OPSWG WG T. Reddy
Internet-Draft McAfee
Intended status: Standards Track D. Wing
Expires: July 19, 2020 Citrix
B. Anderson
Cisco
January 16, 2020
MUD (D)TLS profiles for IoT devices
draft-reddy-opsawg-mud-tls-02
Abstract
This memo extends Manufacturer Usage Description (MUD) to incorporate
(D)TLS profile parameters. This allows a network element to identify
unexpected (D)TLS usage, which can indicate the presence of
unauthorized software or malware on an endpoint.
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 July 19, 2020.
Copyright Notice
Copyright (c) 2020 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
(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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Overview of MUD (D)TLS profiles for IoT devices . . . . . . . 4
4. (D)TLS 1.3 handshake . . . . . . . . . . . . . . . . . . . . 5
4.1. Full (D)TLS 1.3 handshake inspection . . . . . . . . . . 5
4.2. Encrypted SNI . . . . . . . . . . . . . . . . . . . . . . 7
5. (D)TLS profile YANG module . . . . . . . . . . . . . . . . . 7
5.1. Tree Structure . . . . . . . . . . . . . . . . . . . . . 9
5.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 10
6. MUD File Example . . . . . . . . . . . . . . . . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.1. Normative References . . . . . . . . . . . . . . . . . . 16
10.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
Encryption is necessary to protect the privacy of end users using IoT
devices. In a network setting, TLS [RFC8446] and DTLS
[I-D.ietf-tls-dtls13] are the dominant protocols providing encryption
for IoT device traffic. Unfortunately, in conjunction with IoT
applications' rise of encryption, malware is also using encryption
which thwarts network-based analysis such as deep packet inspection
(DPI). Other mechanisms are needed to notice malware is running on
the IoT device.
Malware frequently uses its own libraries for its activities, and
those libraries are re-used much like any other software engineering
project. Research [malware] indicates there are observable
differences in how malware uses encryption compared with how non-
malware uses encryption. There are several interesting findings
specific to DTLS and TLS which were found common to malware:
o Older and weaker cryptographic parameters (e.g.,
TLS_RSA_WITH_RC4_128_SHA).
o TLS SNI and server certificates are composed of subjects with
characteristics of a domain generation algorithm (DGA) (e.g.,
www.33mhwt2j.net).
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o Higher use of self-signed certificates compared with typical
legitimate software.
o Discrepancies in the server name indication (SNI) TLS extension in
the ClientHello message and the DNS names in the
SubjectAltName(SAN) X.509 extension in the server certificate
message.
o Discrepancies in the key exchange algorithm and the client public
key length in comparison with legitimate flows. As a reminder,
Client Key Exchange message has been removed from TLS 1.3.
o Lower diversity in TLS client advertised TLS extensions compared
to legitimate clients.
o Malware using privacy enhancing technologies like Tor, Psiphon and
Ultrasurf (see [malware-tls]) and, evasion techniques such as
ClientHello randomization to evade detection in order to continue
exploiting the end user.
If observable (D)TLS profile parameters are used, the following
functions are possible which have a favorable impact on network
security:
o Permit intended DTLS or TLS use and block malicious DTLS or TLS
use. This is superior to the layer 3 and layer 4 ACLs of
Manufacturer Usage Description Specification (MUD) [RFC8520] which
are not suitable for broad communication patterns.
o Ensure TLS certificates are valid. Several TLS deployments have
been vulnerable to active Man-In-The-Middle (MITM) attacks because
of the lack of certificate validation. By observing (D)TLS
profile parameters, a network element can detect when the TLS SNI
mismatches the SubjectAltName and when the server's certificate is
invalid. In TLS 1.2, the ClientHello, ServerHello and Certificate
messages are all sent in clear-text, however in TLS 1.3, the
Certificate message is encrypted thereby hiding the server
identity from any intermediary. In TLS 1.3, the middle-box needs
to act as a TLS proxy to validate the server certificate and to
detect TLS SNI mismatch with the server certificate.
o Support new communication patterns. An IoT device can learn a new
capability, and the new capability can change the way the IoT
device communicates with other devices located in the local
network and Internet. There would be an inaccurate policy if an
IoT device rapidly changes the IP addresses and domain names it
communicates with while the MUD ACLs were slower to update. In
such a case, observable (D)TLS profile parameters can be used to
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permit intended use and to block malicious behaviour from the IoT
device.
