[Docs] [txt|pdf|xml|html] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04 05 06 07 08 09 10

Independent Stream                                               F. Dold
Internet-Draft                                          Taler Systems SA
Intended status: Informational                               C. Grothoff
Expires: September 25, 2019                                          BFH
                                                          March 24, 2019


                  The 'payto' URI scheme for payments
                          draft-dold-payto-05

Abstract

   This document defines the 'payto' Uniform Resource Identifier (URI)
   scheme for designating targets for payments.

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 https://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."

   This Internet-Draft will expire on September 25, 2019.

Copyright Notice

   Copyright (c) 2019 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
   (https://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.





Dold & Grothoff        Expires September 25, 2019               [Page 1]


Internet-Draft           The 'payto' URI scheme               March 2019


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Syntax of a 'payto' URL . . . . . . . . . . . . . . . . . . .   2
   3.  Semantics . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Examples  . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   5.  Generic Options . . . . . . . . . . . . . . . . . . . . . . .   3
   6.  Internationalization and Character Encoding . . . . . . . . .   4
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
     8.1.  URI Scheme Registration . . . . . . . . . . . . . . . . .   5
     8.2.  Payment Target Type Registry  . . . . . . . . . . . . . .   5
       8.2.1.  ACH Bank Account  . . . . . . . . . . . . . . . . . .   6
       8.2.2.  Business Identifier Code  . . . . . . . . . . . . . .   6
       8.2.3.  International Bank Account Number . . . . . . . . . .   6
       8.2.4.  Unified Payments Interface  . . . . . . . . . . . . .   7
       8.2.5.  Bitcoin Address . . . . . . . . . . . . . . . . . . .   7
       8.2.6.  Interledger Protocol Address  . . . . . . . . . . . .   7
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     9.2.  Informational References  . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   This document defines the 'payto' Uniform Resource Identifier (URI)
   [RFC3986] scheme for designating targets for payments.  In its
   simplest form, a 'payto' URL identifies a payment target type and
   optionally a target identifier.  Additional parameters, such as an
   amount or a payment reference, can be provided.

   The interpretation of the target identifier is defined by the payment
   target type, and typically represents either a bank account or an
   (unsettled) transaction.

   A unified URI scheme for all payment target types allows applications
   to offer user interactions with URIs that represent payment targets,
   without delay and churn when new payment systems are introduced.

2.  Syntax of a 'payto' URL

   This document uses the Augmented Backus-Naur Form (ABNF) of
   [RFC5234].








Dold & Grothoff        Expires September 25, 2019               [Page 2]


Internet-Draft           The 'payto' URI scheme               March 2019


     payto-URI = "payto" "://" authority path-abempty [ "?" opts ]
     opts = opt *( "&" opt )
     opt = (generic-opt / authority-specific-opt) "=" *( pchar )
     generic-opt = "amount" / "creditor-name" / "debitor-name" /
                   "message" / "instruction"
     authority = ALPHA *( ALPHA / DIGIT / "-" / "." )
     path-abempty = <path-abempty, see [RFC3986], Section 3.3>
     pchar = <pchar, see [RFC3986], Appendix A.>


3.  Semantics

   The authority component of a payment URI identifies the payment
   target type.  The payment target types are defined in the Payto
   Payment Target Type Registry, see Section 8.2.  The path component of
   the URI identifies the target for a payment as interpreted by the
   respective payment target type.  The query component of the URI can
   provide additional parameters for a payment.  Every payment method
   SHOULD accept the options defined in generic-opt.  The default
   operation of applications that invoke a URI with the payto scheme
   SHOULD be to launch an application (if available) associated with the
   payment target type that can initiate a payment.  If multiple
   handlers are registered for the same payment target type, the user
   SHOULD be able to choose which application to launch.  This allows
   users with multiple bank accounts (each accessed the respective
   bank's banking application) to choose which account to pay with.
   Details of the payment MUST be taken from the path and options given
   in the URI.  The user SHOULD be allowed to modify these details
   before confirming a payment.

