rfc4930
Network Working Group S. Hollenbeck
Request for Comments: 4930 VeriSign, Inc.
Obsoletes: 3730 May 2007
Category: Standards Track
Extensible Provisioning Protocol (EPP)
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This document describes an application layer client-server protocol
for the provisioning and management of objects stored in a shared
central repository. Specified in XML, the protocol defines generic
object management operations and an extensible framework that maps
protocol operations to objects. This document includes a protocol
specification, an object mapping template, and an XML media type
registration. This document obsoletes RFC 3730.
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RFC 4930 EPP May 2007
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions Used in This Document . . . . . . . . . . . . 3
2. Protocol Description . . . . . . . . . . . . . . . . . . . . . 4
2.1. Transport Mapping Considerations . . . . . . . . . . . . . 7
2.2. Protocol Identification . . . . . . . . . . . . . . . . . 8
2.3. Hello Format . . . . . . . . . . . . . . . . . . . . . . . 8
2.4. Greeting Format . . . . . . . . . . . . . . . . . . . . . 8
2.5. Command Format . . . . . . . . . . . . . . . . . . . . . . 12
2.6. Response Format . . . . . . . . . . . . . . . . . . . . . 13
2.7. Protocol Extension Framework . . . . . . . . . . . . . . . 18
2.7.1. Protocol Extension . . . . . . . . . . . . . . . . . . 18
2.7.2. Object Extension . . . . . . . . . . . . . . . . . . . 18
2.7.3. Command-Response Extension . . . . . . . . . . . . . . 19
2.8. Object Identification . . . . . . . . . . . . . . . . . . 20
2.9. Protocol Commands . . . . . . . . . . . . . . . . . . . . 21
2.9.1. Session Management Commands . . . . . . . . . . . . . 21
2.9.1.1. EPP <login> Command . . . . . . . . . . . . . . . 21
2.9.1.2. EPP <logout> Command . . . . . . . . . . . . . . . 24
2.9.2. Query Commands . . . . . . . . . . . . . . . . . . . . 25
2.9.2.1. EPP <check> Command . . . . . . . . . . . . . . . 25
2.9.2.2. EPP <info> Command . . . . . . . . . . . . . . . . 27
2.9.2.3. EPP <poll> Command . . . . . . . . . . . . . . . . 28
2.9.2.4. EPP <transfer> Query Command . . . . . . . . . . . 32
2.9.3. Object Transform Commands . . . . . . . . . . . . . . 34
2.9.3.1. EPP <create> Command . . . . . . . . . . . . . . . 34
2.9.3.2. EPP <delete> Command . . . . . . . . . . . . . . . 36
2.9.3.3. EPP <renew> Command . . . . . . . . . . . . . . . 37
2.9.3.4. EPP <transfer> Command . . . . . . . . . . . . . . 39
2.9.3.5. EPP <update> Command . . . . . . . . . . . . . . . 41
3. Result Codes . . . . . . . . . . . . . . . . . . . . . . . . . 42
4. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 48
4.1. Base Schema . . . . . . . . . . . . . . . . . . . . . . . 48
4.2. Shared Structure Schema . . . . . . . . . . . . . . . . . 58
5. Internationalization Considerations . . . . . . . . . . . . . 60
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 61
7. Security Considerations . . . . . . . . . . . . . . . . . . . 62
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 63
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 63
9.1. Normative References . . . . . . . . . . . . . . . . . . . 63
9.2. Informative References . . . . . . . . . . . . . . . . . . 64
Appendix A. Object Mapping Template . . . . . . . . . . . . . . . 66
Appendix B. Media Type Registration: application/epp+xml . . . . 68
Appendix C. Changes from RFC 3730 . . . . . . . . . . . . . . . . 69
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1. Introduction
This document describes specifications for the Extensible
Provisioning Protocol (EPP) version 1.0, an XML text protocol that
permits multiple service providers to perform object provisioning
operations using a shared central object repository. EPP is
specified using the Extensible Markup Language (XML) 1.0 as described
in [W3C.REC-xml-20040204] and XML Schema notation as described in
[W3C.REC-xmlschema-1-20041028] and [W3C.REC-xmlschema-2-20041028].
EPP meets and exceeds the requirements for a generic registry
registrar protocol as described in [RFC3375]. This document
obsoletes RFC 3730 [RFC3730].
EPP content is identified by MIME media type application/epp+xml.
Registration information for this media type is included in an
appendix to this document.