This document extends MUD [RFC8520] to model observable (D)TLS
profile parameters. Using these (D)TLS profile parameters, an active
MUD-enforcing firewall can identify MUD non-compliant (D)TLS behavior
indicating outdated cryptography or malware. This detection can
prevent malware downloads, block access to malicious domains, enforce
use of strong ciphers, stop data exfiltration, etc. In addition,
organizations may have policies around acceptable ciphers and
certificates on the websites the IoT devices connect to. Examples
include no use of old and less secure versions of TLS, no use of
self-signed certificates, deny-list or accept-list of Certificate
Authorities, valid certificate expiration time, etc. These policies
can be enforced by observing the (D)TLS profile parameters.
Enterprise firewalls can use the IoT device's (D)TLS profile
parameters to identify legitimate flows by observing (D)TLS sessions,
and can make inferences to permit legitimate flows and to block
malicious or insecure flows. The proposed technique is also suitable
in deployments where decryption techniques are not ideal due to
privacy concerns, non-cooperating end-points and expense.
2. 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.
"(D)TLS" is used for statements that apply to both Transport Layer
Security [RFC8446] and Datagram Transport Layer Security [RFC6347].
Specific terms are used for any statement that applies to either
protocol alone.
3. Overview of MUD (D)TLS profiles for IoT devices
In Enterprise networks, protection and detection are typically done
both on end hosts and in the network. Host agents have deep
visibility on the devices where they are installed, whereas the
network has broader visibility. Installing host agents may not be a
viable option on IoT devices, and network-based security is an
efficient means to protect such IoT devices. (D)TLS profile
parameters of IoT device can be used by middle-boxes to detect and
block malware communication, while at the same time preserving the
privacy of legitimate uses of encryption. Middle-boxes need not
proxy (D)TLS but can passively observe the parameters of (D)TLS
handshakes from IoT devices and gain good visibility into TLS 1.0 to
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1.2 parameters and partial visibility into TLS 1.3 parameters.
Malicious agents can try to use the (D)TLS profile parameters of
legitimate agents to evade detection, but it becomes a challenge to
mimic the behavior of various IoT device types and IoT device models
from several manufacturers. In other words, malware developers will
have to develop malicious agents per IoT device type, manufacturer
and model, infect the device with the tailored malware agent and will
have keep up with updates to the device's (D)TLS profile parameters
over time. Further, the malware's command and control server
certificates need to be signed by the same certifying authorities
trusted by the IoT devices. Typically, IoT devices have an
infrastructure that supports a rapid deployment of updates, and
malware agents will have a near-impossible task of similarly
deploying updates and continuing to mimic the TLS behavior of the IoT
device it has infected.
The compromised IoT devices are typically used for launching DDoS
attacks (Section 3 of [RFC8576]). Some of the DDoS attacks like
Slowloris and Transport Layer Security (TLS) re-negotiation can be
detected by observing the (D)TLS profile parameters. For example,
the victim's server certificate need not be signed by the same
certifying authorities trusted by the IoT device.
