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Versions: 00 01 02 03 04 05 06 07 08                                    
Internet Engineering Task Force (IETF)              Phillip Hallam-Baker
Internet-Draft                                         Comodo Group Inc.
Intended Status: Standards Track                            May 19, 2014
Expires: November 20, 2014


                          OmniBroker Protocol
                    draft-hallambaker-omnibroker-08

Abstract

   An Omnibroker is an agent chosen and trusted by an Internet user to
   provide information such as name and certificate status information
   that are in general trusted even if they are not trustworthy. Rather
   than acting as a mere conduit for information provided by existing
   services, an Omnibroker is responsible for curating those sources to
   protect the user.

   The Omnibroker Protocol (OBP) provides an aggregated interface to
   trusted Internet services including DNS, OCSP and various forms of
   authentication service. Multiple transport bindings are supported to
   permit efficient access in virtually every common deployment scenario
   and ensure access in any deployment scenario in which access is not
   being purposely denied.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document. Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as



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   described in the Simplified BSD License.





















































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Table of Contents

   1.  Definitions  . . . . . . . . . . . . . . . . . . . . . . . . .  4
      1.1.  Requirements Language . . . . . . . . . . . . . . . . . .  4
   2.  Purpose  . . . . . . . . . . . . . . . . . . . . . . . . . . .  4
      2.1.  Omnibroker Discovery and Publication Services . . . . . .  4
      2.2.  Omnibroker Implementation . . . . . . . . . . . . . . . .  4
         2.2.1.  Establishing service . . . . . . . . . . . . . . . .  5
         2.2.2.  Protocol Bindings  . . . . . . . . . . . . . . . . .  5
   3.  OmniDiscovery Service  . . . . . . . . . . . . . . . . . . . .  6
      3.1.  Related Work  . . . . . . . . . . . . . . . . . . . . . .  6
   4.  Walled Gardens . . . . . . . . . . . . . . . . . . . . . . . .  6
      4.1.  Censorship  . . . . . . . . . . . . . . . . . . . . . . .  7
      4.2.  Trust Substitution  . . . . . . . . . . . . . . . . . . .  7
      4.3.  Censorship Bypass . . . . . . . . . . . . . . . . . . . .  8
   5.  Use  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8
      5.1.  Connection Broker . . . . . . . . . . . . . . . . . . . .  8
         5.1.1.  Service Connection Broker  . . . . . . . . . . . . .  8
         5.1.2.  Peer Connection Broker . . . . . . . . . . . . . . . 10
         5.1.3.  Credential Validation  . . . . . . . . . . . . . . . 11
         5.1.4.  Message: QMessage  . . . . . . . . . . . . . . . . . 12
         5.1.5.  Message: QRequest  . . . . . . . . . . . . . . . . . 12
         5.1.6.  Message: QResponse . . . . . . . . . . . . . . . . . 12
         5.1.7.  Structure: Identifier  . . . . . . . . . . . . . . . 12
         5.1.8.  Structure: Connection  . . . . . . . . . . . . . . . 13
         5.1.9.  Structure: Credential  . . . . . . . . . . . . . . . 13
         5.1.10.  Structure: CertificateID  . . . . . . . . . . . . . 13
         5.1.11.  Structure: Advice . . . . . . . . . . . . . . . . . 13
         5.1.12.  Structure: Service  . . . . . . . . . . . . . . . . 14
   6.  OBPQuery . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
      6.1.  QueryConnect  . . . . . . . . . . . . . . . . . . . . . . 14
         6.1.1.  Message: QueryConnectRequest . . . . . . . . . . . . 14
         6.1.2.  Message: QueryConnectResponse  . . . . . . . . . . . 14
      6.2.  Validate  . . . . . . . . . . . . . . . . . . . . . . . . 15
         6.2.1.  Message: ValidateRequest . . . . . . . . . . . . . . 15
         6.2.2.  Message: ValidateResponse  . . . . . . . . . . . . . 15
   7.  Transport Bindings . . . . . . . . . . . . . . . . . . . . . . 15
      7.1.  JSON Payload Binding  . . . . . . . . . . . . . . . . . . 16
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 17
      9.1.  Denial of Service . . . . . . . . . . . . . . . . . . . . 17
      9.2.  Breach of Trust . . . . . . . . . . . . . . . . . . . . . 17
      9.3.  Coercion  . . . . . . . . . . . . . . . . . . . . . . . . 17
   10.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
   11.  Example Data  . . . . . . . . . . . . . . . . . . . . . . . . 17
      11.1.  Ticket A . . . . . . . . . . . . . . . . . . . . . . . . 17
      11.2.  Ticket B . . . . . . . . . . . . . . . . . . . . . . . . 17
   12.  References  . . . . . . . . . . . . . . . . . . . . . . . . . 17
      12.1.  Normative References . . . . . . . . . . . . . . . . . . 17
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 18




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1. Definitions

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 [RFC2119].

2. Purpose

   Today, a network client is required to make queries against multiple
   information sources to establish a secure connection to a network
   resource. A DNS query is required to translate network names to
   Internet addresses. If TLS transport is used, an OSCP query may be
   required to validate the server certificate. Support for client
   authentication may require interaction with another service.

   Servers require similar support when accepting Internet connections.
   Even though most networking infrastructure supports some form of
   network administration, it is left to the network administrator to
   fill in the gap between server applications and network
   infrastructure. Making use of such facilities is rarely cost
   effective except at the very largest installations.

   An Omnibroker is a trusted agent that acts as a single point of
   service for client queries requesting a connection to a named network
   resource and server advertisements accepting connections to a named
   network resource.

2.1. Omnibroker Discovery and Publication Services

   The Omnibroker protocol is a meta-directory access protocol. As with
   any directory protocol, the two principal functions supported by
   Omnibroker are discovery and publication. These functions are
   supported by the OmniDiscover and OmniPublish Web Services.

   This specification document describes the architectural approach
   shared by both protocols and the OmniDiscover protocol. The
   OmniPublish protocol is described separately in [I-D.hallambaker-
   omnipublish].

2.2. Omnibroker Implementation

   Omnibroker Discovery and Omnibroker Publication make use of the
   following mechanisms defined in other specifications:

      Service Connection Service (SXS) [!I-D.hallambaker-wsconnect]
         To establish and manage the long term trust relationship with
         the Omnibroker provider.





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      HTTP Session Authentication [!I-D.hallambaker-httpsession]
         To provide message authentication in the HTTP/REST transport.

      UDP Framed Messaged (UYFM) described in [!I-D.hallambaker-
         wsconnect]
         For low latency transactions.

      JSON Encoding [!RFC4627]
         For encoding messages in the HTTP transport.

      JSON Binary and Compressed encodings described in [!I-
         D.hallambaker-jsonbcd]
         For efficient encoding messages in the low latency UYFM
         transport.

2.2.1. Establishing service

   In normal use, an omnibroker client receives service from a single
   Omnibroker service provider. For performance and reliability reasons,
   an Omnibroker service provider is expected to provide multiple
   Omnibroker service instances.

   An Omnibroker client acquires the network address information and
   credentials necessary to access an omnibroker service using the JCX
   Web Service to establish a connection binding. To ensure reliabilty
   and the ability to access the service in all circumstances, an
   Omnibroker connection binding SHOULD specify multiple service
   instances.

2.2.2. Protocol Bindings

   Due to the need for low latency and the need to function in a
   compromised network environment, two protocol bindings are defined:

      *  A HTTP binding using HTTP [!RFC2616] for session layer framing
         and HTTP Session Continuation [!I-D.hallambaker-httpsession]
         for message authentication and JSON encoding [!RFC4627] of
         protocol messages.

      *  A UDP Binding using UYFM framing [!I-D.hallambaker-wsconnect]
         and JSON-B encoding [!I-D.hallambaker-jsonbcd] for framing and
         encoding of protocol messages.

   The implementation overhead of support for three different protocol
   bindings is reduced by the choice of a binary encoding for JSON
   (JSON-B) that is very close in structure to JSON encoding allowing
   encoders and decoders to support both encodings with minimal
   additional code.






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   Regardless of the protocol binding used, all Omnibroker messages are
   authenticated with protection against replay attack under the
   cryptographic credentials established in the connection binding
   service instance.

3. OmniDiscovery Service

   Directing queries through a single point of contact has performance,
   relability and security advantages. Directing queries to multiple
   network information sources degrades performance and may cause a
   connection request to fail if an information resource is not
   available. This has led many application providers to limit the
   information sources they consult. Directing queries through an
   Omnibroker allows as many information sources to be brought to bear
   as the broker has local cached data for without loss of performance
   or reliability.

   Making use of additional data sources allows the broker to 'curate'
   the response. If the broker knows that a Web site always returns a
   redirect to a TLS secured version of the same site, it can tell a Web
   Browser to go straight to the secure version. If a Web Server is
   hosted on a known botnet, the Omnibroker can tell the client that it
   really does not want to visit that location.

   Unlike the traditional DNS configuration, an Omnibroker client
   decides which source(s) of trusted information to use rather than
   relying on whatever happens to be the nearest source to hand.

   The traditional DNS approach creates an obvious security risk as DNS
   is a trusted service and deciding to choose a random DNS service
   advertised by the local DHCP service is clearly a poor decision
   process for a trusted service. Further the DNS protocol does not
   protect the confidentiality or integrity of messages exchanged.

3.1. Related Work

   Omnibroker provides security for interactions with a DNS service by
   replacing the DNS protocol with a new protocol that provides a higher
   level abstract service. [I-D.hallambaker-privatedns] applies the same
   approach and platforms to provide confidentiality and integrity for
   legacy DNS protocol messages.

4. Walled Gardens

   IETF culture has traditionally resisted attempts to establish
   partitions within the open Internet with restricted access to network
   resources or compromised security. Such 'Walled Gardens' models
   typically exist for the benefits of those who own the walls rather
   than those forced to live inside them.





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   While virtually all residential Internet users reject such controls,
   most find them acceptable, if not desirable in workplaces and
   schools.

   Omnibroker simplifies the process of establishing such a walled
   garden but does not make the walls any easier to defend.

4.1. Censorship

   From a censorship point of view, the censorship concerns of running
   an Omnibroker are essentially the same as those of running a DNS
   service. The party who decides which discovery service to use can
   determine which content is visible to the users.

4.2. Trust Substitution

   Like SCVP [RFC5055] /> and XKMS [TBS], Omnibroker permits an Internet
   client to delegate some or all aspects of PKIX [RFC5280] certificate
   path chain discovery and validation.

   In the normal mode of operation, the Omnibroker service performs only
   path chain discovery, leaving the client to re-check the PKIX
   certificate path before relying on it. This gives the Omnibroker the
   power to veto a client connection to a server that it considers to be
   unsafe but not the power to tell the client to trust a site of its
   own choosing.

   This ability to veto but not assert trust is appropriate and
   sufficient for the vast majority of network applications. It allows
   the broker to make use of additional path validation checks that are
   not supported in the client such as DANE [RFC6698] or Certificate
   Transparency [RFC6962] />.

   There are however some workplace environments where the ability to
   access external network resources with strong encryption is not
   permissible by enterprise policy or in some cases by law. An
   intelligence analyst working at the NSA may have a need to access
   external Web sites that contain important information but must on no
   account have access to a covert channel that could be used to
   exfiltrate information. Certain Financial institutions with access to
   valuable commercial information are required to monitor and record
   all communications into and out of the company to deter insider
   trading.

   The traditional response to such needs has been to tell the parties
   affected to look elsewhere for support. As a consequence the
   techniques used to satisfy such requirements are generally unfriendly
   to network applications in general and have in some cases put the
   public Web PKI trust infratructure at risk.





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   There is an argument to be made that rather than attempting to
   prohibit such activities entirely, it would be better to provide a
   principled method of achieving those ends and for mainstream software
   providers to support it in such a fashion that ensures that network
   applications configured for that mode of use can be readilly
   identified as such by end users.

4.3. Censorship Bypass

   As the preceeding examples demonstrate, a party with control over the
   Omnibroker service chosen by a user has full control over the network
   activities of that user. An important corrolary of this fact is that
   all a user need do to achieve full control over their network
   activities is to run their own Omnibroker service and connect to
   that.

   For example such an Omnibroker service might be configured to return
   connection data for permitted domestic Web sites as normal but direct
   attempts to connect to forbidden foreign news or social media through
   a privacy network such as TOR.

5. Use

   For illustrative purposes, all the examples in this section are shown
   using the Web Services Transport binding. The security connection has
   already been established as described in [I-D.hallambaker-wsconnect].

5.1. Connection Broker

   The OBP service connection broker answers the query 'what connection
   parameters should be used to establish the best connection to
   interract with party X according to protocol Y. Where 'best' is
   determined by the Omnibroker which MAY take into account parameters
   specified by the relying party.

5.1.1. Service Connection Broker

   The OBP service connection broker supports and extends the
   traditional DNS resolution service that resolves a DNS name (e.g.
   www.example.com) to return an IP address (e.g. 10.1.2.3).

   When using an Omnibroker as a service connection broker, a client
   specifies both the DNS name (e.g. www.example.com) and the Internet
   protocol to be used (e.g. _http._tcp). The returned connection
   parameters MAY include:

   The IP protocol version, address and port number to establish a
   connection to. If appropriate, a security transport such as TLS or
   IPSEC. If appropriate, a description of a service credential such as
   a TLS certificate or a constraint on the type of certificates that
   the client should consider acceptable. If appropriate, application



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   protocol details such as version and protocol options.

   If an attempt to connect with the parameters specified fails, a
   client MAY report the failure and request a new set of parameters.

5.1.1.1. Service Connection Broker Example

   Alice uses her Web browser to access the URL http://www.example.com/.
   The Web browser sends a QueryConnectRequest request to obtain the
   best connection parameters for the http protocol at www.example.com:

   POST /.well-known/omni-query/ HTTP/1.1
   Content-Type: application/json;charset=UTF-8
   Cache-Control: no-store
   Session: Value=5_AlS4yMTeE82T6ZP9qAZN7TOhXtvqZ__zsLOmCxNrQ;
     Id=o7znkpTHfrqcwsI1eHkPghCj7YsGUCp0KV2DcV1qXGlCt9wzmr2T6UcO_0YI
     AcEqVdTsqRsYBtVNGs9SJyTCnMvjIlU1xQ9ZzoUtqtJsT4A
   Host: localhost:8080
   Content-Length: 123
   Expect: 100-continue

   {
     "QueryConnectRequest": {
       "Identifier": {
         "Name": "Example.com",
         "Service": "_http",
         "Port": 80}}}

   The service responds with an ordered list of possible connections. In
   this case the site is accessible via plain TCP transport or with TLS.
   Since TLS is the preferred protocol, that connection is listed first.























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   HTTP/1.1 OK Success
   Content-Length: 371
   Date: Mon, 19 May 2014 17:17:43 GMT
   Server: Microsoft-HTTPAPI/2.0

   {
     "QueryConnectResponse": {
       "Status": 200,
       "StatusDescription": "Success",
       "Connection": [{
           "IPAddress": "10.3.2.1",
           "IPPort": 443,
           "Transport": "TLS",
           "TransportPolicy": "TLS=Optional",
           "ProtocolPolicy": "Strict"},
         {
           "IPAddress": "10.3.2.1",
           "IPPort": 80,
           "ProtocolPolicy": "Strict"}]}}

5.1.2. Peer Connection Broker

   Each OBP request identifies both the account under which the request
   is made and the device from which it is made. An OBP broker is thus
   capable of acting as a peer connection broker service or providing a
   gateway to such a service.

   When using Omnibroker as a peer connection broker, a client specifies
   the account name and DNS name of the party with which a connection is
   to be established (e.g. alice@example.com) and the connection
   protocol to be used (e.g. _xmpp-client._tcp)

   The returned connection parameters are similar to those returned in
   response to a service broker query.

5.1.2.1. Service Connection Broker Example

   Although the QueryConnectResponse returned the hash of a PKIX
   certificate considered valid for that connection, the server returns
   a different certificate which the client verifies using the
   ValidateRequest query.













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   [POST /.well-known/omni-query/ HTTP/1.1
   Content-Type: application/json;charset=UTF-8
   Cache-Control: no-store
   Session: Value=ebgTLvWjZFeTMnowmomslUu9rPvzAPAciO11QK26NQg;
     Id=o7znkpTHfrqcwsI1eHkPghCj7YsGUCp0KV2DcV1qXGlCt9wzmr2T6UcO_0YI
     AcEqVdTsqRsYBtVNGs9SJyTCnMvjIlU1xQ9ZzoUtqtJsT4A
   Host: localhost:8080
   Content-Length: 1126
   Expect: 100-continue

   {
     "ValidateRequest": {
       "Service": {
         "Identifier": [{
             "Name": "example.com"}]},
       "Credential": [{
           "Data": "
   MIIC0DCCAbigAwIBAgIQQut6m1F0PodIjIzop_d1uDANBgkqhkiG9w0BAQUFADAR
   MQ8wDQYDVQQDEwZWb29kb28wHhcNMTMwNjI2MTczOTQyWhcNMTQwNjI2MDAwMDAw
   WjARMQ8wDQYDVQQDEwZWb29kb28wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEK
   AoIBAQCdc7Qgx71o6Tq5dFUUhcCn8Nt-2Y9SGhm3WvsMYIqOIcHq3gjIKN9FWvXz
   pBbTjz4lCwx-CJT82RBLNDFtsysfc0G7K_RsNKosYaM-L-DshO6R_314tptn9gnT
   9tjTPXuiiICQlAP83BuTI148iEJWL36vbmv5AG6vrtk3T6ah5r2hBXQjt46sLQYw
   eiM-peYIhPTIy9OYugogfqdzPvaJpDfAukqJBXqMxfscagKPYAGPaICKhobKr11a
   Pam1Tchk2cBbtuYgSDz6ZGttsKE2omDbcmhbF7gBpRug-E2OH79Q4EVlSSoO9gZ6
   AF4Km1A9uK9W_Pg8EPugY3Mgns6lAgMBAAGjJDAiMAsGA1UdDwQEAwIEMDATBgNV
   HSUEDDAKBggrBgEFBQcDATANBgkqhkiG9w0BAQUFAAOCAQEACK9LQNkewOOugaYh
   s4LfE3xdrRzrcaR0w5cf3wVcgR0ZZo98rDOtu3FAexpdh6vNaIdU4zAzNJPKKSso
   3XF2LpQZovKIpUuN9pkZqslqZ0TLXqlyXMbheShcqIP1-m6qjZOp95N7jwgxBlEm
   i_ne-rg1DicXFtAu90LpAZludaQGAyrj-LC37gzeMo2AG7BAuyFURXJFfxjpGmnu
   euYfzZIMIQY-lNl6qm_vSMIz4uUKqq4lWndahnkJAwI2p5zUM0z3O6OMr_zr8eyr
   dAL__H4NnG3gVyBbNoSbvbkxUt_C3oBwFFTupzRMQqJVjzbApyw5H0OzJPJKKkxx
   hmIYTg"}]}}

   The service validates the certificate according to the Omnibroker
   service policy.

   [HTTP/1.1 OK Success
   Content-Length: 81
   Date: Mon, 19 May 2014 17:17:43 GMT
   Server: Microsoft-HTTPAPI/2.0

   {
     "ValidateResponse": {
       "Status": 200,
       "StatusDescription": "Success"}}








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5.1.3. Credential Validation

   The credential validation query provides certificate path validation
   and status checking.

   The service provided by OBP is similar to that provided by OCSP and
   SCVP. Like SCVP, OBP is an agent selected by the relying party to
   validate certificates and/or construct trust paths on its behalf.

5.1.4. Message: QMessage

5.1.5. Message: QRequest

   Every query request contains the following common elements:

      Index :
         Integer [0..1] Index used to request a specific response when
         multiple responses are available.

5.1.6. Message: QResponse

   Every Query Response contains the following common elements:

      Status :
         Integer [1..1] Status return code value

      StatusDescription :
         String [0..1] Describes the status code (ignored by processors)

      Index :
         Integer [0..1] Index of the current response.

      Count :
         Integer [0..1] Number of responses available.

5.1.7. Structure: Identifier

   Specifies an Internet service by means of a DNS address and either a
   DNS service prefix, an IP port number or both. An Internet peer
   connection MAY be specified by additionally specifying an account.

      Name :
         Name [1..1] The DNS name of the service to connect to.
         Internationalized DNS names MUST be encoded in punycode
         encoding.

      Account :
         Label [0..1] Identifies the account to connect to in the case
         that a peer connection is to be established.





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      Service :
         Name [0..1] The DNS service prefix defined for use with DNS
         records that take a service prefix including SRV.

      Port :
         Integer [0..1] IP Port number. A service identifier MUST
         specify either a service or a port or both.

5.1.8. Structure: Connection

      IPAddress :
         String [0..1] IP address in string representation

      IPPort :
         Integer [0..1] IP port. 1-65535

      Transport :
         String [0..1] Transport (RAW, TLS, IPSEC)

      TransportPolicy :
         String [0..1] Transport security policy as specified in [TBS]

      ProtocolPolicy :
         String [0..1] Application security policy specification as
         specified by the application protocol.

      Advice :
         Advice [0..1] Additional information that a service MAY return
         to support a service connection identification.

5.1.9. Structure: Credential

      Type :
         String [0..1] [TBS]

      Data :
         Binary [0..1] [TBS]

5.1.10. Structure: CertificateID

      Type :
         String [0..1] [TBS]

      Data :
         Binary [0..1] [TBS]

5.1.11. Structure: Advice

   Additional information that a service MAY return to support a service
   connection identification. For example, DNSSEC signatures chains,
   SAML assertions, DANE records, Certificate Transparency proof chains,



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   etc.

      Type :
         Label [0..1] The IANA MIME type of the content type

      Data :
         Binary [0..1] The advice data.

5.1.12. Structure: Service

   Describes a service connection

      Identifier :
         Identifier [0..Many] Internet addresses to which the service is
         to be bound.

      Connection :
         Connection [0..1] Service connection parameters.

6. OBPQuery

6.1. QueryConnect

   Requests a connection context to connect to a specified Internet
   service or peer.

6.1.1. Message: QueryConnectRequest

   Specifies the Internet service or peer that a connection is to be
   established to and the acceptable security policies.

      Identifier :
         Identifier [0..1] Identifies the service or peer to which a
         connection is requested.

      Policy :
         Label [0..Many] Acceptable credential validation policy.

      ProveIt :
         Boolean [0..1] If set the broker SHOULD send advice to permit
         the client to validate the proposed connection context.

6.1.2. Message: QueryConnectResponse

   Returns one or more connection contexts in response to a
   QueryConnectRequest Message.

      Connection :
         Connection [0..Many] An ordered list of connection contexts
         with the preferred connection context listed first.




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      Advice :
         Advice [0..1] Proof information to support the proposed
         connection context.

      Policy :
         Label [0..Many] Policy under which the credentials have been
         verified.

6.2. Validate

   The Validate query requests validation of credentials presented to
   establish a connection. For example credentials presented by a server
   in the process of setting up a TLS session.

6.2.1. Message: ValidateRequest

   Specifies the credentials to be validated and the purpose for which
   they are to be used.

      Service :
         Service [0..1] Describes the service for which the credentials
         are presented for access.

      Credential :
         Credential [0..Many] Credentials for which validation is
         requested.

      CertificateID :
         CertificateID [0..Many] OCSP Certificate Identifiers for which
         validation is requested.

      Policy :
         Label [0..Many] Policy under which the credentials have been
         verified.

6.2.2. Message: ValidateResponse

   Reports the status of the credential presented.

      Policy :
         Label [0..Many] Policy under which the credentials have been
         verified.

7. Transport Bindings

   To achieve an optimal balance of efficiency and availability, two
   transport bindings are defined:







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      JSON over HTTP (TLS or TCP)
         Supports all forms of OBP transaction in all network
         environments.

      JSON-B over UYFM (UDP)
         Provides efficient support for all OBP query transactions and
         is accessible in most network environments.

   Support for the HTTP binding is REQUIRED.

   An OBP message consists of three parts:

      Ticket [If required]
         If specified, identifies the cryptographic key and algorithm
         parameters to be used to secure the message payload.

      Payload [Required]
         If the ticket context does not specify use of an encryption
         algorithm, contains the message data. Otherwise contains the
         message data encrypted under the encryption algorithm and key
         specified in the ticket context.

      Authenticator [If required]
         If the ticket context specifies use of a Message Authentication
         Code (MAC), contains the MAC value calculated over the payload
         data using the authentication key bound to the ticket.

   Note that although each of the transport bindings defined in this
   specification entail the use of a JSON encoding for the message data,
   this is not a necessary requirement for a transport binding.

7.1. JSON Payload Binding

      Integer
         Data of type Integer is encoded using the JSON number encoding.

      Name
         Data of type Name is encoded using the JSON string encoding.

      String
         Data of type String is encoded using the JSON string encoding.

      Binary
         Data of type Binary is converted to strings using the Base64url
         encoding specified in [!RFC4648] /> and encoded using the JSON
         string type.

      DateTime
         Data of type DateTime is converted to string using the UTC time
         conversion specified in [!RFC3339] /> with a UTC offset of
         00:00.



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8. Acknowledgements

   Rob Stradling, Robin Alden...

9. Security Considerations

9.1. Denial of Service

9.2. Breach of Trust

9.3. Coercion

10. IANA Considerations

   [TBS list out all the code points that require an IANA registration]

11. Example Data

11.1. Ticket A

11.2. Ticket B

12. References

12.1. Normative References

   [RFC6698]  Hoffman, P.,Schlyter, J., "The DNS-Based Authentication of
              Named Entities (DANE) Transport Layer Security (TLS)
              Protocol: TLSA", RFC 6698, August 2012.

   [RFC5280]  Cooper, D.,Santesson, S.,Farrell, S.,Boeyen, S.,Housley,
              R.,Polk, W., "Internet X.509 Public Key Infrastructure
              Certificate and Certificate Revocation List (CRL)
              Profile", RFC 5280, May 2008.

   [RFC5055]  Freeman, T.,Housley, R.,Malpani, A.,Cooper, D.,Polk, W.,
              "Server-Based Certificate Validation Protocol (SCVP)", RFC
              5055, December 2007.

   [RFC6962]  Laurie, B.,Langley, A.,Kasper, E., "Certificate
              Transparency", RFC 6962, June 2013.

   [I-D.hallambaker-omnipublish]  , "[Reference Not Found!]".

   [RFC3339]  ,Klyne, G.,Newman, C., "Date and Time on the Internet:
              Timestamps", RFC 3339, July 2002.

   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, October 2006.




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   [I-D.hallambaker-httpsession]  Hallam-Baker, P, "HTTP Session
              Management", Internet-Draft draft-hallambaker-httpsession-
              02, 21 January 2014.

   [I-D.hallambaker-wsconnect]  Hallam-Baker, P, "JSON Service Connect
              (JCX) Protocol", Internet-Draft draft-hallambaker-
              wsconnect-05, 21 January 2014.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC4627]  Crockford, D., "The application/json Media Type for
              JavaScript Object Notation (JSON)", RFC 4627, July 2006.

   [I-D.hallambaker-privatedns]  Hallam-Baker, P, "Private-DNS",
              Internet-Draft draft-hallambaker-privatedns-00, 9 May
              2014.

   [RFC2616]  Fielding, R.,Gettys, J.,Mogul, J.,Frystyk, H.,Masinter,
              L.,Leach, P.,Berners-Lee, T., "Hypertext Transfer Protocol
              -- HTTP/1.1", RFC 2616, June 1999.

   [I-D.hallambaker-jsonbcd]  Hallam-Baker, P, "Binary Encodings for
              JavaScript Object Notation: JSON-B, JSON-C, JSON-D",
              Internet-Draft draft-hallambaker-jsonbcd-01, 21 January
              2014.

Author's Address

   Phillip Hallam-Baker
   Comodo Group Inc.

   philliph@comodo.com





















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