Internet DRAFT - draft-ietf-dhc-sedhcpv6
draft-ietf-dhc-sedhcpv6
DHC Working Group L. Li
Internet-Draft Tsinghua University
Intended status: Standards Track S. Jiang
Expires: August 25, 2017 Huawei Technologies Co., Ltd
Y. Cui
Tsinghua University
T. Jinmei
Infoblox Inc.
T. Lemon
Nominum, Inc.
D. Zhang
February 21, 2017
Secure DHCPv6
draft-ietf-dhc-sedhcpv6-21
Abstract
DHCPv6 includes no deployable security mechanism that can protect
end-to-end communication between DHCP clients and servers. This
document describes a mechanism for using public key cryptography to
provide such security. The mechanism provides encryption in all
cases, and can be used for authentication based on pre-sharing of
authorized certificates.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 25, 2017.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Security Issues of DHCPv6 . . . . . . . . . . . . . . . . . . 4
5. Secure DHCPv6 Overview . . . . . . . . . . . . . . . . . . . 5
5.1. Solution Overview . . . . . . . . . . . . . . . . . . . . 5
5.2. New Components . . . . . . . . . . . . . . . . . . . . . 6
5.3. Support for Algorithm Agility . . . . . . . . . . . . . . 7
5.4. Impact on RFC3315 . . . . . . . . . . . . . . . . . . . . 7
5.5. Applicability . . . . . . . . . . . . . . . . . . . . . . 8
6. DHCPv6 Client Behavior . . . . . . . . . . . . . . . . . . . 8
7. DHCPv6 Server Behavior . . . . . . . . . . . . . . . . . . . 11
8. Relay Agent Behavior . . . . . . . . . . . . . . . . . . . . 13
9. Processing Rules . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Increasing Number Check . . . . . . . . . . . . . . . . . 14
9.2. Encryption Key Tag Calculation . . . . . . . . . . . . . 14
10. Extensions for Secure DHCPv6 . . . . . . . . . . . . . . . . 15
10.1. New DHCPv6 Options . . . . . . . . . . . . . . . . . . . 15
10.1.1. Algorithm Option . . . . . . . . . . . . . . . . . . 15
10.1.2. Certificate Option . . . . . . . . . . . . . . . . . 17
10.1.3. Signature option . . . . . . . . . . . . . . . . . . 18
10.1.4. Increasing-number Option . . . . . . . . . . . . . . 20
10.1.5. Encryption-Key-Tag Option . . . . . . . . . . . . . 20
10.1.6. Encrypted-message Option . . . . . . . . . . . . . . 21
10.2. New DHCPv6 Messages . . . . . . . . . . . . . . . . . . 21
10.3. Status Codes . . . . . . . . . . . . . . . . . . . . . . 22
11. Security Considerations . . . . . . . . . . . . . . . . . . . 22
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25
14. Change log [RFC Editor: Please remove] . . . . . . . . . . . 25
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
15.1. Normative References . . . . . . . . . . . . . . . . . . 28
15.2. Informative References . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30
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1. Introduction
The Dynamic Host Configuration Protocol for IPv6 (DHCPv6, [RFC3315])
allows DHCPv6 servers to flexibly provide addressing and other
configuration information relating to local network infrastructure to
DHCP clients. The protocol provides no deployable security
mechanism, and consequently is vulnerable to various attacks.
This document provides a brief summary of the security
vulnerabilities of the DHCPv6 protocol and then describes a new
extension to the protocol that provides two additional types of
security:
o authentication of the DHCPv6 client and the DHCPv6 server to
defend against active attacks, such as spoofing.
o encryption between the DHCPv6 client and the DHCPv6 server in
order to protect the DHCPv6 communication from pervasive
monitoring.
The extension specified in this document applies only to end-to-end
communication between DHCP servers and clients. Options added by
relay agents in Relay-Forward messages, and options other than the
client message in Relay-Reply messages sent by DHCP servers, are not
protected. Such communications are already protected using the
mechanism described in [I-D.ietf-dhc-relay-server-security].
This extension introduces two new DHCPv6 messages: the Encrypted-
Query and the Encrypted-Response messages. It defines six new DHCPv6
options: the Algorithm, Certificate, Signature, Increasing-number,
Encryption-Key-Tag option and Encrypted-message options.
2. 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 [RFC2119] when they
appear in ALL CAPS. When these words are not in ALL CAPS (such as
"should" or "Should"), they have their usual English meanings, and
are not to be interpreted as [RFC2119] key words.
3. Terminology
This section defines terminology specific to secure DHCPv6 used in
this document.
secure DHCPv6 client: A node that initiates a DHCPv6 request on a
link to obtain DHCPv6 configuration parameters from
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one or more DHCPv6 servers using the encryption and
optional authentication mechanisms defined in this
document.
secure DHCPv6 server: A DHCPv6 server that implements the
authentication and encryption mechanisms defined in
this document, and is configured to use them.
4. Security Issues of DHCPv6
[RFC3315] defines an authentication mechanism with integrity
protection. This mechanism uses a symmetric key that is shared by
the client and server for authentication. It does not provide any
key distribution mechanism.
For this approach, operators can set up a key database for both
servers and clients from which the client obtains a key before
running DHCPv6. However, manual key distribution runs counter to the
goal of minimizing the configuration data needed at each host.
Consequently, there are no known deployments of this security
mechanism.
[RFC3315] provides an additional mechanism for preventing off-network
timing attacks using the Reconfigure message: the Reconfigure Key
authentication method. However, this method protects only the
Reconfigure message. The key is transmitted in plaintext to the
client in earlier exchanges and so this method is vulnerable to on-
path active attacks.
Anonymity Profile for DHCP Clients [RFC7844] explains how to generate
DHCPv4 or DHCPv6 requests that minimize the disclosure of identifying
information. However, the anonymity profile limits the use of the
certain options. It also cannot anticipate new options that may
contain private information. In addition, the anonymity profile does
not work in cases where the client wants to maintain anonymity from
eavesdroppers but must identify itself to the DHCP server with which
it intends to communicate.
Privacy consideration for DHCPv6 [RFC7824] presents an analysis of
the privacy issues associated with the use of DHCPv6 by Internet
users. No solutions are presented.
Current DHCPv6 messages are still transmitted in cleartext and the
privacy information within the DHCPv6 message is not protected from
passive attack, such as pervasive monitoring [RFC7258]. The privacy
information of the IPv6 host, such as DUID, may be gleaned to find
location information, previous visited networks and so on. [RFC7258]
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claims that pervasive monitoring should be mitigated in the design of
IETF protocol, where possible.
To better address the problem of passive monitoring and to achieve
authentication without requiring a symmetric key distribution
solution for DHCP, this document defines an asymmetric key
authentication and encryption mechanism. This protects against both
active attacks, such as spoofing, and passive attacks, such as
pervasive monitoring.
5. Secure DHCPv6 Overview
5.1. Solution Overview
The following figure illustrates the secure DHCPv6 procedure.
Briefly, this extension establishes the server's identity with an
anonymous Information-Request exchange. Once the server's identity
has been established, the client may either choose to communicate
with the server or not. Not communicating with an unknown server
avoids revealing private information, but if there is no known server
on a particular link, the client will be unable to communicate with a
DHCP server.
If the client chooses to communicate with the selected server(s), it
uses the Encrypted-Query message to encapsulate its communications to
the DHCP server. The server responds with Encrypted-Response
messages. Normal DHCP messages are encapsulated in these two new
messages using the new defined Encrypted-message option. Besides the
Encrypted-message option, the Signature option is defined to verify
the integrity of the DHCPv6 messages and then authentication of the
client and the server. The Increasing number option is defined to
detect a replay attack.
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+-------------+ +-------------+
|DHCPv6 Client| |DHCPv6 Server|
+-------------+ +-------------+
| Information-request |
|----------------------------------------->|
| Algorithm option |
| Option Request option |
| |
| Reply |
|<-----------------------------------------|
| Certificate option |
| Signature option |
| Increasing-number option |
| Server Identifier option |
| |
| Encryption-Query |
|----------------------------------------->|
| Encrypted-message option |
| Server Identifier option |
| Encryption-Key-Tag option |
| |
| Encryption-Response |
|<-----------------------------------------|
| Encrypted-message option |
| |
Figure 1: Secure DHCPv6 Procedure
5.2. New Components
The new components of the mechanism specified in this document are as
follows:
o Servers and clients that use certificates first generate a public/
private key pair and then obtain a certificate that signs the
public key. The Certificate option is defined to carry the
certificate of the sender.
o The algorithm option is defined to carry the algorithms lists for
algorithm agility.
o The signature is generated using the private key to verify the
integrity of the DHCPv6 messages. The Signature option is defined
to carry the signature.
o The increasing number is used to detect replayed packet. The
Increasing-number option is defined to carry a strictly-increasing
serial number.
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o The encryption key Tag is calculated from the public key data.
The Encryption-Key-Tag option is defined to identify the used
public/private key pair.
o The Encrypted-message option is defined to contain the encrypted
DHCPv6 message.
o The Encrypted-Query message is sent from the secure DHCPv6 client
to the secure DHCPv6 server. The Encrypted-Query message MUST
contain the Encrypted-message option and Encryption-Key-Tag
option. In addition, the Server Identifier option MUST be
included if it is contained in the original DHCPv6 message. The
Encrypted-Query message MUST NOT contain any other options.
o The Encrypted-Response message is sent from the secure DHCPv6
server to the secure DHCPv6 client. The Encrypted-Response
message MUST contain the Encrypted-message option. The Encrypted-
Response message MUST NOT contain any other options.
5.3. Support for Algorithm Agility
In order to provide a means of addressing problems that may emerge
with existing hash algorithms, signature algorithm and encryption
algorithms in the future, this document provides a mechanism to
support algorithm agility. The support for algorithm agility in this
document is mainly a algorithm notification mechanism between the
client and the server. The same client and server MUST use the same
algorithm in a single communication session. The client can offer a
set of algorithms, and then the server selects one algorithm for the
future communication.
5.4. Impact on RFC3315
For secure DHCPv6, the Solicit and Rebind messages can be sent only
to the selected server(s) which share one common certificate. If the
client doesn't like the received Advertise(s) it could restart the
whole process and selects another certificate, but it will be more
expensive, and there's no guarantee that other servers can provide
better Advertise(s).
[RFC3315] provides an additional mechanism for preventing off-network
timing attacks using the Reconfigure message: the Reconfigure Key
authentication method. Secure DHCPv6 can protect the Reconfigure
message using the encryption method. So the Reconfigure Key
authentication method SHOULD NOT be used if Secure DHCPv6 is applied.
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5.5. Applicability
In principle, secure DHCPv6 is applicable in any environment where
physical security on the link is not assured and attacks on DHCPv6
are a concern. In practice, however, authenticated and encrypted
DHCPv6 configuration will rely on some operational assumptions mainly
regarding public key distribution and management. In order to
achieve the wider use of secure DHCPv6, opportunistic security
[RFC7435] can be applied to secure DHCPv6 deployment, which allows
DHCPv6 encryption in environments where support for authentication or
a key distribution mechanism is not available.
Secure DHCPv6 can achieve authentication and encryption based on pre-
sharing of authorized certificates. One feasible environment in an
early deployment stage would be enterprise networks. In enterprise
networks, the client is manually pre-configured with the trusted
servers' public key and the server can also be manually pre-
configured with the trusted clients' public keys. In some scenario,
such as coffee shop where the certificate cannot be validated and one
wants access to the Internet, then the DHCPv6 configuration process
can be encrypted without authentication.
Note that this deployment scenario based on manual operation is not
much different from the existing, shared-secret based authentication
mechanisms defined in [RFC3315] in terms of operational costs.
However, Secure DHCPv6 is still securer than the shared-secret
mechanism in that even if clients' keys stored for the server are
stolen that does not mean an immediate threat as these are public
keys. In addition, if some kind of Public Key Infrastructure (PKI)
is used with Secure DHCPv6, even if the initial installation of the
certificates is done manually, it will help reduce operational costs
of revocation in case a private key (especially that of the server)
is compromised.
6. DHCPv6 Client Behavior
The secure DHCPv6 client is pre-configured with a certificate and its
corresponding private key for client authentication. If the client
does not obtain a certificate from Certificate Authority (CA), it can
generate the self-signed certificate.
The secure DHCPv6 client sends an Information-request message as per
[RFC3315]. The Information-request message is used by the DHCPv6
client to request the server's certificate information without having
addresses, prefixes or any non-security options assigned to it. The
contained Option Request option MUST carry the option code of the
Certificate option. In addition, the contained Algorithm option MUST
be constructed as explained in Section 10.1.1. The Information-
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request message MUST NOT include any other DHCPv6 options except the
above options to minimize the client's privacy information leakage.
When receiving the Reply messages from the DHCPv6 servers, a secure
DHCPv6 client discards any DHCPv6 message that meets any of the
following conditions:
o the Signature option is missing,
o multiple Signature options are present,
o the Certificate option is missing.
And then the client first checks acknowledged hash, signature and
encryption algorithms that the server supports. The client checks
the signature/encryption algorithms through the certificate option
and checks the signature/hash algorithms through the signature
option. The SA-id in the certificate option must be equal to the SA-
id in the signature option. If they are different, then the client
drops the Reply message. The client uses the acknowledged algorithms
in the subsequent messages.
Then the client checks the authority of the server. In some scenario
where non-authenticated encryption can be accepted, such as coffee
shop, then authentication is optional and can be skipped. For the
certificate check method, the client validates the certificates
through the pre-configured local trusted certificates list or other
methods. A certificate that finds a match in the local trust
certificates list is treated as verified. If the certificate check
fails, the Reply message is dropped.
The client MUST now authenticate the server by verifying the
signature and checking increasing number, if there is a Increasing-
number option. The order of two procedures is left as an
implementation decision. It is RECOMMENDED to check increasing
number first, because signature verification is much more
computationally expensive. The client checks the Increasing-number
option according to the rule defined in Section 9.1. For the message
without an Increasing-number option, according to the client's local
policy, it MAY be acceptable or rejected. The Signature field
verification MUST show that the signature has been calculated as
specified in Section 10.1.3. Only the messages that get through both
the signature verification and increasing number check (if there is a
Increasing-number option) are accepted. Reply message that does not
pass the above tests MUST be discarded.
If there are multiple authenticated DHCPv6 certs, the client selects
one DHCPv6 cert for the following communication. The selected
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certificate may correspond to multiple DHCPv6 servers. If there are
no authenticated DHCPv6 certs or existing servers fail
authentication, the client should retry a number of times. The
client conducts the server discovery process as per section 18.1.5 of
[RFC3315] to avoid a packet storm. In this way, it is difficult for
a rogue server to beat out a busy "real" server. And then the client
takes some alternative action depending on its local policy, such as
attempting to use an unsecured DHCPv6 server.
Once the server has been authenticated, the DHCPv6 client sends the
Encrypted-Query message to the DHCPv6 server. The Encrypted-Query
message contains the Encrypted-message option, which MUST be
constructed as explained in Section 10.1.6. The Encrypted-message
option contains the encrypted DHCPv6 message using the public key
contained in the selected cert. In addition, the Server Identifier
option MUST be included if it is in the original message (i.e.
Request, Renew, Decline, Release) to avoid the need for other servers
receiving the message to attempt to decrypt it. The Encrypted-Query
message MUST include the Encryption-Key-Tag option to identify the
used public/private key pair, which is constructed as explained in
Section 10.1.5. The Encrypted-Query message MUST NOT contain any
other DHCPv6 option except the Server Identifier option, Encryption-
Key-Tag option, Encrypted-Message option.
The first DHCPv6 message sent from the client to the server, such as
Solicit message, MUST contain the related information for client
authentication. The encryption text SHOULD be formatted as explain
in [RFC5652]. The Certificate option MUST be constructed as
explained in Section 10.1.2. In addition, one and only one Signature
option MUST be contained, which MUST be constructed as explained in
Section 10.1.3. One and only one Increasing-number option SHOULD be
contained, which MUST be constructed as explained in Section 10.1.4.
In addition, the subsequent encrypted DHCPv6 message sent from the
client can also contain the Increasing-number option to defend
against replay attack.
For the received Encrypted-Response message, the client MUST drop the
Encrypted-Response message if other DHCPv6 option except Encrypted-
message option is contained. If the transaction-id is 0, the client
also try to decrypt it. Then, the client extracts the Encrypted-
message option and decrypts it using its private key to obtain the
original DHCPv6 message. In this document, it is assumed that the
client will not have multiple DHCPv6 sessions with different DHCPv6
servers using different key pairs and only one key pair is used for
the encrypted DHCPv6 configuration process. After the decryption, it
handles the message as per [RFC3315].If the decrypted DHCPv6 message
contains the Increasing-number option, the DHCPv6 client checks it
according to the rule defined in Section 9.1.
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If the client fails to get the proper parameters from the chosen
server(s), it can select another authenticated certificate and send
the Encrypted-Query message to another authenticated server(s) for
parameters configuration until the client obtains the proper
parameters.
When the decrypted message is Reply message with an error status
code, the error status code indicates the failure reason on the
server side. According to the received status code, the client MAY
take follow-up action:
o Upon receiving an AuthenticationFail error status code, the client
is not able to build up the secure communication with the server.
However, there may be other DHCPv6 servers available that
successfully complete authentication. The client MAY use the
AuthenticationFail as a hint and switch to other DHCPv6 server if
it has another one. The client SHOULD retry with another
authenticated certificate. However, if the client decides to
retransmit using the same certificate after receiving
AuthenticationFail, it MUST NOT retransmit immediately and MUST
follow normal retransmission routines defined in [RFC3315].
o Upon receiving a ReplayDetected error status code, the client MAY
resend the message with an adjusted Increasing-number option
according to the returned number from the DHCPv6 server.
o Upon receiving a SignatureFail error status code, the client MAY
resend the message following normal retransmission routines
defined in [RFC3315].
7. DHCPv6 Server Behavior
The secure DHCPv6 server is pre-configured with a certificate and its
corresponding private key for server authentication. If the server
does not obtain the certificate from Certificate Authority (CA), it
can generate the self-signed certificate.