4. (D)TLS 1.3 handshake
In (D)TLS 1.3, full (D)TLS handshake inspection is not possible since
all (D)TLS handshake messages excluding the ClientHello message are
encrypted. (D)TLS 1.3 has introduced new extensions in the handshake
record layers called Encrypted Extensions. Using these extensions
handshake messages will be encrypted and network devices (such as a
firewall) are incapable deciphering the handshake, thus cannot view
the server certificate. However, the ClientHello and ServerHello
still have some fields visible, such as the list of supported
versions, named groups, cipher suites, signature algorithms and
extensions in ClientHello and, chosen cipher in the ServerHello. For
instance, if the malware uses evasion techniques like ClientHello
randomization, the observable list of cipher suites and extensions
offered by the malware agent in the ClientHello message will not
match the list of cipher suites and extensions offered by the
legitimate client in the ClientHello message, and the middle-box can
block malicious flows without acting as a (D)TLS 1.3 proxy.
4.1. Full (D)TLS 1.3 handshake inspection
To obtain more visibility into negotiated TLS 1.3 parameters, a
middlebox needs to act as a (D)TLS 1.3 proxy. The middlebox MUST
follow the behaviour explained in Section 9.3 of [RFC8446] to act as
a compliant (D)TLS 1.3 proxy.
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To function as a (D)TLS proxy the middlebox creates a signed
certificate using itself as a certificate authority. That
certificate authority has to be trusted by the (D)TLS client. The
following steps explain the mechanism to automatically bootstrap IoT
devices with the middlebox's CA certificate.
Bootstrapping Remote Secure Key Infrastructures (BRSKI) discussed in
[I-D.ietf-anima-bootstrapping-keyinfra] provides a solution for
secure automated bootstrap of devices. BRSKI specifies means to
provision credentials on devices to be used to operationally access
networks. In addition, BRSKI provides an automated mechanism for the
bootstrap distribution of CA certificates from the Enrollment over
Secure Transport (EST) [RFC7030] server. The IoT device can use
BRSKI to automatically bootstrap the IoT device using the IoT
manufacturer provisioned X.509 certificate, in combination with a
registrar provided by the local network and IoT device manufacturer's
authorizing service (MASA).
1. The IoT device authenticates to the local network using the IoT
manufacturer provisioned X.509 certificate. The IoT device can
request and get a voucher from the MASA service via the
registrar. The voucher is signed by the MASA service and
includes the local network's CA public key.
2. The IoT device validates the signed voucher using the
manufacturer installed trust anchor associated with the MASA,
stores the CA's public key and validates the provisional TLS
connection to the registrar.
3. The IoT device requests the full EST distribution of current CA
certificates (Section 5.9.1 in
[I-D.ietf-anima-bootstrapping-keyinfra]) from the registrar
operating as a BRSKI-EST server. The IoT device stores the CA
certificates as Explicit Trust Anchor database entries. The IoT
device uses the Explicit Trust Anchor database to validate the
server certificate.
4. The middle-box uses the "supported_versions" TLS extension
(defined in TLS 1.3 to negotiate the supported TLS versions
between client and server) to determine the TLS version. During
the (D)TLS handshake, If (D)TLS version 1.3 is used, the middle-
box ((D)TLS proxy) modifies the certificate provided by the
server and signs it with the private key from the local CA
certificate. The middle-box has visibility into further
exchanges between the IoT device and server which enables it to
inspect the (D)TLS 1.3 handshake, enforce the MUD (D)TLS profile
and can inspect subsequent network traffic.
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5. The IoT device uses the Explicit Trust Anchor database to
validate the server certificate.
4.2. Encrypted SNI
To increase privacy, encrypted SNI (ESNI,
[I-D.ietf-tls-sni-encryption]) prevents passive observation of the
TLS Server Name Indication which improves privacy. To effectively
provide that privacy protection, SNI encryption needs to be used in
conjunction with DNS encryption (e.g., DNS-over-(D)TLS or DNS-over-
HTTPS). An in-line network device (e.g., firewall) passively
inspecting an encrypted SNI (D)TLS handshake cannot observe the
encrypted SNI nor observe the encrypted DNS traffic. If an IoT
device is pre-configured to use public DNS-over-(D)TLS or DNS-over-
HTTPS servers, the middle-box needs to act as a DNS-over-TLS or DNS-
over-HTTPS proxy and replace the esni_keys in the ESNI record with
the middle box's esni_keys. Instead of an unappealing DNS-over-TLS
or DNS-over-HTTPS proxy, the IoT device can be bootstrapped to
discover and authenticate DNS-over-(D)TLS and DNS-over-HTTPS servers
provided by a local network using
[I-D.reddy-dprive-bootstrap-dns-server] and [I-D.sah-resinfo-doh].