EPP is intended for use in diverse operating environments where
transport and security requirements vary greatly. It is unlikely
that a single transport or security specification will meet the needs
of all anticipated operators, so EPP was designed for use in a
layered protocol environment. Bindings to specific transport and
security protocols are outside the scope of this specification.
The original motivation for this protocol was to provide a standard
Internet domain name registration protocol for use between domain
name registrars and domain name registries. This protocol provides a
means of interaction between a registrar's applications and registry
applications. It is expected that this protocol will have additional
uses beyond domain name registration.
XML is case sensitive. Unless stated otherwise, XML specifications
and examples provided in this document MUST be interpreted in the
character case presented to develop a conforming implementation.
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 [RFC2119].
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.
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2. Protocol Description
EPP is a stateful XML protocol that can be layered over multiple
transport protocols. Protected using lower-layer security protocols,
clients exchange identification, authentication, and option
information, and then engage in a series of client-initiated command-
response exchanges. All EPP commands are atomic (there is no partial
success or partial failure) and designed so that they can be made
idempotent (executing a command more than once has the same net
effect on system state as successfully executing the command once).
EPP provides four basic service elements: service discovery,
commands, responses, and an extension framework that supports
definition of managed objects and the relationship of protocol
requests and responses to those objects.
An EPP server MUST respond to client-initiated communication (which
can be either a lower-layer connection request or an EPP service
discovery message) by returning a greeting to a client. A server
MUST promptly respond to each EPP command with a coordinated response
that describes the results of processing the command. The following
server state machine diagram illustrates the message exchange process
in detail:
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|
V
+-----------------+ +-----------------+
| Waiting for | Connected | Prepare |
| Client |----------------->| Greeting |
+-----------------+ or <hello> +-----------------+
^ |
| Close Connection Send |
| or Idle Greeting |
+-----------------+ V
| End | Timeout +-----------------+
| Session |<-----------------| Waiting for |
+-----------------+ | Client |
^ ^ ^ Send +-------->| Authentication |
| | | Response | +-----------------+
| | | +--------------+ |
| | | | Prepare Fail | | <login>
| | +-----| Response | | Received
| | Send +--------------+ V
| | 2501 ^ +-----------------+
| | Response | | Processing |
| | +---------| <login> |
| | Auth Fail +-----------------+
| | Timeout |
| +-------------------------------+ | Auth OK
| | V
| +-----------------+ <hello> +-----------------+
| | Prepare |<----------| Waiting for |
| | Greeting |---------->| Command or |
| +-----------------+ Send | <hello> |
| Send x5xx Greeting +-----------------+
| Response +-----------------+ Send ^ |
+-----------| Prepare | Response | | Command
| Response |----------+ | Received
+-----------------+ V
^ +-----------------+
Command | | Processing |
Processed +----------| Command |
+-----------------+
Figure 1: EPP Server State Machine
EPP commands fall into three categories: session management commands,
query commands, and object transform commands. Session management
commands are used to establish and end persistent sessions with an
EPP server. Query commands are used to perform read-only object
information retrieval operations. Transform commands are used to
perform read-write object management operations.
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Commands are processed by a server in the order they are received
from a client. Though an immediate response confirming receipt and
processing of the command is produced by the server, the protocol
includes features that allow for offline review of transform commands
before the requested action is actually completed. In such
situations, the response from the server MUST clearly note that the
command has been received and processed, but the requested action is
pending. The state of the corresponding object MUST clearly reflect
processing of the pending action. The server MUST also notify the
client when offline processing of the action has been completed.
Object mappings SHOULD describe standard formats for notices that
describe completion of offline processing.
EPP uses XML namespaces to provide an extensible object management
framework and to identify schemas required for XML instance parsing
and validation. These namespaces and schema definitions are used to
identify both the base protocol schema and the schemas for managed
objects. The XML namespace prefixes used in examples (such as the
string "foo" in "xmlns:foo") are solely for illustrative purposes. A
conforming implementation MUST NOT require the use of these or any
other specific namespace prefixes.
All XML instances SHOULD begin with an <?xml?> declaration to
identify the version of XML that is being used, optionally identify
use of the character encoding used, and optionally provide a hint to
an XML parser that an external schema file is needed to validate the
XML instance. Conformant XML parsers recognize both UTF-8 (defined
in RFC 3629 [RFC3629]) and UTF-16 (defined in RFC 2781 [RFC2781]);
per RFC 2277 [RFC2277] UTF-8 is the RECOMMENDED character encoding
for use with EPP.
