Internet DRAFT - draft-gould-regext-secure-authinfo-transfer
draft-gould-regext-secure-authinfo-transfer
Network Working Group J. Gould
Internet-Draft R. Wilhelm
Intended status: Best Current Practice VeriSign, Inc.
Expires: July 17, 2020 January 14, 2020
Extensible Provisioning Protocol (EPP) Secure Authorization Information
for Transfer
draft-gould-regext-secure-authinfo-transfer-03
Abstract
The Extensible Provisioning Protocol (EPP), in RFC 5730, defines the
use of authorization information to authorize a transfer. The
authorization information is object-specific and has been defined in
the EPP Domain Name Mapping, in RFC 5731, and the EPP Contact
Mapping, in RFC 5733, as password-based authorization information.
Other authorization mechanisms can be used, but in practice the
password-based authorization information has been used at the time of
object create, managed with the object update, and used to authorize
an object transfer request. What has not been fully considered is
the security of the authorization information that includes the
complexity of the authorization information, the time-to-live (TTL)
of the authorization information, and where and how the authorization
information is stored. This document defines an operational
practice, using the EPP RFCs, that leverages the use of strong random
authorization information values that are short-lived, that are not
stored by the client, and that are stored using a cryptographic hash
by the server to provide for secure authorization information used
for transfers.
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
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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 17, 2020.
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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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions Used in This Document . . . . . . . . . . . . 4
2. Registrant, Registrar, Registry . . . . . . . . . . . . . . . 5
3. Secure Authorization Information . . . . . . . . . . . . . . 6
3.1. Secure Random Authorization Information . . . . . . . . . 6
3.2. Authorization Information Time-To-Live (TTL) . . . . . . 7
3.3. Authorization Information Storage and Transport . . . . . 7
3.4. Authorization Information Matching . . . . . . . . . . . 8
4. Create, Transfer, and Secure Authorization Information . . . 8
4.1. Create Command . . . . . . . . . . . . . . . . . . . . . 9
4.2. Update Command . . . . . . . . . . . . . . . . . . . . . 11
4.3. Info Command and Response . . . . . . . . . . . . . . . . 14
4.4. Transfer Request Command . . . . . . . . . . . . . . . . 15
5. Transition Considerations . . . . . . . . . . . . . . . . . . 16
5.1. Transition Phase 1 - Features . . . . . . . . . . . . . . 18
5.2. Transition Phase 2 - Storage . . . . . . . . . . . . . . 18
5.3. Transition Phase 3 - Enforcement . . . . . . . . . . . . 19
6. Implementation Status . . . . . . . . . . . . . . . . . . . . 19
6.1. Verisign EPP SDK . . . . . . . . . . . . . . . . . . . . 20
6.2. RegistryEngine EPP Service . . . . . . . . . . . . . . . 20
7. Security Considerations . . . . . . . . . . . . . . . . . . . 21
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1. Normative References . . . . . . . . . . . . . . . . . . 21
9.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Appendix A. Change History . . . . . . . . . . . . . . . . . . . 22
A.1. Change from 00 to 01 . . . . . . . . . . . . . . . . . . 22
A.2. Change from 01 to 02 . . . . . . . . . . . . . . . . . . 22
A.3. Change from 02 to 03 . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24
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1. Introduction
The Extensible Provisioning Protocol (EPP), in [RFC5730], defines the
use of authorization information to authorize a transfer. The
authorization information is object-specific and has been defined in
the EPP Domain Name Mapping, in [RFC5731], and the EPP Contact
Mapping, in [RFC5733], as password-based authorization information.
Other authorization mechanisms can be used, but in practice the
password-based authorization information has been used at the time of
object create, managed with the object update, and used to authorize
an object transfer request. What has not been considered is the
security of the authorization information that includes the
complexity of the authorization information, the time-to-live (TTL)
of the authorization information, and where and how the authorization
information is stored. This document defines an operational
practice, using the EPP RFCs, that leverages the use of strong,
random authorization information values that are short-lived, that
are not stored by the client, and that are stored by the server using
a cryptographic hash to provide, for secure authorization information
used for transfers. This operational practice can be used to support
transfers of any EPP object, where the domain name object defined in
[RFC5731] is used in this document for illustration purposes.
Elements of the practice may be used to support the secure use of the
authorization information for purposes other than transfer, but any
other purposes and the applicable elements are out-of-scope for this
document.
The overall goal is to have strong, random authorization information
values, that are short-lived, and that are either not stored or
stored as a cryptographic hash values by the non-responsible parties.
In a registrant, registrar, and registry model, the registrant
registers the object through the registrar to the registry. The
registrant is the responsible party and the registrar and the
registry are the non-responsible parties. EPP is a protocol between
the registrar and the registry, where the registrar is referred to as
the client and the registry is referred to as the server. The
following are the elements of the operational practice and how the
existing features of the EPP RFCs can be leveraged to satisfy them:
"Strong Random Authorization Information": The EPP RFCs define the
password-based authorization information value using an XML
schema "normalizedString" type, so they don't restrict what can
be used in any way. This operational practice defines the
recommended mechanism for creating a strong random authorization
value, that would be generated by the client.
"Short-Lived Authorization Information": The EPP RFCs don't
explicitly support short-lived authorization information or a
time-to-live (TTL) for authorization information, but there are
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EPP RFC features that can be leveraged to support short-lived
authorization information. If authorization information is set
only when there is a transfer in process, the server needs to
support empty authorization information on create, support
setting and unsetting authorization information, and support
automatically unsetting the authorization information upon a
successful transfer. All of these features can be supported by
the EPP RFCs.
"Storing Authorization Information Securely": The EPP RFCs don't
specify where and how the authorization information is stored in
the client or the server, so there are no restrictions to define
an operational practice for storing the authorization information
securely. The operational practice will not require the client
to store the authorization information and will require the
server to store the authorization information using a
cryptographic hash, with at least a 256-bit hash function, such
as SHA-256. Returning the authorization information set in an
EPP info response will not be supported.
1.1. 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].
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.
The examples reference XML namespace prefixes that are used for the
associated XML namespaces. Implementations MUST NOT depend on the
example XML namespaces and instead employ a proper namespace-aware
XML parser and serializer to interpret and output the XML documents.
The example namespace prefixes used and their associated XML
namespaces include:
"domain": urn:ietf:params:xml:ns:domain-1.0
"contact": urn:ietf:params:xml:ns:contact-1.0
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2. Registrant, Registrar, Registry
The EPP RFCs refer to client and server, but when it comes to
transfers, there are three types of actors that are involved. This
document will refer to the actors as registrant, registrar, and
registry. [RFC8499] defines these terms formally for the Domain Name
System (DNS). The terms are further described below to cover their
roles as actors of using the authorization information in the
transfer process of any object in the registry, such as a domain name
or a contact:
"registrant": [RFC8499] defines the registrant as "an individual or
organization on whose behalf a name in a zone is registered by
the registry". The registrant can be the owner of any object in
the registry, such as a domain name or a contact. The registrant
interfaces with the registrar for provisioning the objects. A
transfer is coordinated by the registrant to transfer the
sponsorship of the object from one registrar to another. The
authorization information is meant to authenticate the registrant
as the owner of the object to the non-sponsoring registrar and to
authorize the transfer.
"registrar": [RFC8499] defines the registrar as "a service provider
that acts as a go-between for registrants and registries". The
registrar interfaces with the registrant for the provisioning of
objects, such as domain names and contacts, and with the
registries to satisfy the registrant's provisioning requests. A
registrar may directly interface with the registrant or may
indirectly interface with the registrant, typically through one
or more resellers. Implementing a transfer using secure
authorization information extends through the registrar's
reseller channel up to the direct interface with the registrant.
The registrar's interface with the registries uses EPP. The
registrar's interface with its reseller channel or the registrant
is registrar-specific. In the EPP RFCs, the registrar is
referred to as the "client", since EPP is the protocol used
between the registrar and the registry. The sponsoring registrar
is the authorized registrar to manage objects on behalf of the
registrant. A non-sponsoring registrar is not authorized to
manage objects on behalf of the registrant. A transfer of an
object's sponsorship is from one registrar, referred to as the
losing registrar, to another registrar, referred to as the
gaining registrar.
"registry": [RFC8499] defines the registry as "the administrative
operation of a zone that allows registration of names within the
zone". The registry typically interfaces with the registrars
over EPP and generally does not interact directly with the
registrant. In the EPP RFCs, the registry is referred to as the
"server", since EPP is the protocol used between the registrar
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and the registry. The registry has a record of the sponsoring
registrar for each object and provides the mechanism (over EPP)
to coordinate a transfer of an object's sponsorship between
registrars.