The local DNS-over-(D)TLS and DNS-over-HTTPS server replaces the
sni_keys in the ESNI record with the middle box's esni_keys.
Note that if an IoT device is pre-configured to use public DNS-
over-(D)TLS or DNS-over-HTTPS servers, the MUD policy enforcement
point is moved to that public server, which cannot enforce the MUD
policy based on domain names (Section 8 of [RFC8520]). Thus the use
of a public DNS-over-(D)TLS or DNS-over-HTTPS server is incompatible
with MUD in general. A local DNS server is necessary to allow MUD
policy enforcement on the local network.
5. (D)TLS profile YANG module
This document specifies a YANG module for representing (D)TLS
profile. The (D)TLS profile YANG module provides a method for
firewall to observe the (D)TLS profile parameters in the (D)TLS
handshake to permit intended use and to block malicious behavior.
This module uses the common YANG types defined in [RFC6991] , rules
defined in [RFC8519] and cryptographic types defined in
[I-D.ietf-netconf-crypto-types].
The (D)TLS profiles and the parameters in each (D)TLS profile include
the following:
o Profile name
o (D)TLS version in ClientHello.legacy_version
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o (D)TLS versions supported by the IoT device. As a reminder,
"supported_versions" extension defined in (D)TLS 1.3 is used by
the client to indicate which versions of (D)TLS it supports and a
client is considered to be attempting to negotiate (D)TLS 1.3 if
the ClientHello contains a "supported_versions" extension with
0x0304 contained in its body.
o If GREASE [I-D.ietf-tls-grease] (Generate Random Extensions And
Sustain Extensibility) values are offered by the client or not.
o List of supported symmetric encryption algorithms
o List of supported compression methods
o List of supported extension types
o List of trust anchor certificates used by the IoT device. If the
server certificate is signed by one of the trust anchors, the
middle-box continues with the connection as normal. Otherwise,
the middle-box will react as if the server certificate validation
has failed and takes appropriate action (e.g, block the (D)TLS
session). Note that server certificate is encrypted in (D)TLS 1.3
and the middle-box without acting as (D)TLS proxy cannot validate
the server certificate.
o List of SPKI pin set pre-configured on the client to validate
self-signed server certificates or raw public keys. A SPKI pin
set is a cryptographic digest to "pin" public key information in a
manner similar to HTTP Public Key Pinning (HPKP) [RFC7469]. If
SPKI pin set is present in the (D)TLS profile of a IoT device and
the server certificate does not pass the PKIX certification path
validation, the middle-box computes the SPKI Fingerprint for the
public key found in the server's certificate (or in the raw public
key, if the server provides that instead). If a computed
fingerprint exactly matches one of the SPKI pin sets in the (D)TLS
profile, the middle-box continues with the connection as normal.
Otherwise, the middle-box will act on the SPKI validation failure
and takes appropriate action.
o Cryptographic hash algorithm used to generate the SPKI pinsets
o List of pre-shared key exchange modes
o List of named groups (DHE or ECDHE) supported by the client
o List signature algorithms the client can validate in X.509 server
certificates
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o List of client key exchange algorithms and the client public key
lengths in versions prior to (D)TLS 1.3
The (D)TLS profile parameters MUST NOT include the GREASE values for
extension types, named groups, signature algorithms, (D)TLS versions,
pre-shared key exchange modes and cipher suites. Note that the
GREASE values are random and peers will ignore these values and
interoperate.
