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Versions: 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 RFC 7472

Network Working Group                                       Ira McDonald
INTERNET-DRAFT                                            High North Inc
Updates: 2910, 2911 (if approved)                          Michael Sweet
Intended Status: Standards Track                               Apple Inc
Expires: 20 October 2014                                   20 April 2014


         IPP over HTTPS Transport Binding and 'ipps' URI Scheme
                 draft-mcdonald-ipps-uri-scheme-12.txt


Abstract

   This memo defines the Internet Printing Protocol (IPP) over HTTPS
   transport binding and the corresponding 'ipps' URI scheme, that is
   used to designate the access to the network location of a secure IPP
   print service or a network resource (for example, a print job)
   managed by such a service.

   This memo is an individual submission to the IETF by the Internet
   Printing Protocol Working Group of the IEEE-ISTO Printer Working
   Group, as part of their PWG IPP Everywhere (PWG 5100.14) project for
   secure mobile printing with vendor-neutral Client software.

   This memo defines an alternate IPP transport binding to that defined
   in the original IPP URL Scheme (RFC 3510), but this memo does not
   update or obsolete (RFC 3510).

   This memo updates RFC 2910 and RFC 2911.


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), its areas,
   and its working groups.  Note that other groups may also distribute
   working documents as Internet-Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html

   This Internet-Draft will expire on 20 October 2014.


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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
   described in the Simplified BSD License.


                           Table of Contents

1.  Introduction ...............................................       4
  1.1.  Structure of this document .............................       4
  1.2.  Rationale for this document ............................       5
2.  Conventions Used in this Document ..........................       5
  2.1.  Printing Terminology ...................................       5
  2.2.  Abbreviations ..........................................       6
3.  IPP over HTTPS Transport Binding ...........................       7
4.  Definition of 'ipps' URI Scheme ............................       8
  4.1.  Applicability of 'ipps' URI Scheme .....................       8
  4.2.  Syntax of 'ipps' URI Scheme ............................       9
  4.3.  Associated Port for 'ipps' URI Scheme ..................      10
  4.4.  Associated MIME Type for 'ipps' URI Scheme .............      11
  4.5.  Character Encoding of 'ipps' URI Scheme ................      11
  4.6.  Examples of 'ipps' URI .................................      11
    4.6.1.  Examples of 'ipps' URI for Printers ................      11
    4.6.2.  Examples of 'ipps' URI for Jobs ....................      12
  4.7.  Comparisons of 'ipps' URI ..............................      13
5.  Applicability of this Specification ........................      13
  5.1.  Applicability to IPP Clients ...........................      13
  5.2.  Applicability to IPP Printers ..........................      14
6.  IANA Considerations ........................................      15
7.  Security Considerations ....................................      16
  7.1.  Problem Statement ......................................      16
    7.1.1.  Targets of Attacks .................................      16
    7.1.2.  Layers of Attacks ..................................      17
  7.2.  Attacks and Defenses ...................................      17
    7.2.1.  Faked 'ipps' URI ...................................      17
    7.2.2.  Unauthorized Access by IPP Client ..................      18
    7.2.3.  Compromise at Application Layer Gateway ............      18
    7.2.4.  No Client Authentication for 'ipps' URI ............      18
  7.3.  TLS Cipher Suite Requirements ..........................      18

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8.  Acknowledgments ............................................      19
9.  References .................................................      20
  9.1.  Normative References ...................................      20
  9.2.  Informative References .................................      21
10.  Appendix A - Summary of IPP URL Scheme (Informative) ......      22
11.  Appendix X - Change History ...............................      23
12.  Authors' Addresses ........................................      28













































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1.  Introduction

   This document defines the Internet Printing Protocol (IPP) over HTTPS
   transport binding and the corresponding 'ipps' URI scheme, that is
   used to designate the access to the network location of a secure IPP
   print service or a network resource (for example, a print job)
   managed by such a service.

   This document is an individual submission to the IETF by the Internet
   Printing Protocol Working Group of the IEEE-ISTO Printer Working
   Group, as part of their PWG IPP Everywhere [PWG5100.14] project for
   secure mobile printing with vendor-neutral Client software.

   This document defines an alternate IPP transport binding to that
   defined in the original IPP URL Scheme [RFC3510], but this document
   does not update or obsolete [RFC3510].

   This document updates [RFC2910] and [RFC2911].

   This document updates:
   a) IPP/1.1 Encoding and Transport [RFC2910], by extending section 4
      'Encoding of the Transport Layer', section 5 'IPP URL Scheme', and
      section 8.2 'Using IPP with TLS';
   b) IPP/1.1 Model and Semantics [RFC2911], by extending section 4.1.6
      'uriScheme' and section 4.4.1 'printer-uri-supported'; and
   c) IEEE-ISTO PWG IPP Version 2.0 Second Edition [PWG5100.12], by
      extending section 4 'IPP Standards' and section 10 'Security
      Considerations'.

   The following versions of IPP are currently defined:
   - 1.0 in [RFC2566] (obsolete)
   - 1.1 in [RFC2911]
   - 2.0 in [PWG5100.12]
   - 2.1 in [PWG5100.12]
   - 2.2 in [PWG5100.12]

   Overview information about IPP is available in section 1 of RFC 2911
   [RFC2911], section 1 of RFC 3196 [RFC3196], and section 1 of PWG IPP
   Version 2.0 Second Edition [PWG5100.12].



1.1.  Structure of this document

   This document contains the following sections:  Section 2 defines the
   conventions used throughout the document.

   Section 3 defines the IPP over HTTPS transport binding.


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   Section 4 defines the 'ipps' URI scheme.

   Section 5 defines the applicability of this specification to IPP
   Clients and IPP Printers.

   Sections 6 and 7 contain IANA and security considerations,
   respectively.

   Section 8 containes acknowledgments.

   Section 9 contains references.

   Appendix A contains an informative summary of the original IPP URL
   Scheme [RFC3510] and associated IPP over HTTP transport binding.



1.2.  Rationale for this document

   The 'ipps' URI scheme was defined for the following reasons:

   1) Some existing IPP Client and IPP Printer implementations of
      Upgrading to TLS Within HTTP/1.1 [RFC 2817] are flawed and
      unreliable.

   2) Some existing IPP Client and IPP Printer implementations of HTTP
      Upgrade [RFC 2717] do not perform upgrade at the beginning of
      every HTTP connection, but instead only shift to secure IPP for
      selected IPP operations (inherently dangerous behavior on the same
      underlying TCP connection).

   3) IPP Printer server-mandated HTTP Upgrade [RFC 2817] can still lead
      to exposure of IPP Client data if the Expect request header is not
      used - basically the IPP Client can send its whole Print-Job
      request before the IPP Printer has a chance to respond and say,
      "Wait!  You need to encrypt first!"



