EPP login security: Login Security Extension for the Extensible Provisioning Protocol (EPP)

Internet Engineering Task Force (IETF)                          J. Gould
Request for Comments: 8807                                      M. Pozun
Category: Standards Track                                 VeriSign, Inc.
ISSN: 2070-1721                                              August 2020


Login Security Extension for the Extensible Provisioning Protocol (EPP)

Abstract

   The Extensible Provisioning Protocol (EPP) includes a client
   authentication scheme that is based on a user identifier and
   password.  The structure of the password field is defined by an XML
   Schema data type that specifies minimum and maximum password length
   values, but there are no other provisions for password management
   other than changing the password.  This document describes an EPP
   extension that allows longer passwords to be created and adds
   additional security features to the EPP login command and response.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc8807.

Copyright Notice

   Copyright (c) 2020 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.

Table of Contents

   1.  Introduction
     1.1.  Conventions Used in This Document
   2.  Migrating to Newer Versions of This Extension
   3.  Object Attributes
     3.1.  Event
     3.2.  "[LOGIN-SECURITY]" Password
     3.3.  Dates and Times
   4.  EPP Command Mapping
     4.1.  EPP <login> Command
   5.  Formal Syntax
     5.1.  Login Security Extension Schema
   6.  IANA Considerations
     6.1.  XML Namespace
     6.2.  EPP Extension Registry
   7.  Security Considerations
   8.  References
     8.1.  Normative References
     8.2.  Informative References
   Acknowledgements
   Authors' Addresses

1.  Introduction

   This document describes an Extensible Provisioning Protocol (EPP)
   extension for enhancing the security of the EPP login command in EPP
   [RFC5730].  EPP [RFC5730] includes a maximum password length of 16
   characters, which inhibits implementing stronger password security
   policies with higher entropy.  The enhancements include supporting
   longer passwords (or passphrases) than the 16-character maximum and
   providing a list of security events in the login response.  The
   password (current and new) in EPP [RFC5730] can be overridden by the
   password included in the extension to extend past the 16-character
   maximum.  The security events supported include password expiry,
   client certificate expiry, insecure cipher, insecure TLS protocol,
   new password complexity, login security statistical warning, and a
   custom event.  The attributes supported by the security events
   include an identified event type or a subtype, an indicated security
   level of warning or error, a future or past-due expiration date, the
   value that resulted in the event, the duration of the statistical
   event, and a free-form description with an optional language.

1.1.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   XML is case sensitive.  Unless stated otherwise, XML specifications
   and examples provided in this document MUST be interpreted in the
   character case presented in order to develop a conforming
   implementation.

   In examples, "C:" represents lines sent by a protocol client and "S:"
   represents lines returned by a protocol server.  In examples,
   indentation and whitespace are provided only to illustrate element
   relationships and are not a required feature of this protocol.

   "loginSec-1.0" is used as an abbreviation for
   "urn:ietf:params:xml:ns:epp:loginSec-1.0".  The XML namespace prefix
   "loginSec" is used, but implementations MUST NOT depend on it.
   Instead, they are to employ a proper namespace-aware XML parser and
   serializer to interpret and output the XML documents.

   "whitespace" is defined by the XML Schema whiteSpace data type in
   [W3C.REC-xmlschema-2-20041028], which only includes the ASCII
   whitespace characters #x9 (tab), #xA (linefeed), #xD (carriage
   return), and #x20 (space).

2.  Migrating to Newer Versions of This Extension

   Servers that implement this extension SHOULD provide a way for
   clients to progressively update their implementations when a new
   version of the extension is deployed.  A newer version of the
   extension is expected to use an XML namespace with a higher version
   number than the prior versions.

   Servers SHOULD (for a temporary migration period up to server policy)
   provide support for older versions of the extension in parallel to
   the newest version and allow clients to select their preferred
   version via the <svcExtension> element of the <login> command.

   If a client requests multiple versions of the extension at login,
   then, when preparing responses to commands that do not include
   extension elements, the server SHOULD only include extension elements
   in the namespace of the newest version of the extension requested by
   the client.

   When preparing responses to commands that do include extension
   elements, the server SHOULD only include extension elements for the
   extension versions present in the command.

