draft-ietf-dhc-sedhcpv6-04.txt   draft-ietf-dhc-sedhcpv6-05.txt 
DHC Working Group S. Jiang, Ed. DHC Working Group S. Jiang, Ed.
Internet-Draft Huawei Technologies Co., Ltd Internet-Draft Huawei Technologies Co., Ltd
Intended status: Standards Track S. Shen Intended status: Standards Track S. Shen
Expires: April 2, 2015 CNNIC Expires: June 11, 2015 CNNIC
D. Zhang D. Zhang
Huawei Technologies Co., Ltd Huawei Technologies Co., Ltd
T. Jinmei T. Jinmei
Infoblox Inc. Infoblox Inc.
September 29, 2014 December 8, 2014
Secure DHCPv6 Secure DHCPv6
draft-ietf-dhc-sedhcpv6-04 draft-ietf-dhc-sedhcpv6-05
Abstract Abstract
The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) enables The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) enables
DHCPv6 servers to pass configuration parameters. It offers DHCPv6 servers to pass configuration parameters. It offers
configuration flexibility. If not being secured, DHCPv6 is configuration flexibility. If not being secured, DHCPv6 is
vulnerable to various attacks, particularly spoofing attacks. This vulnerable to various attacks, particularly spoofing attacks. This
document analyzes the security issues of DHCPv6 and specifies a document analyzes the security issues of DHCPv6 and specifies a
Secure DHCPv6 mechanism for communications between DHCPv6 clients and Secure DHCPv6 mechanism for communications between DHCPv6 clients and
DHCPv6 servers. This document provides a DHCPv6 client/server DHCPv6 servers. This document provides a DHCPv6 client/server
skipping to change at page 1, line 45 skipping to change at page 1, line 45
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 2, 2015. This Internet-Draft will expire on June 11, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 37 skipping to change at page 2, line 37
4.2. Support for Algorithm Agility . . . . . . . . . . . . . . 6 4.2. Support for Algorithm Agility . . . . . . . . . . . . . . 6
4.3. Applicability . . . . . . . . . . . . . . . . . . . . . . 6 4.3. Applicability . . . . . . . . . . . . . . . . . . . . . . 6
5. Extensions for Secure DHCPv6 . . . . . . . . . . . . . . . . 7 5. Extensions for Secure DHCPv6 . . . . . . . . . . . . . . . . 7
5.1. Public Key Option . . . . . . . . . . . . . . . . . . . . 7 5.1. Public Key Option . . . . . . . . . . . . . . . . . . . . 7
5.2. Certificate Option . . . . . . . . . . . . . . . . . . . 8 5.2. Certificate Option . . . . . . . . . . . . . . . . . . . 8
5.3. Signature Option . . . . . . . . . . . . . . . . . . . . 9 5.3. Signature Option . . . . . . . . . . . . . . . . . . . . 9
5.4. Timestamp Option . . . . . . . . . . . . . . . . . . . . 10 5.4. Timestamp Option . . . . . . . . . . . . . . . . . . . . 10
5.5. Status Codes . . . . . . . . . . . . . . . . . . . . . . 11 5.5. Status Codes . . . . . . . . . . . . . . . . . . . . . . 11
6. Processing Rules and Behaviors . . . . . . . . . . . . . . . 11 6. Processing Rules and Behaviors . . . . . . . . . . . . . . . 11
6.1. Processing Rules of Sender . . . . . . . . . . . . . . . 11 6.1. Processing Rules of Sender . . . . . . . . . . . . . . . 11
6.2. Processing Rules of Recipient . . . . . . . . . . . . . . 12 6.2. Processing Rules of Recipient . . . . . . . . . . . . . . 13
6.3. Processing Rules of Relay Agent . . . . . . . . . . . . . 14 6.3. Processing Rules of Relay Agent . . . . . . . . . . . . . 15
6.4. Timestamp Check . . . . . . . . . . . . . . . . . . . . . 15 6.4. Timestamp Check . . . . . . . . . . . . . . . . . . . . . 15
7. Deployment Consideration . . . . . . . . . . . . . . . . . . 16 7. Deployment Consideration . . . . . . . . . . . . . . . . . . 17
7.1. Authentication on a client . . . . . . . . . . . . . . . 16 7.1. Authentication on a client . . . . . . . . . . . . . . . 17
7.2. Authentication on a server . . . . . . . . . . . . . . . 17 7.2. Authentication on a server . . . . . . . . . . . . . . . 17
8. Security Considerations . . . . . . . . . . . . . . . . . . . 17 8. Security Considerations . . . . . . . . . . . . . . . . . . . 18
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 19 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20
11. Change log [RFC Editor: Please remove] . . . . . . . . . . . 20 11. Change log [RFC Editor: Please remove] . . . . . . . . . . . 21
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
12.1. Normative References . . . . . . . . . . . . . . . . . . 21 12.1. Normative References . . . . . . . . . . . . . . . . . . 22
12.2. Informative References . . . . . . . . . . . . . . . . . 22 12.2. Informative References . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction 1. Introduction
The Dynamic Host Configuration Protocol for IPv6 (DHCPv6, [RFC3315]) The Dynamic Host Configuration Protocol for IPv6 (DHCPv6, [RFC3315])
enables DHCPv6 servers to pass configuration parameters and offers enables DHCPv6 servers to pass configuration parameters and offers
configuration flexibility. If not being secured, DHCPv6 is configuration flexibility. If not being secured, DHCPv6 is
vulnerable to various attacks, particularly spoofing attacks. vulnerable to various attacks, particularly spoofing attacks.
This document analyzes the security issues of DHCPv6 in details. This document analyzes the security issues of DHCPv6 in details.
This document provides mechanisms for improving the security of This document provides mechanisms for improving the security of
skipping to change at page 4, line 22 skipping to change at page 4, line 22
the basic DHCPv6 specification [RFC3315], security of DHCPv6 messages the basic DHCPv6 specification [RFC3315], security of DHCPv6 messages
can be improved. can be improved.
The basic DHCPv6 specifications can optionally authenticate the The basic DHCPv6 specifications can optionally authenticate the
origin of messages and validate the integrity of messages using an origin of messages and validate the integrity of messages using an
authentication option with a symmetric key pair. [RFC3315] relies on authentication option with a symmetric key pair. [RFC3315] relies on
pre-established secret keys. For any kind of meaningful security, pre-established secret keys. For any kind of meaningful security,
each DHCPv6 client would need to be configured with its own secret each DHCPv6 client would need to be configured with its own secret
key; [RFC3315] provides no mechanism for doing this. key; [RFC3315] provides no mechanism for doing this.
