Remote Procedure Call (RPC) Security Version 3
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Transport
NFSv4
This document specifies version 3 of the Remote Procedure Call (RPC)
security protocol (RPCSEC_GSS). This protocol provides support
for multi-principal authentication of client hosts and
user principals to a server (constructed by
generic composition), security label assertions for
multi-level and type enforcement, structured privilege assertions,
and channel bindings.
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.
The original RPCSEC_GSS protocol provided for
authentication of RPC clients and servers to each other using the
Generic Security Services Application Programming Interface (GSS-API)
. The second version of
RPCSEC_GSS added support
for channel bindings .
Existing GSS-API mechanisms are insufficient for communicating
certain authorization and authentication information to a server.
The GSS-API and its mechanisms certainly could be extended to address
this shortcoming. However, here it is addressed at the
application layer, i.e., in RPCSEC_GSS.
A major motivation for version 3 RPCSEC_GSS (RPCSEC_GSSv3) is to add
support for multi-level (labeled) security and server-side copy for NFSv4.
Multi-Level Security (MLS) is a traditional model where subjects
(processes) are given a security level (Unclassified, Secret, Top Secret,
etc.) and objects (files) are given security labels that mandate the
access of the subject to the object (see
Section 9.2).
Labeled NFS (see Section 9 of ) uses
an MLS policy with Mandatory Access Control (MAC) systems
as defined in .
Labeled NFS stores MAC file object labels on the NFS server and
enables client
Guest Mode MAC as described in Section 9.6.2 of .
RPCSEC_GSSv3 label assertions assert client MAC process subject labels to
enable Full Mode MAC when combined with Labeled NFS as described in
Section 9.6.1 of .
A traditional inter-server file copy entails the user gaining access to
a file on the source, reading it, and writing it to a file on
the destination. In secure NFSv4 inter-server server-side copy
(see Section 4 of ),
the user first secures access to both source and destination files,
and then uses NFSv4.2 defined RPCSEC_GSSv3 structured
privileges to authorize the destination to copy the file from the
source on behalf of the user.
Multi-principal assertions can be used to address shared cache
poisoning attacks (see Section 9 of )
on the client cache by a user. As described
in Section 7 of , multi-user machines
with a single cache manager can fetch and cache data on a users'
behalf, and re-display it for another user from the cache without
re-fetching the data from the server.
The initial data acquisition is authenticated by the first user's
credentials, and if only that user's credentials are used, it may be
possible for a malicious user or users to "poison" the cache for
other users by introducing bogus data into the cache.
Another use of the multi-principal assertion is the secure conveyance
of privilege information for processes running with more (or even with
less) privilege than the user normally would be accorded.
RPCSEC_GSS version 3 (RPCSEC_GSSv3) is therefore described. RPCSEC_GSSv3
is the same as RPCSEC_GSSv2, except that
the following assertions of authority have been added.
Security labels for Full Mode security type enforcement,
and other labeled security models (See Section 9.6.2 in
).
Application-specific structured privileges. These allow an RPC
application client to pass structured information to the
corresponding application code in a server to control the
applicability of the privilege and/or the conditions in which
the privilege may be exercised. For an example
see server-side copy .
Multi-principal authentication of the client host and user to the
server done by binding two RPCSEC_GSS handles.
Simplified channel binding.
Assertions of labels and privileges are evaluated by the
server, which may then map the asserted values to other values, all
according to server-side policy. See .
An option for enumerating server supported label format specifiers
(LFS) is provided. See Section 9.2 in .
Note that there is no RPCSEC_GSS_CREATE payload that is REQUIRED to
implement. RPCSEC_GSSv3 implementations are feature driven.
Besides implementing the RPCSEC_GSS_CREATE operation and payloads for
the desired features, all RPCSEC_GSSv3 implementation MUST implement:
The new GSS version number.
The new reply verifier.
The new auth stat values.
RPCSEC_GSSv3 targets implementing a desired feature must also implement
the RPCSEC_GSS_LIST operation, and the RPCSEC_GSS_CREATE operation
replies for unsupported features.
For label assertions the target indicates no support by returning
the new RPCSEC_GSS_LABEL_PROBLEM auth stat
(See ).
For structured privilege assertions the target indicates no support
by returning the new RPCSEC_GSS_UNKNOWN_MESSAGE auth stat
(See ).
