Internet DRAFT - draft-reddy-dots-home-network
draft-reddy-dots-home-network
DOTS T. Reddy
Internet-Draft McAfee
Intended status: Standards Track M. Boucadair
Expires: October 3, 2019 Orange
J. Shallow
April 01, 2019
Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal
Channel Call Home
draft-reddy-dots-home-network-04
Abstract
This document presents DOTS signal channel Call Home service, which
enables a DOTS server to initiate a secure connection to a DOTS
client, and to receive the attack traffic information from the DOTS
client. The DOTS server in turn uses the attack traffic information
to identify the compromised devices launching the outgoing DDoS
attack and takes appropriate mitigation action.
The Call Home service is not specific to the home networks; the
solution targets any deployment which requires to block DDoS attack
traffic closer to the source(s) of a DDoS attack.
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 https://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 3, 2019.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
Reddy, et al. Expires October 3, 2019 [Page 1]
Internet-Draft DOTS Signal Call Home April 2019
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://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 . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. The Problem . . . . . . . . . . . . . . . . . . . . . . . 2
1.2. The Solution . . . . . . . . . . . . . . . . . . . . . . 4
1.3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Notational Conventions and Terminology . . . . . . . . . . . 5
3. DOTS Signal Channel Call Home . . . . . . . . . . . . . . . . 5
3.1. Procedure . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2. DOTS Signal Channel Extension . . . . . . . . . . . . . . 6
3.2.1. Mitigation Request . . . . . . . . . . . . . . . . . 6
3.2.2. DOTS Signal Call Home YANG Module . . . . . . . . . . 9
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
4.1. DOTS Signal Channel Call Home UDP and TCP Port Number . . 12
4.2. DOTS Signal Channel CBOR Mappings Registry . . . . . . . 12
4.3. New DOTS Conflict Cause . . . . . . . . . . . . . . . . . 13
4.4. DOTS Signal Call Home YANG Module . . . . . . . . . . . . 13
5. Security Considerations . . . . . . . . . . . . . . . . . . . 14
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 14
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
9.1. Normative References . . . . . . . . . . . . . . . . . . 16
9.2. Informative References . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
1.1. The Problem
The DOTS signal channel protocol [I-D.ietf-dots-signal-channel] is
used to carry information about a network resource or a network (or a
part thereof) that is under a Distributed Denial of Service (DDoS)
attack. Such information is sent by a DOTS client to one or multiple
DOTS servers so that appropriate mitigation actions are undertaken on
traffic deemed suspicious. Various use cases are discussed in
[I-D.ietf-dots-use-cases].
Reddy, et al. Expires October 3, 2019 [Page 2]
Internet-Draft DOTS Signal Call Home April 2019
IoT devices are becoming more and more prevalent in home networks,
and with compute and memory becoming cheaper and cheaper, various
types of IoT devices become available in the consumer market at
affordable price. But on the downside, the main threat being most of
these IoT devices are bought off-the-shelf and most manufacturers
haven't considered security in the product design. IoT devices
deployed in home networks can be easily compromised, they do not have
an easy mechanism to upgrade, and IoT manufactures may cease
manufacture and/or discontinue patching vulnerabilities on IoT
devices. However, these vulnerable and compromised devices will
continue be used for a long period of time in the home, and the end-
user does not know that IoT devices in his/her home are compromised.
The compromised IoT devices are typically used for launching DDoS
attacks on the victim while the owner/administrator of the home
network is not aware about such misbehaviors. Similar to other DDoS
attacks, the victim in this attack can be an application server, a
host, a router, a firewall, or an entire network.
Nowadays, network devices in a home network offer network security,
for instance, firewall/IPS service on a home router or gateway to
protect the devices connected to the home network from external and
internal attacks. Over the years several techniques have been
identified to detect DDoS attacks, some of these techniques can be
enabled on home network devices but most of them are used in the
Internet Service Provider (ISP)'s network. The ISP offering DDoS
mitigation service can detect outgoing DDoS attack traffic
originating from its subscribers or the ISP may receive filtering
rules (for example, using BGP flowspec [RFC5575]) from downstream
service provider to filter, block, or rate-limit DDoS attack traffic
originating from the ISP's subscribers to the downstream target.