3. Secure Authorization Information
The authorization information in the EPP RFCs ([RFC5731] and
[RFC5733]) that support transfer use password-based authorization
information. Other EPP objects that support password-based
authorization information for transfer can use the Secure
Authorization Information defined in this document. For the
authorization information to be secure it must be a strong random
value and must have a short time-to-live (TTL). The security of the
authorization information is defined in the following sections.
3.1. Secure Random Authorization Information
For authorization information to be secure, it MUST be generated
using a secure random value. The authorization information is
treated as a password, where according to [RFC4086] a high-security
password must have at least 49 bits of randomness or entropy. The
required length L of a password, rounded up to the largest whole
number, is based on the set of characters N and the desired entropy
H, in the equation L = ROUNDUP(H / log2 N). With a target entropy of
49, the required length can be calculated after deciding on the set
of characters that will be randomized. The following are a set of
possible character sets and the calculation of the required length.
Calculation of the required length with 49 bits of entropy and with
the set of all printable ASCII characters except space (0x20), which
consists of the 94 characters 0x21-0x7E.
ROUNDUP(49 / log2 94) =~ ROUNDUP(49 / 6.55) =~ ROUNDUP(7.48) = 8
Calculation of the required length with 49 bits of entropy and with
the set of case-insensitive alphanumeric characters, which consists
of 36 characters (a-z A-Z 0-9).
ROUNDUP(49 / log2 36) =~ ROUNDUP(49 / 5.17) =~ ROUNDUP(9.48) = 10
Considering the age of [RFC4086], the evolution of security
practices, and that the authorization information is a machine-
generated value, the recommendation is to use at least 128 bits of
entropy. The lengths are recalculated below using 128 bits of
entropy.
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Calculation of the required length with 128 bits of entropy and with
the set of all printable ASCII characters except space (0x20), which
consists of the 94 characters 0x21-0x7E.
ROUNDUP(128 / log2 94) =~ ROUNDUP(128 / 6.55) =~ ROUNDUP(19.54) = 20
Calculation of the required length with 128 bits of entropy and with
the set of case insensitive alphanumeric characters, which consists
of 36 characters (a-z A-Z 0-9).
ROUNDUP(128 / log2 36) =~ ROUNDUP(128 / 5.17) =~ ROUNDUP(24.76) = 25
The strength of the random authorization information is dependent on
the actual entropy of the underlying random number generator. For
the random number generator, the practices defined in [RFC4086] and
section 4.7.1 of the NIST Federal Information Processing Standards
(FIPS) Publication 140-2 [1] SHOULD be followed to produce random
values that will be resistant to attack. A random number generator
(RNG) is preferable over the use of a pseudorandom number generator
(PRNG) to reduce the predictability of the authorization information.
The more predictable the random number generator is, the lower the
true entropy, and the longer the required length for the
authorization information.
3.2. Authorization Information Time-To-Live (TTL)
The authorization information SHOULD only be set when there is a
transfer in process. This implies that the authorization information
has a Time-To-Live (TTL) by which the authorization information is
cleared when the TTL expires. The EPP RFCs have no definition of
TTL, but since the server supports the setting and unsetting of the
authorization information by the sponsoring registrar, then the
sponsoring registrar can apply a TTL based on client policy. The TTL
client policy may be based on proprietary registrar-specific criteria
which provides for a transfer-specific TTL tuned for the particular
circumstances of the transaction. The sponsoring registrar will be
aware of the TTL and the sponsoring registrar MUST inform the
registrant of the TTL when the authorization information is provided
to the registrant.
3.3. Authorization Information Storage and Transport
To protect the disclosure of the authorization information, the
following requirements apply:
1. The authorization information MUST be stored by the registry
using a strong one-way cryptographic hash, with at least a
256-bit hash function, such as SHA-256.
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2. An empty authorization information MUST be stored with a NULL
(undefined) value.
3. The authorization information MUST NOT be stored by the losing
registrar.
4. The authorization information MUST only be stored by the gaining
registrar as a "transient" value in support of the transfer
process.
5. The plain text version of the authorization information MUST NOT
be written to any logs by the registrar or the registry.
6. All communication that includes the authorization information
MUST be over an encrypted channel, such as defined in [RFC5734]
for EPP.
