draft-ietf-krb-wg-anon-02.txt   draft-ietf-krb-wg-anon-03.txt 
NETWORK WORKING GROUP L. Zhu NETWORK WORKING GROUP L. Zhu
Internet-Draft P. Leach Internet-Draft P. Leach
Updates: 4120 (if approved) K. Jaganathan Updates: 4120 (if approved) K. Jaganathan
Intended status: Standards Track Microsoft Corporation Intended status: Standards Track Microsoft Corporation
Expires: April 14, 2007 October 11, 2006 Expires: September 3, 2007 March 2, 2007
Anonymity Support for Kerberos Anonymity Support for Kerberos
draft-ietf-krb-wg-anon-02 draft-ietf-krb-wg-anon-03
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
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This Internet-Draft will expire on April 14, 2007. This Internet-Draft will expire on September 3, 2007.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
Abstract Abstract
This document defines extensions to the Kerberos protocol for the This document defines extensions to the Kerberos protocol for the
Kerberos client to authenticate the Kerberos Key Distribution Center Kerberos client to authenticate the Kerberos Key Distribution Center
and the Kerberos server, without revealing the client's identity. and the Kerberos server, without revealing the client's identity.
These extensions can be used to secure communication between the These extensions can be used to secure communication between the
anonymous client and the server. anonymous client and the server.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 3 2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Protocol Description . . . . . . . . . . . . . . . . . . . . . 5 4. Protocol Description . . . . . . . . . . . . . . . . . . . . . 4
5. GSS-API Implementation Notes . . . . . . . . . . . . . . . . . 7 5. GSS-API Implementation Notes . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
9. Normative References . . . . . . . . . . . . . . . . . . . . . 9 9. Normative References . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10
Intellectual Property and Copyright Statements . . . . . . . . . . 11 Intellectual Property and Copyright Statements . . . . . . . . . . 11
1. Introduction 1. Introduction
In certain situations, the Kerberos [RFC4120] client may wish to In certain situations, the Kerberos [RFC4120] client may wish to
authenticate a server and/or protect communications without revealing authenticate a server and/or protect communications without revealing
its own identity. For example, consider an application which its own identity. For example, consider an application which
provides read access to a research database, and which permits provides read access to a research database, and which permits
queries by arbitrary requestors. A client of such a service might queries by arbitrary requestors. A client of such a service might
wish to authenticate the service, to establish trust in the wish to authenticate the service, to establish trust in the
information received from it, but might not wish to disclose its information received from it, but might not wish to disclose its
identity to the service for privacy reasons. identity to the service for privacy reasons.
Extensions to [RFC4120] are specified in this document by which a Extensions to [RFC4120] are specified in this document by which a
client can authenticate the KDC and request an anonymous ticket. The client can authenticate the Key Distribution Center (KDC) and request
client can use the anonymous ticket to authenticate the server and an anonymous ticket. The client can use the anonymous ticket to
protect subsequent client-server communications. These extensions authenticate the server and protect subsequent client-server
provide Kerberos with functional equivalence to Transport Layer communications. These extensions provide Kerberos with functional
Security (TLS) [RFC4346]. equivalence to Transport Layer Security (TLS) [RFC4346].
By using the extensions defined in this specification, the client MAY By using the extensions defined in this specification, the client may
reveal its identity in its initial request to its own KDC, but it can reveal its identity in its initial request to its own KDC, but it can
remain anonymous thereafter to KDCs on the cross-realm authentication remain anonymous thereafter to KDCs on the cross-realm authentication
path, and to the server with which it communicates. path, and to the server with which it communicates.
2. Conventions Used in This Document 2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
3. Definitions 3. Definitions
The anonymous Kerberos realm name is a reserved realm name based on The anonymous Kerberos realm name is defined as a well-known realm
[KRBNAM]. The value is the literal "RESERVED:ANONYMOUS". name based on [KRBNAM]. The value is the literal "WELLKNOWN:
ANONYMOUS". An anonymous Kerberos realm name MUST NOT be present in
the transited field [RFC4120] of a ticket.