When the DHCPv6 server receives the Information-request message and
the contained Option Request option identifies the request is for the
server's certificate information, it SHOULD first check the hash,
signature, encryption algorithms sets that the client supports. The
server selects one hash, signature, encryption algorithm from the
acknowledged algorithms sets for the future communication. And then,
the server replies with a Reply message to the client. The Reply
message MUST contain the requested Certificate option, which MUST be
constructed as explained in Section 10.1.2, and Server Identifier
option. In addition, the Reply message MUST contain one and only one
Signature option, which MUST be constructed as explained in
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Section 10.1.3. Besides, the Reply message SHOULD contain one and
only one Increasing-number option, which MUST be constructed as
explained in Section 10.1.4.
Upon the receipt of Encrypted-Query message, the server MUST drop the
message if the other DHCPv6 option is contained except Server
Identifier option, Encryption-Key-Tag option, Encrypted-message
option. Then, the server checks the Server Identifier option. The
DHCPv6 server drops the message that is not for it, thus not paying
cost to decrypt messages. If it is the target server, according to
the Encryption-Key-Tag option, the server identifies the used public/
private key pair and decrypts the Encrypted-message option using the
corresponding private key. It is essential to note that the
encryption key tag is not a unique identifier. It is theoretically
possible for two different public keys to share one common encryption
key tag. The encryption key tag is used to limit the possible
candidate keys, but it does not uniquely identify a public/private
key pair. The server MUST try all corresponding key pairs. If the
server cannot find the corresponding private key of the key tag or
the corresponding private key of the key tag is invalid for
decryption, then the server drops the received message.
If secure DHCPv6 server needs client authentication and decrypted
message is a Solicit/Information-request message which contains the
information for client authentication, the secure DHCPv6 server
discards the received message that meets any of the following
conditions:
o the Signature option is missing,
o multiple Signature options are present,
o the Certificate option is missing.
For the signature failure, the server SHOULD send an encrypted Reply
message with an UnspecFail (value 1, [RFC3315]) error status code to
the client.
The server validates the client's certificate through the local pre-
configured trusted certificates list. A certificate that finds a
match in the local trust certificates list is treated as verified.
If the server does not know the certificate and can accept the non-
authenticated encryption, then the server skips the authentication
process and uses it for encryption only. The message that fails
authentication validation MUST be dropped. In such failure, the
DHCPv6 server replies with an encrypted Reply message with an
AuthenticationFail error status code, defined in Section 10.3, back
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to the client. At this point, the server has either recognized the
authentication of the client, or decided to drop the message.
If the decrypted message contains the Increasing-number option, the
server checks it according to the rule defined in Section 9.1. If
the check fails, an encrypted Reply message with a ReplayDetected
error status code, defined in Section 10.3, should be sent back to
the client. In the Reply message, a Increasing-number option is
carried to indicate the server's stored number for the client to use.
According to the server's local policy, the message without an
Increasing-number option MAY be acceptable or rejected.
The Signature field verification MUST show that the signature has
been calculated as specified in Section 10.1.3. If the signature
check fails, the DHCPv6 server SHOULD send an encrypted Reply message
with a SignatureFail error status code. Only the clients that get
through both the signature verification and increasing number check
(if there is a Increasing-number option) are accepted as
authenticated clients and continue to be handled their message as
defined in [RFC3315].
Once the client has been authenticated, the DHCPv6 server sends the
Encrypted-response message to the DHCPv6 client. If the DHCPv6
message is Reconfigure message, then the server set the transaction-
id of the Encrypted-Response message to 0. The Encrypted-response
message MUST only contain the Encrypted-message option, which MUST be
constructed as explained in Section 10.1.6. The encryption text
SHOULD be formatted as explain in [RFC5652]. The Encrypted-message
option contains the encrypted DHCPv6 message that is encrypted using
the authenticated client's public key. To provide the replay
protection, the Increasing-number option SHOULD be contained in the
encrypted DHCPv6 message.
8. Relay Agent Behavior
When a DHCPv6 relay agent receives an Encrypted-query or Encrypted-
response message, it may not recognize this message. The unknown
messages MUST be forwarded as described in [RFC7283].
When a DHCPv6 relay agent recognizes the Encrypted-query and
Encrypted-response messages, it forwards the message according to
section 20 of [RFC3315]. There is nothing more the relay agents have
to do, it neither needs to verify the messages from client or server,
nor add any secure DHCPv6 options. Actually, by definition in this
document, relay agents MUST NOT add any secure DHCPv6 options.
Relay-forward and Relay-reply messages MUST NOT contain any
additional Certificate option or Increasing-number option, aside from
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those present in the innermost encapsulated messages from the client
or server.
9. Processing Rules
9.1. Increasing Number Check
In order to check the Increasing-number option, defined in
Section 10.1.4, the client/server has one stable stored number for
replay attack detection. The server should keep a record of the
increasing number forever. And the client keeps a record of the
increasing number during the DHCPv6 configuration process with the
DHCPv6 server. And the client can forget the increasing number
information after the transaction is finished. The client's initial
locally stored increasing number is set to zero.
It is essential to remember that the increasing number is finite.
All arithmetic dealing with sequence numbers must be performed modulo
2^64. This unsigned arithmetic preserves the relationship of
sequence numbers as they cycle from 2^64 - 1 to 0 again.
In order to check the Increasing-number option, the following
comparison is needed.
NUM.STO = the stored number in the client/server
NUM.REC = the acknowledged number from the received message
The Increasing-number option in the received message passes the
increasing number check if NUM.REC is more than NUM.STO. And then,
the value of NUM.STO is changed into the value of NUM.REC.
The increasing number check fails if NUM.REC is equal with or less
than NUM.STO.
9.2. Encryption Key Tag Calculation
The generation method of the encryption key tag adopts the method
define in Appendix B in [RFC4034].
The following reference implementation calculates the value of the
encryption key tag. The input is the data of the public key. The
code is written for clarity not efficiency.
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/*
* First octet of the key tag is the most significant 8 bits of the
* return value;
* Second octet of the key tag is the least significant 8 bits of the
* return value.