3.  Object Attributes

   This extension adds additional elements to [RFC5730] login command
   and response.  Only those new elements are described here.

3.1.  Event

   A security event using the <loginSec:event> element represents either
   a warning or error identified by the server after the client has
   connected and submitted the login command.  The <loginSec:event>
   element is contained in a list of one or more elements in the
   <loginSec:loginSecData> element, so there MAY be multiple events
   returned that provide information for the client to address.  The
   <loginSec:event> MAY include a free-form description.  All of the
   security events use a consistent set of attributes, where the exact
   set of applicable attributes is based on the event type.  The
   supported set of <loginSec:event> element attributes include:

   "type":  A REQUIRED attribute that defines the type of security
       event.  The enumerated list of "type" values includes:

       "password":  Identifies a password expiry event where the
           password expires in the future or has expired based on the
           "exDate" date and time.  The "exDate" attribute MUST be set
           with the password expiry date and time.

       "certificate":  Identifies a client certificate expiry event
           where the client certificate will expire at the "exDate" date
           and time.  The "exDate" attribute MUST be set with the
           certificate expiry date and time.

       "cipher":  Identifies the use of an insecure or deprecated TLS
           cipher suite.  The "name" attribute MUST be set with the name
           of the cipher suite, which is free-form and is not expected
           to be parsed and automatically addressed by the client.  An
           example of cipher suite names can be found in the TLS Cipher
           Suites of the "Transport Layer Security (TLS) Parameters"
           registry (https://www.iana.org/assignments/tls-parameters/
           tls-parameters.xhtml#tls-parameters-4).

       "tlsProtocol":  Identifies the use of an insecure or deprecated
           TLS protocol.  The "name" attribute MUST be set with the name
           of the TLS protocol, which is free-form and is not expected
           to be parsed and automatically addressed by the client.

       "newPW":  The new password does not meet the server password
           complexity requirements.

       "stat":  Provides a login security statistical warning that MUST
           set the "name" attribute to the name of the statistic
           subtype.

       "custom":  Custom event type that MUST set the "name" attribute
           with the custom event type name.

   "name":  Used to define a subtype when the "type" attribute is not
       "custom" or the full type name when the "type" attribute is
       "custom".  The "name" attribute MUST be set when the "type"
       attribute is "stat" or "custom".  The possible set of "name"
       values, by event type, can be discovered/negotiated out of band
       to EPP or using a separate EPP extension designed to provide
       server policy information to the client.

   "level":  Defines the level of the event as either "warning" for a
       warning event that needs action or "error" for an error event
       that requires immediate action.

   "exDate":  Contains the date and time that a "warning" level has or
       will become an "error" level.  At expiry, there MAY be a
       connection failure or MAY be a login failure.  An example is an
       expired certification that will result in a connection failure or
       an expired password that may result in a login failure.

   "value":  Identifies the value that resulted in the login security
       event.  An example is the negotiated insecure cipher suite or the
       negotiated insecure TLS protocol.

   "duration":  Defines the duration that a statistical event is
       associated with, ending when the login command was received.  The
       format of the duration is defined by the duration primitive data
       type in Section 3.2.6 of [W3C.REC-xmlschema-2-20041028].

   "lang":  Identifies the negotiated language of the free-form
       description.  The format of the language is defined by the
       language primitive data type in Section 3.3.3 of
       [W3C.REC-xmlschema-2-20041028].  The default is "en" (English).

   Example login security event for password expiration, where the
   current date is 2020-03-25:

   <loginSec:event
     type="password"
     level="warning"
     exDate="2020-04-01T22:00:00.0Z"
     lang="en">
     Password expiration soon
   </loginSec:event>

   Example login security event for identifying 100 failed logins over
   the last day, using the "stat" subtype of "failedLogins":

   <loginSec:event
     type="stat"
     name="failedLogins"
     level="warning"
     value="100"
     duration="P1D">
     Excessive invalid daily logins
   </loginSec:event>