7. The registrar's interface for communicating the authorization
information with the registrant MUST be over an authenticated and
encrypted channel.
3.4. Authorization Information Matching
To support the authorization information TTL, as defined in
Section 3.2, the authorization information must have either a set or
unset state. The unset authorization information is stored with a
NULL (undefined) value. Based on the requirement to store the
authorization information using a strong one-way cryptographic hash,
as defined in Section 3.3, a set authorization information is stored
with a non-NULL hashed value. The empty authorization information is
used as input in both the create command (Section 4.1) and the update
command (Section 4.2) to define the unset state. The matching of the
authorization information in the info command (Section 4.3) and the
transfer request command (Section 4.4) is based on the following
rules:
1. Any input authorization information value MUST NOT match an unset
authorization information value.
2. An empty input authorization information value MUST NOT match any
authorization information value.
3. A non-empty input authorization information value MUST be hashed
and matched against the set authorization information value,
which is stored using the same hash algorithm.
4. Create, Transfer, and Secure Authorization Information
To make the transfer process secure using secure authorization
information, as defined in Section 3, the client and server need to
implement steps where the authorization information is set only when
a transfer is actively in process and ensure that the authorization
information is stored securely and transported only over secure
channels. The steps in management of the authorization information
for transfers include:
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1. Registrant requests to register the object with the registrar.
Registrar sends the create command, with empty authorization
information, to the registry, as defined in Section 4.1.
2. Registrant requests from the losing registrar the authorization
information to provide to the gaining registrar.
3. Losing registrar generates a secure random authorization
information value, sends it to the registry as defined in
Section 4.2, and provides it to the registrant.
4. Registrant provides the authorization information value to the
gaining registrar.
5. Gaining registrar optionally verifies the authorization
information with the info command to the registry, as defined in
Section 4.3.
6. Gaining registrar sends the transfer request with the
authorization information to the registry, as defined in
Section 4.4.
7. If the transfer successfully completes, the registry
automatically unsets the authorization information; otherwise the
losing registrar unsets the authorization information when the
TTL expires, as defined in Section 4.2.
The following sections outline the practices of the EPP commands and
responses between the registrar and the registry that supports secure
authorization information for transfer.
4.1. Create Command
For a create command, the registry MUST allow for the passing of an
empty authorization information and MAY disallow for the passing of a
non-empty authorization information. By having an empty
authorization information on create, the object is initially not in
the transfer process. Any EPP object extension that supports setting
the authorization information with a "eppcom:pwAuthInfoType" element,
can have an empty authorization information passed, such as [RFC5731]
and [RFC5733].
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Example of passing empty authorization information in an [RFC5731]
domain name create command.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <create>
C: <domain:create
C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
C: <domain:name>example.com</domain:name>
C: <domain:authInfo>
C: <domain:pw/>
C: </domain:authInfo>
C: </domain:create>
C: </create>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Example of passing empty authorization information in an [RFC5733]
contact create command.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <create>
C: <contact:create
C: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
C: <contact:id>sh8013</contact:id>
C: <contact:postalInfo type="int">
C: <contact:name>John Doe</contact:name>
C: <contact:addr>
C: <contact:city>Dulles</contact:city>
C: <contact:cc>US</contact:cc>
C: </contact:addr>
C: </contact:postalInfo>
C: <contact:email>jdoe@example.com</contact:email>
C: <contact:authInfo>
C: <contact:pw/>
C: </contact:authInfo>
C: </contact:create>
C: </create>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
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4.2. Update Command
For an update command, the registry MUST allow for the setting and
unsetting of the authorization information. The registrar sets the
authorization information by first generating a strong, random
authorization information value, based on Section 3.1, and setting it
in the registry in the update command. The registry SHOULD validate
the randomness of the authorization information based on the length
and character set required by the registry. For example, a registry
that requires 20 random printable ASCII characters except space
(0x20), should validate that the authorization information contains
at least one upper case alpha character, one lower case alpha
character, and one non-alpha numeric character. If the authorization
information fails the randomness validation, the registry MUST return
an EPP error result code of 2202.
Often the registrar has the "clientTransferProhibited" status set, so
to start the transfer process, the "clientTransferProhibited" status
needs to be removed, and the strong, random authorization information
value needs to be set. The registrar MUST define a time-to-live
(TTL), as defined in Section 3.2, where if the TTL expires the
registrar will unset the authorization information.