The anonymous Kerberos principal name is a reserved Kerberos The anonymous Kerberos principal name is defined as a well-known
principal name based on [KRBNAM]. The value of the name-type field Kerberos principal name based on [KRBNAM]. The value of the name-
is KRB_NT_RESRVED [KRBNAM], and the value of the name-string field is type field [RFC4120] is KRB_NT_RESRVED [KRBNAM], and the value of the
a sequence of two KerberosString components: "RESERVED", "ANONYMOUS". name-string field [RFC4120] is a sequence of two KerberosString
components: "WELLKNOWN", "ANONYMOUS".
Note that in this specification, the anonymous principal name and Note that in this specification, the anonymous principal name and
realm are only applicable to the client in Kerberos messages, the realm are only applicable to the client in Kerberos messages, the
server MUST NOT be anonymous in any Kerberos message. server MUST NOT be anonymous in any Kerberos message.
The transited field [RFC4120] of a ticket is an anonymous
authentication path if the tr-type field of the TransitedEncoding
type [RFC4120] is NO-TRANSITED-INFO and the contents field is an
empty OCTET STRING.
NO-TRANSITED-INFO TBA
This means that no information of the authentication path is
disclosed.
The anonymous ticket flag is defined as bit TBA (with the first bit The anonymous ticket flag is defined as bit TBA (with the first bit
being bit 0) in the TicketFlags: being bit 0) in the TicketFlags:
TicketFlags ::= KerberosFlags TicketFlags ::= KerberosFlags
-- anonymous(TBA) -- anonymous(TBA)
-- TicketFlags and KerberosFlags are defined in [RFC4120] -- TicketFlags and KerberosFlags are defined in [RFC4120]
An anonymous ticket is a ticket that has all of the following An anonymous ticket is a ticket that has all of the following
properties: properties:
o The cname field [RFC4120] contains the anonymous Kerberos o The cname field [RFC4120] contains the anonymous Kerberos
principal name. principal name.
o The crealm field [RFC4120] contains either the client's realm name o The crealm field [RFC4120] contains the client's realm name, or
or the anonymous realm name. the name of the realm that issued the initial ticket for the
client principal, or the anonymous realm name.
o The transited field [RFC4120] can contain either the client's
authentication path as described in Section 3.3.3.2 of [RFC4120]
or the anonymous authentication path.
o The anonymous ticket contains no information that can reveal the o The anonymous ticket contains no information that can reveal the
client's identity. However the ticket MAY contain the client client's identity. However the ticket may contain the client
realm and the realms on the authentication path, and authorization realm, intermediate realms on the client's authentication path,
data that MAY provide information related to the client's and authorization data that may provide information related to the
identity. For example, an anonymous principal that is only client's identity. For example, an anonymous principal that is
identifiable within a particular group of users can be implemented identifiable only within a particular group of users can be
using authorization data and such authorization data, if included implemented using authorization data and such authorization data,
in the anonymous ticket, shall disclose the client's membership of if included in the anonymous ticket, shall disclose the client's
that group. membership of that group.
o The anonymous ticket flag is set. o The anonymous ticket flag is set.
The request-anonymous KDC option is defined as bit TBA (with the The request-anonymous KDC option is defined as bit TBA (with the
first bit being bit 0) in the KDCOptions: first bit being bit 0) in the KDCOptions:
KDCOptions ::= KerberosFlags KDCOptions ::= KerberosFlags
-- request-anonymous(TBA) -- request-anonymous(TBA)
-- KDCOptions and KerberosFlags are defined in [RFC4120] -- KDCOptions and KerberosFlags are defined in [RFC4120]
As described in Section 4, the request-anonymous KDC option is set to
request an anonymous ticket.
