draft-ietf-hip-cert-04.txt   draft-ietf-hip-cert-05.txt 
Host Identity Protocol Heer Host Identity Protocol Heer
Internet-Draft Distributed Systems Group, RWTH Internet-Draft Distributed Systems Group, RWTH
Intended status: Experimental Aachen University Intended status: Experimental Aachen University
Expires: March 27, 2011 Varjonen Expires: May 12, 2011 Varjonen
Helsinki Institute for Information Helsinki Institute for Information
Technology Technology
September 23, 2010 November 8, 2010
HIP Certificates Host Identity Protocol Certificates
draft-ietf-hip-cert-04 draft-ietf-hip-cert-05
Abstract Abstract
The CERT parameter is a container for X.509.v3 certificates and The CERT parameter is a container for X.509.v3 certificates and
Simple Public Key Infrastructure (SPKI) certificates. It is used for Simple Public Key Infrastructure (SPKI) certificates. It is used for
carrying these certificates in HIP control packets. This document carrying these certificates in Host Identity Protocol (HIP) control
only specifies the certificate parameter and the error signaling in packets. This document only specifies the certificate parameter and
case of a failed verification. The use of certificates including how the error signaling in case of a failed verification. The use of
certificates are obtained, requested, and which actions are taken certificates including how certificates are obtained, requested, and
upon successful or failed verification are to be defined in the which actions are taken upon successful or failed verification are to
documents that use the certificate parameter. Additionally, this be defined in the documents that use the certificate parameter.
document specifies the representations of Host Identity Tags in Additionally, this document specifies the representations of Host
X.509.v3 and SPKI certificates. Identity Tags in X.509.v3 and SPKI certificates.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. This document may not be modified, provisions of BCP 78 and BCP 79. This document may not be modified,
and derivative works of it may not be created, except to format it and derivative works of it may not be created, except to format it
for publication as an RFC or to translate it into languages other for publication as an RFC or to translate it into languages other
than English. than English.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
skipping to change at page 2, line 4 skipping to change at page 1, line 44
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
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."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on March 27, 2011. This Internet-Draft will expire on May 12, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2010 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 39 skipping to change at page 2, line 34
Digital certificates bind a piece of information to a public key by Digital certificates bind a piece of information to a public key by
means of a digital signature, and thus, enable the holder of a means of a digital signature, and thus, enable the holder of a
private key to generate cryptographically verifiable statements. The private key to generate cryptographically verifiable statements. The
Host Identity Protocol (HIP) [RFC5201] defines a new cryptographic Host Identity Protocol (HIP) [RFC5201] defines a new cryptographic
namespace based on asymmetric cryptography. The identity of each namespace based on asymmetric cryptography. The identity of each
host is derived from a public key, allowing hosts to digitally sign host is derived from a public key, allowing hosts to digitally sign
data with their private key. This document specifies the CERT data with their private key. This document specifies the CERT
parameter, which is used to transmit digital certificates in HIP. It parameter, which is used to transmit digital certificates in HIP. It
fills the placeholder specified in Section 5.2 of [RFC5201]. fills the placeholder specified in Section 5.2 of [RFC5201].
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. CERT Parameter 2. CERT Parameter
The CERT parameter is a container for certain types of digital The CERT parameter is a container for certain types of digital
certificates. It MAY either carry SPKI certificates or X.509.v3 certificates. It MAY either carry SPKI certificates or X.509.v3
certificates. It does not specify any certificate semantics. certificates. It does not specify any certificate semantics.
However, it defines supplementary parameters that help HIP hosts to However, it defines supplementary parameters that help HIP hosts to
transmit semantically grouped CERT parameters in a more systematic transmit semantically grouped CERT parameters in a more systematic
way. The specific use of the CERT parameter for different use cases way. The specific use of the CERT parameter for different use cases
is intentionally not discussed in this document. is intentionally not discussed in this document.
skipping to change at page 4, line 23 skipping to change at page 4, line 23
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ | Padding | / | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type 768 Type 768
Length Length in octets, excluding Type, Length, and Padding Length Length in octets, excluding Type, Length, and Padding
Cert group Group ID grouping multiple related CERT parameters Cert group Group ID grouping multiple related CERT parameters
Cert count Total count of certificates that are sent, possibly Cert count Total count of certificates that are sent, possibly
in several consecutive HIP control packets. in several consecutive HIP control packets.