For multi-principal authentication,
the target indicates no support by not including a
rgss3_gss_mp_auth value in the rgss3_create_res.
For channel bindings
the target indicates no support by not including a
rgss3_chan_binding value in the rgss3_create_res.
This document contains the External Data Representation (XDR)
() definitions for the RPCSEC_GSSv3 protocol.
The XDR description is provided in this document in a way
that makes it simple for the reader to extract into ready
to compile form. The reader can feed this document in the
following shell script to produce the machine readable XDR
description of RPCSEC_GSSv3:
<CODE BEGINS>
<CODE ENDS>
I.e. if the above script is stored in a file called "extract.sh",
and this document
is in a file called "spec.txt", then the reader can do:
<CODE BEGINS>
<CODE ENDS>
The effect of the script is to remove leading white space
from each line, plus a sentinel sequence of "///".
RPCSEC_GSS version 3 (RPCSEC_GSSv3) is very similar to
RPCSEC_GSS version 2 (RPCSEC_GSSv2).
The differences are the addition of support for assertions and
channel bindings are supported via a different mechanism.
The entire RPCSEC_GSSv3 protocol is not presented here. Only the differences
between it and RPCSEC_GSSv2 are shown.
The use of RPCSEC_GSSv3 is structured as follows:
A client uses an existing RPCSEC_GSSv3 context handle established in the
usual manner (See Section 5.2 ) to protect
RPCSEC_GSSv3 exchanges, this will be termed the "parent" handle.
The server issues a "child" RPCSEC_GSSv3 handle in the
RPCSEC_GSS_CREATE response which uses the
underlying GSS-API security context of the parent handle in all
subsequent exchanges that uses the child handle.
An RPCSEC_GSSv3 child handle MUST NOT be used as the parent handle
in an RPCSEC_GSS3_CREATE control message.
The functionality of RPCSEC_GSSv2 is fully
supported by RPCSEC_GSSv3 with the exception of the
RPCSEC_GSS_BIND_CHANNEL operation which is not supported when
RPCSEC_GSSv3 is in use (see ).
An initiator that supports version 3 of RPCSEC_GSS simply issues an
RPCSEC_GSS request with the rgc_version field set to
RPCSEC_GSS_VERS_3. If the target does not recognize
RPCSEC_GSS_VERS_3, the target will return an RPC error per Section
5.1 of .
The initiator MUST NOT attempt to use an RPCSEC_GSS handle returned
by version 3 of a target with version 1 or version 2 of the same target.
The initiator MUST NOT attempt to use an RPCSEC_GSS handle returned by
version 1 or version 2 of a target with version 3 of the same target.
A new reply verifier is needed for RPCSEC_GSSv3 because of a situation that
arises from the use of the same GSS context by child and parent handles.
Because the RPCSEC_GSSv3 child handle uses the same GSS context as the
parent handle, a child and parent RPCSEC_GSSv3 handle could have the same
RPCSEC_GSS sequence numbers. Since the reply verifier of previous
versions of RPCSEC_GSS computes a Message Integrity Code (MIC) on just
the sequence number,
this provides opportunities for man in the middle attacks.
This issue is addressed in RPCSEC_GSS version 3 by computing
the verifier using the exact same input as is used to compute the
request verifier, except that the mtype is changed from CALL
to REPLY. The new reply verifier computes a MIC over the following RPC
reply header data:
The following code fragment replaces the corresponding preliminary code
shown in Figure 1 of . The values in the code
fragment in are additions to the auth_stat
enumeration. Subsequent code fragments are additions to the code
for version 2 that support the new procedures defined in version 3.
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As seen above, the RPCSEC_GSSv3 credential has the same format as the
RPCSEC_GSSv1 and
RPCSEC_GSSv2 credential. Setting
the rgc_version field
to 3 indicates that the initiator and target support the new RPCSEC_GSSv3
control procedures.
RPCSEC_GSSv3 provides a channel binding assertion that replaces
the RPCSEC_GSSv2 RPCSEC_GSS_BIND_CHANNEL operation.