*/
unsigned int
keytag (
unsigned char key[], /* the RDATA part of the DNSKEY RR */
unsigned int keysize /* the RDLENGTH */
)
{
unsigned long ac; /* assumed to be 32 bits or larger */
int i; /* loop index */
for ( ac = 0, i = 0; i < keysize; ++i )
ac += (i & 1) ? key[i] : key[i] << 8;
ac += (ac >> 16) & 0xFFFF;
return ac & 0xFFFF;
}
10. Extensions for Secure DHCPv6
This section describes the extensions to DHCPv6. Six new DHCPv6
options, two new DHCPv6 messages and six new status codes are
defined.
10.1. New DHCPv6 Options
10.1.1. Algorithm Option
The Algorithm option carries the algorithms sets for algorithm
agility, which is contained in the Information-request message.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_ALGORITHM | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. EA-id List .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. SHA-id List .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Algorithm Option
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o option-code: OPTION_ALGORITHM (TBA1).
o option-len: length of EA-id List + length of SHA-id List in
octets.
o EA-id: The format of the EA-id List field is shown in Figure 3.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| EA-len | EA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| EA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
EA-len The length of the following EA-ids.
EA-id 2-octets value to indicate the Encryption Algorithm id.
The client enumerates the list of encryption algorithms it
supports to the server. The encryption algorithm is used
for the encrypted DHCPv6 configuration process. This design
is adopted in order to provide encryption algorithm agility.
The value is from the Encryption Algorithm for Secure DHCPv6
registry in IANA. A registry of the initial assigned values
is defined in Section 12. The RSA algorithm, as the mandatory
encryption algorithm, MUST be included.
Figure 3: EA-id List Field
o SHA-id List: The format of the SHA-id List field is shown in
Figure 4. The SHA-id List contains multiple pair of (SA-id, HA-
id). Each pair of (SA-id[i], HA-id[i]) is considered to specify a
specific signature method.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SHA-len | SA-id[1] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HA-id[1] | SA-id[2] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HA-id[2] | ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SA-id[n] | HA-id[n] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
SHA-len The length of the following SA-id and HA-id pairs.
SA-id 2-octets value to indicate the Signature Algorithm id.
The client enumerates the list of signature algorithms it
supports to the server. This design is adopted in
order to provide signature algorithm agility. The
value is from the Signature Algorithm for Secure
DHCPv6 registry in IANA. The support of RSASSA-PKCS1-v1_5
is mandatory. A registry of the initial assigned
values is defined in Section 12. The mandatory
signature algorithms MUST be included.
HA-id 2-octets value to indicate the Hash Algorithm id.
The client enumerates the list of hash algorithms it
supports to the server. This design is adopted in order to
provide hash algorithm agility. The value is from the
Hash Algorithm for Secure DHCPv6 registry in IANA. The
support of SHA-256 is mandatory. A registry of the
initial assigned values is defined in Section 12.
The mandatory hash algorithms MUST be included.
Figure 4: SHA-id List Field
10.1.2. Certificate Option
The Certificate option carries the certificate of the client/server,
which is contained in the Reply message. The format of the
Certificate option is described as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_CERTIFICATE | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| EA-id | SA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. Certificate .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Certificate Option
o option-code: OPTION_CERTIFICATE (TBA2).
o option-len: 4 + length of Certificate in octets.
o EA-id: Encryption Algorithm id which is used for the certificate.
If the value of the EA-id is 0, then the public key in the
certificate is not used for encryption calculation.
o SA-id: Signature Algorithm id which is used for the certificate.
If the value of the EA-id is 0, then the public key in the
certificate is not used for signature calculation.
o Certificate: A variable-length field containing certificates. The
encoding of certificate and certificate data MUST be in format as
defined in Section 3.6, [RFC7296]. The support of X.509
certificate is mandatory.
It should be noticed that the scenario where the values of EA-id and
SA-id are both 0 makes no sense and the client MUST discard a message
with such values.
10.1.3. Signature option
The Signature option contains a signature that is signed by the
private key to be attached to the Reply message. The Signature
option could be in any place within the DHCPv6 message while it is
logically created after the entire DHCPv6 header and options. It
protects the entire DHCPv6 header and options, including itself. The
format of the Signature option is described as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_SIGNATURE | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SA-id | HA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. Signature (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Signature Option
o option-code: OPTION_SIGNATURE (TBA3).
o option-len: 4 + length of Signature field in octets.
o SA-id: Signature Algorithm id. The signature algorithm is used
for computing the signature result. This design is adopted in
order to provide signature algorithm agility. The value is from
the Signature Algorithm for Secure DHCPv6 registry in IANA. The
support of RSASSA-PKCS1-v1_5 is mandatory. A registry of the
initial assigned values is defined in Section 12.
o HA-id: Hash Algorithm id. The hash algorithm is used for
computing the signature result. This design is adopted in order
to provide hash algorithm agility. The value is from the Hash
Algorithm for Secure DHCPv6 registry in IANA. The support of
SHA-256 is mandatory. A registry of the initial assigned values
is defined in Section 12.
o Signature: A variable-length field containing a digital signature.
The signature value is computed with the hash algorithm and the
signature algorithm, as described in HA-id and SA-id. The
Signature field MUST be padded, with all 0, to the next octet
boundary if its size is not a multiple of 8 bits. The padding
length depends on the signature algorithm, which is indicated in
the SA-id field.
Note: If Secure DHCPv6 is used, the DHCPv6 message is encrypted in a
way that the authentication mechanism defined in RFC3315 does not
understand. So the Authentication option SHOULD NOT be used if
Secure DHCPv6 is applied.
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10.1.4. Increasing-number Option
The Increasing-number option carries the strictly increasing number
for anti-replay protection, which is contained in the Reply message
and the encrypted DHCPv6 message. It is optional.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_INCREASING_NUM | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Increasing-Num (64-bit) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code OPTION_INCREASING_NUM (TBA4).
option-len 8, in octets.
Increasing-Num A strictly increasing number for the replay attack detection
which is more than the local stored number.