Cert ID The sequence number for this certificate Cert ID The sequence number for this certificate
Cert Type Describes the type of the certificate Cert Type Indicates the type of the certificate
Padding Any Padding, if necessary, to make the TLV a multiple Padding Any Padding, if necessary, to make the TLV a multiple
of 8 bytes. of 8 bytes.
The following certificate types are defined: The following certificate types are defined:
+--------------------------------+-------------+ +--------------------------------+-------------+
| Cert format | Type number | | Cert format | Type number |
+--------------------------------+-------------+ +--------------------------------+-------------+
| X.509.v3 | 1 | | X.509.v3 | 1 |
| SPKI | 2 | | SPKI | 2 |
skipping to change at page 4, line 48 skipping to change at page 4, line 48
| Distinguished Name of X.509.v3 | 7 | | Distinguished Name of X.509.v3 | 7 |
| Distinguished Name of SPKI | 8 | | Distinguished Name of SPKI | 8 |
+--------------------------------+-------------+ +--------------------------------+-------------+
The next sections outline the use of HITs in X.509.v3 and in SPKI The next sections outline the use of HITs in X.509.v3 and in SPKI
certificates. X.509.v3 certificates are defined in [RFC3280]. The certificates. X.509.v3 certificates are defined in [RFC3280]. The
wire format for X.509.v3 is Distinguished Encoding Rules format as wire format for X.509.v3 is Distinguished Encoding Rules format as
defined in [X.690]. The SPKI and its formats are defined in defined in [X.690]. The SPKI and its formats are defined in
[RFC2693]. [RFC2693].
Hash and URL encodings (3 to 4) are used as defined in [RFC4306] Hash and URL encodings (3 and 4) are used as defined in [RFC4306]
Section 3.6. Using hash and URL encodings results in smaller HIP Section 3.6. Using hash and URL encodings results in smaller HIP
control packets, but requires the receiver to resolve the URL or control packets, but requires the receiver to resolve the URL or
check a local cache against the hash. check a local cache against the hash.
LDAP URL encodings (5 and 6) are used as defined in [RFC2255]. Using LDAP URL encodings (5 and 6) are used as defined in [RFC2255]. Using
LDAP URL encoding results in smaller HIP control packets but requires LDAP URL encoding results in smaller HIP control packets but requires
the receiver to retrieve the certificate or check a local cache the receiver to retrieve the certificate or check a local cache
against the URL. against the URL.
Distinguished name (DN) encodings (7 and 8) are used as defined in Distinguished name (DN) encodings (7 and 8) are used as defined in
[RFC1779]. Using the DN encoding results in smaller HIP control [RFC1779]. Using the DN encoding results in smaller HIP control
packets, but requires the receiver to retrieve the certificate or packets, but requires the receiver to retrieve the certificate or
check a local cache against the DN. check a local cache against the DN.
3. X.509.v3 Certificate Object and Host Identities 3. X.509.v3 Certificate Object and Host Identities
When using X.509.v3 certificates to transmit information related to When using X.509.v3 certificates to transmit information related to
HIP hosts, HITs MAY be enclosed within the certificates. HITs can HIP hosts, HITs MAY be enclosed within the certificates. HITs can
represent an issuer, a subject, or both. In X.509.v3 HITs are represent an issuer, a subject, or both. In X.509.v3 HITs are
represented as issuer and subject alternative name extensions as represented as issuer or subject alternative name extensions as
defined in [RFC2459]. If only HIP information is presented as either defined in [RFC2459]. If only HIT of the host is presented as either
the issuer or the subject the HIT is also placed into the respective the issuer or the subject the respective HIT MUST be placed into the
entity's DNs Common Name (CN) section in a colon delimited respective entity's DN's Common Name (CN) section in a colon
presentation format. Inclusion of CN is not necessary if DN contains delimited presentation format defined in [RFC5952]. Inclusion of CN
any other information. It is RECOMMENDED to use the FQDN/NAI from is not necessary if DN contains any other naming information. It is
the hosts HOST_ID parameter in the DN if one exists. The full HIs RECOMMENDED to use the FQDN/NAI from the hosts HOST_ID parameter in
are presented in the public key entries of X.509.v3 certificates. the DN if one exists. The full HIs are presented in the public key
entries of X.509.v3 certificates.