3.2.  "[LOGIN-SECURITY]" Password

   When the [RFC5730] <pw> element contains the predefined value of
   "[LOGIN-SECURITY]", the <loginSec:pw> element overrides the <pw>
   element, which is a constant value for the server to use the
   <loginSec:pw> element for the password.  Similarly, when the
   [RFC5730] <newPw> element contains the predefined value of "[LOGIN-
   SECURITY]", the <loginSec:newPw> element overrides the <newPw>
   element, which is a constant value for the server to use the
   <loginSec:newPW> element for the new password.  The "[LOGIN-
   SECURITY]" predefined string MUST be supported by the server for the
   client to explicitly indicate to the server whether to use
   <loginSec:pw> element in place of the [RFC5730] <pw> element or to
   use the <loginSec:newPW> in place of the [RFC5730] <newPW> element.
   The server MUST NOT allow the client to set the password to the value
   "[LOGIN-SECURITY]".

3.3.  Dates and Times

   Date and time attribute values MUST be represented in Universal
   Coordinated Time (UTC) using the Gregorian calendar.  The extended
   date-time form using upper case "T" and "Z" characters defined in
   [W3C.REC-xmlschema-2-20041028] MUST be used to represent date-time
   values, as XML Schema does not support truncated date-time forms or
   lower case "T" and "Z" characters.

4.  EPP Command Mapping

   A detailed description of the EPP syntax and semantics can be found
   in the EPP core protocol specification [RFC5730].

4.1.  EPP <login> Command

   This extension defines additional elements to extend the EPP <login>
   command and response to be used in conjunction with [RFC5730].

   The EPP <login> command is used to establish a session with an EPP
   server.  This extension overrides the password that is passed with
   the [RFC5730] <pw> or the <newPW> element, as defined in Section 3.2.
   A <loginSec:loginSec> element is sent along with the [RFC5730]
   <login> command and MUST contain at least one of the following child
   elements:

   <loginSec:userAgent>:  OPTIONAL client user-agent information that
       identifies the client application software, technology, and
       operating system used by the server to identify functional or
       security constraints, current security issues, and potential
       future functional or security issues for the client.  The server
       may use the information for real-time identification and client
       notification of security issues, such as keying off of the client
       application software for executing security rule checks.  The
       server may capture the information to identify future security
       policy issues, such as deprecating or removing TLS cipher suites
       or TLS protocols.  The <loginSec:userAgent> element MUST contain
       at least one of the following child elements:

       <loginSec:app>:  OPTIONAL name of the client application software
           with version if available, such as the name of the client SDK
           "EPP SDK 1.0.0".  The <loginSec:app> element value can be
           created by appending the version number to the name of the
           application software, such as the Augmented Backus-Naur Form
           (ABNF) grammar [RFC5234] format:

           app = name SP version
           name = 1*VCHAR
           version = 1*VCHAR

       <loginSec:tech>:  OPTIONAL technology used for the client
           software with version if available, such as "Vendor Java
           11.0.6".  The <loginSec:tech> element value can be created by
           including the technology vendor, technology name, and
           technology version, such as the Augmented Backus-Naur Form
           (ABNF) grammar [RFC5234] format:

           tech = vendor SP name SP version
           vendor = 1*VCHAR
           name = 1*VCHAR
           version = 1*VCHAR

       <loginSec:os>:  OPTIONAL client operating system used with
           version if available, such as "x86_64 Mac OS X 10.15.2".  The
           <loginSec:os> element value can be created by including the
           operating system architecture, operating system name, and
           operating system version, such as the Augmented Backus-Naur
           Form (ABNF) grammar [RFC5234] format:

           os = arch SP name SP version
           arch = 1*VCHAR
           name = 1*VCHAR
           version = 1*VCHAR

   <loginSec:pw>:  OPTIONAL plain text password that is case sensitive,
       has a minimum length of 6 characters, and has a maximum length
       that is up to server policy.  All leading and trailing whitespace
       is removed, and all internal contiguous whitespace that includes
       #x9 (tab), #xA (linefeed), #xD (carriage return), and #x20
       (space) is replaced with a single #x20 (space).  This element
       MUST only be set if the [RFC5730] <pw> element is set to the
       "[LOGIN-SECURITY]" value.