For the key of the hash function, there are two key management For the keyed hash function, there are two key management mechanisms.
mechanisms. Firstly, the key management is done out of band, usually The first one is a key management done out of band, usually through
through some manual process. For example, operators can set up a key some manual process. The second approach is use Public Key
database for both servers and clients which the client obtains a key Infrastructure (PKI).
before running DHCPv6.
Manual key distribution runs counter to the goal of minimizing the As an example of the first approach, operators can set up a key
configuration data needed at each host. database for both servers and clients which the client obtains a key
before running DHCPv6. Manual key distribution runs counter to the
goal of minimizing the configuration data needed at each host.
[RFC3315] provides an additional mechanism for preventing off-network [RFC3315] provides an additional mechanism for preventing off-network
timing attacks using the Reconfigure message: the Reconfigure Key timing attacks using the Reconfigure message: the Reconfigure Key
authentication method. However, this method provides no message authentication method. However, this method provides little message
integrity or source integrity check. This key is transmitted in integrity or source integrity check, and it protects only the
plaintext. Reconfigure message. This key is transmitted in plaintext.
In comparison, the security mechanism defined in this document allows In comparison, the security mechanism defined in this document allows
the public key database on the client to be populated the public key database on the client to be populated
opportunistically or manually, depending on the degree of confidence opportunistically or manually, depending on the degree of confidence
desired in a specific application. PKI security mechanism is simpler desired in a specific application. PKI security mechanism is simpler
in the local key management respect. in the local key management respect.
4. Overview of Secure DHCPv6 Mechanism with Public Key 4. Overview of Secure DHCPv6 Mechanism with Public Key
This document introduces a Secure DHCPv6 mechanism that uses This document introduces a Secure DHCPv6 mechanism that uses
signatures to secure the DHCPv6 protocol. In order to enable DHCPv6 signatures to secure the DHCPv6 protocol. In order to enable DHCPv6
clients and DHCPv6 servers to perform mutual authentication without clients and DHCPv6 servers to perform mutual authentication without
previous key deployment, this solution provides a DHCPv6 client/ previous key deployment, this solution provides a DHCPv6 client/
server authentication mechanism based on server's public/private key server authentication mechanism based on server's public/private key
pairs and client's certificates: the server only accept the client pairs and client's certificates: the server only accept the client
messages that are protected by the client certificate that is signed messages that are protected by the client public key certificate that
by a trusted CA; a client can build up trust relationship with a is signed by a trusted CA (Certificate Authority) ; a client can
server for subsequent message exchanges based on leap of faith (LoF) build up trust relationship with a server for subsequent message
mechanism. This purpose of this design is to simplify the exchanges based on leap of faith mechanism. This purpose of this
precondition of deploying DHCPv6 authentication and provides limited design is to simplify the precondition of deploying DHCPv6
protection of DHCPv6 message. authentication and provides limited protection of DHCPv6 message.
In this document, we introduce a public key option (only sent by In this document, we introduce a public key option (only sent by
servers), a certificate option (only sent by clients), a signature servers), a certificate option (only sent by clients), a signature
option and a timestamp with corresponding verification mechanisms. A option and a timestamp with corresponding verification mechanisms. A
DHCPv6 message from a server is attached with a public key option, DHCPv6 message from a server is attached with a public key option,
and carrying a digital signature and a timestamp option. It can be and carrying a digital signature and a timestamp option. It can be
verified by the client. The client processes the payload of the verified by the client. The client processes the payload of the
DHCPv6 message only if the validation is successful. Reversely, a DHCPv6 message only if the validation is successful. Reversely, a
DHCPv6 message from a client is attached with a certificate option, DHCPv6 message from a client is attached with a certificate option,
and also carrying a digital signature and a timestamp option. It can and also carrying a digital signature and a timestamp option. It can
skipping to change at page 5, line 35 skipping to change at page 5, line 36
By recording the public key that was used by the DHCPv6 server, when By recording the public key that was used by the DHCPv6 server, when
the first time it is seen, the DHCPv6 client can make a leap of faith the first time it is seen, the DHCPv6 client can make a leap of faith
that the server is trustworthy. If no evidence to the contrary that the server is trustworthy. If no evidence to the contrary
surfaces, the client can then validate the server as trustworthy when surfaces, the client can then validate the server as trustworthy when
it subsequently sees the same public key used to sign messages from it subsequently sees the same public key used to sign messages from
the same server. In opposite, once the client has determined that it the same server. In opposite, once the client has determined that it
is being attacked, it can either forget that server, or remember that is being attacked, it can either forget that server, or remember that
server in a blacklist and drop further packets associated with that server in a blacklist and drop further packets associated with that
server. server.
On the server DHCPv6 side, upon receiving the client's certificate, On the server DHCPv6 side, upon receiving the client's public key
the server asserts the validity of the certificate, for example certificate, the server asserts the validity of the certificate, for
through PKI. example through PKI.
Secure DHCPv6 messages are commonly large. IPv6 fragments [RFC2460] Secure DHCPv6 messages are commonly large. IPv6 fragments [RFC2460]
are highly possible. Hence, deployment of Secure DHCPv6 should also are highly possible. Hence, deployment of Secure DHCPv6 should also
consider the issues of IP fragment, PMTU, etc. Also, if there are consider the issues of IP fragment, PMTU, etc. Also, if there are
firewalls between secure DHCPv6 clients and secure DHCPv6 servers, it firewalls between secure DHCPv6 clients and secure DHCPv6 servers, it
is RECOMMENDED that the firewalls are configured to pass ICMP Packet is RECOMMENDED that the firewalls are configured to pass ICMP Packet
Too Big messages [RFC4443]. Too Big messages [RFC4443].
