Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-18.txt
"Bernie Volz (volz)" <volz@cisco.com> Sun, 18 December 2016 21:57 UTC
Return-Path: <volz@cisco.com>
X-Original-To: dhcwg@ietfa.amsl.com
Delivered-To: dhcwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id DC144129450 for <dhcwg@ietfa.amsl.com>; Sun, 18 Dec 2016 13:57:28 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -17.621
X-Spam-Level:
X-Spam-Status: No, score=-17.621 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RP_MATCHES_RCVD=-3.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LbKYp_uGALyj for <dhcwg@ietfa.amsl.com>; Sun, 18 Dec 2016 13:57:22 -0800 (PST)
Received: from alln-iport-2.cisco.com (alln-iport-2.cisco.com [173.37.142.89]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 57ED112944C for <dhcwg@ietf.org>; Sun, 18 Dec 2016 13:57:22 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=405914; q=dns/txt; s=iport; t=1482098242; x=1483307842; h=from:to:subject:date:message-id:references:in-reply-to: mime-version; bh=SinsJFdFmcFfDy83kzA/rx/pif+3oEpoLCaRNLxIhCM=; b=NGY52AZQEJ8GmrFU8yGBObeUkSAvnHQYdgjj2Ywq9GAOH8i4Q0B538G1 pPadeUfdQeheGowIiVshH9f5TS4g6DC98/smfzlEAc5+/kLATmp+fxSXm jA+OOjt4j2KJ16H6PKkRj9kyYb8iuXbWWrRJHlIua/IEqLyP/BsyspDHb k=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0CmBACNBVdY/4MNJK2ERAEBAQEBxkwEAgECAYEK
X-IronPort-AV: E=Sophos;i="5.33,371,1477958400"; d="scan'208,217";a="361133971"
Received: from alln-core-1.cisco.com ([173.36.13.131]) by alln-iport-2.cisco.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 18 Dec 2016 21:57:21 +0000
Received: from XCH-RCD-001.cisco.com (xch-rcd-001.cisco.com [173.37.102.11]) by alln-core-1.cisco.com (8.14.5/8.14.5) with ESMTP id uBILvLC6010318 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Sun, 18 Dec 2016 21:57:21 GMT
Received: from xch-aln-003.cisco.com (173.36.7.13) by XCH-RCD-001.cisco.com (173.37.102.11) with Microsoft SMTP Server (TLS) id 15.0.1210.3; Sun, 18 Dec 2016 15:57:20 -0600
Received: from xch-aln-003.cisco.com ([173.36.7.13]) by XCH-ALN-003.cisco.com ([173.36.7.13]) with mapi id 15.00.1210.000; Sun, 18 Dec 2016 15:57:20 -0600
From: "Bernie Volz (volz)" <volz@cisco.com>
To: Lishan Li <lilishan48@gmail.com>, dhcwg <dhcwg@ietf.org>
Thread-Topic: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-18.txt
Thread-Index: AQHSTs4GXMOx5uePjkC6PykSIXEqwqD56A0AgBRbwzA=
Date: Sun, 18 Dec 2016 21:57:19 +0000
Message-ID: <352fe8719ab34fd3ad7b0af2e7127bb8@XCH-ALN-003.cisco.com>
References: <148092498114.3294.14134801279747342720.idtracker@ietfa.amsl.com> <CAJ3w4NfufMn9yzACowX728Cxxn4Rdci5pXAwVYB3d2fKDtNF2Q@mail.gmail.com>
In-Reply-To: <CAJ3w4NfufMn9yzACowX728Cxxn4Rdci5pXAwVYB3d2fKDtNF2Q@mail.gmail.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [10.98.1.196]
Content-Type: multipart/alternative; boundary="_000_352fe8719ab34fd3ad7b0af2e7127bb8XCHALN003ciscocom_"
MIME-Version: 1.0
Archived-At: <https://mailarchive.ietf.org/arch/msg/dhcwg/Kb8yi-jPKRrHZZV0kIojm2wAYNs>
X-Mailman-Approved-At: Sun, 18 Dec 2016 13:58:18 -0800
Subject: Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-18.txt
X-BeenThere: dhcwg@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: <dhcwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dhcwg/>
List-Post: <mailto:dhcwg@ietf.org>
List-Help: <mailto:dhcwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 18 Dec 2016 21:57:29 -0000
Hi:
I read through this draft and do have extensive comments. While there are a lot of improvements, I think some work is needed on the document. Please note that I still have to re-review some of section 6 and 7, but as there were plenty of comments already, I figured it best to provide you these earlier than waiting to finish (as it may also be a bit difficult to finish that review over the next several weeks because of the holidays).
I’ve included much of the draft below as that makes it easier to comment on the issues. My comments should start with BV>.
Let me first raise a few points to consider:
- A server could have multiple algorithms and (possibly multiple certificates) and so when a server receives a client’s Encrypted-Query message how does it decrypt it (choose from its algorithms or certificates)? If it tries several, how can it tell when it is successful? I guess by verifying the signature? But this also requires the server to decrypt the packet and look for this option – and the decrypted packet could be complete junk (which the server obviously should deal with but there is a risk that this junk could cause the server to crash)? I’m not sure if the Encryption Key Tag was supposed to provide for this as (commented below) there are no details on how this is generated (section 10.1.5 does not indicate anything useful). Also, having the server have to try to decrypt several times seems a bit costly to me. (Again, the server cannot even tell who the client is so there’s no easy way for the server even to remember this and associate it with something in the received packet.) I wonder whether there should be some mechanism for the server to provide some “encryption-id” to the client (in the Encrypted-Response) which the client then sends in an option in the Encrypted-Query so the server knows how to decrypt the message?
- Is Trust on First Use (TOFU) supported? It didn’t seem so? (Section 6 says to “or decide[d] to drop the message”). That may be fine and perhaps it was dropped in recent discussions (I had not followed all of them carefully). Or perhaps that will be for some follow on work.
Secure DHCPv6
draft-ietf-dhc-sedhcpv6-18
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.
Jiang, et al. Expires June 7, 2017 [Page 2]
Internet-Draft SeDHCPv6 December 2016
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 section 21.1 in [RFC3315].
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. The
Algorithm, Certificate, Signature, and Increasing-number options are
used for authentication. The Encryption-Query message, Encryption-
Response message, Encrypted-message option and Encryption Key Tag
option are used for encryption.
BV> To be consistent, should “Encryption Key Tag” be changed to “Encryption-Key-Tag” throughout?
2. Requirements Language and Terminology
BV> Shouldn’t this just be Requirements Language as section 3 is Terminology? Or, perhaps combine these sections into one?
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.
Jiang, et al. Expires June 7, 2017 [Page 3]
Internet-Draft SeDHCPv6 December 2016
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
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.
BV> There are some other abbreviations used in this document that are not “defined” on first use and perhaps best added here? For example, PKI and CA (there may be others). Or, do you want to pull in terminology from a security document (RFC)?
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.
BV> Not sure if it matters, but this was deprecated in 3315bis?
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 is defined. In addition, the anonymity
BV> Drop “is defined”?
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.
Jiang, et al. Expires June 7, 2017 [Page 4]
Internet-Draft SeDHCPv6 December 2016
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]
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 secure DHCPv6 procedure. Briefly,
BV> add the (illustrates the secure)
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
BV> Then should be the?
client and server. The Increasing number option is defined to detect
replay attack.
BV> a replay attack (or replay attacks)?
Jiang, et al. Expires June 7, 2017 [Page 5]
Internet-Draft SeDHCPv6 December 2016
+-------------+ +-------------+
|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
Timestamp is one of the possible implementation choices. The
BV> What is “The Timestamp”? Drop this sentence or perhaps provide more on what that is?
Jiang, et al. Expires June 7, 2017 [Page 6]
Internet-Draft SeDHCPv6 December 2016
Increasing-number option is defined to carry a strictly-increasing
serial number.
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. In addition, the Server
Identifier option MUST be contained if it is contained in the
BV> chain be contained to be included? Kind of odd to so contained twice?
original DHCPv6 message. The Encrypted-Query message MUST NOT
contain other options except the above options.
BV> Later on page 10 it is stated that the Encrypted-Query can also contain the Encryption-Key-Tag option?
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 except it.
BV> Drop “except it”? Other already makes that clear?
BV> So with respect to the Encrypted-Query and the Server Identifier option. When the client sends a Solicit (Confirm or Rebind) and there is no Server-Identifier, this will go to all servers but they probably won’t be able to decrypt? Does that make sense? Should the Server Identifier ALSO be in the Encrypted-Query (I’m NOT suggesting to allow it in the Client’s Solicit, Confirm, Rebind!)
BV> Also, given that the WG is working on Failover Protocol in parallel, how would seDHCPv6 work with Failover? And should we consider anything related to this. One possibility is that the failover partners could exchange some information (so we might have to define a new failover option eventually). But then my comment above about the Server Identifier may cause other issues? It may just be that once a client picks one of the failover partners, it will have to stick with that partner or return to the server discovery phase? But that would be too bad. (I had thought about whether the failover partners should share a Server Identifier, but that likely complicates other cases so not sure it is best.) Perhaps when the failover partners exchange the above mentioned information, that could include the Server Identifier which would allow them to be used.
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 SHOULD use the
same algorithm in a single communication session. The sender can
offer a set of algorithms, and then the receiver selects one
algorithm for the future communication.
5.4. Caused change to RFC3315
BV> Odd title. Perhaps “Impact on RFC3315” or something similar?
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.
Jiang, et al. Expires June 7, 2017 [Page 7]
Internet-Draft SeDHCPv6 December 2016
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 more wide use of secure DHCPv6, opportunistic security
BV> replace more wide with wider?
[RFC7435] can be applied to secure DHCPv6 deployment, which allows
DHCPv6 encryption in environments where support for authentication is
not available.
BV> perhaps “for authentication or a key distribution mechanism”?
Secure DHCPv6 can achieve authentication and encryption based on pre-
sharing of authorized certificates. The 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 is also manually pre-
configured with the trusted clients' public keys. In some scenario,
such as coffee shop where the certificate cannot be validated and
don't want to be blocked from the Internet, then the DHCPv6
BV> replace don’t want… with “one wants access to the Internet”?
configuration process can be encrypted without authentication.
Note that this deployment scenario based on manual operation is not
different very much from the existing, shared-secret based
BV> replace different very much with “much different”?
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 PKI is used with Secure
BV> See earlier, but PKI not defined.
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 CA, it can generate the self-
BV> See earlier, CA not defined?
signed certificate.
The secure DHCPv6 client sends Information-request message as per
BV> sends an Information-request message (or sends Information-request messages)?
[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-
Jiang, et al. Expires June 7, 2017 [Page 8]
Internet-Draft SeDHCPv6 December 2016
request message MUST NOT include any other DHCPv6 options except the
above options to minimize client's privacy information leakage.
BV> add the (the client’s)
When receiving the Reply messages from DHCPv6 servers, a secure
BV> add the (the DHCPv6 servers)
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. If the hash
algorithm field is zero, then it indicates that the hash algorithm is
fixed according to the corresponding signature algorithm. The client
also uses the acknowledged algorithms in the return messages.
Then the client checks the authority of the server. 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. At this
point, the client has either recognized the certificate of the
server, or decided to drop the message.
BV> decided -> decide?
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
BV> If this is the first message, what can client validate the Increasing Number against? From the flow, we are just in processing the Reply from the Information-Request so there is unlikely to be any information? Or is client expected to remember past values from a specific Server-ID?
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 if it is
contained. 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
BV> How are these multiple DHCPv6 certs received? I think you mean if multiple servers responded (hence multiple certs), the client has to pick one? I think stating this more clearly would be good?
one DHCPv6 cert for the following communication. The selected
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
Jiang, et al. Expires June 7, 2017 [Page 9]
Internet-Draft SeDHCPv6 December 2016
[RFC3315] to avoid the packet storm. In this way, it is difficult
BV> avoid a packet storm?
for the rogue server to beat out a busy "real" server. And then the
BV> change the rogue to a rogue?
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
BV> I don’t see that section 10.1.5 provides really any useful explanation as to how this data is constructed? Also, as I believe the server is supposed to use this information, how does it make sense for the client to generate it? If there is a clear algorithm that both the client and server can use to generate this (and the server has what it needs), OK. But more details are needed!!
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 Certificate option, Signature
option and Increasing-number option 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 can also contain
the Increasing-number option to defend against replay attack.
BV> Might help to clarify where this Increasing-Number option goes (in the client’s message).
For the received Encrypted-Response message, the client MUST drop the
Encrypted-Response message if other DHCPv6 option except Encrypted-
message option is contained. 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 uses only one certificate for the encrypted DHCPv6
configuration. So, the corresponding private key is used for
decryption. 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.
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
Jiang, et al. Expires June 7, 2017 [Page 10]
Internet-Draft SeDHCPv6 December 2016
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 DecryptionFail error status code, the client MAY
resend the message following 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].