Character encodings other than UTF-8 and UTF-16 are allowed by XML.
UTF-8 is the default encoding assumed by XML in the absence of an
"encoding" attribute or a byte order mark (BOM); thus, the "encoding"
attribute in the XML declaration is OPTIONAL if UTF-8 encoding is
used. EPP clients and servers MUST accept a UTF-8 BOM if present,
though emitting a UTF-8 BOM is NOT RECOMMENDED.
Example XML declarations:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?xml version="1.0" standalone="no"?>
<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0"?>
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2.1. Transport Mapping Considerations
As described previously, EPP can be layered over multiple transport
protocols. There are, however, a common set of considerations that
MUST be addressed by any transport mapping defined for EPP. These
include:
- The transport mapping MUST preserve command order.
- The transport mapping MUST address the relationship between
sessions and the client-server connection concept.
- The transport mapping MUST preserve the stateful nature of the
protocol.
- The transport mapping MUST frame data units.
- The transport mapping MUST be onto a transport such as TCP
[RFC0793] or Stream Control Transmission Protocol (SCTP) [RFC2960]
that provides congestion avoidance that follows RFC 2914
[RFC2914], or if it maps onto a protocol such as SMTP [RFC2821] or
Blocks Extensible Exchange Protocol (BEEP) [RFC3080], then the
performance issues need to take into account issues of overload,
server availability, and so forth.
- The transport mapping MUST ensure reliability.
- The transport mapping MUST explicitly allow or prohibit
pipelining.
Pipelining, also known as command streaming, is when a client sends
multiple commands to a server without waiting for each corresponding
response. After sending the commands, the client waits for the
responses to arrive in the order corresponding to the completed
commands. Performance gains can sometimes be realized with
pipelining, especially with high-latency transports, but there are
additional considerations associated with defining a transport
mapping that supports pipelining:
- Commands MUST be processed independent of each other.
- Depending on the transport, pipelining MAY be possible in the form
of sending a complete session in a well-defined "batch".
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- The transport mapping MUST describe how an error in processing a
command affects continued operation of the session.
A transport mapping MUST explain how all of these requirements are
met given the transport protocol being used to exchange data.
2.2. Protocol Identification
All EPP XML instances MUST begin with an <epp> element. This element
identifies the start of an EPP protocol element and the namespace
used within the protocol. The <epp> start element and the associated
</epp> ending element MUST be applied to all structures sent by both
clients and servers.
Example "start" and "end" EPP elements:
<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
</epp>
2.3. Hello Format
EPP MAY be carried over both connection-oriented and connection-less
transport protocols. An EPP client MAY request a <greeting> from an
EPP server at any time between a successful <login> command and a
<logout> command by sending a <hello> to a server. Use of this
element is essential in a connection-less environment where a server
cannot return a <greeting> in response to a client-initiated
connection. An EPP <hello> MUST be an empty element with no child
elements.
Example <hello>:
C:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
C: <hello/>
C:</epp>
2.4. Greeting Format
An EPP server responds to a successful connection and <hello> element
by returning a <greeting> element to the client. An EPP greeting
contains the following elements:
- An <svID> element that contains the name of the server.
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- An <svDate> element that contains the server's current date and
time in UTC.
- An <svcMenu> element that identifies the services supported by the
server, including:
- One or more <version> elements that identify the protocol
versions supported by the server.
- One or more <lang> elements that contain the identifiers of the
text response languages known by the server. Language
identifiers MUST be structured as documented in [RFC3066].
- One or more <objURI> elements that contain namespace URIs
representing the objects that the server is capable of
managing. A server MAY limit object management privileges on a
per-client basis.
- An OPTIONAL <svcExtension> element that contains one or more
<extURI> elements that contain namespace URIs representing
object extensions supported by the server.
- A <dcp> (data collection policy) element that contains child
elements used to describe the server's privacy policy for data
collection and management. Policy implications usually extend
beyond the client-server relationship. Both clients and
servers can have relationships with other entities that need to
know the server operator's data collection policy to make
informed provisioning decisions. Policy information MUST be
disclosed to provisioning entities, though the method of
disclosing policy data outside of direct protocol interaction
is beyond the scope of this specification. Child elements
include the following:
- An <access> element that describes the access provided by
the server to the client on behalf of the originating data
source. The <access> element MUST contain one of the
following child elements:
- <all/>: Access is given to all identified data.