4.1. New Components 4.1. New Components
The components of the solution specified in this document are as The components of the solution specified in this document are as
follows: follows:
o The server generates a public/private key pair. A DHCPv6 option o The server generates a public/private key pair. A DHCPv6 option
that carries the public key is defined. that carries the public key is defined.
o The client obtains a certificate from a Certificate Authority that o The client obtains a public key certificate from a Certificate
can be used to establish the trustworthiness with the server. Authority that can be used to establish the trustworthiness with
Another option is defined to carry the certificate. the server. Another option is defined to carry the certificate.
o A signature generated using the private key which is used by the o A signature generated using the private key which is used by the
receiver to verify the integrity of the DHCPv6 messages and then receiver to verify the integrity of the DHCPv6 messages and then
the identity of the sender. the identity of the sender.
o A timestamp, to detect replayed packet. The secure DHCPv6 nodes o A timestamp, to detect replayed packet. The secure DHCPv6 nodes
need to meet some accuracy requirements and be synced to global need to meet some accuracy requirements and be synced to global
time, while the timestamp checking mechanism allows a configurable time, while the timestamp checking mechanism allows a configurable
time value for clock drift. The real time provision is out of time value for clock drift. The real time provision is out of
scope. scope.
skipping to change at page 6, line 35 skipping to change at page 6, line 35
order to provide a means of addressing problems that may emerge in order to provide a means of addressing problems that may emerge in
the future with existing hash algorithms, as recommended in the future with existing hash algorithms, as recommended in
[RFC4270], this document provides a mechanism for negotiating the use [RFC4270], this document provides a mechanism for negotiating the use
of more secure hashes in the future. of more secure hashes in the future.
In addition to hash algorithm agility, this document also provides a In addition to hash algorithm agility, this document also provides a
mechanism for signature algorithm agility. mechanism for signature algorithm agility.
The support for algorithm agility in this document is mainly a The support for algorithm agility in this document is mainly a
unilateral notification mechanism from sender to recipient. A unilateral notification mechanism from sender to recipient. A
recipient MAY support various algorithms simultaneously, and the recipient MAY support various algorithms simultaneously among
different senders in a same administrative domain may be allowed to different senders, and the different senders in a same administrative
use various algorithms simultaneously. domain may be allowed to use various algorithms simultaneously. It
is NOT RECOMMENDED that the same sender and recipient use various
algorithms in a single communication session.
If the recipient does not support the algorithm used by the sender, If the recipient does not support the algorithm used by the sender,
it cannot authenticate the message. In the client-to-server case, it cannot authenticate the message. In the client-to-server case,
the server SHOULD reply with an AlgorithmNotSupported status code the server SHOULD reply with an AlgorithmNotSupported status code
(defined in Section 5.5). Upon receiving this status code, the (defined in Section 5.5). Upon receiving this status code, the
client MAY resend the message protected with the mandatory algorithm client MAY resend the message protected with the mandatory algorithm
(defined in Section 5.3). (defined in Section 5.3).
4.3. Applicability 4.3. Applicability
skipping to change at page 8, line 8 skipping to change at page 8, line 8
DHCPv6 message exchange. DHCPv6 message exchange.
5.1. Public Key Option 5.1. Public Key Option
The Public Key option carries the public key of the server. The The Public Key option carries the public key of the server. The
format of the Public Key option is described as follows: format of the Public Key option is described as follows:
0 1 2 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 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_PK_PARAMETER | option-len | | OPTION_PUBLIC_KEY | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
. Public Key (variable length) . . Public Key (variable length) .
. . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code OPTION_PK_PARAMETER (TBA1). option-code OPTION_PUBLIC_KEY (TBA1).
option-len Length of public key in octets. option-len Length of public key in octets.
Public Key A variable-length field containing public key and Public Key A variable-length field containing a
identify the algorithm with which the key is used SubjectPublicKeyInfo object specified in [RFC5280].
(e.g., RSA, DSA, or Diffie-Hellman). The algorithm The SubjectPublicKeyInfo structure is comprised with
is identified using the AlgorithmIdentifier structure a public key and a AlgorithmIdentifier object
specified in section 4.1.1.2, [RFC5280]. The object which is specified in section 4.1.1.2, [RFC5280]. The
identifiers for the supported algorithms and the object identifiers for the supported algorithms and
methods for encoding the public key materials the methods for encoding the public key materials
(public key and parameters) are specified in (public key and parameters) are specified in
[RFC3279], [RFC4055], and [RFC4491]. [RFC3279], [RFC4055], and [RFC4491].
5.2. Certificate Option 5.2. Certificate Option
The Certificate option carries the certificate of the client. The The Certificate option carries the public key certificate of the
format of the Certificate option is described as follows: client. The format of the Certificate option is described as
follows:
0 1 2 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 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_CERT_PARAMETER | option-len | | OPTION_CERTIFICATE | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
. Certificate (variable length) . . Certificate (variable length) .
. . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code OPTION_CERT_PARAMETER (TBA2). option-code OPTION_CERTIFICATE (TBA2).
option-len Length of certificate in octets. option-len Length of certificate in octets.
Certificate A variable-length field containing certificate. The Certificate A variable-length field containing certificate. The
encoding of certificate and certificate data MUST encoding of certificate and certificate data MUST
be in format as defined in Section 3.6, [RFC5996]. be in format as defined in Section 3.6, [RFC7296].
The support of X.509 certificate is mandatory. The support of X.509 certificate - Signature (4)
is mandatory.
5.3. Signature Option 5.3. Signature Option
The Signature option allows a signature that is signed by the private The Signature option allows a signature that is signed by the private
key to be attached to a DHCPv6 message. The Signature option could key to be attached to a DHCPv6 message. The Signature option could
be any place within the DHCPv6 message while it is logically created be any place within the DHCPv6 message while it is logically created
after the entire DHCPv6 header and options, except for the after the entire DHCPv6 header and options, except for the
Authentication Option. It protects the entire DHCPv6 header and Authentication Option. It protects the entire DHCPv6 header and
options, including itself, except for the Authentication Option. The options, including itself, except for the Authentication Option. The
format of the Signature option is described as follows: format of the Signature option is described as follows:
skipping to change at page 10, line 18 skipping to change at page 10, line 38
2. All DHCPv6 options including the Signature 2. All DHCPv6 options including the Signature
option (fill the signature field with zeroes) option (fill the signature field with zeroes)
except for the Authentication Option. except for the Authentication Option.
The signature field MUST be padded, with all 0, to The signature field MUST be padded, with all 0, to
the next octet boundary if its size is not a the next octet boundary if its size is not a
multiple of 8 bits. The padding length depends on multiple of 8 bits. The padding length depends on
the signature algorithm, which is indicated in the the signature algorithm, which is indicated in the
SA-id field. SA-id field.