2.  Conventions Used in this Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].


2.1.  Printing Terminology

   The reader of this document needs to be familiar with the printing
   terms defined in IPP/1.1 Model and Semantics [RFC2911] as well as the

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   following:

   IPP Client:  The software (on some hardware platform) that submits
   IPP Job creation and IPP Printer and IPP Job management operations
   via the IPP over HTTP transport binding defined in the IPP/1.1
   Encoding and Transport [RFC2910] and/or the IPP over HTTPS transport
   binding defined in section 3 of this specification to a downstream
   IPP Printer (print spooler, print gateway, or physical printing
   device).

   IPP Job:  The set of attributes and documents for one print job
   instantiated in an IPP Printer.

   IPP Job object:  Synonym for IPP Job.

   IPP Printer:  The software (on some hardware platform) that receives
   IPP Job creation and IPP Printer and IPP Job management operations
   via the IPP over HTTP transport binding defined in the IPP/1.1
   Encoding and Transport [RFC2910] and/or the IPP over HTTPS transport
   binding defined in section 3 of this specification from an upstream
   IPP Client or IPP Printer.

   IPP Printer object:  Synonym for IPP Printer.

   'ipps' URI:  A URI using the 'ipps' URI scheme defined in section 4
   of this specification.



2.2.  Abbreviations

   This document makes use of the following abbreviations (given with
   their expanded forms and references for further reading):

   ABNF   - Augmented Backus-Naur Form [STD68]

   ASCII  - American Standard Code for Information Interchange [ASCII]

   HTTP   - HyperText Transfer Protocol [RFC2616]

   HTTPS  - HTTP over TLS [RFC2818]

   IANA   - Internet Assigned Numbers Authority
            <http://www.iana.org>

   IEEE   - Institute of Electrical and Electronics Engineers
            <http://www.ieee.org>

   IESG   - Internet Engineering Steering Group
            <http://www.ietf.org/iesg/>


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   IPP    - Internet Printing Protocol [RFC2911] and [PWG5100.12]
            <http://www.pwg.org/ipp/>

   ISTO   - IEEE Industry Standards and Technology Organization
            <http://www.ieee-isto.org/>

   LPD    - Line Printer Daemon Protocol [RFC1179]

   PWG    - IEEE-ISTO Printer Working Group
            <http://www.pwg.org>

   RFC    - Request for Comments
            <http://www.rfc-editor.org/rfc.html>

   TCP    - Transmission Control Protocol [STD7]

   TLS    - Transport Layer Security [RFC5246]

   URI    - Uniform Resource Identifier [STD66]

   URL    - Uniform Resource Locator [STD66]

   UTF-8  - Unicode Transformation Format - 8-bit [STD63]



3.  IPP over HTTPS Transport Binding

   This section is a normative description of the protocol steps taken
   by an IPP Client using and an IPP Printer supporting the 'ipps' URI
   scheme.

   This document defines the following alternate IPP over HTTPS
   transport binding for the abstract protocol defined in IPP/1.1 Model
   and Semantics [RFC2911] and IEEE-ISTO PWG IPP Version 2.0 Second
   Edition [PWG5100.12].

   When using an 'ipps' URI, an IPP Client MUST establish an IPP
   application layer connection according to the following sequence:

   1) The IPP Client selects an 'ipps' URI value from
      "printer-uri-supported" Printer attribute [RFC2911], a directory
      entry, discovery info, a web page, etc.;

   2) The IPP Client converts the 'ipps' URI to an 'https' URI
      (replacing 'ipps' with 'https' and inserting the port number from
      the URI or port 631 if the URI doesn't include a port number);

   3) The IPP Client establishes a TCP [STD7] reliable transport layer
      connection to the target endpoint - see section 3.4 'Establishing

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      a connection' in TCP [STD7];

   4) The IPP Client establishes a TLS/1.0 [RFC2246], TLS/1.1 [RFC4346],
      TLS/1.2 [RFC5246], or later TLS version secure transport layer
      connection to the target endpoint - see section 7 'The TLS
      Handshake Protocol' in [RFC2246], [RFC4346], and [RFC5246];

   5) The IPP Client establishes an HTTPS [RFC2818] secure session layer
      connection over the TLS secure transport layer to the target
      endpoint; and

   6) The IPP Client sends IPP application layer requests to and
      receives responses from the IPP Printer over the HTTPS [RFC2818]
      secure session layer connection using the POST method defined in
      section 9.5 of HTTP/1.1 [RFC2616], as specified in section 4
      'Encoding of Transport Layer' in IPP/1.1 Encoding and Transport
      [RFC2910].

   See:  Section 'Security Considerations' in [RFC2818].

   See:  Section 10 'Security Considerations' in [PWG5100.12].



4.  Definition of 'ipps' URI Scheme



4.1.  Applicability of 'ipps' URI Scheme

   The 'ipps' URI scheme MUST only be used to specify absolute URI
   (relative 'ipps' URI are not allowed) for IPP secure print services
   and their associated network resources.  The 'ipps' URI scheme MUST
   only be used to specify the use of the abstract protocol defined in
   IPP/1.1 Model and Semantics [RFC2911] and IEEE-ISTO PWG IPP Version
   2.0 Second Edition [PWG5100.12] over an HTTPS [RFC2818] transport, as
   defined in this specification.  Any other transport binding for IPP
   would require a different URI scheme.

   The 'ipps' URI scheme allows an IPP Client to choose an appropriate
   IPP secure print service (for example, from a directory).  The IPP
   Client can establish an HTTPS connection to the specified IPP secure
   print service.  The IPP Client can send IPP protocol requests (for
   example, 'Print-Job' requests) and receive IPP protocol responses
   over that HTTPS connection.

   See:  Section 4.2 (syntax) of this document.

   See:  Section 4.4.1 'printer-uri-supported' in IPP/1.1 Model and
   Semantics [RFC2911].


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   See:  Section 5 'IPP URL Scheme' in IPP/1.1 Encoding and Transport
   [RFC2910].

   See:  Section 4 'IPP Standards' and section 10 'Security
   Considerations' of IEEE-ISTO PWG IPP Version 2.0 Second Edition
   [PWG5100.12].



4.2.  Syntax of 'ipps' URI Scheme

   The abstract protocol defined in IPP/1.1 Model and Semantics
   [RFC2911] places a limit of 1023 octets (NOT characters) on the
   length of a URI.

   See:  Section 4.1.5 'uri' in [RFC2911].

   Note:  IPP Printers SHOULD be cautious about depending on URI lengths
   above 255 octets, because some older IPP Client implementations might
   not properly support these lengths.

   'ipps' URI MUST be represented in absolute form.  Absolute URI MUST
   always begin with a scheme name followed by a colon.  For definitive
   information on URI syntax and semantics, see "Uniform Resource
   Identifiers (URI) Generic Syntax and Semantics" [STD66].  This
   specification adopts the definitions of "host", "port",
   "path-absolute", and "query" from [STD66].

   The 'ipps' URI scheme syntax in ABNF [STD68] is defined as follows:

   ipps-uri =
       "ipps:" "//" host [ ":" port ] [ path-absolute [ "?" query ]]

   If the port is empty or not given, then port 631 MUST be used.

   See:  Section 4.3 (port) of this document.