Some of the DDoS attacks like spoofed RST or FIN packets, Slowloris,
and TLS re-negotiation are difficult to detect on the home network
devices without adversely affecting its performance. The reason is
typically home routers have fast path to boost the throughput. For
every new TCP/UDP flow, only the first few packets are punted through
the slow path. Hence, it is not possible to detect various DDoS
attacks in the slow path, since the attack payload is sent to the
target server after the flow is switched to fast path. Deep packet
inspection (DPI) of all the packets of a flow would be able to detect
some of the attacks. However, a full-fledged DPI to detect these
type of DDoS attacks is functionally or operationally not possible
for all the devices attached to the home network owing to the memory
and CPU limitations of the home routers. Further, for certain DDoS
attacks the ability to distinguish legitimate traffic from attacker
traffic on a per packet basis is complex. This complexity originates
from the fact that the packet itself may look "legitimate" and no
Reddy, et al. Expires October 3, 2019 [Page 3]
Internet-Draft DOTS Signal Call Home April 2019
attack signature can be identified. The anomaly can be identified
only after detailed statistical analysis.
The ISP on the other hand can detect the DDoS attack originating from
a home network, but the ISP does not have a mechanism to detect which
device in the home network is generating the DDoS attack traffic.
The primary reason being that devices in a IPv4 Home network are
typically behind a NAT border. Even in case of a IPv6 Home network,
although the ISP can identify the infected device in the Home network
launching the DDoS traffic by tracking its unique IPv6 address, the
infected device can easily change the IP address to evade
remediation.
Existing approaches are still suffering from misused access network
resources by abusing devices; the support of means for blocking such
attacks close to the sources are missing. In particular, the DOTS
signal protocol does not discuss cooperative DDoS mitigation between
the home network and ISP to the suppress the outbound DDoS attack
traffic originating from the home network.
1.2. The Solution
This specification addresses the problems discussed in Section 1.1
and presents DOTS signal channel Call Home extension, which enables
the DOTS server to initiate a secure connection to the DOTS client,
and the DOTS client then conveys the attack traffic information to
the DOTS server.
In a typical deployment scenario, the DOTS server is enabled on a
CPE, which is aligned with recent trends to enrich the CPE with
advanced security features. Unlike classic DOTS deployments
[I-D.ietf-dots-use-cases], such DOTS server maintains a single DOTS
signal channel session for each DOTS-capable upstream provisioning
domain [I-D.ietf-dots-multihoming].
For instance, the DOTS server in the home network initiates the Call
Home in 'idle' time and then subsequently the DOTS client in the ISP
environment can initiate a mitigation request whenever the ISP
detects there is an attack from a compromised device in the DOTS
server domain.
The DOTS server uses the DDoS attack traffic information to identify
the compromised device in its domain launching the DDoS attack,
notifies the network administrator, and takes appropriate mitigation
action. The mitigation action can be to quarantine the compromised
device or block its traffic to the attack target until the mitigation
request is withdrawn.
Reddy, et al. Expires October 3, 2019 [Page 4]
Internet-Draft DOTS Signal Call Home April 2019
1.3. Scope
The aforementioned problems may be encountered in other deployments
than those discussed in Section 1.1. The solution specified in this
document can be used for those deployments to block DDoS attack
traffic closer to the source(s) of the attack.
It is out of the scope of this document to identify an exhaustive
list of such deployments.
2. Notational Conventions and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119][RFC8174] when, and only when, they appear in all
capitals, as shown here.
The reader should be familiar with the terms defined in
[I-D.ietf-dots-requirements].
3. DOTS Signal Channel Call Home
3.1. Procedure
The DOTS signal channel Call Home extension preserves all but one of
the DOTS client/server roles in the DOTS protocol stack, as compared
to DOTS client-initiated DOTS signal channel protocol
[I-D.ietf-dots-signal-channel]. The one and only role reversal that
occurs are at the TCP/TLS or DTLS layers; that is, the DOTS server
acts as a DTLS client and the DOTS client acts as a DTLS server or
the DOTS server acts as a TCP/TLS client and the DOTS client acts as
a TCP/TLS server. The DOTS server initiates TCP/TLS handshake or
DTLS handshake to the DOTS client.