Note: if both signature and authentication option are presented, Note: if both signature and authentication option are present,
signature option does not protect the Authentication Option. It signature option does not protect the Authentication Option. It
allows the Authentication Option be created after signature has been allows the Authentication Option be created after signature has been
calculated and filled with the valid signature. It is because both calculated and filled with the valid signature. It is because both
options need to apply hash algorithm to whole message, so there must options need to apply hash algorithm to whole message, so there must
be a clear order and there could be only one last-created option. In be a clear order and there could be only one last-created option. In
order to avoid update [RFC3315] because of changing auth option, the order to avoid update [RFC3315] because of changing auth option, the
authors chose not include authentication option in the signature. authors chose not include authentication option in the signature.
5.4. Timestamp Option 5.4. Timestamp Option
skipping to change at page 11, line 7 skipping to change at page 11, line 28
option-len 8, in octets. option-len 8, in octets.
Timestamp The current time of day (NTP-format timestamp Timestamp The current time of day (NTP-format timestamp
[RFC5905] in UTC (Coordinated Universal Time), a [RFC5905] in UTC (Coordinated Universal Time), a
64-bit unsigned fixed-point number, in seconds 64-bit unsigned fixed-point number, in seconds
relative to 0h on 1 January 1900.). It can reduce relative to 0h on 1 January 1900.). It can reduce
the danger of replay attacks. the danger of replay attacks.
5.5. Status Codes 5.5. Status Codes
The following new status codes, see Section 5.4 of [RFC3315] are
defined.
o AlgorithmNotSupported (TBD5): indicates that the DHCPv6 server o AlgorithmNotSupported (TBD5): indicates that the DHCPv6 server
does not support algorithms that sender used. does not support algorithms that sender used.
o AuthenticationFail (TBD6): indicates that the DHCPv6 client fails o AuthenticationFail (TBD6): indicates that the DHCPv6 client fails
authentication check. authentication check.
o TimestampFail (TBD7): indicates the message from DHCPv6 client o TimestampFail (TBD7): indicates the message from DHCPv6 client
fails the timestamp check. fails the timestamp check.
o SignatureFail (TBD8): indicates the message from DHCPv6 client o SignatureFail (TBD8): indicates the message from DHCPv6 client
skipping to change at page 11, line 30 skipping to change at page 12, line 6
This section only covers the scenario where both DHCPv6 client and This section only covers the scenario where both DHCPv6 client and
DHCPv6 server are secure enabled. DHCPv6 server are secure enabled.
6.1. Processing Rules of Sender 6.1. Processing Rules of Sender
The sender of a Secure DHCPv6 message could be a DHCPv6 server or a The sender of a Secure DHCPv6 message could be a DHCPv6 server or a
DHCPv6 client. DHCPv6 client.
The server must have a public/private key pair in order to create The server must have a public/private key pair in order to create
Secure DHCPv6 messages. The client must have a certificate which is Secure DHCPv6 messages. The client must have a public key
signed by a CA trusted by both server and client. certificate, which is signed by a CA trusted by both server and
client, and its corresponding private key.
To support secure DHCPv6, the secure DHCPv6 enabled sender MUST To support secure DHCPv6, the secure DHCPv6 enabled sender MUST
construct the DHCPv6 message following the rules defined in construct the DHCPv6 message following the rules defined in
[RFC3315]. [RFC3315].
A Secure DHCPv6 message, except for Relay-forward and Relay-reply A Secure DHCPv6 message, except for Relay-forward and Relay-reply
messages, MUST contain either a Public Key or a Certificate option, messages, MUST contain either a Public Key or a Certificate option,
which MUST be constructed as explained in Section 5.1 or Section 5.2. which MUST be constructed as explained in Section 5.1 or Section 5.2.
A Secure DHCPv6 message, except for Relay-forward and Relay-reply A Secure DHCPv6 message, except for Relay-forward and Relay-reply
messages, MUST contain one and only one Signature option, which MUST messages, MUST contain one and only one Signature option, which MUST
be constructed as explained in Section 5.3. It protects the message be constructed as explained in Section 5.3. It protects the message
header and all DHCPv6 options except for the Authentication Option. header and all DHCPv6 options except for the Authentication Option.
A Secure DHCPv6 message, except for Relay-forward and Relay-reply A Secure DHCPv6 message, except for Relay-forward and Relay-reply
messages, MAY contain one and only one Timestamp option. The messages, SHOULD contain one and only one Timestamp option. The
Timestamp field SHOULD be set to the current time, according to Timestamp field SHOULD be set to the current time, according to
sender's real time clock. sender's real time clock.
A Relay-forward and relay-reply message MUST NOT contain any A Relay-forward and relay-reply message MUST NOT contain any
additional Public Key or Certificate option or Signature Option or additional Public Key or Certificate option or Signature Option or
Timestamp Option, aside from those present in the innermost Timestamp Option, aside from those present in the innermost
encapsulated messages from the client or server. encapsulated messages from the client or server.
If the sender is a DHCPv6 client, in the failure cases, it receives a If the sender is a DHCPv6 client, in the failure cases, it receives a
Reply message with an error status code. The error status code Reply message with an error status code. The error status code
indicates the failure reason on the server side. According to the indicates the failure reason on the server side. According to the
received status code, the client MAY take follow-up action: received status code, the client MAY take follow-up action:
o Upon receiving an AlgorithmNotSupported error status code, the o Upon receiving an AlgorithmNotSupported error status code, the
client SHOULD resend the message protected with the mandatory client SHOULD resend the message protected with one of the
algorithms. mandatory algorithms.
o Upon receiving an AuthenticationFail error status code, the client o Upon receiving an AuthenticationFail error status code, the client
is not able to build up the secure communication with the is not able to build up the secure communication with the
recipient. The client MAY switch to other certificate if it has. recipient. The client MAY switch to other public key certificate
But it SHOULD NOT retry with the same certificate. It MAY retry if it has another one. But it SHOULD NOT retry with the same
with the same certificate following normal retransmission routines certificate. However, if the client decides to retransmit using
defined in [RFC3315]. the same certificate after receiving AuthenticationFail, it MUST
NOT retransmit immediately and MUST follow normal retransmission
routines defined in [RFC3315].
o Upon receiving a TimestampFail error status code, the client MAY o Upon receiving a TimestampFail error status code, the client MAY
fall back to unsecured mode, or resend the message without a fall back to unsecured mode, or resend the message without a
Timestamp option. However, the DHCP server MAY not accept the Timestamp option. However, the DHCP server MAY not accept the
message without a Timestamp option. message without a Timestamp option.
o Upon receiving a SignatureFail error status code, the client MAY o Upon receiving a SignatureFail error status code, the client MAY
resend the message following normal retransmission routines resend the message following normal retransmission routines
defined in [RFC3315]. defined in [RFC3315].
skipping to change at page 12, line 47 skipping to change at page 13, line 26
reply a correspondent error status code, while the client does reply a correspondent error status code, while the client does
nothing. The specific behavior depends on the configured local nothing. The specific behavior depends on the configured local
policy. policy.