4.  Examples

     payto://iban/DE75512108001245126199?amount=EUR:200.0&message=hello

     INVALID (authority missing):  payto:iban/12345


5.  Generic Options

   Applications MUST accept URIs with options in any order.  The
   "amount" option MUST only occur at most once.  Other options MAY be
   allowed multiple times, with further restrictions depending on the
   payment method.  The following options SHOULD be understood by every
   payment method.

   amount: The amount to transfer, including currency information if
   applicable.  The format MUST be:




Dold & Grothoff        Expires September 25, 2019               [Page 3]


Internet-Draft           The 'payto' URI scheme               March 2019


     amount = [ currency ":" ] unit [ "." fraction ]
     currency = 1*ALPHA
     unit = 1*(DIGIT / ",")
     fraction = 1*(DIGIT / ",")


   The unit value MUST be smaller than 2^53.  If present, the fraction
   MUST consist of no more than 8 decimal digits.  The use of commas is
   optional for readability and they MUST be ignored.

   creditor-name: Name of the entity that is credited (receives the
   payment).

   debitor-name: Name of the entity that is debited (makes the payment).

   message: A short message to identify the purpose of the payment,
   which MAY be subject to lossy conversions (for example, due to
   character set encoding limitations).

   instruction: A short message giving instructions to the recipient,
   which MUST NOT be subject to lossy conversions.  Character set
   limitations allowed for such instructions depend on the payment
   method.

6.  Internationalization and Character Encoding

   Various payment systems use restricted character sets.  An
   application that processes 'payto' URIs MUST convert characters that
   are not allowed by the respective payment systems into allowable
   character using either an encoding or a replacement table.  This
   conversion process MAY be lossy, except for the instruction field.

   To avoid special encoding rules for the payment target identifier,
   the userinfo component [RFC3986] is disallowed in payto URIs.
   Instead, the payment target identifier is given as an option, where
   encoding rules are uniform for all options.

7.  Security Considerations

   Interactive applications handling the payto URI scheme MUST NOT
   initiate any financial transactions without prior review and
   confirmation from the user, and MUST take measures to prevent
   clickjacking [HMW12].

   Unless a payto URI is received over a trusted, authenticated channel,
   a user might not be able to identify the target of a payment.  In
   particular due to homographs [unicode-tr36], a payment target type
   SHOULD NOT use human-readable names in combination with unicode in



Dold & Grothoff        Expires September 25, 2019               [Page 4]


Internet-Draft           The 'payto' URI scheme               March 2019


   the target account specification, as it could give the user the
   illusion of being able to identify the target account from the URL.

   To avoid unnecessary data collection, payment target types SHOULD NOT
   include personally identifying information about the sender of a
   payment that is not essential for an application to conduct a
   payment.

8.  IANA Considerations

8.1.  URI Scheme Registration

   The "payto" URI scheme is to be registered in the "Permanent URI
   Schemes" registry.

      Scheme name: payto

      Status: permanent

      URI scheme syntax: See Section 2.

      URI scheme semantics: See Section 3.

      Applications/protocols that use this scheme name: payto URIs are
      mainly used by financial software, as well as by interactive
      applications (e.g. email clients, chat applications) that detect
      payto URIs and allow the user to interact with them (e.g. make
      them clickable)

      Contact: grothoff@gnu.org

      Change controller: grothoff@gnu.org

      References: See References section of this document.

8.2.  Payment Target Type Registry

   This document defines a registry for payment methods.  The name of
   the registry is "Payment Target Type Registry".

   The registry shall record for each entry:

   o  Name: The name of the payment target type (case insensitive ASCII
      string, restricted to alphanumeric characters, dots and dashes)

   o  Description: A description of the payment target type, including
      the semantics of the path in the URI if applicable.




Dold & Grothoff        Expires September 25, 2019               [Page 5]


Internet-Draft           The 'payto' URI scheme               March 2019


   o  Example: Example URI to illustrate the payment target type.

   o  Contact: The contact information of a person to contact for
      further information

   o  References: Optionally, references describing the payment method
      (such as an RFC) and method-specific options

   The registration policy for this registry is "First Come First
   Served", as described in [RFC5226].