   The semantics are that the identified resource (see section 5.1.2 of
   [RFC2616]) is located at the IPP secure print service listening for
   HTTPS connections on that port of that host, and the Request-URI for
   the identified resource is 'path-absolute'.

   Note:  The higher-level "authority" production is not imported from
   [STD66], because it includes an optional "userinfo" component which
   cannot be used in 'ipps' URI.

   Note:  The "query" production does not have defined semantics in IPP
   and was never used in examples in IPP/1.1 Encoding and Transport
   [RFC2910] or the original IPP URL Scheme [RFC3510].  The "query" is
   retained here for consistency, but IPP Clients SHOULD avoid its use

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   (because the semantics could only be implementation-defined).

   Note:  Literal IPv4 or IPv6 addresses SHOULD NOT be used in 'ipps'
   URI, because:
   a) IP addresses are often changed after network device installation
      (for example, based on DHCP reassignment after a power cycle);
   b) IP addresses often don't map simply to security domains;
   c) IP addresses are difficult to validate with X.509 server
      certificates (because they do not map to common name or alternate
      name attributes); and
   d) IPv6 link local addresses are not "portable" due to link identity

   If the 'path-absolute' is not present in the URI, it MUST be given as
   "/" when used as a Request-URI for a resource (see section 5.1.2 of
   [RFC2616]).

   An 'ipps' URI is transformed into an 'https' URI by replacing "ipps:"
   with "https:" and inserting port 631 (if the 'port' is not present in
   the original 'ipps' URI).

   See:  Section 4.3 (port) of this document.



4.3.  Associated Port for 'ipps' URI Scheme

   All 'ipps' URI which do NOT explicitly specify a port MUST be
   resolved to IANA-assigned well-known port 631, already registered in
   [PORTREG] for IPP/1.1 Encoding and Transport [RFC2910].

   Note:  Port 631 is used for both 'ipp' [RFC3510] and 'ipps' URI, both
   of which refer to an IPP print service or a network resource managed
   by such a service (for example, a print job), for consistency with
   recent IETF best practices.  IPP Printer implementors can refer to
   the CUPS [CUPS] source code for an example of incoming connection
   handling for the dual use of port 631.

   Note:  For compatibility with existing IPP Client and IPP Printer
   implementations, explicit port 443 (assigned in the 'https' URI
   scheme [RFC2818]) MUST be accepted in 'ipps' URI and processed
   normally by IPP Clients and IPP Printers.

   See:  IANA Port Numbers Registry [PORTREG].

   See:  IPP/1.1 Encoding and Transport [RFC2910].







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4.4.  Associated MIME Type for 'ipps' URI Scheme

   All 'ipps' URI MUST be used to specify secure print services which
   support the "application/ipp" MIME media type as registered in
   [MIMEREG] for IPP protocol requests and responses.

   See:  IANA MIME Media Types Registry [MIMEREG].

   See:  IPP/1.1 Encoding and Transport [RFC2910].



4.5.  Character Encoding of 'ipps' URI Scheme

   'ipps' URI MUST use the UTF-8 [STD63] charset for all components.
   'ipps' URI MUST use [STD66] rules for percent encoding data octets
   outside the US-ASCII coded character set [ASCII].



4.6.  Examples of 'ipps' URI



4.6.1.  Examples of 'ipps' URI for Printers

   The following are examples of well-formed 'ipps' URI for IPP Printers
   (for example, to be used as protocol elements in 'printer-uri'
   operation attributes of 'Print-Job' request messages):

       ipps://example.com
       ipps://example.com/ipp
       ipps://example.com/ipp/tiger
       ipps://example.com/ipp/fox
       ipps://example.com/ipp/tiger/bob
       ipps://example.com/ipp/tiger/ira

   Each of the above URI are well-formed URI for IPP Printers and each
   would reference a logically different IPP Printer, even though some
   of those IPP Printers might share the same host system.  The 'bob' or
   'ira' last path components might represent two different physical
   printer devices, while 'tiger' might represent some grouping of IPP
   Printers (for example, a load-balancing spooler).  Or the 'bob' and
   'ira' last path components might represent separate human recipients
   on the same physical printer device (for example, a physical printer
   supporting two job queues).  In either case, both 'bob' and 'ira'
   would behave as different and independent IPP Printers.

   The following are examples of well-formed 'ipps' URI for IPP Printers

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   with (optional) ports and paths:

       ipps://example.com
       ipps://example.com/ipp
       ipps://example.com:631/ipp
       ipps://example.com:443/ipp

   The first and second 'ipps' URI above MUST be resolved to port 631
   (IANA assigned well-known port for IPP).  The second and third 'ipps'
   URI above are equivalent (see section 4.7 below).  The fourth 'ipps'
   URI above uses the explicit port 443 (see section 4.3 above).

   See:  Section 4.2 (syntax) and section 4.3 (port) of this document.



4.6.2.  Examples of 'ipps' URI for Jobs

   The following are examples of well-formed 'ipps' URI for IPP Jobs
   (for example, to be used as protocol elements in 'job-uri' attributes
   of 'Print-Job' response messages):

       ipps://example.com/ipp/123
       ipps://example.com/ipp/tiger/job123

   'ipps' URI for Jobs are valid and meaningful only until Job
   completion and possibly an implementation defined optional period of
   persistence after Job completion (see IPP Model [RFC2911]).

   Ambiguously, section 4.3.1 'job-uri' of IPP Model [RFC2911] states
   that:

      "the precise format of a Job URI is implementation dependent."

   Thus, the relationship between the value of the "printer-uri"
   operation attribute used in a 'Print-Job' request and the value of
   the "job-uri" attribute returned in the corresponding 'Print-Job'
   response is entirely implementation dependent.  Also, section 4.3.3
   'job-printer-uri' of IPP Model [RFC2911] states that the
   'job-printer-uri' attribute of a Job object:

      "permits a client to identify the Printer object that created this
      Job object when only the Job object's URI is available to the
      client."

   However, the above statement is erroneous, because the transform from
   a URI for an IPP Job to the corresponding URI for the associated IPP
   Printer is unspecified in either IPP/1.1 Model and Semantics
   [RFC2911] or IPP/1.1 Encoding and Transport [RFC2910].

   Note:  IPP Printers that implement this specification SHOULD only

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   generate 'ipps' URI for Jobs (for example, in the "job-uri" attribute
   in a 'Print-Job' response) by appending exactly one path component to
   the corresponding 'ipps' URI for the associated Printer.



4.7.  Comparisons of 'ipps' URI

   When comparing two 'ipps' URI to decide if they match or not, an IPP
   Client MUST use the same rules as those defined for 'http' URI
   comparisons in [RFC2616] as updated by the 'https' URI scheme
   [RFC2818], with the sole following exception:

   - A port that is empty or not given MUST be treated as equivalent to
     the well-known port for that 'ipps' URI (port 631).

   See:  Section 4.3 (port) in this document.

   See:  Section 3.2.3 'URI Comparison' in [RFC2616].

   See:  Section 2.4 'URI Format' in [RFC2818].