Figure 7: Increasing-number Option
10.1.5. Encryption-Key-Tag Option
The Encryption-Key-Tag option carries the key identifier which is
calculated from the public key data. The Encrypted-Query message
MUST contain the Encryption-Key-Tag option to identify the used
public/private key pair.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_ENCRYPTION_KEY_TAG | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| encryption key tag(16-bit) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: Encryption-Key-Tag Option
option-code OPTION_ENCRYPTION_KEY_TAG (TBA5).
option-len 2, in octets.
encryption key tag A 16 bits field containing the encryption key tag
sent from the client to server to identify the used public/private
key pair. The encryption key tag is calculated from the public
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key data, like fingerprint of a specific public key. The specific
calculation method of the encryption key tag is illustrated in
Section 9.2.
10.1.6. Encrypted-message Option
The Encrypted-message option carries the encrypted DHCPv6 message,
which is calculated with the recipient's public key. The Encrypted-
message option is contained in the Encrypted-Query message or the
Encrypted-Response message.
The format of the Encrypted-message option is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. encrypted DHCPv6 message .
. (variable) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: Encrypted-message Option
option-code OPTION_ENCRYPTED_MSG (TBA6).
option-len Length of the encrypted DHCPv6 message in octets.
encrypted DHCPv6 message A variable length field containing the
encrypted DHCPv6 message. In Encrypted-Query message, it contains
encrypted DHCPv6 message sent from a client to server. In
Encrypted-response message, it contains encrypted DHCPv6 message
sent from a server to client.
10.2. New DHCPv6 Messages
Two new DHCPv6 messages are defined to achieve the DHCPv6 encryption:
Encrypted-Query and Encrypted-Response. Both the DHCPv6 messages
defined in this document share the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type | transaction-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. options .
. (variable) .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: The format of Encrypted-Query and Encrypted-Response
Messages
msg-type Identifier of the message type. It can be either
Encrypted-Query (TBA7) or DHCPv6-Response (TBA8).
transaction-id The transaction ID for this message exchange.
options The Encrypted-Query message MUST contain the
Encrypted-message option, Encryption-Key-Tag option
and Server Identifier option if the message in the
Encrypted-message option has a Server Identifier
option. The Encrypted-Response message MUST only
contain the Encrypted-message option.
10.3. Status Codes
The following new status codes, see Section 5.4 of [RFC3315] are
defined.
o AuthenticationFail (TBD9): indicates that the message from the
DHCPv6 client fails authentication check.
o ReplayDetected (TBD10): indicates the message from DHCPv6 client
fails the increasing number check.
o SignatureFail (TBD11): indicates the message from DHCPv6 client
fails the signature check.
11. Security Considerations
This document provides the authentication and encryption mechanisms
for DHCPv6.
There are some mandatory algorithm for encryption algorithm in this
document. It may be at some point that the mandatory algorithm is no
longer safe to use.
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A server or a client, whose local policy accepts messages without a
Increasing-number option, may have to face the risk of replay
attacks.
Since the algorithm option isn't protected by a signature, the list
can be forged without detection, which can lead to a downgrade
attack.
Likewise, since the Encryption-Key-Tag Option isn't protected, an
attacker that can intercept the message can forge the value without
detection.
If the client tries more than one cert for client authentication, the
server can easily get a client that implements this to enumerate its
entire cert list and probably learn a lot about a client that way.
For this security item, It is RECOMMENDED that client certificates
could be tied to specific server certificates by configuration.
12. IANA Considerations
This document defines six new DHCPv6 [RFC3315] options. The IANA is
requested to assign values for these six options from the DHCPv6
Option Codes table of the DHCPv6 Parameters registry maintained in
http://www.iana.org/assignments/dhcpv6-parameters. The six options
are:
The Algorithm Option (TBA1), described in Section 10.1.2.
The Certificate Option (TBA2), described in Section 10.1.2.
The Signature Option (TBA3), described in Section 10.1.3.
The Increasing-number Option (TBA4),described in Section 10.1.4.
The Encryption-Key-Tag Option (TBA5),described in Section 10.1.5.
The Encrypted-message Option (TBA6), described in Section 10.1.6.
The IANA is also requested to assign value for these two messages
from the DHCPv6 Message Types table of the DHCPv6 Parameters registry
maintained in http://www.iana.org/assignments/dhcpv6-parameters. The
two messages are:
The Encrypted-Query Message (TBA7), described in Section 10.2.
The Encrypted-Response Message (TBA8), described in Section 10.2.
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The IANA is also requested to add three new registry tables to the
DHCPv6 Parameters registry maintained in
http://www.iana.org/assignments/dhcpv6-parameters. The three tables
are the Hash Algorithm for Secure DHCPv6 table, the Signature
Algorithm for Secure DHCPv6 table and the Encryption Algorithm for
Secure DHCPv6 table.
Initial values for these registries are given below. Future
assignments are to be made through Standards Action [RFC5226].
Assignments for each registry consist of a name, a value and a RFC
number where the registry is defined.
Hash Algorithm for Secure DHCPv6. The values in this table are
16-bit unsigned integers. The following initial values are assigned
for Hash Algorithm for Secure DHCPv6 in this document:
Name | Value | RFCs
-------------------+---------+--------------
SHA-256 | 0x01 | this document
SHA-512 | 0x02 | this document
Signature Algorithm for Secure DHCPv6. The values in this table are
16-bit unsigned integers. The following initial values are assigned
for Signature Algorithm for Secure DHCPv6 in this document:
Name | Value | RFCs
-------------------+---------+--------------
Non-SigAlg | 0x00 | this document
RSASSA-PKCS1-v1_5 | 0x01 | this document
Encryption algorithm for Secure DHCPv6. The values in this table are
16-bit unsigned integers. The following initial values are assigned
for encryption algorithm for Secure DHCPv6 in this document:
Name | Value | RFCs
-------------------+---------+--------------
Non-EncryAlg | 0x00 | this document
RSA | 0x01 | this document
IANA is requested to assign the following new DHCPv6 Status Codes,
defined in Section 10.3, in the DHCPv6 Parameters registry maintained
in http://www.iana.org/assignments/dhcpv6-parameters:
Code | Name | Reference
---------+-----------------------+--------------
TBD9 | AuthenticationFail | this document
TBD10 | ReplayDetected | this document
TBD11 | SignatureFail | this document
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13. Acknowledgements
The authors would like to thank Tomek Mrugalski, Bernie Volz,
Jianping Wu, Randy Bush, Yiu Lee, Sean Shen, Ralph Droms, Jari Arkko,
Sean Turner, Stephen Farrell, Christian Huitema, Stephen Kent, Thomas
Huth, David Schumacher, Francis Dupont, Gang Chen, Suresh Krishnan,
Fred Templin, Robert Elz, Nico Williams, Erik Kline, Alan DeKok,
Bernard Aboba, Sam Hartman, Zilong Liu and other members of the IETF
DHC working group for their valuable comments.