For example, a home network element (e.g., home router) co-located
with a DOTS server (likely, a client-domain DOTS gateway) is the TCP/
TLS server and DTLS server. However, when calling home, the DOTS
server initially assumes the role of the TCP/TLS client and DTLS
client, but the network element's role as a DOTS server remains the
same. Furthermore, existing certificate chains and mutual
authentication mechanisms between the DOTS agents are unaffected by
the Call Home function. This Call Home function enables the DOTS
server co-located with a network element (possibly behind NATs and
firewalls) reachable by only the intended DOTS client and hence the
DOTS server cannot be subjected to DDoS attacks. Other motivations
for introducing the Call Home function are discussed in Section 1.1
of [RFC8071].
Reddy, et al. Expires October 3, 2019 [Page 5]
Internet-Draft DOTS Signal Call Home April 2019
This document assumes that DOTS servers are provisioned with a way to
know how to reach the upstream DOTS client(s), which could occur by a
variety of means (e.g., [I-D.ietf-dots-server-discovery]). The
specification of such means are out of scope of this document.
Figure 1 illustrates a sample Call Home flow exchange:
DOTS DOTS
Server Client
| |
| 1. (D)TLS connection |
|----------------------------------->|
| 2. Mitigation request |
|<-----------------------------------|
| |
Figure 1: DOTS Signal Channel Call Home Sequence Diagram
The Call Home procedure is as follows:
1. If UDP transport is used, the DOTS server begins by initiating a
DTLS connection to the DOTS client. The DOTS client MUST support
accepting DTLS connection on the IANA-assigned port number
defined in Section 4.1, but MAY be configured to listen to a
different port number.
If TCP is used, the DOTS server begins by initiating a TCP
connection to the DOTS client. The DOTS client MUST support
accepting TCP connections on the IANA-assigned port number
defined in Section 4.1, but MAY be configured to listen to a
different port number. Using this TCP connection, the DOTS
server initiates a TLS connection to the DOTS client.
The Happy Eyeballs mechanism explained in Section 4.3 of
[I-D.ietf-dots-signal-channel] can be used for initiating (D)TLS
connections.
2. Using this (D)TLS connection, the DOTS client may request,
withdraw, or retrieve the status of mitigation requests.
3.2. DOTS Signal Channel Extension
3.2.1. Mitigation Request
This specification extends the mitigation request defined in
[I-D.ietf-dots-signal-channel] to convey the attacker source prefixes
and source port numbers. The DOTS client conveys the following new
parameters in the CBOR body of the mitigation request:
Reddy, et al. Expires October 3, 2019 [Page 6]
Internet-Draft DOTS Signal Call Home April 2019
source-prefix: A list of attacker prefixes used to attack the
target. Prefixes are represented using Classless Inter-Domain
Routing (CIDR) notation [RFC4632].
As a reminder, the prefix length MUST be less than or equal to 32
(resp. 128) for IPv4 (resp. IPv6).
The prefix list MUST NOT include broadcast, loopback, or multicast
addresses. These addresses are considered as invalid values. In
addition, the DOTS client MUST validate that attacker prefixes are
within the scope of the DOTS server domain.
This is an optional attribute.
source-port-range: A list of port numbers used by the attack traffic
flows.
A port range is defined by two bounds, a lower port number (lower-
port) and an upper port number (upper-port). When only 'lower-
port' is present, it represents a single port number.
For TCP, UDP, Stream Control Transmission Protocol (SCTP)
[RFC4960], or Datagram Congestion Control Protocol (DCCP)
[RFC4340], a range of ports can be, for example, 0-1023,
1024-65535, or 1024-49151.
This is an optional attribute.
source-icmp-type: A list of ICMP types used by the attack traffic
flows. An ICMP type range is defined by two bounds, a lower ICMP
type (lower-type) and an upper ICMP type (upper-type). When only
'lower-type' is present, it represents a single ICMP type.
This is an optional attribute.
The 'source-prefix' parameter is a mandatory attribute when the
attack traffic information is signaled by a DOTS client in the Call
Home scenario. The 'target-uri' or 'target-fqdn' parameters can be
included in a mitigation request for diagnostic purposes to notify
the DOTS server domain administrator, but SHOULD NOT be used to
determine the target IP addresses. Note that 'target-prefix' becomes
a mandatory attribute in the mitigation request signaling the attack
information because 'target-uri' and 'target-fqdn' are optional
attributes and 'alias-name' will not be conveyed in a mitigation
request.