5.  Applicability of this Specification



5.1.  Applicability to IPP Clients

   IPP Clients that implement this specification:

   a) MUST support the IPP over HTTPS transport binding defined in
      section 3 and the 'ipps' URI scheme defined in section 4;

   b) MUST support the IPP over HTTP transport binding with TLS defined
      in section 8.2 'Using IPP with TLS' of IPP/1.1 Encoding and
      Transport [RFC2910] (for interoperability with existing IPP
      implementations);

   c) MUST support the IPP over HTTPS transport binding defined in
      section 3 of this specification;

   d) MUST use the required TLS version(s) according to the
      corresponding IPP versions as defined in section 7 of this
      specification;

   e) MUST only send IPP protocol connections to IANA assigned
      well-known port 631 or to the explicit port specified in a given
      'ipps' URI;


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   f) MUST only send 'ipps' URI used as protocol elements in outgoing
      IPP protocol request messages that conform to the ABNF specified
      in section 4.2 of this document (for example, in the "printer-uri"
      operation attribute in a 'Print-Job' request);

   g) MUST only convert 'ipps' URI to their corresponding 'https' URI
      forms [RFC2818] according to the rules in section 4.2 of this
      document.

   See:  Section 4.2 (syntax) and section 4.3 (port) of this document.



5.2.  Applicability to IPP Printers

   IPP Printers that implement this specification:

   a) MUST support the IPP over HTTPS transport binding defined in
      section 3 and the 'ipps' URI scheme defined in section 4;

   b) MUST support the IPP over HTTP transport binding with TLS defined
      in section 8.2 'Using IPP with TLS' of IPP/1.1 Encoding and
      Transport [RFC2910] (for interoperability with existing IPP
      implementations);

   c) MUST support the IPP over HTTPS transport binding defined in
      section 3 of this specification;

   d) MUST use the required TLS version(s) according to the
      corresponding IPP versions as defined in section 7 of this
      specification;

   e) MUST only generate 'ipps' URI used as protocol elements in
      outgoing IPP protocol response messages that conform to the ABNF
      specified in section 4.2 of this document (for example, in the
      "job-uri" attribute in a 'Print-Job' response);

   f) SHOULD only accept 'ipps' URI used as protocol elements in
      incoming IPP protocol request messages that conform to the ABNF
      specified in section 4.2 of this document (for example, in the
      "printer-uri" operation attribute in a 'Print-Job' request);

   g) SHOULD only generate 'ipps' URI for Jobs by appending exactly one
      path component to the corresponding 'ipps' URI for the associated
      Printer (for example, in the "job-uri" attribute in a 'Print-Job'
      response);

   h) SHOULD NOT generate 'ipps' URI that use literal IPv6 or IPv4
      addresses (see section 4.2 for rationale).


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   See:  Section 4.2 (syntax) and section 4.3 (port) of this document.



6.  IANA Considerations

   [RFC Editor:  Replace 'xxxx' with assigned RFC number before
   publication]

   IANA is asked to register the 'ipps' URI scheme using the following
   template, which conforms to [BCP35].

   URI scheme name:  ipps

   Status:  Permanent

   URI scheme syntax:  See section 4.2 of RFC xxxx.

   URI scheme semantics:  The 'ipps' URI scheme is used to designate
   secure IPP Printer objects (print spoolers, print gateways, print
   devices, etc.) on Internet hosts accessible using the IPP protocol
   enhanced to support guaranteed data integrity and negotiable data
   privacy using TLS as specified in HTTP over TLS [RFC2818].

   Encoding Considerations:  See section 4.3 of RFC xxxx.

   Applications/protocols that use this URI scheme name:

   The 'ipps' URI scheme is intended to be used by applications that
   need to access secure IPP Printers using the IPP protocol enhanced to
   support guaranteed data integrity and negotiable data privacy using
   TLS as specified in HTTP over TLS [RFC2818].  Such applications may
   include (but are not limited to) IPP-capable web browsers, IPP
   Clients that wish to print a file, and servers (for example, print
   spoolers) wishing to forward a print Job for processing.

   Interoperability Considerations:  The widely deployed, open source
   IPP print service CUPS [CUPS] (on most UNIX, Linux, and Apple OS X
   systems) has supported 'ipps' URI for several years before the
   publication of this document.  PWG IPP Everywhere [PWG5100.14] (IPP
   secure, mobile printing extensions) requires the use of 'ipps' URI
   for mandatory data integrity and negotiable data confidentiality.

   Security Considerations:  See:  Section 7 of RFC xxxx.

   Contact:

   Ira McDonald <blueroofmusic@gmail.com>

   Michael Sweet <msweet@apple.com>

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   Author/Change controller:

   IESG

   References:  RFC 2910, RFC 2911, RFC xxxx, and IEEE-ISTO PWG 5100.12.



7.  Security Considerations



7.1.  Problem Statement

   Powerful mobile devices (laptops, tablets, smartphones, etc.) are now
   commonly used to access enterprise and Cloud print services across
   the public Internet.  This is the primary use case for PWG IPP
   Everywhere [PWG5100.14], which has already been adopted by operating
   system and printer vendors and several other public standards bodies.
   End user and enterprise documents are at greater risk than ever
   before.  This IPP over HTTPS transport binding and 'ipps' URI scheme
   specification was defined to enable high availability combined with
   secure operation (mandatory data integrity and negotiable data
   confidentiality) in this dynamic environment (for example, wireless
   hotspots in hotels, airports, and restaurants).

   See:  Section 1 Introduction of [PWG5100.14].

   See:  Section 3.1 Rationale of [PWG5100.14].



7.1.1.  Targets of Attacks

   A network print spooler (logical printer) or print device (physical
   printer) is potentially subject to attacks, which may target:

   a) The network (to compromise the routing infrastructure, for
      example, by creating congestion);

   b) the Internet Printing Protocol (IPP) [RFC2911] (for example, to
      compromise the normal behavior of IPP); or

   c) the print document content itself (for example, to corrupt the
      documents being transferred).






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7.1.2.  Layers of Attacks

   Attacks against print services can be launched:

   a) against the network infrastructure (for example, TCP congestion
      control).

   b) against the IPP data flow itself (for example, by sending forged
      packets or forcing TLS version downgrade); or

   c) against the IPP operation parameters (for example, by corrupting
      requested document processing attributes).



7.2.  Attacks and Defenses

   This 'ipps' URI Scheme specification adds the following additional
   security considerations to those described in [RFC2616], [RFC2818],
   [RFC2910], [RFC2911], [RFC5246], [PWG5100.12], and [STD66].

   See:  Section 15 'Security Considerations' in [RFC2616].

   See:  Section 'Security Considerations' in [RFC2818].

   See:  Section 8 'Security Considerations' in [RFC2910].

   See:  Section 8 'Security Considerations' in [RFC2911].

   See:  Appendix D 'Implementation Notes', Appendix E 'Backward
   Compatibility', and Appendix F 'Security Analysis' of [RFC5246].

   See:  Section 10 'Security Considerations' in [PWG5100.12].

   See:  Section 7 'Security Considerations' in [STD66].



