Network Working Group | J. Gould |
Internet-Draft | M. Pozun |
Intended status: Standards Track | VeriSign, Inc. |
Expires: August 2, 2020 | January 30, 2020 |
Login Security Extension for the Extensible Provisioning Protocol (EPP)
draft-ietf-regext-login-security-08
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.
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This document describes an Extensible Provisioning Protocol (EPP) extension for enhancing the security of the EPP login command in EPP [RFC5730]. 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 identifying the event type or sub-type, indicating the 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.
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. Indentation and white space in examples 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 and instead employ a proper namespace-aware XML parser and serializer to interpret and output the XML documents.
"whitespace" is defined by the XML schema whiteSpace datatype in [W3C.REC-xmlschema-2-20041028], which only includes the ASCII whitespace characters #x9 (tab), #xA (linefeed), #xD (carriage return), and #x20 (space).
Servers which 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 which 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 which do include extension elements, the server SHOULD only include extension elements for the extension versions present in the command.
This extension adds additional elements to [RFC5730] login command and response. Only those new elements are described here.
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:
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" sub-type of "failedLogins":
<loginSec:event type="stat" name="failedLogins" level="warning" value="100" duration="P1D"> Excessive invalid daily logins </loginSec:event>
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]" pre-defined 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]".
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.
A detailed description of the EPP syntax and semantics can be found in the EPP core protocol specification [RFC5730].
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:
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, such as the OpaqueString PRECIS profile in [RFC8265].
Example login command that uses the <loginSec:pw> element instead of the [RFC5730] <pw> element 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 [RFC5730] <pw> element to establish the session, and uses the <loginSec:newPW> element instead of the [RFC5730] <newPW> element 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 [RFC5730] <pw> element to establish the session, and uses the <loginSec:newPW> element instead of the [RFC5730] <newPW> element 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:
The extension to the EPP response uses the <loginSec:loginSecData> element that contains the following child elements:
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 occured 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>
The EPP Login Security Extension schema is presented here.
The formal syntax presented here is a complete XML schema representation of the object mapping suitable for automated validation of EPP XML instances. The BEGIN and END 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.
BEGIN <?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> END
This document uses URNs to describe XML namespaces and XML schemas conforming to a registry mechanism described in [RFC3688]. The following URI assignment is requested of IANA:
Registration request for the loginSec namespace:
Registration request for the loginSec XML schema:
The EPP extension described in this document should be registered by the IANA in the EPP Extension 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: (insert reference to RFC version of this document)
Registrant Name and Email Address: IESG, <iesg@ietf.org>
TLDs: Any
IPR Disclosure: None
Status: Active
Notes: None
Note to RFC Editor: Please remove this section and the reference to RFC 7942 before publication.
This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in RFC 7942. The description of implementations in this section is intended to assist the IETF in its decision processes in progressing drafts to RFCs. Please note that the listing of any individual implementation here does not imply endorsement by the IETF. Furthermore, no effort has been spent to verify the information presented here that was supplied by IETF contributors. This is not intended as, and must not be construed to be, a catalog of available implementations or their features. Readers are advised to note that other implementations may exist.
According to RFC 7942, "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature. It is up to the individual working groups to use this information as they see fit".
Organization: Verisign Inc.
Name: Verisign EPP SDK
Description: The Verisign EPP SDK includes both a full client implementation and a full server stub implementation of draft-ietf-regext-login-security.
Level of maturity: Development
Coverage: All aspects of the protocol are implemented.
Licensing: GNU Lesser General Public License
Contact: jgould@verisign.com
URL: https://www.verisign.com/en_US/channel-resources/domain-registry-products/epp-sdks
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.
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.
The authors wish to thank the following persons for their feedback and suggestions:
[RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
[RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
[RFC5730] | Hollenbeck, S., "Extensible Provisioning Protocol (EPP)", STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009. |
[RFC7942] | Sheffer, Y. and A. Farrel, "Improving Awareness of Running Code: The Implementation Status Section", BCP 205, RFC 7942, DOI 10.17487/RFC7942, July 2016. |
[RFC8174] | Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017. |
[W3C.REC-xmlschema-2-20041028] | Biron, P. and A. Malhotra, "XML Schema Part 2: Datatypes Second Edition", World Wide Web Consortium Recommendation REC-xmlschema-2-20041028, October 2004. |
[RFC5234] | Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/RFC5234, January 2008. |
[RFC7451] | Hollenbeck, S., "Extension Registry for the Extensible Provisioning Protocol", RFC 7451, DOI 10.17487/RFC7451, February 2015. |
[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. |
[[RFC Editor: Please remove this section.]]
Updates based on the review by Joseph Yee, that include:
Updates based on the review by Barry Leiba, that include:
Updates based on the review by Brian Carpenter, that include: