC4960, September 2007,
<http://www.rfc-editor.org/info/rfc4960>.

[RFC7922] Clarke, J., Salgueiro, G.,

[RFC5246] Dierks, T. and C. Pignataro, "Interface E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<http://www.rfc-editor.org/info/rfc5246>.

[RFC5764] McGrew, D. and E. Rescorla, "Datagram Transport Layer
Security (DTLS) Extension to Establish Keys for the Routing System (I2RS) Traceability: Framework Secure
Real-time Transport Protocol (SRTP)", RFC 5764,
DOI 10.17487/RFC5764, May 2010,
<http://www.rfc-editor.org/info/rfc5764>.

[RFC6238] M'Raihi, D., Machani, S., Pei, M., and
Information Model", J. Rydell, "TOTP:
Time-Based One-Time Password Algorithm", RFC 7922, 6238,
DOI 10.17487/RFC7922, 10.17487/RFC6238, May 2011,
<http://www.rfc-editor.org/info/rfc6238>.

[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June
2016, <http://www.rfc-editor.org/info/rfc7922>.

[RFC7923] Voit, E., Clemm, 2011,
<http://www.rfc-editor.org/info/rfc6241>.

[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
January 2012, <http://www.rfc-editor.org/info/rfc6347>.

[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<http://www.rfc-editor.org/info/rfc6536>.

[RFC6614] Winter, S., McCauley, M., Venaas, S., and K. Wierenga,
"Transport Layer Security (TLS) Encryption for RADIUS",
RFC 6614, DOI 10.17487/RFC6614, May 2012,
<http://www.rfc-editor.org/info/rfc6614>.

[RFC6733] Fajardo, V., Ed., Arkko, J., Loughney, J., and G. Zorn,
Ed., "Diameter Base Protocol", RFC 6733,
DOI 10.17487/RFC6733, October 2012,
<http://www.rfc-editor.org/info/rfc6733>.

[RFC7920] Atlas, A., Ed., Nadeau, T., Ed., and A. Gonzalez Prieto, "Requirements D. Ward, "Problem
Statement for Subscription the Interface to YANG Datastores", the Routing System",
RFC 7923, 7920, DOI 10.17487/RFC7923, 10.17487/RFC7920, June 2016,
<http://www.rfc-editor.org/info/rfc7923>.
<http://www.rfc-editor.org/info/rfc7920>.

Authors' Addresses

Susan Hares
Huawei
7453 Hickory Hill
Saline, MI 48176
USA

Email: shares@ndzh.com

Daniel Migault
Ericsson
8400 boulevard Decarie
Montreal, QC HAP 2N2
Canada

Email: daniel.migault@ericsson.com

Joel Halpern
Ericsson
US

Email: joel.halpern@ericsson.com