If the (D)TLS profile parameters are not observed in a (D)TLS session
from the IoT device, the default behaviour is to block the (D)TLS
session.
Note: The TLS and DTLS IANA registries are available from
<https://www.iana.org/assignments/tls-parameters/tls-parameters.txt>.
5.1. Tree Structure
This document augments the "ietf-mud" MUD YANG module defined in
[RFC8520] for signaling the IoT device (D)TLS profile. This document
defines the YANG module "reddy-opsawg-mud-tls-profile", which has the
following tree structure:
module: reddy-opsawg-mud-tls-profile
augment /mud:mud/mud:from-device-policy:
+--rw client-profile
+--rw tls-profiles* [profile-name]
+--rw profile-name string
+--rw protocol-version? uint16
+--rw supported_versions* uint16
+--rw grease_extension? boolean
+--rw encryption-algorithms* encryption-algorithm
+--rw compression-methods* compression-method
+--rw extension-types* extension-type
+--rw acceptlist-ta-certs* ct:trust-anchor-cert-cms
+--rw SPKI-pin-sets* SPKI-pin-set
+--rw SPKI-hash-algorithm ct:hash-algorithm-t
+--rw psk-key-exchange-modes* psk-key-exchange-mode
+--rw supported-groups* supported-group
+--rw signature-algorithms* signature-algorithm
+--rw client-public-keys
| +--rw key-exchange-algorithms* key-exchange-algorithm
| +--rw client-public-key-lengths* client-public-key-length
+--rw actions
+--rw forwarding identityref
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5.2. YANG Module
module reddy-opsawg-mud-tls-profile {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:reddy-opsawg-mud-tls-profile";
prefix mud-tls-profile;
import ietf-crypto-types {
prefix ct;
reference "draft-ietf-netconf-crypto-types-01:
Common YANG Data Types for Cryptography";
}
import ietf-inet-types {
prefix inet;
reference "Section 4 of RFC 6991";
}
import ietf-mud {
prefix mud;
reference "RFC 8520";
}
import ietf-access-control-list {
prefix ietf-acl;
reference
"RFC 8519: YANG Data Model for Network Access
Control Lists (ACLs)";
}
organization
"IETF Operations and Management Area Working Group Working Group";
contact
"Editor: Konda, Tirumaleswar Reddy
<mailto:TirumaleswarReddy_Konda@McAfee.com>";
description
"This module contains YANG definition for the IoT device
(D)TLS profile.
Copyright (c) 2019 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
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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 2019-06-12 {
description
"Initial revision";
}
typedef compression-method {
type uint8;
description "Compression method";
}
typedef extension-type {
type uint16;
description "Extension type";
}
typedef encryption-algorithm {
type uint16;
description "Encryption algorithm";
}
typedef supported-group {
type uint16;
description "Named group (DHE or ECDHE)";
}
typedef SPKI-pin-set {
type binary;
description "Subject Public Key Info pin set";
}
typedef signature-algorithm {
type uint16;
description "Signature algorithm";
}
typedef key-exchange-algorithm {
type uint8;
description "key exchange algorithm";
}
typedef psk-key-exchange-mode {
type uint8;
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description "pre-shared key exchange mode";
}
typedef client-public-key-length {
type uint8;
description "client public key length";
}
augment "/mud:mud/mud:from-device-policy" {
container client-profile {
list tls-profiles {
key "profile-name";
description
"A list of (D)TLS version profiles supported by the client.";
leaf profile-name {
type string {
length "1..64";
}
description
"The name of (D)TLS profile; space and special
characters are not allowed.";
}
leaf protocol-version {
type uint16;
description "(D)TLS version in ClientHello.legacy_version";
}
leaf-list supported_versions {
type uint16;
description
"TLS versions supported by the client indicated
in the supported_versions extension in (D)TLS 1.3.";
}
leaf Grease_extension {
type boolean;
description
"If set to 'true', Grease extension values are offered by
the client.";
}
leaf-list encryption-algorithms {
type encryption-algorithm;
description "Encryption algorithms";