   <loginSec:newPW>:  OPTIONAL plain text new password that is case
       sensitive, has a minimum length of 6 characters, and has a
       maximum length that is up to server policy.  All leading and
       trailing whitespace is removed, and all internal contiguous
       whitespace that includes #x9 (tab), #xA (linefeed), #xD (carriage
       return), and #x20 (space) is replaced with a single #x20 (space).
       This element MUST only be set if the [RFC5730] <newPW> element is
       set to the "[LOGIN-SECURITY]" value.

   It is RECOMMENDED that the plain text password in the <loginSec:pw>
   and <loginSec:newPw> elements use printable ASCII characters #x20
   (space) - #x7E (~) with high entropy, such as 128 bits.  If non-ASCII
   characters are supported with the plain text password, then use a
   standard for passwords with international characters; the
   OpaqueString PRECIS profile in [RFC8265] is recommended in the
   absence of other considerations.

   Example login command that uses the <loginSec:pw> element instead of
   the <pw> element ([RFC5730]) to establish the session and includes
   the <loginSec:userAgent> element:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <login>
   C:      <clID>ClientX</clID>
   C:      <pw>[LOGIN-SECURITY]</pw>
   C:      <options>
   C:        <version>1.0</version>
   C:        <lang>en</lang>
   C:      </options>
   C:      <svcs>
   C:        <objURI>urn:ietf:params:xml:ns:obj1</objURI>
   C:        <objURI>urn:ietf:params:xml:ns:obj2</objURI>
   C:        <objURI>urn:ietf:params:xml:ns:obj3</objURI>
   C:        <svcExtension>
   C:          <extURI>urn:ietf:params:xml:ns:epp:loginSec-1.0</extURI>
   C:        </svcExtension>
   C:      </svcs>
   C:    </login>
   C:    <extension>
   C:      <loginSec:loginSec
   C:        xmlns:loginSec=
   C:          "urn:ietf:params:xml:ns:epp:loginSec-1.0">
   C:        <loginSec:userAgent>
   C:          <loginSec:app>EPP SDK 1.0.0</loginSec:app>
   C:          <loginSec:tech>Vendor Java 11.0.6</loginSec:tech>
   C:          <loginSec:os>x86_64 Mac OS X 10.15.2</loginSec:os>
   C:        </loginSec:userAgent>
   C:        <loginSec:pw>this is a long password</loginSec:pw>
   C:      </loginSec:loginSec>
   C:    </extension>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   Example login command that uses the <loginSec:pw> element instead of
   the <pw> element ([RFC5730]) to establish the session and that uses
   the <loginSec:newPW> element instead of the <newPW> element
   ([RFC5730]) to set the new password:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <login>
   C:      <clID>ClientX</clID>
   C:      <pw>[LOGIN-SECURITY]</pw>
   C:      <newPW>[LOGIN-SECURITY]</newPW>
   C:      <options>
   C:        <version>1.0</version>
   C:        <lang>en</lang>
   C:      </options>
   C:      <svcs>
   C:        <objURI>urn:ietf:params:xml:ns:obj1</objURI>
   C:        <objURI>urn:ietf:params:xml:ns:obj2</objURI>
   C:        <objURI>urn:ietf:params:xml:ns:obj3</objURI>
   C:        <svcExtension>
   C:          <extURI>urn:ietf:params:xml:ns:epp:loginSec-1.0</extURI>
   C:        </svcExtension>
   C:      </svcs>
   C:    </login>
   C:    <extension>
   C:      <loginSec:loginSec
   C:        xmlns:loginSec=
   C:          "urn:ietf:params:xml:ns:epp:loginSec-1.0">
   C:        <loginSec:pw>this is a long password
   C:        </loginSec:pw>
   C:        <loginSec:newPW>new password that is still long
   C:        </loginSec:newPW>
   C:      </loginSec:loginSec>
   C:    </extension>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   Example login command that uses the <pw> element ([RFC5730]) to
   establish the session and that uses the <loginSec:newPW> element
   instead of the <newPW> element ([RFC5730]) to set the new password:

   C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   C:  <command>
   C:    <login>
   C:      <clID>ClientX</clID>
   C:      <pw>shortpassword</pw>
   C:      <newPW>[LOGIN-SECURITY]</newPW>
   C:      <options>
   C:        <version>1.0</version>
   C:        <lang>en</lang>
   C:      </options>
   C:      <svcs>
   C:        <objURI>urn:ietf:params:xml:ns:obj1</objURI>
   C:        <objURI>urn:ietf:params:xml:ns:obj2</objURI>
   C:        <objURI>urn:ietf:params:xml:ns:obj3</objURI>
   C:        <svcExtension>
   C:          <extURI>urn:ietf:params:xml:ns:epp:loginSec-1.0</extURI>
   C:        </svcExtension>
   C:      </svcs>
   C:    </login>
   C:    <extension>
   C:      <loginSec:loginSec
   C:        xmlns:loginSec=
   C:          "urn:ietf:params:xml:ns:epp:loginSec-1.0">
   C:        <loginSec:newPW>new password that is still long
   C:        </loginSec:newPW>
   C:      </loginSec:loginSec>
   C:    </extension>
   C:    <clTRID>ABC-12345</clTRID>
   C:  </command>
   C:</epp>

   Upon a completed login command (success or failed), the extension
   MUST be included in the response when both of the following
   conditions hold:

   Client supports extension:  The client supports the extension based
       on the <svcExtension> element of the <login> command.

   At least one login security event:  The server has identified at
       least one login security event to communicate to the client.

   The extension to the EPP response uses the <loginSec:loginSecData>
   element that contains the following child elements:

   <loginSec:event>:  One or more <loginSec:event> elements defined in
       Section 3.1.

   Example EPP response to a successful login command on 2020-03-25,
   where the password will expire in a week:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:      <msg>Command completed successfully</msg>
   S:    </result>
   S:    <extension>
   S:      <loginSec:loginSecData
   S:        xmlns:loginSec=
   S:          "urn:ietf:params:xml:ns:epp:loginSec-1.0">
   S:        <loginSec:event
   S:          type="password"
   S:          level="warning"
   S:          exDate="2020-04-01T22:00:00.0Z"
   S:          lang="en">
   S:          Password expiring in a week
   S:        </loginSec:event>
   S:      </loginSec:loginSecData>
   S:    </extension>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54321-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   Example EPP response to a failed login command where the password has
   expired and the new password does not meet the server complexity
   requirements:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="2200">
   S:      <msg>Authentication error</msg>
   S:    </result>
   S:    <extension>
   S:      <loginSec:loginSecData
   S:        xmlns:loginSec=
   S:          "urn:ietf:params:xml:ns:epp:loginSec-1.0">
   S:        <loginSec:event
   S:          type="password"
   S:          level="error"
   S:          exDate="2020-03-24T22:00:00.0Z">
   S:          Password has expired
   S:        </loginSec:event>
   S:        <loginSec:event
   S:          type="newPW"
   S:          level="error">
   S:          New password does not meet complexity requirements
   S:        </loginSec:event>
   S:      </loginSec:loginSecData>
   S:    </extension>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54321-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

   Example EPP response to a successful login command where there is a
   set of login security events:

   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:      <msg>Command completed successfully</msg>
   S:    </result>
   S:    <extension>
   S:      <loginSec:loginSecData
   S:        xmlns:loginSec=
   S:          "urn:ietf:params:xml:ns:epp:loginSec-1.0">
   S:        <loginSec:event
   S:          type="password"
   S:          level="warning"
   S:          exDate="2020-04-01T22:00:00.0Z"
   S:          lang="en">
   S:          Password expiration soon
   S:        </loginSec:event>
   S:        <loginSec:event
   S:          type="certificate"
   S:          level="warning"
   S:          exDate="2020-04-02T22:00:00.0Z"/>
   S:        <loginSec:event
   S:          type="cipher"
   S:          level="warning"
   S:          value="TLS_RSA_WITH_AES_128_CBC_SHA">
   S:          Non-PFS Cipher negotiated
   S:        </loginSec:event>
   S:        <loginSec:event
   S:          type="tlsProtocol"
   S:          level="warning"
   S:          value="TLSv1.0">
   S:          Insecure TLS protocol negotiated
   S:        </loginSec:event>
   S:        <loginSec:event
   S:          type="stat"
   S:          name="failedLogins"
   S:          level="warning"
   S:          value="100"
   S:          duration="P1D">
   S:          Excessive invalid daily logins
   S:        </loginSec:event>
   S:        <loginSec:event
   S:          type="custom"
   S:          name="myCustomEvent"
   S:          level="warning">
   S:          A custom login security event occurred
   S:        </loginSec:event>
   S:      </loginSec:loginSecData>
   S:    </extension>
   S:    <trID>
   S:      <clTRID>ABC-12345</clTRID>
   S:      <svTRID>54321-XYZ</svTRID>
   S:    </trID>
   S:  </response>
   S:</epp>

5.  Formal Syntax

   The EPP Login Security Extension schema is presented here.