- <none/>: No access is provided to identified data.
- <null/>: Data is not persistent, so no access is
possible.
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- <personal/>: Access is given to identified data relating
to individuals and organizational entities.
- <personalAndOther/>: Access is given to identified data
relating to individuals, organizational entities, and
other data of a non-personal nature.
- <other/>: Access is given to other identified data of a
non-personal nature.
- One or more <statement> elements that describe data
collection purposes, data recipients, and data retention.
Each <statement> element MUST contain a <purpose> element, a
<recipient> element, and a <retention> element. The
<purpose> element MUST contain one or more of the following
child elements that describe the purposes for which data is
collected:
- <admin/>: Administrative purposes. Information can be
used for administrative and technical support of the
provisioning system.
- <contact/>: Contact for marketing purposes. Information
can be used to contact individuals, through a
communications channel other than the protocol, for the
promotion of a product or service.
- <prov/>: Object provisioning purposes. Information can
be used to identify objects and inter-object
relationships.
- <other/>: Other purposes. Information may be used in
other ways not captured by the above definitions.
- The <recipient> element MUST contain one or more of the
following child elements that describes the recipients of
collected data:
- <other/>: Other entities following unknown practices.
- <ours>: Server operator and/or entities acting as agents
or entities for whom the server operator is acting as an
agent. An agent in this instance is defined as a third
party that processes data only on behalf of the service
provider for the completion of the stated purposes. The
<ours> element contains an OPTIONAL <recDesc> element
that can be used to describe the recipient.
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- <public/>: Public forums.
- <same/>: Other entities following server practices.
- <unrelated/>: Unrelated third parties.
- The <retention> element MUST contain one of the following
child elements that describes data retention practices:
- <business/>: Data persists per business practices.
- <indefinite/>: Data persists indefinitely.
- <legal/>: Data persists per legal requirements.
- <none/>: Data is not persistent and is not retained for
more than a brief period of time necessary to make use of
it during the course of a single online interaction.
- <stated/>: Data persists to meet the stated purpose.
- An OPTIONAL <expiry> element that describes the lifetime of
the policy. The <expiry> element MUST contain one of the
following child elements:
- <absolute/>: The policy is valid from the current date
and time until it expires on the specified date and time.
- <relative/>: The policy is valid from the current date
and time until the end of the specified duration.
Data collection policy elements are based on work described in the
World Wide Web Consortium's Platform for Privacy Preferences
[W3C.REC-P3P-20020416] specification.
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Example greeting:
S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
S: <greeting>
S: <svID>Example EPP server epp.example.com</svID>
S: <svDate>2000-06-08T22:00:00.0Z</svDate>
S: <svcMenu>
S: <version>1.0</version>
S: <lang>en</lang>
S: <lang>fr</lang>
S: <objURI>urn:ietf:params:xml:ns:obj1</objURI>
S: <objURI>urn:ietf:params:xml:ns:obj2</objURI>
S: <objURI>urn:ietf:params:xml:ns:obj3</objURI>
S: <svcExtension>
S: <extURI>http://custom/obj1ext-1.0</extURI>
S: </svcExtension>
S: </svcMenu>
S: <dcp>
S: <access><all/></access>
S: <statement>
S: <purpose><admin/><prov/></purpose>
S: <recipient><ours/><public/></recipient>
S: <retention><stated/></retention>
S: </statement>
S: </dcp>
S: </greeting>
S:</epp>
2.5. Command Format
An EPP client interacts with an EPP server by sending a command to
the server and receiving a response from the server. In addition to
the standard EPP elements, an EPP command contains the following
elements:
- A command element whose tag corresponds to one of the valid EPP
commands described in this document. The command element MAY
contain either protocol-specified or object-specified child
elements.
- An OPTIONAL <extension> element that MAY be used for server-
defined command extensions.
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- An OPTIONAL <clTRID> (client transaction identifier) element that
MAY be used to uniquely identify the command to the client.
Clients are responsible for maintaining their own transaction
identifier space to ensure uniqueness.
Example command with object-specified child elements:
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: <obj:info xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <obj:name>example</obj:name>
C: </obj:info>
C: </info>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
2.6. Response Format
An EPP server responds to a client command by returning a response to
the client. EPP commands are atomic, so a command will either
succeed completely or fail completely. Success and failure results
MUST NOT be mixed. In addition to the standard EPP elements, an EPP
response contains the following elements:
- One or more <result> elements that document the success or failure
of command execution. If the command was processed successfully,
only one <result> element MUST be returned. If the command was
not processed successfully, multiple <result> elements MAY be
returned to document failure conditions. Each <result> element
contains the following attribute and child elements:
- A "code" attribute whose value is a four-digit, decimal number
that describes the success or failure of the command.