This document was produced using the xml2rfc tool [RFC2629].
14. Change log [RFC Editor: Please remove]
draft-ietf-dhc-sedhcpv6-21: Add the reference of draft-ietf-dhc-relay
-server-security. Change the SA-ID List as SHA-ID List and delete
the HA-id List. The SHA-id List contains the SA-id and HA-id pairs.
Add some statements about the Reconfigure message process. Add some
specific text on the encryption key tag calculation method; Add more
text on security consideration; Changes some mistakes and grammar
mistakes
draft-ietf-dhc-sedhcpv6-20: Correct a few grammar mistakes.
draft-ietf-dhc-sedhcpv6-19: In client behavior part, we adds some
description about opportunistic security. In this way, in some
scenario, authentication is optional. Add the reference of RFC 4034
for the encryption key tag calculation. Delete the part that the
relay agent cache server announcements part. Add the assumption that
the client's initial stored increasing number is set to zero. In
this way, for the first time increasing number check in the Reply
message, the check will always succeed, and then the locally stored
number is changed into the contained number in the Reply message.
Correct many grammar mistakes.
draft-ietf-dhc-sedhcpv6-18: Add the Algorithm option. The algorithm
option contains the EA-id List, SA-id List, HA-id List, and then the
certificate and signature options do not contain the algorithm list;
Add the Encryption Key Tag option to identify the used public/private
key pair; Delete the AlgorithmNotSupported error status code; Delete
some description on that secure DHCPv6 exchanges the server selection
method; Delete the DecryptionFail error status code; For the case
where the client's certificate is missed, then the server discards
the received message. Add the assumption that: For DHCPv6 client,
just one certificate is used for the DHCPv6 configuration. Add the
statement that: For the first Encrypted-Query message, the server
needs to try all the possible private keys and then records the
relationship between the public key and the encryption key tag.
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draft-ietf-dhc-sedhcpv6-17: Change the format of the certificate
option according to the comments from Bernie.
draft-ietf-dhc-sedhcpv6-16: For the algorithm agility part, the
provider can offer multiple EA-id, SA-id, HA-id and then receiver
choose one from the algorithm set.
draft-ietf-dhc-sedhcpv6-15: Increasing number option only contains
the strictly increasing number; Add some description about why
encryption is needed in Security Issues of DHCPv6 part;
draft-ietf-dhc-sedhcpv6-14: For the deployment part, Tofu is out of
scope and take Opportunistic security into consideration; Increasing
number option is changed into 64 bits; Increasing number check is a
separate section; IncreasingnumFail error status code is changed into
ReplayDetected error status code; Add the section of "caused change
to RFC3315";
draft-ietf-dhc-sedhcpv6-13: Change the Timestamp option into
Increasing-number option and the corresponding check method; Delete
the OCSP stampling part for the certificate check; Add the scenario
where the hash and signature algorithms cannot be separated; Add the
comparison with RFC7824 and RFC7844; Add the encryption text format
and reference of RFC5652. Add the consideration of scenario where
multiple DHCPv6 servers share one common DHCPv6 server. Add the
statement that Encrypted-Query and Encrypted-Response messages can
only contain certain options: Server Identifier option and Encrypted-
message option. Add opportunistic security for deployment
consideration. Besides authentication+encyrption mode, encryption-
only mode is added.
draft-ietf-dhc-sedhcpv6-12: Add the Signature option and timestamp
option during server/client authentication process. Add the hash
function and signature algorithm. Add the requirement: The
Information-request message cannot contain any other options except
ORO option. Modify the use of "SHOULD"; Delete the reference of
RFC5280 and modify the method of client/server cert verification; Add
the relay agent cache function for the quick response when there is
no authenticated server. 2016-4-24.
draft-ietf-dhc-sedhcpv6-11: Delete the Signature option, because the
encrypted DHCPv6 message and the Information-request message (only
contain the Certificate option) don't need the Signature option for
message integrity check; Rewrite the "Applicability" section; Add the
encryption algorithm negotiation process; To support the encryption
algorithm negotiation, the Certificate option contains the EA-
id(encryption algorithm identifier) field; Reserve the Timestamp
option to defend against the replay attacks for encrypted DHCPv6
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configuration process; Modify the client behavior when there is no
authenticated DHCPv6 server; Add the DecryptionFail error code.
2016-3-9.
draft-ietf-dhc-sedhcpv6-10: merge DHCPv6 authentication and DHCPv6
encryption. The public key option is removed, because the device can
generate the self-signed certificate if it is pre-configured the
public key not the certificate. 2015-12-10.
draft-ietf-dhc-sedhcpv6-09: change some texts about the deployment
part.2015-12-10.
draft-ietf-dhc-sedhcpv6-08: clarified what the client and the server
should do if it receives a message using unsupported algorithm;
refined the error code treatment regarding to AuthenticationFail and
TimestampFail; added consideration on how to reduce the DoS attack
when using TOFU; other general editorial cleanups. 2015-06-10.
draft-ietf-dhc-sedhcpv6-07: removed the deployment consideration
section; instead, described more straightforward use cases with TOFU
in the overview section, and clarified how the public keys would be
stored at the recipient when TOFU is used. The overview section also
clarified the integration of PKI or other similar infrastructure is
an open issue. 2015-03-23.
draft-ietf-dhc-sedhcpv6-06: remove the limitation that only clients
use PKI- certificates and only servers use public keys. The new text
would allow clients use public keys and servers use PKI-certificates.