The following example illustrates a case in which the issuer and the
subject are both HIP enabled.
Format: The following examples illustrate how HITs are presented as issuer
Issuer: CN=hit-of-host and subject in the DN and in the X.509.v3 extension alternative
Subject: CN=hit-of-host names.
X509v3 extensions: Format of DN:
X509v3 Issuer Alternative Name: Issuer: CN=hit-of-issuer
IP Address:HIT-OF-HOST Subject: CN=hit-of-issuer
X509v3 Subject Alternative Name:
IP Address:HIT-OF-HOST
Example: Example DN:
Issuer: CN=2001:14:6cf:fae7:bb79:bf78:7d64:c056 Issuer: CN=2001:14:6cf:fae7:bb79:bf78:7d64:c056
Subject: CN=2001:14:6cf:fae7:bb79:bf78:7d64:c056 Subject: CN=2001:1c:5a14:26de:a07c:385b:de35:60e3
X509v3 extensions: Format of X509v3 extensions:
X509v3 Issuer Alternative Name: X509v3 Issuer Alternative Name:
IP Address:2001:14:6CF:FAE7:BB79:BF78:7D64:C056 IP Address:HIT-OF-ISSUER
X509v3 Subject Alternative Name: X509v3 Subject Alternative Name:
IP Address:2001:14:6CF:FAE7:BB79:BF78:7D64:C056 IP Address:HIT-OF-SUBJECT
Example X509v3 extensions:
X509v3 Issuer Alternative Name:
IP Address:2001:14:6CF:FAE7:BB79:BF78:7D64:C056
X509v3 Subject Alternative Name:
IP Address:2001:1C:5A14:26DE:A07C:385B:DE35:60E3
Appendix B shows a full example X.509.v3 certificate with HIP Appendix B shows a full example X.509.v3 certificate with HIP
content. content.
As another example, consider a managed PKI environment in which the As another example, consider a managed PKI environment in which the
peers have certificates that are anchored in (potentially different) peers have certificates that are anchored in (potentially different)
managed trust chains. In this scenario, the certificates issued to managed trust chains. In this scenario, the certificates issued to
HIP hosts are signed by intermediate Certificate Authorities (CAs) up HIP hosts are signed by intermediate Certificate Authorities (CAs) up
to a root CA. In this example, the managed PKI environment is to a root CA. In this example, the managed PKI environment is
neither HIP aware, nor can it be configured to compute HITs and neither HIP aware, nor can it be configured to compute HITs and
include them in the certificates. include them in the certificates.
In this scenario, it is recommended that the HIP peers have and use In this scenario, it is RECOMMENDED that the HIP peers have and use
some mechanism of defining trusted root CAs for the purpose of some mechanism of defining trusted root CAs for the purpose of
establishing HIP communications. Furthermore it is recommended that establishing HIP communications. Furthermore it is recommended that
the HIP peers have and use some mechanism of checking peer the HIP peers have and use some mechanism of checking peer
certificate validity for revocation, signature, minimum cryptographic certificate validity for revocation, signature, minimum cryptographic
strength, etc., up to the trusted root CA. strength, etc., up to the trusted root CA.