- A <msg> element containing a human-readable description of the
response code. The language of the response is identified via
an OPTIONAL "lang" attribute. If not specified, the default
attribute value MUST be "en" (English).
- Zero or more OPTIONAL <value> elements that identify a client-
provided element (including XML tag and value) or other
information that caused a server error condition.
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- Zero or more OPTIONAL <extValue> elements that can be used to
provide additional error diagnostic information, including:
- A <value> element that identifies a client-provided element
(including XML tag and value) that caused a server error
condition.
- A <reason> element containing a human-readable message that
describes the reason for the error. The language of the
response is identified via an OPTIONAL "lang" attribute. If
not specified, the default attribute value MUST be "en"
(English).
- An OPTIONAL <msgQ> element that describes messages queued for
client retrieval. A <msgQ> element MUST NOT be present if there
are no messages queued for client retrieval. A <msgQ> element MAY
be present in responses to EPP commands other than the <poll>
command if messages are queued for retrieval. A <msgQ> element
MUST be present in responses to the EPP <poll> command if messages
are queued for retrieval. The <msgQ> element contains the
following attributes:
- A "count" attribute that describes the number of messages that
exist in the queue.
- An "id" attribute used to uniquely identify the message at the
head of the queue.
The <msgQ> element contains the following OPTIONAL child elements
that MUST be returned in response to a <poll> request command and
MUST NOT be returned in response to any other command, including a
<poll> acknowledgement:
- A <qDate> element that contains the date and time that the
message was enqueued.
- A <msg> element containing a human-readable message. The
language of the response is identified via an OPTIONAL "lang"
attribute. If not specified, the default attribute value MUST
be "en" (English). This element MAY contain XML content for
formatting purposes, but the XML content is not specified by
the protocol and will thus not be processed for validity.
- An OPTIONAL <resData> (response data) element that contains child
elements specific to the command and associated object.
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- An OPTIONAL <extension> element that MAY be used for server-
defined response extensions.
- A <trID> (transaction identifier) element containing the
transaction identifier assigned by the server to the command for
which the response is being returned. The transaction identifier
is formed using the <clTRID> associated with the command if
supplied by the client and a <svTRID> (server transaction
identifier) that is assigned by and unique to the server.
Transaction identifiers provide command-response synchronization
integrity. They SHOULD be logged, retained, and protected to ensure
that both the client and the server have consistent temporal and
state management records.
Example response without <value> or <resData>:
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 lang="en">Command completed successfully</msg>
S: </result>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
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Example response with <resData>:
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: <obj:creData xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:name>example</obj:name>
S: </obj:creData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
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Example response with error value elements:
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="2004">
S: <msg>Parameter value range error</msg>
S: <value xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:elem1>2525</obj:elem1>
S: </value>
S: </result>
S: <result code="2005">
S: <msg>Parameter value syntax error</msg>
S: <value xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:elem2>ex(ample</obj:elem2>
S: </value>
S: <extValue>
S: <value xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:elem3>abc.ex(ample</obj:elem3>
S: </value>
S: <reason>Invalid character found.</reason>
S: </extValue>
S: </result>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Example response with notice of waiting server messages:
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: <msgQ count="5" id="12345"/>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
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Command success or failure MUST NOT be assumed if no response is
returned or if a returned response is malformed. Protocol
idempotency ensures the safety of retrying a command in cases of
response delivery failure.
2.7. Protocol Extension Framework
EPP provides an extension framework that allows features to be added
at the protocol, object, and command-response levels.
2.7.1. Protocol Extension
The EPP extension framework allows for definition of new protocol
elements identified using XML namespace notation with a reference to
an XML schema that defines the namespace. The <epp> element that
identifies the beginning of a protocol instance includes multiple
child element choices, one of which is an <extension> element whose
children define the extension. For example, a protocol extension
element would be described in generic terms as follows:
C:<epp>
C: <extension>
C: <!-- One or more extension elements. -->
C: <ext:foo xmlns:ext="urn:ietf:params:xml:ns:ext">
C: <!-- One or more extension child elements. -->
C: </ext:foo>
C: </extension>
C:</epp>
This document does not define mappings for specific extensions.