When receiving a DHCPv6 message, except for Relay-Forward and Relay- When receiving a DHCPv6 message, except for Relay-Forward and Relay-
Reply messages, a secure DHCPv6 enabled recipient SHOULD discard any Reply messages, a secure DHCPv6 enabled recipient SHOULD discard any
DHCPv6 messages that meet any of the following conditions: DHCPv6 messages that meet any of the following conditions:
o the Signature option is absent, o the Signature option is absent,
o multiple Signature option is presented, o multiple Signature options are present,
o the Public Key option is absent in the server-to-client message, o the Public Key option is absent in the server-to-client message,
o the Certificate option is presented in the server-to-client
message, o the Certificate option is present in the server-to-client message,
o the Certificate option is absent in the client-to-server message, o the Certificate option is absent in the client-to-server message,
o the Public Key option is presented in the client-to-server o the Public Key option is present in the client-to-server message.
message.
In such failure, if the recipient is a DHCPv6 server, the server In such failure, if the recipient is a DHCPv6 server, the server
SHOULD reply an UnspecFail (value 1, [RFC3315]) error status code. SHOULD reply an UnspecFail (value 1, [RFC3315]) error status code.
If neither of the Signature, Public Key or Certificate options is If none of the Signature, Public Key or Certificate options is
presented, the sender MAY be a legacy node or in unsecured mode, present, the sender MAY be a legacy node or in unsecured mode, then,
then, the recipient MAY fall back to the unsecured DHCPv6 mode if its the recipient MAY fall back to the unsecured DHCPv6 mode if its local
local policy allows. policy allows.
The recipient SHOULD first check the support of algorithms that The recipient SHOULD first check the support of algorithms that
sender used. If not pass, the message is dropped. In such failure, sender used. If not pass, the message is dropped. In such failure,
if the recipient is a DHCPv6 server, the server SHOULD reply an if the recipient is a DHCPv6 server, the server SHOULD reply an
AlgorithmNotSupported error status code, defined in Section 5.5, back AlgorithmNotSupported error status code, defined in Section 5.5, back
to the client. If all algorithms are supported, the recipient then to the client. If both algorithms are supported, the recipient then
checks the authority of this sender. checks the authority of this sender. The recipient SHOULD also use
the same algorithms in the return messages.
The DHCPv6 server SHOULD validate the client's certificate following The DHCPv6 server SHOULD validate the client's public key certificate
the rules defined in [RFC5280]. An implementation may create a local following the rules defined in [RFC5280]. An implementation may
trust certificate record for verified certificates in order to avoid create a local trust certificate record for verified certificates in
repeated verification procedure in the future. A client certificate order to avoid repeated verification procedure in the future. A
that finds a match in the local trust certificate list is treated as client certificate that finds a match in the local trust certificate
verified. A fast search index may be created for this list. list is treated as verified. A fast search index may be created for
this list.
The DHCPv6 client SHOULD validate it by finding a matching public key The DHCPv6 client SHOULD validate it by finding a matching public key
from the local trust public key list, which is pre-configured or from the local trust public key list, which is pre-configured or
recorded from previous communications. A local trust public key list recorded from previous communications. A local trust public key list
is a data table maintained by the recipient. It restores public keys is a data table maintained by the recipient. It stores public keys
from all trustworthy senders. A fast search index may be created for from all trustworthy senders. A fast search index may be created for
this list. The message that fails authentication check MUST be this list.
dropped. In such failure, the DHCPv6 server SHOULD reply an
AuthenticationFail error status code, defined in Section 5.5, back to The message that fails authentication check MUST be dropped. In such
the client. failure, the DHCPv6 server SHOULD reply an AuthenticationFail error
status code, defined in Section 5.5, back to the client.
The client MAY choose to further process messages from a server for The client MAY choose to further process messages from a server for
which there is no matched public key. By recording the public key, which there is no matched public key. By recording the public key,
when the first time it is seen, the client can make a leap of faith when the first time it is seen, the client can make a leap of faith
(LoF) that the server is trustworthy. If no evidence to the contrary that the server is trustworthy. If no evidence to the contrary
surfaces, the client can then validate the server as trustworthy for surfaces, the client can then validate the server as trustworthy for
subsequent message exchanges. In opposite, once the client has subsequent message exchanges. In opposite, once the client has
determined that it is being attacked, it can either forget that determined that it is being attacked, it can either forget that
public key, or remember that public key in a blacklist and drop public key, or remember that public key in a blacklist and drop
further packets associated with that public key. further packets associated with that public key.
At this point, the recipient has either recognized the authentication At this point, the recipient has either recognized the authentication
of the sender, or decided to drop the message. The recipient MUST of the sender, or decided to drop the message. The recipient MUST
now authenticate the sender by verifying the signature and checking now authenticate the sender by verifying the signature and checking
timestamp (see details in Section 6.4), if there is a Timestamp timestamp (see details in Section 6.4), if there is a Timestamp
option. The order of two procedures is left as an implementation option. The order of two procedures is left as an implementation
decision. It is RECOMMENDED to check timestamp first, because decision. It is RECOMMENDED to check timestamp first, because
signature verification is much more computationally expensive. signature verification is much more computationally expensive.
Depending on server's local policy, the message without a Timestamp Depending on server's local policy, the message without a Timestamp
option MAY be acceptable or rejected. If the server rejects such a option MAY be acceptable or rejected. If the server rejects such a
message, a TimestampFail error status code, defined in Section 5.5, message, a TimestampFail error status code, defined in Section 5.5,
should be sent back to the client. should be sent back to the client. The reply message that carries
the TimestampFail error status code SHOULD NOT carry a timestamp
option.