In order to help attack source identification by a DOTS server, the
DOTS client SHOULD include in its mitigation request additional
Reddy, et al. Expires October 3, 2019 [Page 7]
Internet-Draft DOTS Signal Call Home April 2019
information such as 'source-port-range' or 'source-icmp-type-range'.
The DOTS client MAY NOT include such information if 'source-prefix'
conveys an IPv6 address/prefix.
If a Carrier Grade NAT (CGN, including NAT64) is located between the
DOTS client domain and DOTS server domain, communicating an external
IP address in a mitigation request is likely to be discarded by the
DOTS server because the external IP address is not visible locally to
the DOTS server. The DOTS server is only aware of the internal IP
addresses/prefixes bound to its domain. Thus, the DOTS client MUST
NOT include the external IP address and/or port number identifying
the suspect attack source, but MUST include the internal IP address
and/or port number. To that aim, the DOTS client SHOULD rely on
mechanisms, such as [RFC8512] or [RFC8513], to retrieve the internal
IP address and port number which are mapped to an external IP address
and port number.
If a MAP Border Relay [RFC7597] or lwAFTR [RFC7596] is enabled in the
provider's domain to service its customers, the identification of an
attack source bound to an IPv4 address/prefix MUST also rely on
source port numbers because the same IPv4 address is assigned to
multiple customers. The port information is required to
unambiguously identify the source of an attack.
If a translator is enabled on the boundaries of the domain hosting
the DOTS server (a CPE with NAT enabled, typically), the DOTS server
uses the attack traffic information conveyed in a mitigation request
to find the internal source IP address of the compromised device and
blocks the traffic from the compromised device traffic to the attack
target until the mitigation request is withdrawn. Doing so allows to
isolate the suspicious device while avoiding to disturb other
services.
The DOTS server domain administrator consent MAY be required to block
the traffic from the compromised device to the attack target. An
implementation MAY have a configuration knob to block the traffic
from the compromised device to the attack target with or without DOTS
server domain administrator consent. If the attack traffic is
blocked, the DOTS server informs the DOTS client that the attack is
being mitigated.
If the attack traffic information is identified by the DOTS server or
the DOTS server domain administrator as legitimate traffic, the
mitigation request is rejected, and 4.09 (Conflict) is returned to
the DOTS client. The conflict-clause (defined in Section 4.4.1 of
[I-D.ietf-dots-signal-channel]) indicates the cause of the conflict.
The following new value is defined:
Reddy, et al. Expires October 3, 2019 [Page 8]
Internet-Draft DOTS Signal Call Home April 2019
4: Mitigation request rejected. This code is returned by the DOTS
server to indicate the attack traffic has been classified as
legitimate traffic.
If the DOTS server is co-located with a home router, it can program
the packet processor to punt all the traffic from the compromised
device to the target to slow path. The home router inspects the
punted slow path traffic to detect and block the outgoing DDoS attack
traffic or quarantine the device (e.g., using MAC level filtering)
until it is remediated, and notifies the home administrator about the
compromised device.
3.2.2. DOTS Signal Call Home YANG Module
3.2.2.1. Tree Structure
This document augments the "dots-signal-channel" DOTS signal YANG
module defined in [I-D.ietf-dots-signal-channel] for signaling the
attack traffic information. This document defines the YANG module
"ietf-dots-call-home", which has the following tree structure:
module: ietf-dots-call-home
augment /ietf-signal:dots-signal/ietf-signal:message-type
/ietf-signal:mitigation-scope/ietf-signal:scope:
+--rw source-prefix* inet:ip-prefix {source-signaling}?
+--rw source-port-range*
| | [lower-port upper-port] {source-signaling}?
| +--rw lower-port inet:port-number
| +--rw upper-port inet:port-number
+--rw source-icmp-type-range*
| [lower-type upper-type] {source-signaling}?
+--rw lower-type uint8
+--rw upper-type uint8
3.2.2.2. YANG Module
<CODE BEGINS> file "ietf-dots-call-home@2018-04-01.yang"
module ietf-dots-call-home {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-dots-call-home";
prefix call-home;
import ietf-inet-types {
prefix inet;
reference
"Section 4 of RFC 6991";
Reddy, et al. Expires October 3, 2019 [Page 9]
Internet-Draft DOTS Signal Call Home April 2019
}
import ietf-dots-signal-channel {
prefix ietf-signal;
reference
"RFC YYYY: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel Specification";
}
organization
"IETF DDoS Open Threat Signaling (DOTS) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/dots/>
WG List: <mailto:dots@ietf.org>
Editor: Konda, Tirumaleswar Reddy
<mailto:TirumaleswarReddy_Konda@McAfee.com>;
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>;
Editor: Jon Shallow
<mailto:ietf-supjps@jpshallow.com>";
description
"This module contains YANG definition for the signaling
messages exchanged between a DOTS client and a DOTS server
for the call home deployment scenario.
