TLS Client and Server ModelsJuniper Networkskwatsen@juniper.netCisco Systemsgarywu@cisco.com
Operations
NETCONF Working GroupThis document defines three YANG modules: the first defines
groupings for a generic TLS client, the second defines groupings
for a generic TLS server, and the third defines common identities
and groupings used by both the client and the server. It is
intended that these groupings will be used by applications using
the TLS protocol.This draft contains many placeholder values that need to be replaced
with finalized values at the time of publication. This note summarizes
all of the substitutions that are needed. No other RFC Editor
instructions are specified elsewhere in this document.This document contains references to other drafts in progress, both in
the Normative References section, as well as in body text throughout.
Please update the following references to reflect their final RFC assignments:
I-D.ietf-netconf-keystoreArtwork in this document contains shorthand references to drafts in
progress. Please apply the following replacements:
XXXX --> the assigned RFC value for this draftYYYY --> the assigned RFC value for I-D.ietf-netconf-keystoreArtwork in this document contains placeholder values for the date of
publication of this draft. Please apply the following replacement:
2017-06-13 --> the publication date of this draftThe following Appendix section is to be removed prior to publication:
Appendix A. Change LogThis document defines three YANG
modules: the first defines a grouping for a generic TLS client, the
second defines a grouping for a generic TLS server, and the third
defines identities and groupings common to both the client and the
server (TLS is defined in ). It is
intended that these groupings will be used by applications using
the TLS protocol. For instance, these groupings could be used to
help define the data model for an HTTPS
server or a NETCONF over TLS based
server.The client and server YANG modules in this document each define one grouping,
which is focused on just TLS-specific configuration, and specifically
avoids any transport-level configuration, such as what ports to
listen-on or connect-to. This enables applications the opportunity
to define their own strategy for how the underlying TCP connection
is established. For instance, applications supporting NETCONF Call
Home could use the grouping for the TLS
parts it provides, while adding data nodes for the TCP-level call-home
configuration.The keywords "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 .A simplified graphical representation of the data models
is used in this document. The meaning of the symbols in
these diagrams is as follows:
Brackets "[" and "]" enclose list keys.Braces "{" and "}" enclose feature names, and indicate
that the named feature must be present for the subtree
to be present.Abbreviations before data node names: "rw" means
configuration (read-write) and "ro" state data
(read-only).Symbols after data node names: "?" means an optional
node, "!" means a presence container, and "*" denotes a
list and leaf-list.Parentheses enclose choice and case nodes, and case
nodes are also marked with a colon (":").Ellipsis ("...") stands for contents of subtrees that
are not shown.The TLS client model presented in this section contains one
YANG grouping, to just configure the TLS client omitting, for
instance, any configuration for which IP address or port the
client should connect to.This grouping references data nodes defined by the
keystore model . For
instance, a reference to the keystore model is made to indicate
which trusted CA certificate a client should use to authenticate
the server's certificate.The following tree diagram presents the data model for
the grouping defined in the ietf-tls-client module. Please
see for tree diagram notation.This section shows how it would appear if the
tls-client-grouping were populated with some data.
This example is consistent with the examples presented in
Section 2.2 of .This YANG module has a normative references to
and .The TLS server model presented in this section contains one
YANG grouping, for just the TLS-level configuration omitting,
for instance, configuration for which ports to open to listen
for connections on.This grouping references data nodes defined by the
keystore model .
For instance, a reference to the keystore model is made to indicate
which certificate a server should present.The following tree diagram presents the data model for
the grouping defined in the ietf-tls-server module. Please
see for tree diagram notation.This section shows how it would appear if the
tls-server-grouping were populated with some data.
This example is consistent with the examples presented in
Section 2.2 of .This YANG module has a normative references to ,
and .The TLS common model presented in this section contains identities
and groupings common to both TLS clients and TLS servers. The
hello-params-grouping can be used to configure the list of TLS
algorithms permitted by the TLS client or TLS server. The lists of
algorithms are ordered such that, if multiple algorithms are permitted
by the client, the algorithm that appears first in its list that is
also permitted by the server is used for the TLS transport layer
connection. The ability to restrict the the algorithms allowed is
provided in this grouping for TLS clients and TLS servers that are
capable of doing so and may serve to make TLS clients and TLS servers
compliant with security policies.Features are defined for algorithms that are OPTIONAL or are not
widely supported by popular implementations. Note that the list of
algorithms is not exhaustive.The following tree diagram presents the data model for
the grouping defined in the ietf-tls-common module. Please
see for tree diagram notation.This section shows how it would appear if the
transport-params-grouping were populated with some data.This YANG module has a normative references to ,
, ,
and .The YANG module defined in this document is designed to be accessed via YANG
based management protocols, such as NETCONF and
RESTCONF . Both of these protocols have mandatory-to-implement
secure transport layers (e.g., SSH, TLS) with mutual authentication.The NETCONF access control model (NACM) provides the means
to restrict access for particular users to a pre-configured subset of all available
protocol operations and content.There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., config true, which is the default). These data
nodes may be considered sensitive or vulnerable in some network environments. Write
operations (e.g., edit-config) to these data nodes without proper protection can
have a negative effect on network operations. These are the subtrees and data nodes
and their sensitivity/vulnerability:
The entire data tree defined by this module is sensitive to
write operations. For instance, the addition or removal of references to
keys, certificates, trusted anchors, etc., can dramatically alter the
implemented security policy. However, no NACM annotations are applied as
the data SHOULD be editable by users other than a designated 'recovery session'.Some of the readable data nodes in this YANG module may be considered sensitive
or vulnerable in some network environments. It is thus important to control read
access (e.g., via get, get-config, or notification) to these data nodes. These are
the subtrees and data nodes and their sensitivity/vulnerability:
Some of the RPC operations in this YANG module may be considered sensitive or
vulnerable in some network environments. It is thus important to control access
to these operations. These are the operations and their sensitivity/vulnerability:
This document registers three URIs in the IETF XML
registry . Following the format in
, the following registrations are
requested:This document registers three YANG modules in the
YANG Module Names registry .
Following the format in , the
the following registrations are requested:The authors would like to thank for following for
lively discussions on list and in the halls (ordered
by last name): Andy Bierman, Martin Bjorklund, Benoit Claise,
Mehmet Ersue, Balázs Kovács, David Lamparter, Alan Luchuk, Ladislav Lhotka,
Radek Krejci, Tom Petch, Juergen Schoenwaelder, Phil Shafer,
Sean Turner, and Bert Wijnen.This draft was split out from draft-ietf-netconf-server-model-09.Noted that '0.0.0.0' and '::' might have special meanings.Renamed "keychain" to "keystore".Removed the groupings containing transport-level configuration.
Now modules contain only the transport-independent groupings.Filled in previously incomplete 'ietf-tls-client' module.Added cipher suites for various algorithms into new
'ietf-tls-common' module.Added a 'must' statement to container 'server-auth' asserting
that at least one of the various auth mechanisms must be specified.Fixed description statement for leaf 'trusted-ca-certs'.