7.2.1.  Faked 'ipps' URI

   An 'ipps' URI might be faked to point to a rogue IPP secure print
   service, thus collecting confidential document contents from IPP
   Clients.

   Server authentication mechanisms and security mechanisms specified in
   IPP/1.1 Encoding and Transport [RFC2910], TLS/1.0 [RFC2246], TLS/1.1
   [RFC4346], TLS/1.2 [RFC5246], and HTTP over TLS [RFC2818] can be used
   to address this threat.


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7.2.2.  Unauthorized Access by IPP Client

   An 'ipps' URI might be used to access an IPP secure print service by
   an unauthorized IPP Client.

   Client authentication mechanisms and security mechanisms specified in
   IPP/1.1 Encoding and Transport [RFC2910], TLS/1.0 [RFC2246], TLS/1.1
   [RFC4346], TLS/1.2 [RFC5246], and HTTP over TLS [RFC2818] can be used
   to address this threat.



7.2.3.  Compromise at Application Layer Gateway

   An 'ipps' URI might be used to access an IPP secure print service at
   a print protocol application layer gateway (for example, an IPP to
   LPD [RFC1179] gateway [RFC2569]), potentially causing silent
   compromise of IPP security mechanisms.

   There is no general defense against this threat by an IPP Client.
   System administrators SHOULD avoid such configurations.



7.2.4.  No Client Authentication for 'ipps' URI

   An 'ipps' URI does not define parameters to specify the required IPP
   Client authentication mechanism (for example, 'certificate' as
   defined in section 4.4.2 'uri-authentication-supported' of IPP Model
   [RFC2911]).

   Either service discovery or directory protocols SHOULD be used first
   or an IPP Client SHOULD first establish an 'ipp' connection (without
   TLS or any client authentication) to the target IPP Printer and use a
   Get-Printer-Attributes query to discover the required IPP Client
   authentication mechanism(s) associated with a given 'ipps' URI.



7.3.  TLS Cipher Suite Requirements

   In accordance with section 10 Security Considerations of
   [PWG5100.12], IPP Clients and IPP Printers that support this
   specification and support a given version of TLS MUST support at
   least the mandatory cipher suite(s) required in each supported TLS
   version, which are as follows:



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       TLS/1.0 [RFC2246] - TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
       TLS/1.1 [RFC4346] - TLS_RSA_WITH_3DES_EDE_CBC_SHA
       TLS/1.2 [RFC5246] - TLS_RSA_WITH_AES_128_CBC_SHA

   Note:  IPP Client and IPP Printer implementors SHOULD consider known
   attacks against the mandatory cipher suite(s) in each supported TLS
   version and SHOULD follow best practice advice for alternative cipher
   suites in later IETF specifications.

   In accordance with section 10 Security Considerations of
   [PWG5100.12], this IPP over HTTPS transport binding and 'ipps' URI
   Scheme specification adds the following TLS version support
   requirements:

   a) An IPP Client or IPP Printer that supports this specification and
      supports IPP/1.1 defined in [RFC2911], MUST support TLS/1.0
      [RFC2246], MAY support TLS/1.1 [RFC4346], MAY support TLS/1.2
      [RFC5246], and MAY support future versions of TLS, in every case
      with at least the mandatory cipher suite(s) required in each
      supported TLS version.

   b) An IPP Client or IPP Printer that supports this specification and
      supports IPP/2.0 defined in [PWG5100.12], MUST support TLS/1.0
      [RFC2246], SHOULD support TLS/1.1 [RFC4346], MAY support TLS/1.2
      [RFC5246], and MAY support future versions of TLS, in every case
      with at least the mandatory cipher suite(s) required in each
      supported TLS version.

   c) An IPP Client or IPP Printer that supports this specification and
      supports IPP/2.1 defined in [PWG5100.12], MUST support TLS/1.0
      [RFC2246], MUST support TLS/1.1 [RFC4346], SHOULD support TLS/1.2
      [RFC5246], and MAY support future versions of TLS, in every case
      with at least the mandatory cipher suite(s) required in each
      supported TLS version.

   d) An IPP Client or IPP Printer that supports this specification and
      supports IPP/2.2 defined in [PWG5100.12], MUST support TLS/1.0
      [RFC2246], MUST support TLS/1.1 [RFC4346], MUST support TLS/1.2
      [RFC5246], and MAY support future versions of TLS, in every case
      with at least the mandatory cipher suite(s) required in each
      supported TLS version.



8.  Acknowledgments

   This document is an individual submission to the IETF by the Internet
   Printing Protocol Working Group of the IEEE-ISTO Printer Working
   Group, as part of their PWG IPP Everywhere [PWG5100.14] project for
   secure mobile printing with vendor-neutral Client software.


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   This document defines an alternate IPP transport binding to that
   defined in the original IPP URL Scheme [RFC3510], but this document
   does not update or obsolete [RFC3510].

   Thanks to Claudio Allochio, Tom Hastings (retired from Xerox), Bjoern
   Hoerhmann, S. Mooneswamy, Tom Petch, Jerry Thrasher (Lexmark), Mykyta
   Yevstifeyev, Pete Zehler (Xerox), and the members of the IEEE-ISTO
   PWG IPP WG.



9.  References



9.1.  Normative References

   [ASCII]    "American National Standards Institute, Coded Character
              Set -- 7-bit American Standard Code for Information
              Interchange", ANSI X3.4, 1986.

   [PWG5100.12] Bergman, R., Lewis, H., McDonald, I., and M. Sweet,
              "Internet Printing Protocol Version 2.0 Second Edition
              (IPP/2.0 SE)", PWG 5100.12, February 2011.
              <http://www.pwg.org/standards.html>

   [PWG5100.14] McDonald, I. and M. Sweet, "PWG IPP Everywhere", PWG
              5100.14, January 2013.
              <http://www.pwg.org/standards.html>

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

   [RFC2246]  Dierks, T., and C. Allen, "The TLS Protocol Version 1.0",
              RFC 2246, January 1999.

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

   [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000.

   [RFC2910]  Herriot, R., Ed., Butler, S., Moore, P., Turner, R., and
              J.  Wenn, "Internet Printing Protocol/1.1:  Encoding and
              Transport", RFC 2910, September 2000.

   [RFC2911]  Hastings, T., Ed., Herriot, R., deBry, R., Isaacson, S.,
              and P. Powell, "Internet Printing Protocol/1.1:  Model and
              Semantics", RFC 2911, September 2000.


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   [RFC4346]  Dierks, T., and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.1", RFC 4346, April 2006.

   [RFC5246]  Dierks, T., and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246, August 2008.

   [STD7]     Postel, J., "Transmission Control Protocol", STD 7, RFC
              793, September 1981.

   [STD63]    Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, November 2003.

   [STD66]    Berners-Lee, T., Fielding, R., and L. Masinter, Uniform
              Resource Identifiers (URI) Generic Syntax, STD 66, RFC
              3986, January 2005.

   [STD68]    Crocker, D., Ed., and P. Overell, "Augmented BNF for
              Syntax Specifications:  ABNF", STD 68, RFC 5234, January
              2008.