The signature field verification MUST show that the signature has The signature field verification MUST show that the signature has
been calculated as specified in Section 5.3. Only the messages that been calculated as specified in Section 5.3. Only the messages that
get through both the signature verifications and timestamp check (if get through both the signature verifications and timestamp check (if
there is a Timestamp option) are accepted as secured DHCPv6 messages there is a Timestamp option) are accepted as secured DHCPv6 messages
and continue to be handled for their contained DHCPv6 options as and continue to be handled for their contained DHCPv6 options as
defined in [RFC3315]. Messages that do not pass the above tests MUST defined in [RFC3315]. Messages that do not pass the above tests MUST
be discarded or treated as unsecured messages. In the case the be discarded or treated as unsecured messages. In the case the
recipient is DHCPv6 server, the DHCPv6 server SHOULD reply a recipient is DHCPv6 server, the DHCPv6 server SHOULD reply a
SignatureFail error status code, defined in Section 5.5, for the SignatureFail error status code, defined in Section 5.5, for the
signature verification failure; or a TimestampFail error status code, signature verification failure; or a TimestampFail error status code,
defined in Section 5.5, for the timestamp check failure, back to the defined in Section 5.5, for the timestamp check failure, back to the
client. client.
Furthermore, the node that supports the verification of the Secure Furthermore, the node that supports the verification of the Secure
DHCPv6 messages MAY record the following information: DHCPv6 messages MAY impose additional constraints for the
verification. For example, it may impose limits on minimum and
maximum key lengths.
Minbits The minimum acceptable key length for public keys. An upper Minbits The minimum acceptable key length for public keys. An upper
limit MAY also be set for the amount of computation needed when limit MAY also be set for the amount of computation needed when
verifying packets that use these security associations. The verifying packets that use these security associations. The
appropriate lengths SHOULD be set according to the signature appropriate lengths SHOULD be set according to the signature
algorithm and also following prudent cryptographic practice. For algorithm and also following prudent cryptographic practice. For
example, minimum length 1024 and upper limit 2048 may be used for example, minimum length 1024 and upper limit 2048 may be used for
RSA [RSA]. RSA [RSA].
A Relay-forward or Relay-reply message with any Public Key, A Relay-forward or Relay-reply message with any Public Key,
skipping to change at page 15, line 44 skipping to change at page 16, line 29
Recipients MUST check the Timestamp field as follows: Recipients MUST check the Timestamp field as follows:
o When a message is received from a new peer (i.e., one that is not o When a message is received from a new peer (i.e., one that is not
stored in the cache), the received timestamp, TSnew, is checked, stored in the cache), the received timestamp, TSnew, is checked,
and the message is accepted if the timestamp is recent enough to and the message is accepted if the timestamp is recent enough to
the reception time of the packet, RDnew: the reception time of the packet, RDnew:
-Delta < (RDnew - TSnew) < +Delta -Delta < (RDnew - TSnew) < +Delta
After the signature verification also successes, the RDnew and After the signature verification also succeeds, the RDnew and
TSnew values SHOULD be stored in the cache as RDlast and TSlast. TSnew values SHOULD be stored in the cache as RDlast and TSlast.
o When a message is received from a known peer (i.e., one that o When a message is received from a known peer (i.e., one that
already has an entry in the cache), the timestamp is checked already has an entry in the cache), the timestamp is checked
against the previously received Secure DHCPv6 message: against the previously received Secure DHCPv6 message:
TSnew + fuzz > TSlast + (RDnew - RDlast) x (1 - drift) - fuzz TSnew + fuzz > TSlast + (RDnew - RDlast) x (1 - drift) - fuzz
If this inequality does not hold or RDnew < RDlast, the recipient If this inequality does not hold or RDnew < RDlast, the recipient
SHOULD silently discard the message. If, on the other hand, the SHOULD silently discard the message. If, on the other hand, the
skipping to change at page 16, line 23 skipping to change at page 17, line 7
An implementation MAY use some mechanism such as a timestamp cache to An implementation MAY use some mechanism such as a timestamp cache to
strengthen resistance to replay attacks. When there is a very large strengthen resistance to replay attacks. When there is a very large
number of nodes on the same link, or when a cache filling attack is number of nodes on the same link, or when a cache filling attack is
in progress, it is possible that the cache holding the most recent in progress, it is possible that the cache holding the most recent
timestamp per sender will become full. In this case, the node MUST timestamp per sender will become full. In this case, the node MUST
remove some entries from the cache or refuse some new requested remove some entries from the cache or refuse some new requested
entries. The specific policy as to which entries are preferred over entries. The specific policy as to which entries are preferred over
others is left as an implementation decision. others is left as an implementation decision.
An implementation MAY statefully record the latest timestamps from
clients. In such implementation, the timestamps MUST be strictly
monotonously increasing. This is reasonable given that DHCPv6
messages are rarely misordered.
7. Deployment Consideration 7. Deployment Consideration
This document defines two directions of authentication: This document defines two directions of authentication:
authentication based on client's certificate and authentication based authentication based on client's public key certificate and
on leap-of-faith (LoF) to server's public key. authentication based on leap of faith to server's public key.
7.1. Authentication on a client 7.1. Authentication on a client
For clients, DHCPv6 authentication generally means verifying whether For clients, DHCPv6 authentication generally means verifying whether
the sender of DHCP messages is a legal DHCPv6 server and verifying the sender of DHCP messages is a legal DHCPv6 server and verifying
whether the message has been modified during transmission. Because whether the message has been modified during transmission. Because
the client may have to validate the authentication in the condition the client may have to validate the authentication in the condition
of without connectivity wider than link-local, authentication with of without connectivity wider than link-local, authentication with
certificates may not always be feasible. So, this document only certificates may not always be feasible. So, this document only
sticks on Leaf of Faith model, to make sure the client talks to the sticks on Leaf of Faith model, to make sure the client talks to the
same previous server. same previous server.
Message integrity is provided. But there is a chance for the client Message integrity is provided. But there is a chance for the client
to incorrectly trust a malicious server at the beginning of the first to incorrectly trust a malicious server at the beginning of the first
session with the server (and therefore keep trusting it thereafter). session with the server (and therefore keep trusting it thereafter).
But LoF guarantees the subsequent messages are sent by the same But the leap of faith mechanim guarantees the subsequent messages are
previous server, and therefore narrows the attack scope. This may sent by the same previous server, and therefore narrows the attack
make sense if the network can be reasonably considered secure and scope. This may make sense if the network can be reasonably
requesting pre-configuration is deemed to be infeasible. A small considered secure and requesting pre-configuration is deemed to be
home network would be an example of such cases. infeasible. A small home network would be an example of such cases.