8.2.1.  ACH Bank Account

   o  Name: ach

   o  Description: Automated Clearing House.  The path consist of two
      components, the routing number and the account number.

   o  Example: payto://ach/122000661/1234

   o  Contact: N/A

   o  References: [NACHA]

8.2.2.  Business Identifier Code

   o  Name: bic

   o  Description: Business Identifier Code.  The path consist of just a
      BIC.  This is used for wire transfers between banks.  The registry
      for BICs is provided by SWIFT.  The path does not allow specifying
      a bank account number.

   o  Example: payto://bic/SOGEDEFFXXX

   o  Contact: N/A

   o  References: [BIC]

8.2.3.  International Bank Account Number

   o  Name: iban

   o  Description: International Bank Account Number (IBAN).  Generally
      the IBAN allows to unambiguously derive the the associated
      Business Identifier Code (BIC).  However, some legacy applications
      process payments to the same IBAN differently based on the




Dold & Grothoff        Expires September 25, 2019               [Page 6]


Internet-Draft           The 'payto' URI scheme               March 2019


      specified BIC.  Thus the path can either consist of a single
      component (the IBAN) or two components (BIC and IBAN).

   o  Example: payto://iban/DE75512108001245126199
      payto://iban/SOGEDEFFXXX/DE75512108001245126199

   o  Contact: N/A

   o  References: [ISO20022]

8.2.4.  Unified Payments Interface

   o  Name: upi

   o  Description: Unified Payment Interface.  The path is an account
      alias.  The amount and creditor-name options are mandatory for
      this payment target.

   o  Example: payto://upi/alice@example.com?creditor-
      name=Alice&amount=INR:200

   o  Contact: N/A

   o  References: [UPILinking]

8.2.5.  Bitcoin Address

   o  Name: bitcoin

   o  Description: Bitcoin protocol.  The path is a "bitcoinaddress" as
      per [BIP0021].

   o  Example: payto://bitcoin/12A1MyfXbW6RhdRAZEqofac5jCQQjwEPBu

   o  Contact: N/A

   o  References: [BIP0021]

8.2.6.  Interledger Protocol Address

   o  Name: ilp

   o  Description: Interledger protocol.  The path is an ILP address as
      per [ILP-ADDR].

   o  Example: payto://ilp/g.acme.bob

   o  Contact: N/A



Dold & Grothoff        Expires September 25, 2019               [Page 7]


Internet-Draft           The 'payto' URI scheme               March 2019


   o  References: [ILP-ADDR]

9.  References

9.1.  Normative References

   [ISO20022]
              International Organization for Standardization, "ISO 20022
              Financial Services - Universal financial industry message
              scheme", May 2013.

   [NACHA]    NACHA, "NACHA Operating Rules & Guidelines", January 2017.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", RFC 5226,
              DOI 10.17487/RFC5226, May 2008,
              <https://www.rfc-editor.org/info/rfc5226>.

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234, January 2008.

   [unicode-tr36]
              Davis, M., Ed. and M. Suignard, "Unicode Technical Report
              #36: Unicode Security Considerations", September 2014.

9.2.  Informational References

   [BIC]      International Organization for Standardization, "ISO
              9362:2014 Business Identifier Code (BIC)", March 2019,
              <https://www.iso.org/standard/60390.html>.

   [BIP0021]  Schneider, N. and M. Corallo, "Bitcoin Improvement
              Proposal 21", January 2012,
              <https://en.bitcoin.it/wiki/BIP_0021>.

   [HMW12]    Huang, L., Moshchuk, A., Wang, H., Schecter, S., and C.
              Jackson, "Clickjacking: Attacks and Defenses", January
              2012, <https://www.usenix.org/system/files/conference/
              usenixsecurity12/sec12-final39.pdf>.

   [ILP-ADDR]
              Interledger Team, "ILP Addresses - v2.0.0", September
              2018, <https://interledger.org/rfcs/0015-ilp-addresses/>.



Dold & Grothoff        Expires September 25, 2019               [Page 8]


Internet-Draft           The 'payto' URI scheme               March 2019


   [UPILinking]
              National Payment Corporation of India, "Unified Payment
              Interface - Common URL Specifications For Deep Linking And
              Proximity Integration", May 2016,
              <http://www.npci.org.in/documents/
              UPILinkingSpecificationsVersion10draft.pdf>.

Authors' Addresses

   Florian Dold
   Taler Systems SA
   7, rue de Mondorf
   Erpeldange  L-5421
   LU

   Email: dold@taler.net


   Christian Grothoff
   BFH
   Hoeheweg 80
   Biel/Bienne  CH-2501
   CH

   Email: christian.grothoff@bfh.ch


























Dold & Grothoff        Expires September 25, 2019               [Page 9]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/