}
leaf-list compression-methods {
type compression-method;
description "Compression methods";
}
leaf-list extension-types {
type extension-type;
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description "Extension Types";
}
leaf-list acceptlist-ta-certs {
type ct:trust-anchor-cert-cms;
description
"A list of trust anchor certificates used by the client.";
}
leaf-list SPKI-pin-sets {
type SPKI-pin-set;
description
"A list of SPKI pin sets pre-configured on the client
to validate self-signed server certificate or
raw public key.";
}
leaf SPKI-hash-algorithm {
type ct:hash-algorithm-t;
description
"cryptographic hash algorithm used to generate the
SPKI pinset.";
}
leaf-list psk-key-exchange-modes {
type psk-key-exchange-mode;
description
"pre-shared key exchange modes";
}
leaf-list supported-groups {
type supported-group;
description
"A list of named groups supported by the client.";
}
leaf-list signature-algorithms {
type signature-algorithm;
description
"A list signature algorithms the client can validate
in X.509 certificates.";
}
container client-public-keys {
leaf-list key-exchange-algorithms {
type key-exchange-algorithm;
description
"Key exchange algorithms supported by the client";
}
leaf-list client-public-key-lengths {
type client-public-key-length;
description
"client public key lengths";
}
}
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container actions {
description
"Definitions of action for this profile.";
leaf forwarding {
type identityref {
base ietf-acl:forwarding-action;
}
mandatory true;
description
"Specifies the forwarding action for the (D)TLS profile.";
reference
"RFC 8519: YANG Data Model for Network Access
Control Lists (ACLs)";
}
}
}
}
}
}
6. MUD File Example
This example below contains (D)TLS profile parameters for a IoT
device. JSON encoding of YANG modelled data [RFC7951] is used to
illustrate the example.
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{
"ietf-mud:mud": {
"mud-version": 1,
"mud-url": "https://example.com/IoTDevice",
"last-update": "2019-18-06T03:56:40.105+10:00",
"cache-validity": 100,
"is-supported": true,
"systeminfo": "IoT device name",
"reddy-opsawg-mud-tls-profile:from-device-policy": {
"client-profile": {
"tls-version-profile" : [
{
"protocol-version" : 771,
"supported_versions_ext" : "FALSE",
"encryption-algorithms" : [31354, 4865, 4866, 4867],
"extension-types" : [10],
"supported-groups" : [29],
"actions": {
"forwarding": "accept"
}
}
]
}
}
}
}
7. Security Considerations
Security considerations in [RFC8520] need to be taken into
consideration. Although it is challenging for a malware to mimic the
TLS behavior of various IoT device types and IoT device models from
several manufacturers, malicious agents have a very low probabilty of
using the same (D)TLS profile parameters as legitimate agents on the
IoT device to evade detection. Network security services should also
rely on contextual network data to detect false negatives. In order
to detect such malicious flows, anomaly detection (deep learning
techniques on network data) can be used to detect malicious agents
using the same (D)TLS profile parameters as legitimate agent on the
IoT device. In anomaly detection, the main idea is to maintain
rigorous learning of "normal" behavior and where an "anomaly" (or an
attack) is identified and categorized based on the knowledge about
the normal behavior and a deviation from this normal behavior.
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8. IANA Considerations
This document requests IANA to register the following URIs in the
"ns" subregistry within the "IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:reddy-opsawg-mud-tls-profile
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
9. Acknowledgments
Thanks to Flemming Andreasen, Shashank Jain, and Harsha Joshi for the
discussion and comments.
10. References
10.1. Normative References
[I-D.ietf-netconf-crypto-types]
Watsen, K. and H. Wang, "Common YANG Data Types for
Cryptography", draft-ietf-netconf-crypto-types-13 (work in
progress), November 2019.