4. Protocol Description 4. Protocol Description
In order to request an anonymous ticket, the client sets the request- In order to request an anonymous ticket, the client sets the request-
anonymous KDC option in an Authentication Exchange (AS) or Ticket anonymous KDC option in an Authentication Exchange (AS) or Ticket
Granting Service (TGS) request [RFC4120]. The client can request an Granting Service (TGS) request [RFC4120]. The client can request an
anonymous TGT based on a normal TGT. If the client wishes to anonymous Ticket Granting Ticket (TGT) based on a normal TGT. Unless
authenticate the KDC anonymously, it sets the client name as otherwise specified, the client can obtain an anonymous ticket with
anonymous in the AS exchange and provides a PA_PK_AS_REQ pre- the anonymous realm name only by requesting an anonymous ticket in an
authentication data [RFC4556] where both the signerInfos field and AS exchange with the client realm set as anonymous in the request.
the certificates field of the SignedData [RFC3852] of PA_PK_AS_REQ
are empty. Because the anonymous client does not have an associated If the client wishes to authenticate the KDC anonymously, it sets the
asymmetric key pair, the client MUST use the Diffie-Hellman key client name as anonymous in the AS exchange and provides a
agreement method by filling in the Diffie-Hellman domain parameters PA_PK_AS_REQ pre-authentication data [RFC4556] where both the
in the clientPublicValue [RFC4556]. signerInfos field and the certificates field of the SignedData
[RFC3852] of the PA_PK_AS_REQ are empty. Because the anonymous
client does not have an associated asymmetric key pair, the client
MUST choose the Diffie-Hellman key agreement method by filling in the
Diffie-Hellman domain parameters in the clientPublicValue [RFC4556].
If the ticket in the PA-TGS-REQ [RFC4120] of the TGS request is If the ticket in the PA-TGS-REQ [RFC4120] of the TGS request is
anonymous, or if the client in the AS request is anonymous, the anonymous, or if the client in the AS request is anonymous, the
request-anonymous KDC option MUST be set in the request. request-anonymous KDC option MUST be set in the request. Otherwise,
the KDC MUST return a KRB-ERROR message with the code
KDC_ERR_BADOPTION [RFC4120], and there is no accompanying e-data
defined in this document.
Upon receiving the AS request with a PA_PK_AS_REQ from the anonymous Upon receiving the AS request with a PA_PK_AS_REQ [RFC4556] from the
client, the KDC skips the checks for the client's signature and the anonymous client, the KDC processes the request according to Section
client's public key (such as the verification of the binding between 3.1.2 of [RFC4120]. The KDC skips the checks for the client's
the client's public key and the client name), but performs otherwise- signature and the client's public key (such as the verification of
applicable checks, and proceeds as normal according to [RFC4556]. the binding between the client's public key and the client name), but
For example, the AS MUST check if the client's Diffie-Hellman domain performs otherwise-applicable checks, and proceeds as normal
parameters are acceptable. The Diffie-Hellman key agreement method according to [RFC4556]. For example, the AS MUST check if the
MUST be used and the reply key is derived according to Section client's Diffie-Hellman domain parameters are acceptable. The
3.2.3.1 of [RFC4556]. If the clientPublicValue is not present in the Diffie-Hellman key agreement method MUST be used and the reply key is
request, the KDC MUST return a KRB-ERROR [RFC4120] with the code derived according to Section 3.2.3.1 of [RFC4556]. If the
clientPublicValue is not present in the request, the KDC MUST return
a KRB-ERROR [RFC4120] with the code
KDC_ERR_PUBLIC_KEY_ENCRYPTION_NOT_SUPPORTED [RFC4556] and there is no KDC_ERR_PUBLIC_KEY_ENCRYPTION_NOT_SUPPORTED [RFC4556] and there is no
accompanying e-data. The client that made the anonymous request can accompanying e-data. If all goes well, an anonymous ticket is
authenticate the KDC based on the KDC's signature in the reply. If generated according to Section 3.1.3 of [RFC4120] and a PA_PK_AS_REP
the KDC does not have an asymmetric key pair, it MAY reply [RFC4556] pre-authentication data is included in the KDC reply
anonymously. In which case, both the signerInfos field and the according to [RFC4556]. If the KDC does not have an asymmetric key
pair, it MAY reply anonymously or reject the authentication attempt.