BV> I’m really not sure whether these errors are helpful. Since how can the server even construct these in many cases and how can the client trust these if they aren’t authenticated?
(BV> I am still working through section 7 so may have more comments later). But, I did look at later sections so …
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
those present in the innermost encapsulated messages from the client
or server.
Relay agent is RECOMMENDED to cache server announcements to form the
list of the available DHCPv6 server certs. If the relay agent
BV> NO! I do not think this is a wise idea at all. Please remove this! Relays should not do this!
Jiang, et al. Expires June 7, 2017 [Page 13]
Internet-Draft SeDHCPv6 December 2016
receives the Information-request message, then it replies with a list
of server certs available locally. In this way, the client can be
confident of a quick response, and therefore treat the lack of a
quick response as an indication that no authenticated DHCP servers
exist.
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.
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
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
Jiang, et al. Expires June 7, 2017 [Page 14]
Internet-Draft SeDHCPv6 December 2016
10.1.1. Algorithm Option
The Algorithm option carries the algorithms sets for algorithm
agility, which is sent from the client to server.
BV> Might help if you indicated exactly where (in which message(s)) this option is in. Same goes for the other options defined later. In this case also, I think this is ONLY sent 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_SIGNATURE | option-len |
BV> Isn’t this OPTION_ALGORITHM
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. EA-id List .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. SA-id List .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. HA-id List .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Algorithm Option
o option-code: OPTION_SIGNATURE (TBA1).
o option-len: length of EA-id List + length of SA-id List + length
of HA-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-num | EA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| EA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
EA-num The number of the following EA-ids.
BV> Sadly RFC 7227 never defined a case like this and I think the WG should consider whether this should be LENGTH or a number of items. Personally, I prefer this to be a length (so EA-len which is 2 * number of EA-ids). Same goes for SA and HA. BUT I think this is something that the working group needs to consider. I was going to try to review other options to see if we had any that might resolve this but haven’t do that review (though nothing obvious comes to mind).
EA-id Encryption Algorithm id. 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 mandatory encryption
algorithms MUST be included.
BV> This never says that this is a 2-octet value? Please be clear about that. Same goes for SA and HA below.
BV> I think also saying something like “The client enumerates the list of Encryption algorithms it supports to the server” would be extremely useful for the EA-List (with similar text for the SA and HA lists)?
Figure 3: EA-id List Field
Jiang, et al. Expires June 7, 2017 [Page 15]
Internet-Draft SeDHCPv6 December 2016
o SA-id List: The format of the SA-id List field is shown in
Figure 4.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SA-num | SA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
SA-num The number of the following SA-ids.
SA-id Signature Algorithm id. 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.
Figure 4: SA-id List Field
o HA-id List: The format of the HA-id List field is shown in
Figure 5.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HA-num | HA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. ... .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HA-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
HA-num The number of the following HA-ids.
HA-id Hash Algorithm id. 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 5: HA-id List Field
Jiang, et al. Expires June 7, 2017 [Page 16]
Internet-Draft SeDHCPv6 December 2016
10.1.2. Certificate Option
The Certificate option carries the certificate of the client/server.
The format of the Certificate option is described as follows:
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 6: Certificate Option
o option-code: OPTION_CERTIFICATE (TBA2).
o option-len: 4 + length of Certificate in octets.
o EA-id: Encryption Algorithm id. 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. If the value of EA-id is 0, then the certificate is
not used for encryption.
BV> This seems a bit odd … shouldn’t this just say the Encryption Algorithm ID used for this certificate?
o SA-id: Signature Algorithm id. The signature algorithm is used
for computing the signature result. The value is from the
Signature Algorithm for Secure DHCPv6 registry in IANA. A
registry of the initial assigned values is defined in Section 12.
If the value of SA-id is 0, then the certificate is not used for
signature check.
BV> Same – see above for EA-id?
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 all 0, it makes no sense and MUST NOT be used.
BV> Perhaps say “… are both 0 makes no sense and the client MUST discard a message with such values”?
Jiang, et al. Expires June 7, 2017 [Page 17]
Internet-Draft SeDHCPv6 December 2016
10.1.3. Signature option
The Signature option allows a signature that is signed by the private
key to be attached to a DHCPv6 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:
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 7: 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. If the hash algorithm is fixed
according to the corresponding signature algorithm, the HA-id
field is set to zero.