The RPCSEC_GSS_BIND_CHANNEL operation is not supported on RPCSEC_GSS
version 3 handles. If a server receives an RPCSEC_GSS_BIND_CHANNEL
operation on an RPCSEC_GSSv3 handle, it MUST return a reply status of
MSG_ACCEPTED with an accept stat of PROC_UNAVAIL.
RPCSEC_GSSv3 requires the addition of several values to the auth_stat
enumerated type definition. The use of these new auth_stat
values is explained throughout this document.
There are two new RPCSEC_GSSv3 control procedures: RPCSEC_GSS_CREATE,
RPCSEC_GSS_LIST.
The RPCSEC_GSS_CREATE procedure binds any combination of assertions:
multi-principal authentication, labels, structured privileges, or channel
bindings to a new RPCSEC_GSSv3 context returned in the rgss3_create_res
rcr_handle field.
The RPCSEC_GSS_LIST procedure queries the target for supported
assertions.
RPCSEC_GSS version 3 control messages are similar to the
RPCSEC_GSS version 1 and version 2
RPCSEC_GSS_DESTROY control message (see section 5.4
) in that the sequence number
in the request must be valid, and the header checksum in the verifier
must be valid. As in RPCSEC_GSS version 1 and version 2, the
RPCSEC_GSS version 3 control messages may contain call data
following the verifier in the body of the NULLPROC procedure.
In other words, they look a lot like an
RPCSEC_GSS data message with the header procedure set to NULLPROC.
The client MUST use one of the following security services to protect the
RPCSEC_GSS_CREATE or RPCSEC_GSS_LIST control message:
rpc_gss_svc_integrity
rpc_gss_svc_privacy
Specifically the client MUST NOT use rpc_gss_svc_none.
RPCSEC_GSS_LIST can also use rpc_gss_svc_channel_prot (see
RPCSEC_GSSv2) if the request is sent
using an RPCSEC_GSSv3 child handle with channel bindings enabled
as described in .
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The call data for an RPCSEC_GSS_CREATE request
consists of an rgss3_create_args which
binds one or more items of several kinds to the returned rcr_handle
RPCSEC_GSSv3 context handle called the "child" handle:
Multi-principal authentication: another RPCSEC_GSS context handle
A channel binding
Authorization assertions: labels and or privileges
The reply to this message consists of either an error or an
rgss3_create_res structure. As noted in and
successful rgss3_assertions are
enumerated in rcr_assertions, and are REQUIRED to be enumerated in the
same order as they appeared in the rca_assertions argument.
Upon successful RPCSEC_GSS_CREATE, both the client and the server
need to associate the resultant child rcr_handle context handle with the
parent context handle in their GSS context caches so as to be able to
reference the parent context given the child context handle.
RPCSEC_GSSv3 child handles MUST be destroyed upon the destruction of
the associated parent handle.
Server implementation and policy MAY result in labels,
privileges, and identities being mapped to concepts and values that
are local to the server.
Server policies should take into
account the identity of the client and/or user as authenticated via
the GSS-API.
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RPCSEC_GSSv3 clients MAY assert a multi-principal authentication of
the RPC client host principal and a user principal.
This feature is needed, for example, when an RPC client host
wishes to use authority assertions that the server may only
grant if a user and an RPC client host
are authenticated together to the server. Thus a server
may refuse to grant requested authority to a user acting alone
(e.g., via an unprivileged user-space program), or to an RPC client
host acting alone (e.g., when an RPC client host is acting on
behalf of a user) but may grant requested authority to an RPC
client host acting on behalf of a user if the server identifies
the user and trusts the RPC client host.
It is assumed that an unprivileged user-space program would not have
access to RPC client host credentials needed to establish a GSS-API
security context authenticating the RPC client host to the server,
therefore
an unprivileged user-space program could not create an RPCSEC_GSSv3
RPCSEC_GSS_CREATE message that successfully binds an RPC client host
and a user security context.
In addition to the parent handle,
the multi-principal authentication call data has an
RPCSEC_GSS version 3 handle referenced via the rgmp_handle field
termed the "inner" handle.
Clients using RPCSEC_GSSv3 multi-principal authentication MUST use
an RPCSEC_GSSv3 context handle that corresponds to a
GSS-API security context that authenticates the RPC client host for
the parent handle. For the inner context handle with RPCSEC_GSSv3
it MUST use a context handle to authenticate a user.