For environments that are neither controlled nor really trustworthy, For environments that are neither controlled nor really trustworthy,
such as a network cafe, while LoF model, i.e. silently trusting the such as a network in a cafeteria, while the leap of faith model,
server at the first time, would be too insecure. But some middle i.e., silently trusting the server at the first time, would be too
ground might be justified, such as requiring human intervention at insecure. But some middle ground might be justified, such as
the point of LoF. requiring human intervention at the point of the leap of faith.
7.2. Authentication on a server 7.2. Authentication on a server
As for authentication on a server, there are several different As for authentication on a server, there are several different
scenarios to consider, each of which has different applicability scenarios to consider, each of which has different applicability
issues. If the server allows LoF any malicious user can pretend to issues. If the server allows the leap of faith model, any malicious
be a new legitimate client. While the server can always be user can pretend to be a new legitimate client. While the server can
considered to have connectivity to validate certificate, it is always be considered to have connectivity to validate certificate, it
feasible to check client certificates. is feasible to check client certificates.
Network administrators may wish to constrain the allocation of Network administrators may wish to constrain the allocation of
addresses to authorized hosts to avoid denial of service attacks in addresses to authorized hosts to avoid denial of service attacks in
"hostile" environments where the network medium is not physically "hostile" environments where the network medium is not physically
secured, such as wireless networks or college residence halls. A secured, such as wireless networks or college residence halls. A
server may have to selectively serve a specific client or deny server may have to selectively serve a specific client or deny
specific clients depending on the identity of the client in a specific clients depending on the identity of the client in a
controlled environment, like a corporate intranet. But the support controlled environment, like a corporate intranet. But the support
from skilled staff or administrator may be required to set up the from skilled staff or administrator may be required to set up the
clients. clients.
skipping to change at page 17, line 36 skipping to change at page 18, line 25
8. Security Considerations 8. Security Considerations
This document provides new security features to the DHCPv6 protocol. This document provides new security features to the DHCPv6 protocol.
Using public key based security mechanism and its verification Using public key based security mechanism and its verification
mechanism in DHCPv6 message exchanging provides the authentication mechanism in DHCPv6 message exchanging provides the authentication
and data integrity protection. Timestamp mechanism provides anti- and data integrity protection. Timestamp mechanism provides anti-
replay function. replay function.
The Secure DHCPv6 mechanism is based on the pre-condition that the The Secure DHCPv6 mechanism is based on the pre-condition that the
client knows the public key of servers or the client's certificate client knows the public key of servers or the client's public key
can be verified through a trust CA. It prevents DHCPv6 server certificate can be verified through a trust CA. It prevents DHCPv6
spoofing. The clients may discard the DHCPv6 messages from unknown/ server spoofing. The clients may discard the DHCPv6 messages from
unverified servers, which may be fake servers; or may prefer DHCPv6 unknown/unverified servers, which may be fake servers; or may prefer
messages from known/verified servers over unsigned messages or DHCPv6 messages from known/verified servers over unsigned messages or
messages from unknown/unverified servers. The pre-configuration messages from unknown/unverified servers. The pre-configuration
operation also needs to be protected, which is out of scope. The operation also needs to be protected, which is out of scope. The
deployment of PKI is also out of scope. deployment of PKI is also out of scope.
However, when a DHCPv6 client first encounters a new public key, it However, when a DHCPv6 client first encounters a new public key, it
can make a leap of faith. If the DHCPv6 server that used that public can make a leap of faith. If the DHCPv6 server that used that public
key is in fact legitimate, then all future communication with that key is in fact legitimate, then all future communication with that
DHCPv6 server can be protected by storing the public key. This does DHCPv6 server can be protected by storing the public key. This does
not provide complete security, but it limits the opportunity to mount not provide complete security, but it limits the opportunity to mount
an attack on a specific DHCPv6 client to the first time it an attack on a specific DHCPv6 client to the first time it
skipping to change at page 18, line 39 skipping to change at page 19, line 28
of scope of this work. of scope of this work.
Attacks against time synchronization protocols such as NTP [RFC5905] Attacks against time synchronization protocols such as NTP [RFC5905]
may cause Secure DHCPv6 nodes to have an incorrect timestamp value. may cause Secure DHCPv6 nodes to have an incorrect timestamp value.
This can be used to launch replay attacks, even outside the normal This can be used to launch replay attacks, even outside the normal
window of vulnerability. To protect against these attacks, it is window of vulnerability. To protect against these attacks, it is
recommended that Secure DHCPv6 nodes keep independently maintained recommended that Secure DHCPv6 nodes keep independently maintained
clocks or apply suitable security measures for the time clocks or apply suitable security measures for the time
synchronization protocols. synchronization protocols.
One more consideration is that this protocol does reveal additional
client information in their certificate. It means less privacy. In
current practice, the client privacy and the client authentication
are mutually exclusive.
9. IANA Considerations 9. IANA Considerations
This document defines three new DHCPv6 [RFC3315] options. The IANA This document defines four new DHCPv6 [RFC3315] options. The IANA is
is requested to assign values for these three options from the DHCPv6 requested to assign values for these four options from the DHCPv6
Option Codes table of the DHCPv6 Parameters registry maintained in Option Codes table of the DHCPv6 Parameters registry maintained in
http://www.iana.org/assignments/dhcpv6-parameters. The three options http://www.iana.org/assignments/dhcpv6-parameters. The four options
are: are:
The Public Key Option (TBA1), described in Section 5.1. The Public Key Option (TBA1), described in Section 5.1.
The Certificate Option (TBA2), described in Section 5.2. The Certificate Option (TBA2), described in Section 5.2.
The Signature Option (TBA3), described in Section 5.3. The Signature Option (TBA3), described in Section 5.3.
The Timestamp Option (TBA4),described in Section 5.4. The Timestamp Option (TBA4),described in Section 5.4.
skipping to change at page 19, line 24 skipping to change at page 20, line 18
assignments are to be made through Standards Action [RFC5226]. assignments are to be made through Standards Action [RFC5226].
Assignments for each registry consist of a name, a value and a RFC Assignments for each registry consist of a name, a value and a RFC
number where the registry is defined. number where the registry is defined.