9.2.  Informative References

   [BCP35]    Hansen, T., Hardie, T., and L. Masinter, "Guidelines and
              Registration Procedures for New URI Schemes", BCP 35, RFC
              4395, February 2006.

   [CUPS]     Apple, "CUPS standards-based, open source printing system
              for OS X and other UNIX-like operating systems"
              <https://www.cups.org/>

   [MIMEREG]  Internet Assigned Numbers Authority (IANA) Registry "MIME
              Media Types"
              <http://www.iana.org/assignments/media-types/>

   [PORTREG]  Internet Assigned Numbers Authority (IANA) Registry "Port
              Numbers"
              <http://www.iana.org/assignments/port-numbers>

   [RFC1179]  McLaughlin, L., "Line Printer Daemon Protocol", RFC 1179,
              August 1990.

   [RFC2569]  Herriot, R., Ed., Hastings, T., Jacobs, N., and J.
              Martin, "Mapping between LPD and IPP Protocols", RFC 2569,
              April 1999.

   [RFC2817]  Khare, R.  and S.  Lawrence, "Upgrading to TLS Within
              HTTP/1.1", RFC 2817, May 2000.


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   [RFC3196]  Hastings, T., Manros, C., Zehler, P., Kugler, C., and H.
              Holst, "Internet Printing Protocol/1.1:  Implementor's
              Guide", RFC 3196, November 2001.

   [RFC3510]  Herriot, R.  and I.  McDonald, "Internet Printing
              Protocol/1.1:  IPP URL Scheme", RFC 3510, April 2003.



10.  Appendix A - Summary of IPP URL Scheme (Informative)

   This section is an informative summary of the original IPP URL Scheme
   [RFC3510] and the associated IPP over HTTP transport binding defined
   in [RFC2910].

   When using an 'ipp' URI [RFC3510], an IPP Client establishes an IPP
   application layer connection according to the following sequence:

   1) The IPP Client selects an 'ipp' URI value from
      "printer-uri-supported" Printer attribute [RFC2911], a directory
      entry, discovery info, a web page, etc.;

   2) The IPP Client converts the 'ipp' URI to an 'http' URI (replacing
      'ipp' with 'http' and inserting the port number from the URI or
      port 631 if the URI doesn't include a port number);

   3) The IPP Client establishes a TCP [STD7] reliable transport layer
      connection to the target endpoint - see section 3.4 'Establishing
      a connection' in TCP [STD7];

   4) The IPP Client establishes an HTTP [RFC2616] session layer
      connection to the target endpoint - see section 8 'Connections' in
      HTTP/1.1 [RFC2616];

   5) Optionally, either the IPP Client upgrades to TLS within HTTP/1.1
      per section 3 'Client Requested Upgrade to HTTP over TLS' of
      [RFC2817] or the IPP Printer upgrades to TLS within HTTP/1.1 per
      section 4 'Server Requested Upgrade to HTTP over TLS' of
      [RFC2817], in order to establish a TLS secure transport sublayer
      within the original TCP/HTTP connection - per the
      "uri-security-supported" (section 4.4.3 in [RFC2911]) Printer
      attribute value parallel to the "printer-uri-supported" (see
      section 4.4.1 in [RFC2911]) value that matches this connection;
      and

   6) The IPP Client sends IPP application layer requests to and
      receives responses from the IPP Printer over the HTTP [RFC2616]
      session layer connection using the POST method defined in section
      9.5 of HTTP/1.1 [RFC2616], as specified in section 4 'Encoding of
      Transport Layer' in IPP/1.1 Encoding and Transport [RFC2910].

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   See:  Section 8 'Security Considerations' in [RFC2911].

   See:  Section 8 'Security Considerations' in [RFC2817].



11.  Appendix X - Change History

   [RFC Editor:  Delete this section before publication as an RFC]

   20 April 2014 - draft-mcdonald-ipps-uri-scheme-12.txt
   Editorial - Revised section 4.3 Associated Port for 'ipps' URI
   Scheme, to add informative reference to CUPS, per IEEE-ISTO PWG IPP
   WG review.

   Editorial - Revised section 4.6.1 Examples of 'ipps' URI for
   Printers, to change "third" to "fourth" for the port 443 example, per
   IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 6 IANA Considerations, to add informative
   reference to CUPS, per IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 9.2 Informative References, to add
   informative reference to CUPS, per IEEE-ISTO PWG IPP WG review.

   7 April 2014 - draft-mcdonald-ipps-uri-scheme-11.txt
   Global - revised all references to section 4.2 and section 4.3, to
   add parenthetic (syntax) and (port) respectively, per IEEE-ISTO PWG
   IPP WG review.
   Editorial - Revised section 4.2 Syntax of 'ipps' URI Scheme, to
   correct two typos (extra words) in section 4.3 references, per
   IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 4.3 Associated Port for 'ipps' URI
   Scheme, to add note about compatibility for IPP Clients and IPP
   Printers that MUST accept explicit port 443 (assigned in 'https' URI
   scheme [RFC2818]) and process normally, per IEEE-ISTO PWG IPP WG
   review.
   Editorial - Revised section 4.6.1 Examples of 'ipps' URI for
   Printers, to add example of explicit port 443, per IEEE-ISTO PWG IPP
   WG review.


   30 March 2014 - draft-mcdonald-ipps-uri-scheme-10.txt
   Global - Updated references, per IEEE-ISTO PWG IPP WG review.
   Global - Changed "e.g." to "for example", for readability.
   Editorial - Revised section Copyright Notice, to correct year.
   Editorial - Revised section 3 IPP over HTTPS Transport Binding, item
   2), to clarify that port 631 is ONLY inserted in the derived 'https'
   URI when an explicit port is NOT specified in the original 'ipps'
   URI, per Smith Kennedy and IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 4.2 Syntax of 'ipps' URI Scheme, note
   about URI lengths greater than 255 octets, to change 'ought to' to