When HIP communications are established, the HIP hosts not only need When HIP communications are established, the HIP hosts not only need
to send their identity certificates (or pointers to their to send their identity certificates (or pointers to their
certificates), but also the chain of intermediate CAs (or pointers to certificates), but also the chain of intermediate CAs (or pointers to
the CAs) up to the root CA, or to a CA that is trusted by the remote the CAs) up to the root CA, or to a CA that is trusted by the remote
skipping to change at page 7, line 32 skipping to change at page 7, line 32
5. Revocation of Certificates 5. Revocation of Certificates
Revocation of X.509.v3 certificates is handled as defined in Section Revocation of X.509.v3 certificates is handled as defined in Section
5 in [RFC2459]. Revocation of SPKI certificates is handled as 5 in [RFC2459]. Revocation of SPKI certificates is handled as
defined in Section 5 in [RFC2693]. defined in Section 5 in [RFC2693].
6. Error signaling 6. Error signaling
If the Initiator does not send the certificate that the Responder If the Initiator does not send the certificate that the Responder
requires the Responder may take actions (e.g. blocking the requires the Responder may take actions (e.g. reject the connection).
connection). The Responder MAY signal this to the Initiator by The Responder MAY signal this to the Initiator by sending a HIP
sending a HIP NOTIFY message with NOTIFICATION parameter error type NOTIFY message with NOTIFICATION parameter error type
CREDENTIALS_NEEDED. CREDENTIALS_NEEDED.
If the verification of a certificate fails, a verifier MAY signal If the verification of a certificate fails, a verifier MAY signal
this to the provider of the certificate by sending a HIP NOTIFY this to the provider of the certificate by sending a HIP NOTIFY
message with NOTIFICATION parameter error type INVALID_CERTIFICATE. message with NOTIFICATION parameter error type INVALID_CERTIFICATE.
NOTIFICATION PARAMETER - ERROR TYPES Value NOTIFICATION PARAMETER - ERROR TYPES Value
------------------------------------ ----- ------------------------------------ -----
CREDENTIALS_REQUIRED 48 CREDENTIALS_REQUIRED 48
The Responder is unwilling to set up an association The Responder is unwilling to set up an association
as the Initiator did not send the needed credentials. as the Initiator did not send the needed credentials.
INVALID_CERTIFICATE 50 INVALID_CERTIFICATE 50
Sent in response to a failed verification of a certificate. Sent in response to a failed verification of a certificate.
Notification Data contains 4 octets, in order Cert group, Notification Data MAY contain n groups of 2 octets (n calculated
Cert count, Cert ID, and Cert type of the certificate from the NOTIFICATION parameter length), in order Cert group and
parameter that caused the failure. Cert ID of the certificate parameter that caused the failure.
7. IANA Considerations 7. IANA Considerations
This document defines the CERT parameter for the Host Identity This document defines the CERT parameter for the Host Identity
Protocol [RFC5201]. This parameter is defined in Section 2 with type Protocol [RFC5201]. This parameter is defined in Section 2 with type
768. The parameter type number is also defined in [RFC5201]. 768. The parameter type number is also defined in [RFC5201].
The CERT parameter has 8-bit unsigned integer field for different The CERT parameter has 8-bit unsigned integer field for different
certificate types, for which IANA is to create and maintain a new certificate types, for which IANA is to create and maintain a new
sub-registry entitled "HIP certificate types" under the "Host sub-registry entitled "HIP certificate types" under the "Host
skipping to change at page 8, line 43 skipping to change at page 8, line 43
types" sub-registry under "Host Identity Protocol (HIP) Parameters". types" sub-registry under "Host Identity Protocol (HIP) Parameters".
8. Security Considerations 8. Security Considerations
Certificate grouping allows the certificates to be sent in multiple Certificate grouping allows the certificates to be sent in multiple
consecutive packets. This might allow similar attacks as IP-layer consecutive packets. This might allow similar attacks as IP-layer
fragmentation allows, for example sending of fragments in wrong order fragmentation allows, for example sending of fragments in wrong order
and skipping some fragments to delay or stall packet processing by and skipping some fragments to delay or stall packet processing by
the victim in order to use resources (e.g. CPU or memory). the victim in order to use resources (e.g. CPU or memory).