Example of removing the "clientTransferProhibited" status and setting
the authorization information in an [RFC5731] domain name update
command.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <update>
C: <domain:update
C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
C: <domain:name>example.com</domain:name>
C: <domain:rem>
C: <domain:status s="clientTransferProhibited"/>
C: </domain:rem>
C: <domain:chg>
C: <domain:authInfo>
C: <domain:pw>LuQ7Bu@w9?%+_HK3cayg$55$LSft3MPP
C: </domain:pw>
C: </domain:authInfo>
C: </domain:chg>
C: </domain:update>
C: </update>
C: <clTRID>ABC-12345-XYZ</clTRID>
C: </command>
C:</epp>
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When the registrar-defined TTL expires, the sponsoring registrar
cancels the transfer process by unsetting the authorization
information value and may add back statuses like the
"clientTransferProbited" status. Any EPP object extension that
supports setting the authorization information with a
"eppcom:pwAuthInfoType" element, can have an empty authorization
information passed, such as [RFC5731] and [RFC5733]. Setting an
empty authorization information unsets the value. [RFC5731] supports
an explicit mechanism of unsetting the authorization information, by
passing the <domain:null> authorization information value. The
registry MUST support unsetting the authorization information by
accepting an empty authorization information value and accepting an
explicit unset element if it is supported by the object extension.
Example of adding the "clientTransferProhibited" status and unsetting
the authorization information explicitly in an [RFC5731] domain name
update command.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <update>
C: <domain:update
C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
C: <domain:name>example.com</domain:name>
C: <domain:add>
C: <domain:status s="clientTransferProhibited"/>
C: </domain:add>
C: <domain:chg>
C: <domain:authInfo>
C: <domain:null/>
C: </domain:authInfo>
C: </domain:chg>
C: </domain:update>
C: </update>
C: <clTRID>ABC-12345-XYZ</clTRID>
C: </command>
C:</epp>
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Example of unsetting the authorization information with an empty
authorization information in an [RFC5731] domain name update command.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <update>
C: <domain:update
C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
C: <domain:name>example.com</domain:name>
C: <domain:add>
C: <domain:status s="clientTransferProhibited"/>
C: </domain:add>
C: <domain:chg>
C: <domain:authInfo>
C: <domain:pw/>
C: </domain:authInfo>
C: </domain:chg>
C: </domain:update>
C: </update>
C: <clTRID>ABC-12345-XYZ</clTRID>
C: </command>
C:</epp>
Example of unsetting the authorization information with an empty
authorization information in an [RFC5733] contact update command.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <update>
C: <contact:update
C: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
C: <contact:id>sh8013</contact:id>
C: <contact:chg>
C: <contact:authInfo>
C: <contact:pw/>
C: </contact:authInfo>
C: </contact:chg>
C: </contact:update>
C: </update>
C: <clTRID>ABC-12345-XYZ</clTRID>
C: </command>
C:</epp>
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4.3. Info Command and Response
For an info command, the registry MUST allow for the passing of a
non-empty authorization information for verification. The gaining
registrar can pre-verify the authorization information provided by
the registrant prior to submitting the transfer request with the use
of the info command. The registry compares the hash of the passed
authorization information with the hashed authorization information
value stored for the object. When the authorization information is
not set or the passed authorization information does not match the
previously set value, the registry MUST return an EPP error result
code of 2202 [RFC5730].
Example of passing a non-empty authorization information in an
[RFC5731] domain name info command to verify the authorization
information value.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <info>
C: <domain:info
C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
C: <domain:name>example.com</domain:name>
C: <domain:authInfo>
C: <domain:pw>LuQ7Bu@w9?%+_HK3cayg$55$LSft3MPP
C: </domain:pw>
C: </domain:authInfo>
C: </domain:info>
C: </info>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
The info response in object extensions, such as [RFC5731] and
[RFC5733], MUST NOT include the optional authorization information
element with a non-empty authorization value. The authorization
information is stored as a hash in the registry, so returning the
plain text authorization information is not possible, unless a valid
plain text authorization information is passed in the info command.
The registry MUST NOT return any indication of whether the
authorization information is set or unset to the non-sponsoring
registrar by not returning the authorization information element in
the response. The registry MAY return an indication to the
sponsoring registrar that the authorization information is set by
using an empty authorization information value. The registry MAY
return an indication to the sponsoring registrar that the
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authorization information is unset by not returning the authorization
information element.