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
Jiang, et al. Expires June 7, 2017 [Page 18]
Internet-Draft SeDHCPv6 December 2016
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.
10.1.4. Increasing-number Option
The Increasing-number option carries the strictly increasing number
for anti-replay protection. 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| InreasingNum (64-bit) |
BV> Increasing-Num? (also use – below?)
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code OPTION_INCREASING_NUM (TBA4).
option-len 8, in octets.
IncreasingNum A strictly increasing number for the replay attack detection
which is more than the local stored number.
Figure 8: 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.
Jiang, et al. Expires June 7, 2017 [Page 19]
Internet-Draft SeDHCPv6 December 2016
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 |
BV> Earlier you placed option name – OPTION_ENCRYPTION_KEY_TAG
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. encryption key tag .
. (variable) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: Encryption Key Tag Option
option-code OPTION_ENCRY_KT (TBA5).
BV> I’d recommend OPTION_ENCRYPTION_KEY_TAG as it isn’t that long and more clear?
option-len Length of the encryption key tag.
encryption key tag A variable length 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 key data, like fingerprint of a specific public
key.
BV> This is really unclear to me? How is this calculated? I think more details are needed as client generates this from server’s data so server must know how client generated it?
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 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 10: Encrypted-message Option
option-code OPTION_ENCRYPTED_MSG (TBA6).
option-len Length of the encrypted DHCPv6 message.
Jiang, et al. Expires June 7, 2017 [Page 20]
Internet-Draft SeDHCPv6 December 2016
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:
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 11: 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.
Jiang, et al. Expires June 7, 2017 [Page 21]
Internet-Draft SeDHCPv6 December 2016
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.
[RFC6273] has analyzed possible threats to the hash algorithms used
in SEND. Since Secure DHCPv6 defined in this document uses the same
hash algorithms in similar way to SEND, analysis results could be
applied as well: current attacks on hash functions do not constitute
any practical threat to the digital signatures used in the signature
algorithm in Secure DHCPv6.
A server, whose local policy accepts messages without a Increasing-
number option, may have to face the risk of replay attacks.
BV> Isn’t this also an issue for the client?
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.
BV> Isn’t this related to the 2nd paragraph in this section? Perhaps move this as third paragraph?
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.
BV> Are there any recommendations we could make about this? Perhaps this is more related to client configuration but perhaps in some cases client certificates could be tied to specific server certificates by configuration?
- Bernie
From: dhcwg [mailto:dhcwg-bounces@ietf.org] On Behalf Of Lishan Li
Sent: Monday, December 05, 2016 10:59 AM
To: dhcwg <dhcwg@ietf.org>
Subject: Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-18.txt
Dear All,
We have submitted the new version of secure DHCPv6.
In the new version, we made the following updates:
1. Add the Algorithm option, Encryption Key Tag option;
2. Delete the AlgorithmNotSupported error status code;
3. Delete some description on that secure DHCPv6
exchanges the server selection method;
4. Add the assumption that: For DHCPv6 client, just one
certificate is used for the DHCPv6 configuration;
5. 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;
5. For the case where the client's certificate is missed
and decryption fails, the server discards the received
message.
Could you please review the current version? Looking
forward to your guidance.
Best Regards,
Lishan
2016-12-05 16:03 GMT+08:00 <internet-drafts@ietf.org<mailto:internet-drafts@ietf.org>>:
A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Dynamic Host Configuration of the IETF.
Title : Secure DHCPv6
Authors : Sheng Jiang
Lishan Li
Yong Cui
Tatuya Jinmei
Ted Lemon
Dacheng Zhang
Filename : draft-ietf-dhc-sedhcpv6-18.txt
Pages : 30
Date : 2016-12-05
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.
The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-dhc-sedhcpv6/
There's also a htmlized version available at:
https://tools.ietf.org/html/draft-ietf-dhc-sedhcpv6-18
A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-dhc-sedhcpv6-18
Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org<http://tools.ietf.org>.
Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
_______________________________________________
dhcwg mailing list
dhcwg@ietf.org<mailto:dhcwg@ietf.org>
https://www.ietf.org/mailman/listinfo/dhcwg
- [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-18.txt internet-drafts
- Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-1… Lishan Li
- Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-1… Bernie Volz (volz)
- Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-1… Lishan Li
- Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-1… Bernie Volz (volz)
- Re: [dhcwg] I-D Action: draft-ietf-dhc-sedhcpv6-1… Lishan Li