The reverse (parent handle authenticates user, inner authenticates
an RPC client host) MUST NOT be used.
Other multi-principal parent and inner context handle uses might
eventually make sense, but would need to be introduced in a new
revision of the RPCSEC_GSS protocol.
The child context handle returned by a successful multi-principal
assertion binds the inner RPCSEC_GSSv3 context handle to the parent
RPCSEC_GSS context and MUST be treated by servers as authenticating
the GSS-API initiator principal authenticated by the inner context
handle's GSS-API security context. This principal may be mapped to
a server-side notion of user or principal.
Multi-principal binding is done by including an assertion of type
rgss3_gss_mp_auth in the RPCSEC_GSS_CREATE rgss3_create_args call
data. The inner context handle is placed in the rgmp_handle field.
A MIC of the RPC call header up to and including the credential is
computed using the GSS-API security context associated with the
inner context handle and is placed in rgmp_rpcheader_mic field.
Note that the rgmp_rpcheader_mic only identifies the client host
GSS context by it’s context handle (the parent context handle)
in the rpc header.
An RPCSEC_GSS_CREATE control procedure with a multi-principal
authentication payload MUST use the rpc_gss_svc_privacy security
service for protection. This is to prevent an attacker from
intercepting the RPCSEC_GSS_CREATE control procedure, re-assigning
the (parent) context handle, and stealing the user’s identity.
The target verifies the multi-principal authentication by first
confirming that the parent context used is an RPC client host context,
and then verifies the rgmp_rpcheader_mic using the GSS-API
security context associated with the rgmp_handle field.
On a successful verification, the rgss3_gss_mp_auth field in the
rgss3_create_res reply MUST be filled in with the inner
RPCSEC_GSSv3 context handle
as the rgmp_handle, and a MIC computed over the RPC reply header
(see section ) using
the GSS-API security context associated with the inner handle.
On failure, the rgss3_gss_mp_auth field is not sent
(rgss3_gss_mp_auth is an optional field).
A MSG_DENIED reply to the RPCSEC_GSS_CREATE call is formulated
as usual.
As described in Section 5.3.3.3 of
the server maintains a list of contexts for the clients that are
currently in session with it. When a client request comes in, there
may not be a context corresponding to its handle. When this occurs
on an RPCSEC_GSS3_CREATE request processing of the parent handle,
the server rejects the request with a reply status of MSG_DENIED
with the reject_stat of AUTH_ERROR and with an auth_stat value of
RPCSEC_GSS_CREDPROBLEM.
A new value, RPCSEC_GSS_INNER_CREDPROBLEM, has been added to the
auth_stat type.
With a multi-pricipal authorization request, the server must also have
a context corresponding to the inner context handle. When the server
does not have a context handle corresponding to the inner
context handle of a multi-pricipal authorization request, the server
sends a reply status of MSG_DENIED with the reject_stat of AUTH_ERROR
and with an auth_stat value of RPCSEC_GSS_INNER_CREDPROBLEM.
When processing the multi-principal authentication request, if the
GSS_VerifyMIC() call on the rgmp_rpcheader_mic fails to return
GSS_S_COMPLETE, the server sends a reply status of MSG_DENIED with
the reject_stat of AUTH_ERROR and with an auth_stat value of
RPCSEC_GSS_INNER_CREDPROBLEM.
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RPCSEC_GSSv3 provides a different way to do channel binding than
RPCSEC_GSSv2. Specifically:
RPCSEC_GSSv3 builds on RPCSEC_GSSv1 by reusing existing,
established context handles rather than providing a different
RPC security flavor for establishing context handles,
channel bindings data are not hashed because there is now
general agreement that it is the secure channel's
responsibility to produce channel bindings data of
manageable size.
(a) is useful in
keeping RPCSEC_GSSv3 simple in general, not just for channel binding.
(b) is useful in keeping RPCSEC_GSSv3 simple specifically for channel
binding.
Channel binding is accomplished as follows. The client prefixes the
channel bindings data octet string with the channel type as described
in , then the client calls GSS_GetMIC()
to get a MIC of
resulting octet string, using the parent RPCSEC_GSSv3 context handle's
GSS-API security context. The MIC is then placed in the
rca_chan_bind_mic field of RPCSEC_GSS_CREATE arguments
(rgss3_create_args).
If the rca_chan_bind_mic field of the arguments of a
RPCSEC_GSS_CREATE control message is set, then the server MUST
verify the client's channel binding MIC if the server supports this
feature. If channel binding verification succeeds then the server
MUST generate a new MIC of the same channel bindings and place it in
the rcr_chan_bind_mic field of the RPCSEC_GSS_CREATE rgss3_create_res
results. If channel binding verification fails or the server
doesn't support
channel binding then the server MUST indicate this in its reply by
not including a rgss3_chan_binding value in rgss3_create_res
(rgss3_chan_binding is an optional field).
The client MUST verify the result's rcr_chan_bind_mic value
by calling GSS_VerifyMIC() with the given MIC and
the channel bindings data (including the channel type prefix). If
client-side channel binding verification fails then the client MUST
call RPCSEC_GSS_DESTROY. If the client requested channel binding
but the server did not include an rcr_chan_binding_mic field in the
results, then the client MAY continue to use the resulting context
handle as though channel binding had never been requested.
If the client considers channel binding critical, it MUST call
RPCSEC_GSS_DESTROY.
As per-RPCSEC_GSSv2 :
"Once a successful [channel binding] procedure has been performed
on an [RPCSEC_GSSv3] context handle, the initiator's
implementation may map application requests for rpc_gss_svc_none
and rpc_gss_svc_integrity to rpc_gss_svc_channel_prot credentials.
And if the secure channel has privacy enabled, requests for
rpc_gss_svc_privacy can also be mapped to
rpc_gss_svc_channel_prot."
Any RPCSEC_GSSv3 child context handle that has been bound to a secure
channel in this way SHOULD be used only with the
rpc_gss_svc_channel_prot, and SHOULD NOT be used with
rpc_gss_svc_none nor rpc_gss_svc_integrity -- if the secure channel
does not provide privacy protection then the client MAY use
rpc_gss_svc_privacy where privacy protection is needed or desired.
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The client discovers which label format specifiers (LFS) the server
supports via the RPCSEC_GSS_LIST control message.
Full mode MAC is enabled when an RPCSEC_GSS version 3 process subject
label assertion is combined with a file object label provided by
the NFSv4.2 sec_label attribute.
Label encoding is specified to mirror the NFSv4.2 sec_label attribute
described in Section 12.2.4 of . The
label format specifier (LFS) is an identifier used by the client to
establish the syntactic format of the security label and the
semantic meaning of its components. The policy identifier (PI) is
an optional part of the definition of an LFS which allows for
clients and server to identify specific security policies.
The opaque label field of rgss3_label is dependent on the MAC
model to interpret and enforce.
If a label itself requires privacy protection (i.e., that the user
can assert that label is a secret) then the client MUST use the
rpc_gss_svc_privacy protection service for the RPCSEC_GSS_CREATE
request.
RPCSEC_GSSv3 clients MAY assert a set of subject security labels in
some LSF by binding a label assertion to the RPCSEC_GSSv3 child context
handle. This is done by including an assertion of type rgss3_label in the
RPCSEC_GSS_CREATE rgss3_create_args rca_assertions call data.
The label assertion payload is the set of subject labels asserted by the
calling NFS client process. The resultant child context is used for NFS
requests asserting the client process subject labels. The NFS server process
that handles such requests then asserts the (client) process subject label(s)
as it attempts to access a file that has associated LNFS object labels.
Servers that support labeling in the requested LFS MAY
map the requested subject label to a different subject label as
a result of server-side policy evaluation.
The labels that are accepted by the target and bound to the
RPCSEC_GSSv3 context MUST be enumerated in the rcr_assertions
field of the rgss3_create_res RPCSEC_GSS_CREATE reply.
Servers that do not support labeling or that do not support the
requested LFS reject the label assertion with a reply status of
MSG_DENIED, a reject_status of AUTH_ERROR, and an auth_stat of
RPCSEC_GSS_LABEL_PROBLEM.
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A structured privilege is a capability defined by a specific RPC
application. To support the assertion of this privilege, by a
client using the application, in a server that also supports the
application, the application may define a private data structure
that is understood by clients and servers implementing the
RPC application.