[I-D.ietf-tls-dtls13]
Rescorla, E., Tschofenig, H., and N. Modadugu, "The
Datagram Transport Layer Security (DTLS) Protocol Version
1.3", draft-ietf-tls-dtls13-34 (work in progress),
November 2019.
[I-D.ietf-tls-grease]
Benjamin, D., "Applying GREASE to TLS Extensibility",
draft-ietf-tls-grease-04 (work in progress), August 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>.
[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
January 2012, <https://www.rfc-editor.org/info/rfc6347>.
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[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[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>.
[RFC8519] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair,
"YANG Data Model for Network Access Control Lists (ACLs)",
RFC 8519, DOI 10.17487/RFC8519, March 2019,
<https://www.rfc-editor.org/info/rfc8519>.
10.2. Informative References
[I-D.ietf-anima-bootstrapping-keyinfra]
Pritikin, M., Richardson, M., Eckert, T., Behringer, M.,
and K. Watsen, "Bootstrapping Remote Secure Key
Infrastructures (BRSKI)", draft-ietf-anima-bootstrapping-
keyinfra-34 (work in progress), January 2020.
[I-D.ietf-tls-sni-encryption]
Huitema, C. and E. Rescorla, "Issues and Requirements for
SNI Encryption in TLS", draft-ietf-tls-sni-encryption-09
(work in progress), October 2019.
[I-D.reddy-dprive-bootstrap-dns-server]
Reddy.K, T., Wing, D., Richardson, M., and M. Boucadair,
"A Bootstrapping Procedure to Discover and Authenticate
DNS-over-(D)TLS and DNS-over-HTTPS Servers", draft-reddy-
dprive-bootstrap-dns-server-06 (work in progress), January
2020.
[I-D.sah-resinfo-doh]
Sood, P., Arends, R., and P. Hoffman, "DNS Resolver
Information: "doh"", draft-sah-resinfo-doh-00 (work in
progress), May 2019.
[malware] Anderson, B., Paul, S., and D. McGrew, "Deciphering
Malware's use of TLS (without Decryption)", July 2016,
<https://arxiv.org/abs/1607.01639>.
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[malware-tls]
Anderson, B. and D. McGrew, "Deciphering Malware's use of
TLS (without Decryption)", October 2019,
<https://dl.acm.org/citation.cfm?id=3355601>.
[RFC7030] Pritikin, M., Ed., Yee, P., Ed., and D. Harkins, Ed.,
"Enrollment over Secure Transport", RFC 7030,
DOI 10.17487/RFC7030, October 2013,
<https://www.rfc-editor.org/info/rfc7030>.
[RFC7469] Evans, C., Palmer, C., and R. Sleevi, "Public Key Pinning
Extension for HTTP", RFC 7469, DOI 10.17487/RFC7469, April
2015, <https://www.rfc-editor.org/info/rfc7469>.
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/info/rfc7951>.
[RFC8520] Lear, E., Droms, R., and D. Romascanu, "Manufacturer Usage
Description Specification", RFC 8520,
DOI 10.17487/RFC8520, March 2019,
<https://www.rfc-editor.org/info/rfc8520>.
[RFC8576] Garcia-Morchon, O., Kumar, S., and M. Sethi, "Internet of
Things (IoT) Security: State of the Art and Challenges",
RFC 8576, DOI 10.17487/RFC8576, April 2019,
<https://www.rfc-editor.org/info/rfc8576>.
Authors' Addresses
Tirumaleswar Reddy
McAfee, Inc.
Embassy Golf Link Business Park
Bangalore, Karnataka 560071
India
Email: kondtir@gmail.com
Dan Wing
Citrix Systems, Inc.
4988 Great America Pkwy
Santa Clara, CA 95054
USA
Email: danwing@gmail.com
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Blake Anderson
Cisco Systems, Inc.
170 West Tasman Dr
San Jose, CA 95134
USA
Email: blake.anderson@cisco.com
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