   The formal syntax shown here is a complete XML Schema representation
   of the object mapping suitable for automated validation of EPP XML
   instances.  The <CODE BEGINS> and <CODE ENDS> tags are not part of
   the XML Schema; they are used to note the beginning and ending of the
   XML Schema for URI registration purposes.

5.1.  Login Security Extension Schema

   <CODE BEGINS>
   <?xml version="1.0" encoding="UTF-8"?>
   <schema xmlns="http://www.w3.org/2001/XMLSchema"
     xmlns:epp="urn:ietf:params:xml:ns:epp-1.0"
     xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
     xmlns:loginSec="urn:ietf:params:xml:ns:epp:loginSec-1.0"
     targetNamespace="urn:ietf:params:xml:ns:epp:loginSec-1.0"
     elementFormDefault="qualified">
     <!--
     Import common element types.
     -->
     <import namespace="urn:ietf:params:xml:ns:eppcom-1.0" />
     <import namespace="urn:ietf:params:xml:ns:epp-1.0" />
     <annotation>
       <documentation>Extensible Provisioning Protocol v1.0
          Login Security Extension Schema.</documentation>
     </annotation>
     <!-- Login command extension elements -->
     <element name="loginSec" type="loginSec:loginSecType" />
     <!--
       Attributes associated with the login command extension.
      -->
     <complexType name="loginSecType">
       <sequence>
         <element name="userAgent"
           type="loginSec:userAgentType" minOccurs="0" />
         <element name="pw"
           type="loginSec:pwType" minOccurs="0" />
         <element name="newPW"
           type="loginSec:pwType" minOccurs="0" />
       </sequence>
     </complexType>
     <simpleType name="pwType">
       <restriction base="token">
         <minLength value="6" />
       </restriction>
     </simpleType>
     <complexType name="userAgentType">
       <choice>
         <sequence>
           <element name="app"
             type="token" />
           <element name="tech"
             type="token" minOccurs="0" />
           <element name="os"
             type="token" minOccurs="0" />
         </sequence>
         <sequence>
           <element name="tech"
             type="token" />
           <element name="os"
             type="token" minOccurs="0" />
         </sequence>
         <element name="os"
           type="token" />
       </choice>
     </complexType>
     <!-- Login response extension elements -->
     <element name="loginSecData"
       type="loginSec:loginSecDataType" />
     <complexType name="loginSecDataType">
       <sequence>
         <element name="event"
           type="loginSec:eventType"
           minOccurs="1" maxOccurs="unbounded" />
       </sequence>
     </complexType>
     <!-- Security event element -->
     <complexType name="eventType">
       <simpleContent>
         <extension base="normalizedString">
           <attribute name="type"
             type="loginSec:typeEnum" use="required" />
           <attribute name="name"
             type="token" />
           <attribute name="level"
             type="loginSec:levelEnum" use="required" />
           <attribute name="exDate"
             type="dateTime" />
           <attribute name="value"
             type="token" />
           <attribute name="duration"
             type="duration" />
           <attribute name="lang"
             type="language" default="en" />
         </extension>
       </simpleContent>
     </complexType>
     <!--
       Enumerated list of event types, with extensibility via "custom".
       -->
     <simpleType name="typeEnum">
       <restriction base="token">
         <enumeration value="password" />
         <enumeration value="certificate" />
         <enumeration value="cipher" />
         <enumeration value="tlsProtocol" />
         <enumeration value="newPW" />
         <enumeration value="stat" />
         <enumeration value="custom" />
       </restriction>
     </simpleType>
     <!--
       Enumerated list of levels.
       -->
     <simpleType name="levelEnum">
       <restriction base="token">
         <enumeration value="warning" />
         <enumeration value="error" />
       </restriction>
     </simpleType>
     <!--
    End of schema.
    -->
   </schema>
   <CODE ENDS>

6.  IANA Considerations

6.1.  XML Namespace

   This document uses URNs to describe XML namespaces and XML schemas
   conforming to a registry mechanism described in [RFC3688].  The
   following URI assignment has been made by IANA:

   Registration request for the loginSec namespace:

   URI:  urn:ietf:params:xml:ns:epp:loginSec-1.0
   Registrant Contact:  IESG
   XML:  None.  Namespace URIs do not represent an XML specification.