If the KDC replies anonymously, both the signerInfos field and the
certificates field of the SignedData [RFC3852] of PA_PK_AS_REP in the certificates field of the SignedData [RFC3852] of PA_PK_AS_REP in the
reply are empty. The server name in an anonymous reply contains the reply are empty. The server name in the anonymous KDC reply contains
name of the TGS. Upon receipt of an anonymous KDC reply, the client the name of the TGS.
MUST reject the returned ticket if it can not authenticate the KDC
otherwise.
The client can use its keys to mutually authenticate with the KDC, Upon receipt of the KDC reply that contains an anonymous ticket and a
and request an anonymous TGT in the AS request. And in that case, PA_PK_AS_REP [RFC4556] pre-authentication data, the client can then
authenticate the KDC based on the KDC's signature in the
PA_PK_AS_REP. If the KDC's signature is missing in the KDC reply
(the reply is anonymous), the client MUST reject the returned ticket
if it cannot authenticate the KDC otherwise.
The client can use the client keys to mutually authenticate with the
KDC, request an anonymous TGT in the AS request. And in that case,
the reply key is selected as normal according to Section 3.1.3 of the reply key is selected as normal according to Section 3.1.3 of
[RFC4120]. [RFC4120].
For the TGS exchange, the reply key is selected as normal according For the TGS exchange, the reply key is selected as normal according
to Section 3.3.3 of [RFC4120]. to Section 3.3.3 of [RFC4120].
When policy allows, the KDC issues an anonymous ticket. Based on When policy allows, the KDC issues an anonymous ticket. Based on
local policy, the client realm in the anonymous ticket can be the local policy, the client realm in the anonymous ticket can be the
anonymous realm name or the realm of the KDC. However, in all cases, anonymous realm name or the realm of the KDC. However, in all cases,
the client name and the client realm in the EncKDCRepPart of the the client name and the client realm in the EncKDCRepPart of the
reply [RFC4120] MUST match with the corresponding client name and the reply [RFC4120] MUST match with the corresponding client name and the
client realm of the anonymous ticket in the reply. The client MUST client realm of the anonymous ticket in the reply. The client MUST
use the client name and the client realm returned in the use the client name and the client realm returned in the
EncKDCRepPart in subsequent message exchanges when using the obtained EncKDCRepPart in subsequent message exchanges when using the obtained
anonymous ticket. anonymous ticket.
During the TGS request, when propagating authorization data, care During the TGS request, when propagating authorization data, care
MUST be taken by the TGS to ensure that the client confidentiality is MUST be taken by the TGS to ensure that the client confidentiality is
not violated. The TGS MUST either fail the request or remove not violated. If a anonymous ticket is returned, any authorization
authorization data that may reveal the client's identity. An element that may reveal the client's identity MUST be removed. The
optional authorization element unknown by the TGS MUST be removed if authentication attempt MUST be rejected if there is an authorization
it can be ignored (such as ones enclosed in the AD-IF-RELEVANT element that is intended to restrict the use of the ticket thus
structure). The TGS can only strip critical unknown authorization cannot be removed or the local policy prevents the removal of an
data if the ticket does not convey any rights such as those conveyed authorization element, and this rule MUST be applied to all critical
by a KDCIssued authorization data element. If a ticket contains a and optional authorization data. An optional authorization element
KDCIssued authorization data element, then no other authorization unknown by the TGS MUST be removed if it does not potentially convey
data elements may be removed if they could serve to limit the rights any rights or limit the rights otherwise conveyed in the ticket. If
conveyed by the KDCIssued element. Here is a table of the known there is a critical unknown authorization element, unless this
authorization-data elements, tagged with whether they interfere with element is encapsulated in a known authorization data element
client anonymity and recommendations for how to process them: amending the criticality of the elements it contains, authentication
MUST fail according to [RFC4120]. If it is inappropriate to remove
ad-type References Can Breach Confidentiality? an authorization element from the TGS request in order to produce an
------------------------------------------------------------------ anonymous ticket, the KDC MUST return an error message with the code
AD-IF-RELEVANT RFC4120 Yes, remove if unknown KDC_ERR_POLICY [RFC4120], and there is no accompanying e-data defined
AD-KDCIssued RFC4120 Yes, fail the request if unknown in this document.