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   'SHOULD', per Smith Kennedy and IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 4.2 Syntax of 'ipps' URI Scheme, to add
   reference to section 4.3 for use of port 631, per Smith Kennedy and
   IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 4.3 Associated Port for 'ipps' URI
   Scheme, to add note about dual-use of port 631 for 'ipp' URI and
   'ipps' URI with reference to CUPS source for example of incoming
   connection handling, per Smith Kennedy and IEEE-ISTO PWG IPP WG
   review.
   Editorial - Revised section 4.3 Associated Port for 'ipps' URI
   Scheme, to add note about compatibility for IPP Clients and IPP
   Printers that should accept explicit port 443 (assigned in 'https'
   URI scheme [RFC2818]) and process normally, per IEEE-ISTO PWG IPP WG
   review.
   Editorial - Revised section 4.6.1 Examples of 'ipps' URI for
   Printers, to add reference to section 4.2 (syntax) and section 4.3
   (port), per Smith Kennedy and IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 4.7 Comparisons of 'ipps' URI, to add
   reference to section 4.3 (port), per Smith Kennedy and IEEE-ISTO PWG
   IPP WG review.
   Editorial - Revised section 5.1 Applicability to IPP Clients, to add
   reference to section 4.2 (syntax) and section 4.3 (port), per Smith
   Kennedy and IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 5.1 Applicability to IPP Clients, item
   d), to change 'MUST the' to 'MUST use the', per Smith Kennedy and
   IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 5.2 Applicability to IPP Printers, to add
   reference to section 4.2 (syntax) and section 4.3 (port), per Smith
   Kennedy and IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 5.2 Applicability to IPP Printers, item
   d), to change 'MUST the' to 'MUST use the', per Smith Kennedy and
   IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 5.2 Applicability to IPP Printers, to
   delete former item e) (listen only on port 631) which conflicted with
   existing IPP implementations (for example, listening on port 443 as
   well), per Smith Kennedy and IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 6 IANA Considerations, to add URI for
   CUPS source, per IEEE-ISTO PWG IPP WG review.
   Editorial - Revised section 7.2.4 No Client Authentication for 'ipps'
   URI, to change "or or" to "or" (typo), per Smith Kennedy and
   IEEE-ISTO PWG IPP WG review.
   Editorial - Revised Appendix A Summary of IPP URL Scheme, item 2), to
   clarify that port 631 is ONLY inserted in the derived 'http' URI when
   an explicit port is NOT specified in the original 'ipp' URI, per
   Smith Kennedy and IEEE-ISTO PWG IPP WG review.

   5 November 2013 - draft-mcdonald-ipps-uri-scheme-09.txt
   Global - Updated references, per IPP WG review.
   Editorial - Revised Abstract, section 1 Introduction, and section 8
   Acknowledgments to clarify that this document is an individual
   submission to the IETF by the IPP WG of the IEEE-ISTO PWG, per S

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   Mooneswamy.
   Editorial - Revised Abstract, section 1 Introduction, and section 8
   Acknowledgments to clarify that this document does not update or
   obsolete [RFC3510], per S Mooneswamy and Tom Petch.
   Editorial - Revised section 1.1 Structure of this Document to align
   with changes below, per Tom Petch.
   Editorial - Revised section 2 Conventions Used in this Document to
   add section 2.1 Printing Terminology and to remove redundant "In this
   document" and clarify definitions, per Tom Petch.
   Editorial - Moved former Appendix B - Abbreviations Used in this
   Document to become section 2.2 Abbreviations, per Tom Petch.
   Technical - Revised section 3 IPP over HTTPS Transport Binding,
   section 5 Applicability of this Specification, and section 7 Security
   Considerations to address specific TLS/1.0 [RFC2246], TLS/1.1
   [RFC4346], and TLS/1.2 [RFC5246] requirements, per Tom Petch.
   Editorial - Moved former section 3.1 IPP over HTTP Transport Binding
   to become Appendix A - Summary of IPP URL Scheme (Informative), per
   Tom Petch.
   Technical - Revised section 4.2 Syntax of 'ipps' URI Scheme to add
   note about the retention of the (unused) "query" production for
   consistency with IPP/1.1 Encoding and Transport [RFC2910] and the
   original IPP URL Scheme [RFC3510], but warn that it has no defined
   semantics in IPP and therefore its use is unsafe for IPP Clients, per
   Tom Petch.
   Technical - Revised section 7 Security Considerations to add section
   8.1 Problem Statement, section 8.2 Attacks, and section 8.3 TLS
   Security Considerations, per Tom Petch.
   Editorial - Moved former section Appendix A - Acknowledgments to
   become section 8 Acknowledgements (in body of document) and updated
   to reflect recent comments on this document, per Tom Petch.
   Technical - Revised section 9.1 Normative References to add TLS/1.0
   [RFC2246] and TLS/1.1 [RFC4346], per Tom Petch.

   19 September 2013 - draft-mcdonald-ipps-uri-scheme-08.txt
   Global - Updated references, per IPP WG review.

   12 May 2013 - draft-mcdonald-ipps-uri-scheme-07.txt
   Editorial - Revised section 1 (introduction) to add 'Rationale for
   this document', per Smith Kennedy.
   Editorial - Global - Changed 'Conformance Requirements' to
   'Applicability', per Barry Leiba.
   Editorial - Global - Changed '[PWG5100.EW]' to '[PWG5100.14]',
   corrected date and URI, and moved section 8.1 (normative references),
   per IPP WG review.

   10 November 2012 - draft-mcdonald-ipps-uri-scheme-06.txt
   Editorial - Global - Fixed typos and indentation, per IPP WG review.
   Editorial - Global - changed 'generic drivers' to 'vendor-neutral
   Client software', per IPP WG review.
   Editorial - Revised section 8.2 (informative references, to correct
   title of "PWG IPP Everywhere" (i.e., delete version number), per IPP

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   WG review.

   14 May 2012 - draft-mcdonald-ipps-uri-scheme-05.txt
   Editorial - Global - Fixed typos and indentation, per IPP WG review.
   Editorial - Revised sections 3.1 and 3.2 (transport bindings) to
   insert missing "to" in "connection to the target endpoint", per IPP
   WG review.
   Editorial - Revised section 4.2 (syntax), to correct indentation of
   first "Note:", per IPP WG review.
   Editorial - Revised sections 5.1 and 5.2 (client/printer conformance)
   and section 7 (security considerations) to delete the out-of-scope
   normative references to [RFC2817], per IPP WG review.

   22 November 2011 - draft-mcdonald-ipps-uri-scheme-04.txt
   Editorial - Global - Fixed typos and indentation, per IPP WG review.
   Editorial - Revised Introduction and Acknowledgments to say 'project
   for mobile, ubiquitous printing with generic drivers', per IPP WG
   review.
   Editorial - Revised sections 3.1 and 3.2 (transport bindings) to add
   references to HTTP POST and section 4 of RFC 2910, per IPP WG review.
   Editorial - Revised sections 3.1 and 3.2 (transport bindings) to add
   section references to all well-known standards (connection setup,
   etc.), per IPP WG review.
   Editorial - Revised section 4.2 (syntax) to move note from from
   section 4.6 (examples) and explain why literal IP addresses SHOULD
   NOT be used in 'ipps' URI, per IPP WG review.
   Editorial - Revised sections 4.6.1 and 4.6.2 (examples) to replace
   'abc.com' w/ 'example.com' (per IETF) and replace '/printer' path
   element w/ '/ipp' (better practice), per IPP WG review.
   Editorial - Revised section 5.2 (Printer conformance) to fold former
   (c) and (d) into a single requirement for standard port 631 and
   reordered other requirements to group MUSTs before SHOULDs, per IPP
   WG review.
   Editorial - Revised section 5.2 (Printer conformance) to add backward
   reference to section 4.2 for rationale for not using IP literal
   addresses, per IPP WG review.
   Editorial - Revised section 6 (IANA) to explicitly state that 'ipps'
   uses secure communications using HTTP over TLS, per IPP WG review.
   Editorial - Revised section 7 (Security) to cleanup numerous loose
   ends, per IPP WG review.
   Editorial - Revised section 8 (References) to cleanup typos and
   links, per IPP WG review.
   Editorial - Revised section 1 (introduction), section 8.2
   (informative references, and section 9 (appendix A) to change
   "[IPPEVE]" to "[PWG5100.EW]", per IPP WG review.

   26 August 2011 - draft-mcdonald-ipps-uri-scheme-03.txt
   Editorial - Revised Abstract and Introduction to state published by
   the IETF on behalf of IEEE-ISTO PWG (to avoid status ambiguity), per
   Mykyta Yevstifeyev.


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   Editorial - Revised section 1 to list all currently defined versions
   of IPP in RFC 2566, RFC 2911, and PWG 5100.12, per Mykyta
   Yevstifeyev.
   Technical - Revised section 1, section 2, section 3.2, section 4.1,
   and section 7, to reference IPP Version 2.0 Second Edition (PWG
   5100.12), per Mykyta Yevstifeyev.
   Editorial - Revised section 3.1, to fix broken STD7 reference, per
   Mykyta Yevstifeyev.
   Editorial - Revised section 6, to add BCP35 reference for template
   (regression loss when the template was moved up from former
   appendix), per Mykyta Yevstifeyev.
   Editorial - Revised section 8.1 to add PWG 5100.12 (normative),
   Editorial - Revised section 8.2 to add PWG IPP Everywhere
   (informative) and RFC 1179 (informative), per Mykyta Yevstifeyev.
   Editorial - Revised appendix B to add references for more reading,
   per Mykyta Yevstifeyev.

   28 February 2011 - draft-mcdonald-ipps-uri-scheme-02.txt
   Editorial - Revised document title to emphasize IPP over HTTPS
   Transport Binding (reason for IETF standards-track status).
   Editorial - Replaced "IPP URI" with "'ipp' URI", "IPPS URI" with
   "'ipps' URI", "HTTP URI" with "'http' URI", and "HTTPS URI" with
   "'https' URI" throughout this document for conformance to section 3.1
   of [STD66], per Mykyta Yevstifeyev.
   Editorial - Revised and simplified Abstract, per Mykyta Yevstifeyev.
   Editorial - Revised and simplified section 1 'Introduction', per
   Mykyta Yevstifeyev.
   Editorial - Renamed section 2 from 'Conformance Terminology' to
   'Conventions Used in this Document', per Mykyta Yevstifeyev.
   Editorial - Moved former section 3.1 'IPP Model Terminology
   (Normative)' content into section 2 'Conventions Used in this
   Document' for readability, per Mykyta Yevstifeyev.
   Editorial - Reordered subsections and reversed word order in all
   subsection titles in section 4 'The 'ipps' URI Scheme' for
   readability, per Mykyta Yevstifeyev.
   Editorial - Added note to section 4.2 'Syntax of 'ipps' URI Scheme'
   to explain why 'authority' production is NOT imported from [STD66],
   because it includes an optional 'userinfo' component which cannot be
   used in 'ipps' URI values.
   Editorial - Deleted note describing empty 'host' component from
   section 4.2 'Syntax of 'ipps' URI Scheme', because 'host' component
   is mandatory in [STD66].
   Editorial - Deleted 'Internationalization Considerations' section
   which was redundant with section 4.3 'Character Encoding of 'ipps'
   URI Scheme', per Mykyta Yevstifeyev.
   Editorial - Revised all references to follow current RFC Editor
   style, per Mykyta Yevstifeyev.
   Editorial - Moved former 'Appendix A - Registration of IPPS URI
   Scheme' content inline into section 6 'IANA Considerations', per
   Mykyta Yevstifeyev.


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   Editorial - Moved former body section 'Acknowledgements' to 'Appendix
   A - Acknowledgements', per Mykyta Yevstifeyev.
   Editorial - Added new 'Appendix B - Abbreviations Used in this
   Document' for readability, per Mykyta Yevstifeyev.
   Editorial - Moved section 'Authors' Addresses' to end of document,
   per Mykyta Yevstifeyev.

   1 December 2010 - draft-mcdonald-ipps-uri-scheme-01.txt
   - Technical - added UTF-8 [STD63] as required charset for all IPPS
   URI in section 4.4 and section 7, per Bjoern Hoehrmann.
   - Technical - corrected percent encoding for data octets outside the
   US-ASCII range in section 4.4 and section 7, per Bjoern Hoehrmann.
   - Editorial - global - changed "[RFC4395]" to "[BCP35]", changed
   "[RFC3629]" to "[STD63]", changed "[RFC3986]" to "[STD66]", and
   changed "[RFC5234]" to "[STD68]", per Bjoern Hoehrmann.
   - Editorial - restored trailing "]]" in ABNF syntax in section 4.5,
   per Bjoern Hoehrmann.
   - Editorial - changed "Author/Change controller" to "IESG" in section
   12 Appendix A registration template, as required by section 5.3 of
   [BCP35], per Bjoern Hoehrmann.

   10 October 2010 - draft-mcdonald-ipps-uri-scheme-00.txt
   - Editorial - complete rewrite of RFC 3510 for new transport binding
   - Editorial - moved Abstract to beginning of first page, per ID-Nits
   - Editorial - fixed copyright, boilerplate, and typos, per ID-Nits
   - Editorial - added references to RFCs 2119 and 3510, per ID-Nits
   - Editorial - deleted obsolete references to RFCs 2246 and 4346, per
   ID-Nits
   - Technical - changed Intended Status to Standards Track to reflect
   the new normative IPPS URI scheme and transport binding
   - Technical - added section 3.2 IPP over HTTP Transport Binding
   (informative)
   - Technical - added section 3.3 IPP over HTTPS Transport Binding
   (normative)
   - Technical - updated section 5 Conformance Requirements to require
   HTTP Upgrade (RFC 2817) support (for interoperability with existing
   IPP implementations), per discussion on IPP WG mailing list
   - Editorial - updated Appendix A w/ registration template from RFC
   4395




12.  Authors' Addresses

   Ira McDonald
   High North Inc
   221 Ridge Ave
   Grand Marais, MI  49839

   Phone: +1 906-494-2434

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   Email: blueroofmusic@gmail.com


   Michael Sweet
   Apple Inc
   10431 N De Anza Blvd, M/S 38-4LPT
   Cupertino, CA  95014

   Phone: +1 408-974-8798
   Email: msweet@apple.com


   Usage questions and comments on this 'ipps' URI Scheme can be sent
   directly to the editors at their above addresses and also to the PWG
   IPP WG mailing list.  Instructions for subscribing to the PWG IPP WG
   mailing list can be found at:

   PWG IPP WG Web Page:      http://www.pwg.org/ipp/
   PWG IPP WG Mailing List:  ipp@pwg.org
   PWG IPP WG Subscription:  http://www.pwg.org/mailhelp.html

   Implementers of this specification are encouraged to join the PWG IPP
   WG Mailing List in order to participate in any discussions of
   clarification issues and comments.  Note that this IEEE-ISTO PWG
   mailing list rejects mail from non-subscribers (in order to reduce
   spam).


























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