Example of returning an empty authorization information in an
[RFC5731] domain name info response to indicate to the sponsoring
registrar that the authorization information is set.
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: <resData>
S: <domain:infData
S: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
S: <domain:name>example.com</domain:name>
S: <domain:roid>EXAMPLE1-REP</domain:roid>
S: <domain:status s="ok"/>
S: <domain:clID>ClientX</domain:clID>
S: <domain:authInfo>
S: <domain:pw/>
S: </domain:authInfo>
S: </domain:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
4.4. Transfer Request Command
For a Transfer Request Command, the registry MUST allow for the
passing of a non-empty authorization information to authorize a
transfer. The registry compares the hash of the passed authorization
information with the hashed authorization information value stored
for the object. When the authorization information is not set or the
passed authorization information does not match the previously set
value, the registry MUST return an EPP error result code of 2202
[RFC5730]. Whether the transfer occurs immediately or is pending is
up to server policy. When the transfer occurs immediately, the
registry MUST return the EPP success result code of 1000 and when the
transfer is pending, the registry MUST return the EPP success result
code of 1001. The losing registrar MUST be informed of a successful
transfer request using an EPP poll message.
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Example of passing a non-empty authorization information in an
[RFC5731] domain name transfer request command to authorize the
transfer.
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <command>
C: <transfer op="request">
C: <domain:transfer
C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
C: <domain:name>example1.com</domain:name>
C: <domain:authInfo>
C: <domain:pw>LuQ7Bu@w9?%+_HK3cayg$55$LSft3MPP
C: </domain:pw>
C: </domain:authInfo>
C: </domain:transfer>
C: </transfer>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Upon successful completion of the transfer, the registry MUST
automatically unset the authorization information. If the transfer
request is not submitted within the time-to-live (TTL) (Section 3.2)
or the transfer is cancelled or rejected, the registrar MUST unset
the authorization information as defined in Section 4.2.
5. Transition Considerations
The goal of the transition considerations to the practice defined in
this document, referred to as the Secure Authorization Information
Model, is to minimize the impact to the registrars by supporting
incremental steps of adoption. The transtion steps are dependent on
the starting point of the registry. Registries may have different
starting points, since some of the elements of the Secure
Authorization Information Model may have already been implemented.
The considerations assume a starting point, referred to as the
Classic Authorization Information Model, that have the following
steps in the management of the authorization information for
transfers:
1. Registrant requests to register the object with the registrar.
Registrar sends the create command, with a non-empty
authorization information, to the registry. The registry stores
the authorization information as an encrypted value and requires
a non-empty authorization information for the life of the object.
The registrar may store the long-lived authorization information.
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2. At the time of transfer, Registrant requests from the losing
registrar the authorization information to provide to the gaining
registrar.
3. Losing registrar retrieves the stored authorization information
locally or queries the registry for authorization information
using the info command, and provides it to the registrant. If
the registry is queried, the authorization information is
decrypted and the plain text authorization information is
returned in the info response to the registrar.
4. Registrant provides the authorization information value to the
gaining registrar.
5. Gaining registrar optionally verifies the authorization
information with the info command to the registry, by passing the
authorization information in the info command to the registry.
6. Gaining registrar sends the transfer request with the
authorization information to the registry. The registry will
decrypt the stored authorization information to compare to the
passed authorization information.
7. If the transfer successfully completes, the authorization
information is not touched by the registry and may be updated by
the gaining registrar using the update command. If the transfer
is cancelled or rejected, the losing registrar may reset the
authorization information using the update command.
The gaps between the Classic Authorization Information Model and the
Secure Authorization Information Model include:
1. Registry requirement for a non-empty authorization information on
create and for the life of the object versus the authorization
information not being set on create and only being set when a
transfer is in process.
2. Registry not allowing the authorization information to be unset
versus supporting the authorization to be unset in the update
command.
3. Registry storing the authorization information as an encrypted
value versus as a hashed value.
4. Registry support for returning the authorization information
versus not returning the authorization information in the info
response.
5. Registry not touching the authorization information versus the
registry automatically unsetting the authorization information
upon a successful transfer.
6. Registry may validate a shorter authorization information value
using password complexity rules versus validating the randomness
of a longer authorization information value that meets the
required bits of entropy.