RPCSEC_GSSv3 clients MAY assert a structured privilege by binding
the privilege to the RPCSEC_GSSv3 context handle. This is done by
including an assertion of type rgss3_privs in the RPCSEC_GSS_CREATE
rgss3_create_args rca_assertions call data.
The privilege is identified by the description string that is
used by RPCSEC_GSSv3 to identify the privilege and communicate
the private data between the relevant RPC application-specific
code without needing to be aware of the details of the structure
used. Thus, as far as RPCSEC_GSSv3 is concerned, the defined
structure is passed between client and server as opaque data
encoded in the rpc_gss3_privs rp_privilege field.
Encoding, server verification and any server policies for
structured privileges are described by the RPC application
definition. The rp_name field of rpc_gss3_privs carries the
description string used to identify and list the privilege.
The utf8str_cs definition is from .
A successful structured privilege assertion MUST be enumerated in
the rcr_assertions field of the rgss3_create_res
RPCSEC_GSS_CREATE reply.
If a server receives a structured privilege assertion that it
does not recognize, the assertion is rejected with a reply
status of MSG_DENIED,
a reject_status of AUTH_ERROR, and an auth_stat of
RPCSEC_GSS_UNKNOWN_MESSAGE.
It is assumed that a client asserting more than one structured
privilege to be bound to a context handle would require all
the privilege assertions to succeed.
If a server receives an RPCSEC_GSS_CREATE request containing one
or more structured privilege assertions, any of which it fails
to verify according to the requirements of the RPC application
defined behavior, the request is rejected with a reply status of
MSG_DENIED, a reject_status of AUTH_ERROR, and an auth_stat of
RPCSEC_GSS_PRIVILEGE_PROBLEM.
Section 4.10.1.1. "Inter-Server Copy via ONC RPC with RPCSEC_GSSv3"
of shows an example of structured
privilege definition and use.
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The call data for an RPCSEC_GSS_LIST request consists of a list
of integers (rla_list_what) indicating what assertions are to be listed,
and the reply consists of an error or the requested list.
The result of requesting a list of rgss3_list_item LABEL
is a list of LFSs supported by the server. The client can then use
the LFS list to assert labels via the RPCSEC_GSS_CREATE label
assertions. See .
Assertion types may be added in the future by adding arms to the
'rgss3_assertion_u' union.
Examples of other potential assertion types include:
Client-side assertions of identity:
Primary client/user identity
Supplementary group memberships of the client/user, including
support for specifying deltas to the membership list as seen on
the server.
RPCSEC_GSSv3 is a superset of RPCSEC_GSSv2
which in turn is a superset of RPCSEC_GSSv1,
and so can be used in all situations where RPCSEC_GSSv2 is used, or
where RPCSEC_GSSv1 is used and channel bindings functionality is not
needed. RPCSEC_GSSv3 should be used when the new
functionality is needed.
This entire document deals with security issues.
The RPCSEC_GSSv3 protocol allows for client-side assertions of data
that is relevant to server-side authorization decisions. These
assertions must be evaluated by the server in the context of whether
the client and/or user are authenticated, whether multi-principal
authentication was used, whether the client is trusted, what ranges
of assertions are allowed for the client and the user (separately or
together), and any relevant server-side policy.
The security semantics of assertions carried by RPCSEC_GSSv3 are
application protocol-specific.
Note that RPSEC_GSSv3 is not a complete solution for labeling: it
conveys the labels of actors, but not the labels of objects. RPC
application protocols may require extending in order to carry object
label information.
There may be interactions with NFSv4's callback security scheme and
NFSv4.1's GSS-API "SSV" mechanisms.
Specifically, the NFSv4 callback
scheme requires that the server initiate GSS-API security contexts,
which does not work well in practice, and in the context of
client-side processes running as the same user but with
different privileges
and security labels the NFSv4 callback security scheme seems
particularly unlikely to work well. NFSv4.1 has the server use an
existing, client-initiated RPCSEC_GSS context handle to protect
server-initiated callback RPCs. The NFSv4.1 callback security scheme
lacks all the problems of the NFSv4 scheme, however, it is important
that the server pick an appropriate RPCSEC_GSS context handle to
protect any callbacks. Specifically, it is important that the server
use RPCSEC_GSS context handles which authenticate the client to
protect any callbacks relating to server state initiated by RPCs
protected by RPCSEC_GSSv3 contexts.