AD-AND-OR RFC4120 Yes, remove if unknown
AD-MANDATORY-FOR-KDC RFC4120 Yes, fail the request if unknown
The KDC fills out the transited field of the anonymous ticket in the The TGS MUST add the name of the previous realm according to Section
reply as follows: If the service ticket in a TGS request is an 3.3.3.2 of [RFC4120]. If the client's realm is the anonymous realm,
anonymous ticket with a "normal" authentication path, then the the abbreviation forms [RFC4120] that build on the preceding name
authentication path in the reply ticket MUST also contain a "normal" cannot be used at the start of the transited encoding. The null-
authentication path, the TGS MUST add the name of the previous realm. subfield form (e.g., encoding ending with ",") [RFC4120] could not be
However, if the service ticket in a TGS request is an anonymous used next to the anonymous realm that can potentially be at the
ticket with an anonymous authentication path, then the reply ticket beginning where the client realm is filled in.
can contain either an anonymous authentication path or a "normal"
authentication path, based on local policy of the KDC. Thus a
"normal" authentication path in an anonymous ticket can be a partial
path, it may not include all the intermediate realms on the
authentication path.
The KDC fills out the authtime field of the anonymous ticket in the The KDC fills out the authtime field of the anonymous ticket in the
reply as follows: If the anonymous ticket is returned in an AS reply as follows: If the anonymous ticket is returned in an AS
exchange, the authtime field of the ticket contains the request time. exchange, the authtime field of the ticket contains the request time.
If the anonymous ticket is returned in a TGS exchange, the authtime If the anonymous ticket is returned in a TGS exchange, the authtime
field contains the authtime of the ticket in the PA-TGS-REQ field contains the authtime of the ticket in the PA-TGS-REQ pre-
[RFC4120]. An anonymous ticket can be renewed, and the authtime authentication data [RFC4120]. An anonymous ticket can be renewed,
field of a renewed ticket is the authtime in the anonymous ticket on and the authtime field of a renewed ticket is the authtime in the
which the renewed ticket was based. anonymous ticket on which the renewed ticket was based.
If it is inappropriate to remove an authorization element from the
TGS request in order to produce an anonymous ticket, the KDC MUST
return an error message with the code KDC_ERR_POLICY [RFC4120].
If the client is anonymous and the KDC does not have a key to encrypt If the client is anonymous and the KDC does not have a key to encrypt
the reply, the KDC MUST return an error message with the code the reply (this can happen when, for example, the KDC does not
KDC_ERR_NULL_KEY [RFC4120] and there is no accompanying e-data. support PKINIT [RFC4556]), the KDC MUST return an error message with
the code KDC_ERR_NULL_KEY [RFC4120] and there is no accompanying
e-data defined in this document.
If a client requires anonymous communication then the client MUST If a client requires anonymous communication then the client MUST
check to make sure that the ticket in the reply is actually anonymous check to make sure that the ticket in the reply is actually anonymous
by checking the presence of the anonymous ticket flag. This is by checking the presence of the anonymous ticket flag. This is
because KDCs ignore unknown KDC options. A KDC that does not because KDCs ignore unknown KDC options. A KDC that does not
understand the request-anonymous KDC option will not return an error, understand the request-anonymous KDC option will not return an error,
but will instead return a normal ticket. but will instead return a normal ticket.
The subsequent client and server communications then proceed as The subsequent client and server communications then proceed as
described in [RFC4120]. No transited policy checking is needed for described in [RFC4120].
the anonymous authentication path. However, transited policy checks
defined in Section 2.7 of [RFC4120] would apply to an anonymous
ticket that contains a "normal" authentication path.
A server accepting an anonymous service ticket may assume that A server accepting an anonymous service ticket may assume that
subsequent requests using the same ticket originate from the same subsequent requests using the same ticket originate from the same
client. Requests with different tickets are likely to originate from client. Requests with different tickets are likely to originate from
different clients. different clients.