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The transition can be handled in the three phases defined in the sub-
sections Section 5.1, Section 5.2, Section 5.3.
5.1. Transition Phase 1 - Features
The goal of the "Transition Phase 1 - Features" is to implement the
needed features in EPP so that the registrar can optionally implement
the Secure Authorization Information Model. The features to
implement are broken out by the command and responses below:
Create Command: Change the create command to make the authorization
information optional, by allowing both a non-empty value and an
empty value. This enables a registrar to optionally create
objects without an authorization information value, as defined in
Section 4.1.
Update Command: Change the update command to allow unsetting the
authorization information, as defined in Section 4.2. This
enables the registrar to optionally unset the authorization
information when the TTL expires or when the transfer is cancelled
or rejected.
Transfer Approve Command and Transfer Auto-Approve: Change the
transfer approve command and the transfer auto-approve to
automatically unset the authorization information. This sets the
default state of the object to not have the authorization
information set. The registrar implementing the Secure
Authorization Information Model will not set the authorization
information for an inbound transfer and the registrar implementing
the Classic Authorization Information Model will set the new
authorization information upon the successful transfer.
Info Response: Change the info command to not return the
authorization information in the info response, as defined in
Section 4.3. This sets up the implementation of "Transition Phase
2 - Storage", since the dependency in returning the authorization
information in the info response will be removed. This feature is
the only one that is not an optional change to the registrar.
Info Command and Transfer Request: Change the info command and the
transfer request to ensure that a registrar cannot get an
indication that the authorization information is set or not set by
returning the EPP error result code of 2202 when comparing a
passed authorization to a non-matching set authorization
information value or an unset value.
5.2. Transition Phase 2 - Storage
The goal of the "Transition Phase 2 - Storage" is to transition the
registry to use hashed authorization information instead of encrypted
authorization information. There is no direct impact to the
registrars, since the only visible indication that the authorization
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information has been hashed is by not returning the set authorization
information in the info response, which is addressed in Transition
Phase 1 - Features (Section 5.1). There are three steps to
transition the authorization information storage, which includes:
Hash New Authorization Information Values: Change the create command
and the update command to hash instead of encyrpting the
authorization information.
Supporting Comparing Against Encrypted and Hashed Authorization
Information:
Change the info command and the transfer request command to be
able to compare a passed authorization information value with
either a hashed or encyrpted authorization information value.
Hash Existing Encrypted Authorization Information Values: Convert
the encrypted authorization information values stored in the
registry database to hashed values. The update is not a visible
change to the registrar. The conversion can be done over a period
of time depending on registry policy.
5.3. Transition Phase 3 - Enforcement
The goal of the "Transition Phase 3 - Enforcement" is to complete the
implementation of the "Secure Authorization Information Model", by
enforcing the following:
Disallow Authorization Information on Create Command: Change the
create command to not allow for the passing of a non-empty
authorization information value.
Validate the Strong Random Authorization Information: Change the
validation of the authorization information in the update command
to ensure at least 128 bits of entropy.
6. Implementation Status
Note to RFC Editor: Please remove this section and the reference to
RFC 7942 [RFC7942] 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
[RFC7942]. 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
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implementations or their features. Readers are advised to note that
other implementations may exist.
According to RFC 7942 [RFC7942], "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".
6.1. Verisign EPP SDK
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-gould-
regext-secure-authinfo-transfer.
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
6.2. RegistryEngine EPP Service
Organization: CentralNic
Name: RegistryEngine EPP Service
Description: Generic high-volume EPP service for gTLDs, ccTLDs and
SLDs
Level of maturity: Deployed in CentralNic's production environment as
well as two other gTLD registry systems, and two ccTLD registry
systems.
Coverage: Auhtorization Information is "write only" in that the
registrars can set the Auhtorization Information, but not get the
Auhtorization Information in the Info Response.
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Licensing: Proprietary In-House software
Contact: epp@centralnic.com
URL: https://www.centralnic.com
7. Security Considerations
TBD
8. Acknowledgements
The authors wish to thank the following persons for their feedback
and suggestions:
o Michael Bauland
o Martin Casanova
o Scott Hollenbeck
o Jody Kolker
o Patrick Mevzek
o Matthew Pozun
o Srikanth Veeramachaneni
9. References
9.1. 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>.
[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", BCP 106, RFC 4086,
DOI 10.17487/RFC4086, June 2005,
<https://www.rfc-editor.org/info/rfc4086>.
[RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
<https://www.rfc-editor.org/info/rfc5730>.
[RFC5731] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
Domain Name Mapping", STD 69, RFC 5731,
DOI 10.17487/RFC5731, August 2009,
<https://www.rfc-editor.org/info/rfc5731>.
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[RFC5733] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
Contact Mapping", STD 69, RFC 5733, DOI 10.17487/RFC5733,
August 2009, <https://www.rfc-editor.org/info/rfc5733>.
[RFC5734] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
Transport over TCP", STD 69, RFC 5734,
DOI 10.17487/RFC5734, August 2009,
<https://www.rfc-editor.org/info/rfc5734>.
[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,
<https://www.rfc-editor.org/info/rfc7942>.
[RFC8499] Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
January 2019, <https://www.rfc-editor.org/info/rfc8499>.
9.2. URIs
[1] https://csrc.nist.gov/publications/detail/fips/140/2/final
Appendix A. Change History
A.1. Change from 00 to 01
1. Filled in the "Implementation Status" section with the inclusion
of the "Verisign EPP SDK" and "RegistryEngine EPP Service"
implementations.
2. Made small wording corrections based on private feedback.
3. Added content to the "Acknowledgements" section.
A.2. Change from 01 to 02
1. Revised the language used for the storage of the authorization
information based on the feedback from Patrick Mevzek and Jody
Kolker.
A.3. Change from 02 to 03
1. Updates based on the feedback from the interim REGEXT meeting
held at ICANN-66:
1. Section 3.3, include a reference to the hash algorithm to
use. Broke the requirements into a list and included a the
reference the text ', with at least a 256-bit hash function,
such as SHA-256'.
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2. Add a Transition Considerations section to cover the
transition from the classic authorization information
security model in the EPP RFCs to the model defined in the
document.
3. Add a statement to the Introduction that elements of the
practice can be used for purposes other than transfer, but
with a caveat.
2. Updates based on the review by Michael Bauland, that include:
1. In section 2, change 'there are three actors' to 'there are
three types of actors' to cover the case with transfers that
has two registrar actors (losing and gaining).
2. In section 3.1, change the equations equals to be
approximately equal by using '=~' instead of '=', where
applicable.
3. In section 3.3, change 'MUST be over an encrypted channel,
such as [RFC5734]'' to 'MUST be over an encrypted channel,
such as defined in [RFC5734]''.
4. In section 4.1, remove the optional RFC 5733 elements from
the contact create, which includes the <contact:voice>,
<contact:fax>, <contact:disclose>, <contact:org>,
<contact:street>, <contact:sp>, and <contact:cc> elements.
5. In section 4.2, changed 'Example of unsetting the
authorization information explicitly in an [RFC5731] domain
name update command.' to 'Example of adding the
"clientTransferProhibited" status and unsetting the
authorization information explicitly in an [RFC5731] domain
name update command.'
6. In section 4.3, cover a corner case of the ability to return
the authorization information when it's passed in the info
command.
7. In section 4.4, change 'If the transfer does not complete
within the time-to-live (TTL)' to 'If the transfer is not
initiated within the time-to-live (TTL)', since the TTL is
the time between setting the authorization information and
when it's successfully used in a transfer request. Added the
case of unsetting the authorization information when the
transfer is cancelled or rejected.
3. Updates based on the authorization information messages by Martin
Casanova on the REGEXT mailing list, that include:
1. Added section 3.4 'Authorization Information Matching' to
clarify how the authorization information is matched, when
there is set and unset authorization information in the
database and empty and non-empty authorization information
passed in the info and transfer commands.
2. Added support for signaling that the authorization
information is set or unset to the sponsoring registrar with
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the inclusion of an empty authorization information element
in the response to indicate that the authorization
information is set and the exclusion of the authorization
information element in the response to indicate that the
authorization information is unset.
4. Made the capitalization of command and response references
consistent by uppercasing section and item titles and lowercasing
references elsewhere.
Authors' Addresses
James Gould
VeriSign, Inc.
12061 Bluemont Way
Reston, VA 20190
US
Email: jgould@verisign.com
URI: http://www.verisign.com
Richard Wilhelm
VeriSign, Inc.
12061 Bluemont Way
Reston, VA 20190
US
Email: rwilhelm@verisign.com
URI: http://www.verisign.com
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