It is not recommended to use grouping or hash and URL encodings when It is NOT RECOMMENDED to use grouping or hash and URL encodings when
HIP aware middleboxes are anticipated to be present on the HIP aware middleboxes are anticipated to be present on the
communication path between peers because fetching remote certificates communication path between peers because fetching remote certificates
require the middlebox to buffer the packets and to request remote require the middlebox to buffer the packets and to request remote
data. This makes these devices prone to denial of service (DoS) data. This makes these devices prone to denial of service (DoS)
attacks. Moreover, middleboxes and responders that request remote attacks. Moreover, middleboxes and responders that request remote
certificates can be used as deflectors for distributed denial of certificates can be used as deflectors for distributed denial of
service attacks. service attacks.
9. Acknowledgements 9. Acknowledgements
skipping to change at page 9, line 43 skipping to change at page 9, line 43
X.509 Public Key Infrastructure Certificate and X.509 Public Key Infrastructure Certificate and
Certificate Revocation List (CRL) Profile", RFC 3280, Certificate Revocation List (CRL) Profile", RFC 3280,
April 2002. April 2002.
[RFC4306] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", [RFC4306] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
RFC 4306, December 2005. RFC 4306, December 2005.
[RFC5201] Moskowitz, R., Nikander, P., Jokela, P., and T. Henderson, [RFC5201] Moskowitz, R., Nikander, P., Jokela, P., and T. Henderson,
"Host Identity Protocol", RFC 5201, April 2008. "Host Identity Protocol", RFC 5201, April 2008.
[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
Address Text Representation", RFC 5952, August 2010.
10.2. Informative References 10.2. Informative References
[X.690] ITU-T, "Recommendation X.690 Information Technology - [X.690] ITU-T, "Recommendation X.690 Information Technology -
ASN.1 encoding rules: Specification of Basic Encoding ASN.1 encoding rules: Specification of Basic Encoding
Rules (BER), Canonical Encoding Rules (CER) and Rules (BER), Canonical Encoding Rules (CER) and
Distinguished Encoding Rules (DER)", July 2002, <http:// Distinguished Encoding Rules (DER)", July 2002, <http://
www.itu.int/ITU-T/studygroups/com17/languages/ www.itu.int/ITU-T/studygroups/com17/languages/
X.690-0207.pdf>. X.690-0207.pdf>.
Appendix A. SPKI certificate example Appendix A. SPKI certificate example
skipping to change at page 13, line 5 skipping to change at page 12, line 42
o Changed IANA considerations o Changed IANA considerations
o Revised the type numbers o Revised the type numbers
o RFC 2119 keywords o RFC 2119 keywords
o Updated the IANA considerations section o Updated the IANA considerations section
o Rewrote the abstract o Rewrote the abstract
Changes from version 04 to 05:
o Clarified the examples in Section 3.
o Clarifications to Section Section 3.
o Modified the explanation of INVALID_CERTIFICATE to allow multiple
certs.
o Added reference to the IPv6 colon delimited presentation format.
o Small editorial changes.
Authors' Addresses Authors' Addresses
Tobias Heer Tobias Heer
Distributed Systems Group, RWTH Aachen University Distributed Systems Group, RWTH Aachen University
Ahornstrasse 55 Ahornstrasse 55
Aachen Aachen
Germany Germany
Phone: +49 241 80 214 36 Phone: +49 241 80 214 36
Email: heer@cs.rwth-aachen.de Email: heer@cs.rwth-aachen.de
URI: http://ds.cs.rwth-aachen.de/members/heer URI: http://ds.cs.rwth-aachen.de/members/heer
Samu Varjonen Samu Varjonen
Helsinki Institute for Information Technology Helsinki Institute for Information Technology
Metsaenneidonkuja 4 Gustaf Haellstroemin katu 2b
Helsinki Helsinki
Finland Finland
Email: samu.varjonen@hiit.fi Email: samu.varjonen@hiit.fi
URI: http://www.hiit.fi URI: http://www.hiit.fi
 End of changes. 22 change blocks. 
56 lines changed or deleted 75 lines changed or added

This html diff was produced by rfcdiff 1.40. The latest version is available from http://tools.ietf.org/tools/rfcdiff/