Hash Algorithm for Secure DHCPv6. The values in this table are 8-bit Hash Algorithm for Secure DHCPv6. The values in this table are 8-bit
unsigned integers. The following initial values are assigned for unsigned integers. The following initial values are assigned for
Hash Algorithm for Secure DHCPv6 in this document: Hash Algorithm for Secure DHCPv6 in this document:
Name | Value | RFCs Name | Value | RFCs
-------------------+---------+-------------- -------------------+---------+--------------
SHA-1 | 0x01 | this document SHA-256 | 0x01 | this document
SHA-256 | 0x02 | this document SHA-512 | 0x02 | this document
SHA-512 | 0x03 | this document
Signature Algorithm for Secure DHCPv6. The values in this table are Signature Algorithm for Secure DHCPv6. The values in this table are
8-bit unsigned integers. The following initial values are assigned 8-bit unsigned integers. The following initial values are assigned
for Signature Algorithm for Secure DHCPv6 in this document: for Signature Algorithm for Secure DHCPv6 in this document:
Name | Value | RFCs Name | Value | RFCs
-------------------+---------+-------------- -------------------+---------+--------------
RSASSA-PKCS1-v1_5 | 0x01 | this document RSASSA-PKCS1-v1_5 | 0x01 | this document
IANA is requested to assign the following new DHCPv6 Status Codes, IANA is requested to assign the following new DHCPv6 Status Codes,
skipping to change at page 20, line 4 skipping to change at page 20, line 45
TBD5 | AlgorithmNotSupported | this document TBD5 | AlgorithmNotSupported | this document
TBD6 | AuthenticationFail | this document TBD6 | AuthenticationFail | this document
TBD7 | TimestampFail | this document TBD7 | TimestampFail | this document
TBD8 | SignatureFail | this document TBD8 | SignatureFail | this document
10. Acknowledgments 10. Acknowledgments
The authors would like to thank Bernie Volz, Ted Lemon, Ralph Droms, The authors would like to thank Bernie Volz, Ted Lemon, Ralph Droms,
Jari Arkko, Sean Turner, Stephen Kent, Thomas Huth, David Schumacher, Jari Arkko, Sean Turner, Stephen Kent, Thomas Huth, David Schumacher,
Francis Dupont, Tomek Mrugalski, Gang Chen, Qi Sun, Suresh Krishnan, Francis Dupont, Tomek Mrugalski, Gang Chen, Qi Sun, Suresh Krishnan,
Fred Templin and other members of the IETF DHC working groups for Fred Templin and other members of the IETF DHC working group for
their valuable comments. their valuable comments.
This document was produced using the xml2rfc tool [RFC2629]. This document was produced using the xml2rfc tool [RFC2629].
11. Change log [RFC Editor: Please remove] 11. Change log [RFC Editor: Please remove]
draft-ietf-dhc-sedhcpv6-05: addressed comments from mail list that
responsed to the second WGLC.
draft-ietf-dhc-sedhcpv6-04: addressed comments from mail list. draft-ietf-dhc-sedhcpv6-04: addressed comments from mail list.
Making timestamp an independent and optional option. Reduce the Making timestamp an independent and optional option. Reduce the
serverside authentication to base on only client's certificate. serverside authentication to base on only client's certificate.
Reduce the clientside authentication to only Leaf of Faith base on Reduce the clientside authentication to only Leaf of Faith base on
server's public key. 2014-09-26. server's public key. 2014-09-26.
draft-ietf-dhc-sedhcpv6-03: addressed comments from WGLC. Added a draft-ietf-dhc-sedhcpv6-03: addressed comments from WGLC. Added a
new section "Deployment Consideration". Corrected the Public Key new section "Deployment Consideration". Corrected the Public Key
Field in the Public Key Option. Added consideration for large DHCPv6 Field in the Public Key Option. Added consideration for large DHCPv6
message transmission. Added TimestampFail error code. Refined the message transmission. Added TimestampFail error code. Refined the
skipping to change at page 21, line 49 skipping to change at page 22, line 46
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008. (CRL) Profile", RFC 5280, May 2008.
[RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network [RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
Time Protocol Version 4: Protocol and Algorithms Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, June 2010. Specification", RFC 5905, June 2010.
[RFC5996] Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen, [RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
"Internet Key Exchange Protocol Version 2 (IKEv2)", RFC Kivinen, "Internet Key Exchange Protocol Version 2
5996, September 2010. (IKEv2)", STD 79, RFC 7296, October 2014.
12.2. Informative References 12.2. Informative References
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999. June 1999.
[RFC4270] Hoffman, P. and B. Schneier, "Attacks on Cryptographic [RFC4270] Hoffman, P. and B. Schneier, "Attacks on Cryptographic
Hashes in Internet Protocols", RFC 4270, November 2005. Hashes in Internet Protocols", RFC 4270, November 2005.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
skipping to change at page 22, line 30 skipping to change at page 23, line 30
[RSA] RSA Laboratories, "RSA Encryption Standard, Version 2.1, [RSA] RSA Laboratories, "RSA Encryption Standard, Version 2.1,
PKCS 1", November 2002. PKCS 1", November 2002.
Authors' Addresses Authors' Addresses
Sheng Jiang (editor) Sheng Jiang (editor)
Huawei Technologies Co., Ltd Huawei Technologies Co., Ltd
Q14, Huawei Campus, No.156 Beiqing Road Q14, Huawei Campus, No.156 Beiqing Road
Hai-Dian District, Beijing, 100095 Hai-Dian District, Beijing, 100095
P.R. China CN
Email: jiangsheng@huawei.com Email: jiangsheng@huawei.com
Sean Shen Sean Shen
CNNIC CNNIC
4, South 4th Street, Zhongguancun 4, South 4th Street, Zhongguancun
Beijing 100190 Beijing 100190
P.R. China CN
Email: shenshuo@cnnic.cn Email: shenshuo@cnnic.cn
Dacheng Zhang Dacheng Zhang
Huawei Technologies Co., Ltd Huawei Technologies Co., Ltd
Q14, Huawei Campus, No.156 Beiqing Road Q14, Huawei Campus, No.156 Beiqing Road
Hai-Dian District, Beijing, 100095 Hai-Dian District, Beijing, 100095
P.R. China CN
Email: zhangdacheng@huawei.com Email: zhangdacheng@huawei.com
Tatuya Jinmei Tatuya Jinmei
Infoblox Inc. Infoblox Inc.
3111 Coronado Drive 3111 Coronado Drive
Santa Clara, CA Santa Clara, CA
USA US
Email: jinmei@wide.ad.jp Email: jinmei@wide.ad.jp
 End of changes. 57 change blocks. 
125 lines changed or deleted 154 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/