Copyright (c) 2018 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2018-04-01 {
description
"Initial revision.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel Call Home";
}
Reddy, et al. Expires October 3, 2019 [Page 10]
Internet-Draft DOTS Signal Call Home April 2019
feature source-signaling {
description
"This feature means that source-related information
can be supplied in mitigation requests.";
}
augment "/ietf-signal:dots-signal/ietf-signal:message-type/"
+ "ietf-signal:mitigation-scope/ietf-signal:scope" {
if-feature source-signaling;
description "Attacker source details";
leaf-list source-prefix {
type inet:ip-prefix;
description
"IPv4 or IPv6 prefix identifying the attacker(s).";
}
list source-port-range {
key "lower-port upper-port";
description
"Port range. When only lower-port is
present, it represents a single port number.";
leaf lower-port {
type inet:port-number;
mandatory true;
description
"Lower port number of the port range.";
}
leaf upper-port {
type inet:port-number;
must ". >= ../lower-port" {
error-message
"The upper port number must be greater than
or equal to lower port number.";
}
description
"Upper port number of the port range.";
}
}
list source-icmp-type-range {
key "lower-type upper-type";
description
"ICMP type range. When only lower-type is
present, it represents a single ICMP type.";
leaf lower-type {
type uint8;
mandatory true;
description
"Lower ICMP type of the ICMP type range.";
Reddy, et al. Expires October 3, 2019 [Page 11]
Internet-Draft DOTS Signal Call Home April 2019
}
leaf upper-type {
type uint8;
must ". >= ../lower-type" {
error-message
"The upper ICMP type must be greater than
or equal to lower ICMP type.";
}
description
"Upper type of the ICMP type range.";
}
}
}
}
<CODE ENDS>
4. IANA Considerations
4.1. DOTS Signal Channel Call Home UDP and TCP Port Number
IANA is requested to assign the port number TBD to the DOTS signal
channel Call Home protocol for both UDP and TCP from the "Service
Name and Transport Protocol Port Number Registry" available at:
https://www.iana.org/assignments/service-names-port-numbers/service-
names-port-numbers.xhtml.
The assignment of port number 4647 is strongly suggested (DOTS signal
channel uses port number 4646).
4.2. DOTS Signal Channel CBOR Mappings Registry
This specification registers the 'source-prefix' and 'source-port-
range' parameters in the IANA "DOTS Signal Channel CBOR Mappings"
registry established by [I-D.ietf-dots-signal-channel].
The 'source-prefix', 'source-port-range', and 'source-icmp-type-
range' are comprehension-optional parameters.
o Note to the RFC Editor: Please delete (TBD1)-(TBD5) once CBOR keys
are assigned from the 0x8000 - 0xBFFF range.
Reddy, et al. Expires October 3, 2019 [Page 12]
Internet-Draft DOTS Signal Call Home April 2019
+-------------------+------------+--------+---------------+--------+
| Parameter Name | YANG | CBOR | CBOR Major | JSON |
| | Type | Key | Type & | Type |
| | | | Information | |
+-------------------+------------+--------+---------------+--------+
| source-prefix | leaf-list | 0x8000 | 4 array | Array |
| | inet: | (TBD1) | | |
| | ip-prefix | | 3 text string | String |
| source-port-range | list | 0x8001 | 4 array | Array |
| | | (TBD2) | | |
| source-icmp-type- | list | 0x8002 | 4 array | Array |
| range | | (TBD3) | | |
| lower-type | uint8 | 0x8003 | 0 unsigned | Number |
| | | (TBD4) | | |
| upper-type | uint8 | 0x8004 | 0 unsigned | Number |
| | | (TBD5) | | |
+-------------------+------------+--------+---------------+--------+
4.3. New DOTS Conflict Cause
This document requests IANA to assign a new code from the "DOTS
Conflict Cause Codes" registry:
+------+------------------+-----------------------------+-----------+
| Code | Label | Description | Reference |
+------+------------------+-----------------------------+-----------+
| 4 | request-rejected | Mitigation request | [RFCXXXX] |
| | | rejected. This code is | |
| | | returned by the DOTS server | |
| | | to indicate the attack | |
| | | traffic has been classified | |
| | | as legitimate traffic. | |
+------+------------------+-----------------------------+-----------+
4.4. DOTS Signal Call Home YANG Module
This document requests IANA to register the following URI in the
"IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-dots-call-home
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
This document requests IANA to register the following YANG module in
the "YANG Module Names" registry [RFC7950].