2015-02-18.
draft-ietf-dhc-sedhcpv6-05: addressed comments from mail list that
responsed to the second WGLC. 2014-12-08.
draft-ietf-dhc-sedhcpv6-04: addressed comments from mail list.
Making timestamp an independent and optional option. Reduce the
serverside authentication to base on only client's certificate.
Reduce the clientside authentication to only Leaf of Faith base on
server's public key. 2014-09-26.
draft-ietf-dhc-sedhcpv6-03: addressed comments from WGLC. Added a
new section "Deployment Consideration". Corrected the Public Key
Field in the Public Key Option. Added consideration for large DHCPv6
message transmission. Added TimestampFail error code. Refined the
retransmission rules on clients. 2014-06-18.
draft-ietf-dhc-sedhcpv6-02: addressed comments (applicability
statement, redesign the error codes and their logic) from IETF89 DHC
WG meeting and volunteer reviewers. 2014-04-14.
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draft-ietf-dhc-sedhcpv6-01: addressed comments from IETF88 DHC WG
meeting. Moved Dacheng Zhang from acknowledgement to be co-author.
2014-02-14.
draft-ietf-dhc-sedhcpv6-00: adopted by DHC WG. 2013-11-19.
draft-jiang-dhc-sedhcpv6-02: removed protection between relay agent
and server due to complexity, following the comments from Ted Lemon,
Bernie Volz. 2013-10-16.
draft-jiang-dhc-sedhcpv6-01: update according to review comments from
Ted Lemon, Bernie Volz, Ralph Droms. Separated Public Key/
Certificate option into two options. Refined many detailed
processes. 2013-10-08.
draft-jiang-dhc-sedhcpv6-00: original version, this draft is a
replacement of draft-ietf-dhc-secure-dhcpv6, which reached IESG and
dead because of consideration regarding to CGA. The authors followed
the suggestion from IESG making a general public key based mechanism.
2013-06-29.
15. References
15.1. Normative References
[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>.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
December 1998, <http://www.rfc-editor.org/info/rfc2460>.
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins,
C., and M. Carney, "Dynamic Host Configuration Protocol
for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July
2003, <http://www.rfc-editor.org/info/rfc3315>.
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
"SEcure Neighbor Discovery (SEND)", RFC 3971,
DOI 10.17487/RFC3971, March 2005,
<http://www.rfc-editor.org/info/rfc3971>.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, DOI 10.17487/RFC4034, March 2005,
<http://www.rfc-editor.org/info/rfc4034>.
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[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet
Control Message Protocol (ICMPv6) for the Internet
Protocol Version 6 (IPv6) Specification", RFC 4443,
DOI 10.17487/RFC4443, March 2006,
<http://www.rfc-editor.org/info/rfc4443>.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, DOI 10.17487/RFC5652, September 2009,
<http://www.rfc-editor.org/info/rfc5652>.
[RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
"Network Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
<http://www.rfc-editor.org/info/rfc5905>.
[RFC6840] Weiler, S., Ed. and D. Blacka, Ed., "Clarifications and
Implementation Notes for DNS Security (DNSSEC)", RFC 6840,
DOI 10.17487/RFC6840, February 2013,
<http://www.rfc-editor.org/info/rfc6840>.
[RFC7283] Cui, Y., Sun, Q., and T. Lemon, "Handling Unknown DHCPv6
Messages", RFC 7283, DOI 10.17487/RFC7283, July 2014,
<http://www.rfc-editor.org/info/rfc7283>.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
Kivinen, "Internet Key Exchange Protocol Version 2
(IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
2014, <http://www.rfc-editor.org/info/rfc7296>.
[RFC7435] Dukhovni, V., "Opportunistic Security: Some Protection
Most of the Time", RFC 7435, DOI 10.17487/RFC7435,
December 2014, <http://www.rfc-editor.org/info/rfc7435>.
[RFC7824] Krishnan, S., Mrugalski, T., and S. Jiang, "Privacy
Considerations for DHCPv6", RFC 7824,
DOI 10.17487/RFC7824, May 2016,
<http://www.rfc-editor.org/info/rfc7824>.
[RFC7844] Huitema, C., Mrugalski, T., and S. Krishnan, "Anonymity
Profiles for DHCP Clients", RFC 7844,
DOI 10.17487/RFC7844, May 2016,
<http://www.rfc-editor.org/info/rfc7844>.
15.2. Informative References
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Internet-Draft SeDHCPv6 February 2017
[I-D.ietf-dhc-relay-server-security]
Volz, B. and Y. Pal, "Security of Messages Exchanged
Between Servers and Relay Agents", draft-ietf-dhc-relay-
server-security-03 (work in progress), February 2017.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
DOI 10.17487/RFC2629, June 1999,
<http://www.rfc-editor.org/info/rfc2629>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
[RFC6273] Kukec, A., Krishnan, S., and S. Jiang, "The Secure
Neighbor Discovery (SEND) Hash Threat Analysis", RFC 6273,
DOI 10.17487/RFC6273, June 2011,
<http://www.rfc-editor.org/info/rfc6273>.
[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
2014, <http://www.rfc-editor.org/info/rfc7258>.
[RSA] RSA Laboratories, "RSA Encryption Standard, Version 2.1,
PKCS 1", November 2002.
Authors' Addresses
Lishan Li
Tsinghua University
Beijing 100084
P.R.China
Phone: +86-15201441862
Email: lilishan48@gmail.com
Sheng Jiang
Huawei Technologies Co., Ltd
Q14, Huawei Campus, No.156 Beiqing Road
Hai-Dian District, Beijing, 100095
CN
Email: jiangsheng@huawei.com
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Yong Cui
Tsinghua University
Beijing 100084
P.R.China
Phone: +86-10-6260-3059
Email: yong@csnet1.cs.tsinghua.edu.cn
Tatuya Jinmei
Infoblox Inc.
3111 Coronado Drive
Santa Clara, CA
US
Email: jinmei@wide.ad.jp
Ted Lemon
Nominum, Inc.
2000 Seaport Blvd
Redwood City, CA 94063
USA
Phone: +1-650-381-6000
Email: Ted.Lemon@nominum.com
Dacheng Zhang
Beijing
CN
Email: dacheng.zhang@gmail.com
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