As described in Section 2.10.10
the client is permitted to associate multiple RPCSEC_GSS handles
with a single SSV GSS context. RPCSEC_GSSv3 handles will work well
with SSV in that the man-in-the-middle attacks described in
Section 2.10.10 are solved by
the new reply verifier . Using
an RPCSEC_GSSv3 handle backed by a GSS-SSV mechanism context as
a parent handle in an RPCSEC_GSS_CREATE call while permitted
is complicated by the lifetime rules of SSV contexts and their
associated RPCSEC_GSS handles.
The following new IANA RPC Authentication Status Numbers have been added:
RPCSEC_GSS_INNER_CREDPROBLEM (15) "No credentials for multi-principal assertion
inner context user". See .
RPCSEC_GSS_LABEL_PROBLEM (16) "Problem with label assertion".
See .
RPCSEC_GSS_PRIVILEGE_PROBLEM (17) "Problem with structured privilege assertion".
See .
RPCSEC_GSS_UNKNOWN_MESSAGE (18) "Unknown structured privilege assertion".
See .
Key words for use in RFCs to Indicate Requirement LevelsHarvard University1350 Mass. Ave.CambridgeMA 02138- +1 617 495 3864sob@harvard.eduRPCSEC_GSS Protocol SpecificationSun Microsystems, Inc.M/S UCOS032550 Garcia AvenueMountain ViewCA 94043+1 (719) 599-9026mre@eng.sun.comSun Microsystems, Inc.M/S UMPK17-2032550 Garcia AvenueMountain ViewCA 94043+1 (415) 786-6465hacker@eng.sun.comSun Microsystems, Inc.M/S UMPK17-2012550 Garcia AvenueMountain ViewCA 94043+1 (415) 786-5084lling@eng.sun.com
Security
generic security serviceremote procedure callsecurity
This memo describes an ONC/RPC security flavor that allows RPC
protocols to access the Generic Security Services Application
Programming Interface (referred to henceforth as GSS-API).
Generic Security Service Application
Program Interface Version 2, Update 1RSA Laboratories20 Crosby DriveBedfordMA01730US+1 781 687 7817jlinn@rsasecurity.comThe Generic Security Service Application Program
Interface (GSS-API), Version 2, as defined in, provides
security services to callers in a generic fashion,
supportable with a range of underlying mechanisms and
technologies and hence allowing source-level portability of
applications to different environments. This specification
defines GSS-API services and primitives at a level
independent of underlying mechanism and programming language
environment, and is to be complemented by other, related
specifications:documents defining specific parameter bindings for
particular language environmentsdocuments defining token formats, protocols, and
procedures to be implemented in order to realize GSS-API
services atop particular security mechanismsThis
memo obsoletes making specific, incremental changes in
response to implementation experience and liaison
requests. It is intended, therefore, that this memo or a
successor version thereto will become the basis for
subsequent progression of the GSS-API specification on the
standards track.NFS Version 4 Minor Version 2Network File System (NFS) Version 4 ProtocolNetwork File System (NFS) Version 4 Minor Version 1 ProtocolOn the Use of Channel Bindings to Secure ChannelsSun Microsystems, Inc.XDR: External Data Representation StandardNetAppRPCSEC_GSS Version 2NetApp5765 Chase Point CircleColorado SpringsCO 80919+1 (719) 599-9026mike@eisler.com
Security
generic security serviceremote procedure callsecurity
This document describes version 2 of the RPCSEC_GSS protocol.
Version 2 is the same as version 1 (specified in RFC 2203) except
that support for channel bindings has been added. RPCSEC_GSS allows
remote procedure call (RPC) protocols to access the Generic Security
Services Application Programming Interface (GSS-API).
Internet Security Glossary, Version 2
Integrating rxgk with AFS
Andy Adamson would like to thank NetApp, Inc. for its funding of his
time on this project.
We thank Lars Eggert, Mike Eisler, Ben Kaduk, Bruce Fields, Tom
Haynes, and Dave Noveck for their most helpful reviews.
[RFC Editor: please remove this section prior to publishing
this document as an RFC]
[RFC Editor: prior to publishing this document as an RFC, please replace all occurrences of RFCTBD
with RFCxxxx where xxxx is the RFC number of this document]