   Registration request for the loginSec XML Schema:

   URI:  urn:ietf:params:xml:schema:epp:loginSec-1.0
   Registrant Contact:  IESG
   XML:  See the "Formal Syntax" section of this document.

6.2.  EPP Extension Registry

   The EPP extension described in this document has been registered by
   IANA in the "Extensions for the Extensible Provisioning Protocol
   (EPP)" registry described in [RFC7451].  The details of the
   registration are as follows:

   Name of Extension:  "Login Security Extension for the Extensible
      Provisioning Protocol (EPP)"
   Document status:  Standards Track
   Reference:  RFC 8807
   Registrant Name and Email Address:  IESG, <iesg@ietf.org>
   Top-Level Domains(TLDs):  Any
   IPR Disclosure:  None
   Status:  Active
   Notes:  None

7.  Security Considerations

   The security considerations of [RFC5730] apply in this document, and
   this document enhances these considerations.

   The extension leaves the password (<pw> element) and new password
   (<newPW> element) minimum length greater than 6 characters and the
   maximum length up to server policy.  The server SHOULD enforce
   minimum and maximum length requirements that are appropriate for
   their operating environment.  One example of a guideline for password
   length policies can be found in Section 5 of NIST Special Publication
   800-63B (https://pages.nist.gov/800-63-3/sp800-63b.html).

   The client SHOULD NOT decrease the security of a new password by
   decreasing the length of the current password.  For example, a client
   with a 20-character password set using the extension should not use
   the login command in [RFC5730] without using the extension to set a
   new password that is less than or equal to 16 characters.

   The extension provides an extensible list of login security events to
   inform clients of connection and login warnings and errors.  The
   server returning of security events to unauthenticated users needs to
   take into account the security/privacy issues of returning
   information to potential attackers.

   The user-agent information represents the client system of a system-
   to-system interface, so the user-agent information MUST NOT provide
   any ability to track individual users or classes of users.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234,
              DOI 10.17487/RFC5234, January 2008,
              <https://www.rfc-editor.org/info/rfc5234>.

   [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
              STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
              <https://www.rfc-editor.org/info/rfc5730>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [W3C.REC-xmlschema-2-20041028]
              Biron, P. and A. Malhotra, "XML Schema Part 2: Datatypes
              Second Edition", W3C Recommendation REC-xmlschema-
              2-20041028, October 2004,
              <http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.

8.2.  Informative References

   [RFC7451]  Hollenbeck, S., "Extension Registry for the Extensible
              Provisioning Protocol", RFC 7451, DOI 10.17487/RFC7451,
              February 2015, <https://www.rfc-editor.org/info/rfc7451>.

   [RFC8265]  Saint-Andre, P. and A. Melnikov, "Preparation,
              Enforcement, and Comparison of Internationalized Strings
              Representing Usernames and Passwords", RFC 8265,
              DOI 10.17487/RFC8265, October 2017,
              <https://www.rfc-editor.org/info/rfc8265>.

Acknowledgements

   The authors wish to thank the following persons for their feedback
   and suggestions: Martin Casanova, Scott Hollenbeck, Barry Leiba,
   Patrick Mevzek, and Joseph Yee.

Authors' Addresses

   James Gould
   VeriSign, Inc.
   12061 Bluemont Way
   Reston, VA 20190
   United States of America

   Email: jgould@verisign.com
   URI:   http://www.verisign.com


   Matthew Pozun
   VeriSign, Inc.
   12061 Bluemont Way
   Reston, VA 20190
   United States of America

   Email: mpozun@verisign.com
   URI:   http://www.verisign.com