Reddy, et al. Expires October 3, 2019 [Page 13]
Internet-Draft DOTS Signal Call Home April 2019
Name: ietf-call-home
Namespace: urn:ietf:params:xml:ns:yang:ietf-dots-call-home
Maintained by IANA: N
Prefix: call-home
Reference: RFC XXXX
5. Security Considerations
This document deviates from classic DOTS signal channel usage by
having the DOTS server initiate the TCP/TLS or DTLS connection. DOTS
signal channel related security considerations discussed in
Section 10 of [I-D.ietf-dots-signal-channel] MUST be considered.
DOTS agents MUST authenticate each other using (D)TLS before a DOTS
signal channel session is considered valid.
An attacker may launch a DoS attack on the DOTS client by having it
perform computationally expensive operations, before deducing that
the attacker doesn't possess a valid key. For instance, in TLS 1.3
[RFC8446], the ServerHello message contains a Key Share value based
on an expensive asymmetric key operation for key establishment.
Common precautions mitigating DoS attacks are recommended, such as
temporarily blacklisting the source address after a set number of
unsuccessful authentication attempts.
DOTS servers may not blindly trust mitigation requests from DOTS
clients. For example, DOTS servers can use the attack flow
information in a mitigation request to enable full-fledged packet
inspection function to inspect all the traffic from the compromised
to the target or to re-direct the traffic from the compromised device
to the target to a DDoS mitigation system to scrub the suspicious
traffic. DOTS servers can also seek the consent of DOTS server
domain administrator to block the traffic from the compromised device
to the target (see Section 3.2.1).
6. Privacy Considerations
The considerations discussed in [RFC6973] were taken into account to
assess whether the DOTS Call Home extension introduces privacy
threats.
Concretely, the protocol does not leak any new information that can
be used to ease surveillance. In particular, the DOTS server is not
required to share information that is local to its network (e.g.,
internal identifiers of an attack source) with the DOTS client.
The DOTS Call Home extension does not preclude the validation of
mitigation requests received from a DOTS client. For example, a
security service running on the CPE may require administrator's
Reddy, et al. Expires October 3, 2019 [Page 14]
Internet-Draft DOTS Signal Call Home April 2019
consent before the CPE acts upon the mitigation request indicated by
the DOTS client. How the consent is obtained is out of scope of this
document.
Note that a DOTS server can seek for an administrator's consent,
validate the request by inspecting the traffic, or proceed with both.
The DOTS Call Home extension is only advisory in nature. Concretely,
the DOTS Call Home extension does not impose any action to be
enforced within the home network; it is up to the DOTS server (and/or
network administrator) to decide whether and which actions are
required.
Moreover, the DOTS Call Home extension avoids misattribution by
appropriately identifying the network to which a suspect attack
source belongs to (e.g., address sharing issues discussed in
Section 3.2.1).
Triggers to send a DOTS mitigation request to a DOTS server are
deployment-specific. For example, a DOTS client may rely on the
output of some DDoS detection systems deployed within the DOTS
client's network to detect potential outbound DDoS attacks or on
abuse claims received from remote victim networks. Such DDoS
detection and mitigation techniques are not meant to track the
activity of users, but to protect the Internet and avoid altering the
IP reputation of the DOTS client's domain.
7. Contributors
The following individuals have contributed to this document:
Joshi Harsha
McAfee, Inc.
Embassy Golf Link Business Park
Bangalore, Karnataka 560071
India
Email: harsha_joshi@mcafee.com
8. Acknowledgements
Thanks to Wei Pei, Xia Liang, Roman Danyliw, Dan Wing, and Toema
Gavrichenkov for the comments.