Interoperability and backward-compatibility notes: the KDC is given
the task of rejecting a request for an anonymous ticket when the
anonymous ticket is not acceptable by the server.
5. GSS-API Implementation Notes 5. GSS-API Implementation Notes
At the GSS-API [RFC2743] level, the use of an anonymous principal by At the GSS-API [RFC2743] level, the use of an anonymous principal by
the initiator/client requires the initiator/client to assert the the initiator/client requires the initiator/client to assert the
"anonymous" flag when calling GSS_Init_Sec_Context(). "anonymous" flag when calling GSS_Init_Sec_Context().
GSS-API does not know or define "anonymous credentials", so the GSS-API does not know or define "anonymous credentials", so the
(printable) name of the anonymous principal will rarely be used by or (printable) name of the anonymous principal will rarely be used by or
relevant for the initiator/client. The printable name is relevant relevant for the initiator/client. The printable name is relevant
for the acceptor/server when performing an authorization decision for the acceptor/server when performing an authorization decision
based on the name that pops up from GSS_Accept_Sec_Context() upon based on the initiator name that is returned from the acceptor side
successful security context establishment. upon the successful security context establishment.
A GSS-API initiator MUST carefully check the resulting context A GSS-API initiator MUST carefully check the resulting context
attributes from the initial call to GSS_Init_Sec_Context() when attributes from the initial call to GSS_Init_Sec_Context() when
requesting anonymity, because (as in the GSS-API tradition and for requesting anonymity, because (as in the GSS-API tradition and for
backwards compatibility) anonymity is just another optional context backwards compatibility) anonymity is just another optional context
attribute. It could be that the mechanism doesn't recognize the attribute. It could be that the mechanism doesn't recognize the
attribute at all or that anonymity is not available for some other attribute at all or that anonymity is not available for some other
reasons -- and in that case the initiator must NOT send the initial reasons -- and in that case the initiator must NOT send the initial
security context token to the acceptor, because it will likely reveal security context token to the acceptor, because it will likely reveal
the initiators identity to the acceptor, something that can rarely be the initiators identity to the acceptor, something that can rarely be
skipping to change at page 9, line 19 skipping to change at page 9, line 10
the time that they are received. Traffic analysis on the connection the time that they are received. Traffic analysis on the connection
to the KDC will allow an attacker to match client identities to to the KDC will allow an attacker to match client identities to
anonymous tickets issued. Because there are plaintext parts of the anonymous tickets issued. Because there are plaintext parts of the
tickets that are exposed on the wire, such matching by a third party tickets that are exposed on the wire, such matching by a third party
observer is relatively straightforward. observer is relatively straightforward.
7. Acknowledgements 7. Acknowledgements
Clifford Neuman contributed the core notions of this document. Clifford Neuman contributed the core notions of this document.
Ken Raeburn reviewed the document and provided suggestions for
improvements.
Martin Rex wrote the text for GSS-API considerations. Martin Rex wrote the text for GSS-API considerations.
Nicolas Williams reviewed the GSS-API considerations section and Nicolas Williams reviewed the GSS-API considerations section and
suggested ideas for improvements. suggested ideas for improvements.
Sam Hartman and Nicolas Williams were great champions of this work. Sam Hartman and Nicolas Williams were great champions of this work.
In addition, the following individuals made significant In addition, the following individuals made significant
contributions: Jeffery Altman, Tom Yu, Chaskiel M Grundman, Love contributions: Jeffery Altman, Tom Yu, Chaskiel M Grundman, Love
Hoernquist Aestrand, and Jeffery Hutzelman. Hoernquist Aestrand, and Jeffery Hutzelman.
skipping to change at page 11, line 7 skipping to change at page 11, line 7
Karthik Jaganathan Karthik Jaganathan
Microsoft Corporation Microsoft Corporation
One Microsoft Way One Microsoft Way
Redmond, WA 98052 Redmond, WA 98052
US US
Email: karthikj@microsoft.com Email: karthikj@microsoft.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
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