Reddy, et al. Expires October 3, 2019 [Page 15]
Internet-Draft DOTS Signal Call Home April 2019
9. References
9.1. Normative References
[I-D.ietf-dots-signal-channel]
K, R., Boucadair, M., Patil, P., Mortensen, A., and N.
Teague, "Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel Specification", draft-
ietf-dots-signal-channel-30 (work in progress), March
2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
9.2. Informative References
[I-D.ietf-dots-multihoming]
Boucadair, M. and R. K, "Multi-homing Deployment
Considerations for Distributed-Denial-of-Service Open
Threat Signaling (DOTS)", draft-ietf-dots-multihoming-01
(work in progress), January 2019.
[I-D.ietf-dots-requirements]
Mortensen, A., K, R., and R. Moskowitz, "Distributed
Denial of Service (DDoS) Open Threat Signaling
Requirements", draft-ietf-dots-requirements-22 (work in
progress), March 2019.
Reddy, et al. Expires October 3, 2019 [Page 16]
Internet-Draft DOTS Signal Call Home April 2019
[I-D.ietf-dots-server-discovery]
Boucadair, M., K, R., and P. Patil, "Distributed-Denial-
of-Service Open Threat Signaling (DOTS) Server Discovery",
draft-ietf-dots-server-discovery-00 (work in progress),
March 2019.
[I-D.ietf-dots-use-cases]
Dobbins, R., Migault, D., Fouant, S., Moskowitz, R.,
Teague, N., Xia, L., and K. Nishizuka, "Use cases for DDoS
Open Threat Signaling", draft-ietf-dots-use-cases-17 (work
in progress), January 2019.
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram
Congestion Control Protocol (DCCP)", RFC 4340,
DOI 10.17487/RFC4340, March 2006,
<https://www.rfc-editor.org/info/rfc4340>.
[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing
(CIDR): The Internet Address Assignment and Aggregation
Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August
2006, <https://www.rfc-editor.org/info/rfc4632>.
[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
Denial-of-Service Considerations", RFC 4732,
DOI 10.17487/RFC4732, December 2006,
<https://www.rfc-editor.org/info/rfc4732>.
[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
RFC 4960, DOI 10.17487/RFC4960, September 2007,
<https://www.rfc-editor.org/info/rfc4960>.
[RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
and D. McPherson, "Dissemination of Flow Specification
Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
<https://www.rfc-editor.org/info/rfc5575>.
[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations for Internet Protocols", RFC 6973,
DOI 10.17487/RFC6973, July 2013,
<https://www.rfc-editor.org/info/rfc6973>.
[RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I.
Farrer, "Lightweight 4over6: An Extension to the Dual-
Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596,
July 2015, <https://www.rfc-editor.org/info/rfc7596>.
Reddy, et al. Expires October 3, 2019 [Page 17]
Internet-Draft DOTS Signal Call Home April 2019
[RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S.,
Murakami, T., and T. Taylor, Ed., "Mapping of Address and
Port with Encapsulation (MAP-E)", RFC 7597,
DOI 10.17487/RFC7597, July 2015,
<https://www.rfc-editor.org/info/rfc7597>.
[RFC8071] Watsen, K., "NETCONF Call Home and RESTCONF Call Home",
RFC 8071, DOI 10.17487/RFC8071, February 2017,
<https://www.rfc-editor.org/info/rfc8071>.
[RFC8512] Boucadair, M., Ed., Sivakumar, S., Jacquenet, C.,
Vinapamula, S., and Q. Wu, "A YANG Module for Network
Address Translation (NAT) and Network Prefix Translation
(NPT)", RFC 8512, DOI 10.17487/RFC8512, January 2019,
<https://www.rfc-editor.org/info/rfc8512>.
[RFC8513] Boucadair, M., Jacquenet, C., and S. Sivakumar, "A YANG
Data Model for Dual-Stack Lite (DS-Lite)", RFC 8513,
DOI 10.17487/RFC8513, January 2019,
<https://www.rfc-editor.org/info/rfc8513>.
Authors' Addresses
Tirumaleswar Reddy
McAfee, Inc.
Embassy Golf Link Business Park
Bangalore, Karnataka 560071
India
Email: kondtir@gmail.com
Mohamed Boucadair
Orange
Rennes 35000
France
Email: mohamed.boucadair@orange.com
Jon Shallow
UK
Email: supjps-ietf@jpshallow.com
Reddy, et al. Expires October 3, 2019 [Page 18]