Extension specifications MUST be described in separate documents that
define the objects and operations subject to the extension.
2.7.2. Object Extension
EPP provides an extensible object management framework that defines
the syntax and semantics of protocol operations applied to a managed
object. This framework pushes the definition of each protocol
operation into the context of a specific object, providing the
ability to add mappings for new objects without having to modify the
base protocol.
Protocol elements that contain data specific to objects are
identified using XML namespace notation with a reference to an XML
schema that defines the namespace. The schema for EPP supports use
of dynamic object schemas on a per-command and per-response basis.
For example, the start of an object-specific command element would be
described in generic terms as follows:
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C:<EPPCommandName>
C: <object:command xmlns:object="urn:ietf:params:xml:ns:object">
C: <!-- One or more object-specific command elements. -->
C: </object:command>
C:</EPPCommandName>
An object-specific response element would be described similarly:
S:<resData>
S: <object:resData xmlns:object="urn:ietf:params:xml:ns:object">
S: <!-- One or more object-specific response elements. -->
S: </object:resData>
S:</resData>
This document does not define mappings for specific objects. The
mapping of EPP to an object MUST be described in separate documents
that specifically address each command and response in the context of
the object. A suggested object mapping outline is included as an
appendix to this document.
2.7.3. Command-Response Extension
EPP provides a facility for protocol command and response extensions.
Protocol commands and responses MAY be extended by an <extension>
element that contains additional elements whose syntax and semantics
are not explicitly defined by EPP or an EPP object mapping. This
element is OPTIONAL. Extensions are typically defined by agreement
between client and server and MAY be used to extend EPP for unique
operational needs. A server-extended command element would be
described in generic terms as follows:
C:<command>
C: <!-- EPPCommandName can be "create", "update", etc. -->
C: <EPPCommandName>
C: <object:command xmlns:object="urn:ietf:params:xml:ns:object">
C: <!-- One or more object-specific command elements. -->
C: </object:command>
C: </EPPCommandName>
C: <extension>
C: <!-- One or more server-defined elements. -->
C: </extension>
C:</command>
An server-extended response element would be described similarly:
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S:<response>
S: <result code="1000">
S: <msg lang="en">Command completed successfully</msg>
S: </result>
S: <extension>
S: <!-- One or more server-defined elements. -->
S: </extension>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S:</response>
This document does not define any specific server extensions. The
mapping of server extensions to EPP MUST be described in separate
documents that specifically address extended commands and responses
in the server's operational context.
2.8. Object Identification
Some objects, such as name servers and contacts, can have utility in
multiple repositories. However, maintaining disjoint copies of
object information in multiple repositories can lead to
inconsistencies that have adverse consequences for the Internet. For
example, changing a name server name in one repository, but not in a
second repository that refers to the server for domain name
delegation, can produce unexpected DNS query results.
Globally unique identifiers can help facilitate object information
sharing between repositories. A globally unique identifier MUST be
assigned to every object when the object is created; the identifier
MUST be returned to the client as part of any request to retrieve the
detailed attributes of an object. Specific identifier values are a
matter of repository policy, but they SHOULD be constructed according
to the following algorithm:
a. Divide the provisioning repository world into a number of object
repository classes.
b. Each repository within a class is assigned an identifier that is
maintained by IANA.
c. Each repository is responsible for assigning a unique local
identifier for each object within the repository.
d. The globally unique identifier is a concatenation of the local
identifier, followed by a hyphen ("-", ASCII value 0x002D),
followed by the repository identifier.
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2.9. Protocol Commands
EPP provides commands to manage sessions, retrieve object
information, and perform transformation operations on objects. All
EPP commands are atomic and designed so that they can be made
idempotent, either succeeding completely or failing completely and
producing predictable results in case of repeated executions. This
section describes each EPP command, including examples with
representative server responses.
2.9.1. Session Management Commands
EPP provides two commands for session management: <login> to
establish a session with a server, and <logout> to end a session with
a server. The <login> command establishes an ongoing server session
that preserves client identity and authorization information during
the duration of the session.
2.9.1.1. EPP <login> Command
The EPP <login> command is used to establish a session with an EPP
server in response to a greeting issued by the server. A <login>
command MUST be sent to a server before any other EPP command to
establish an ongoing session. A server operator MAY limit the number
of failed login attempts N, 1 <= N <= infinity, after which a login
failure results in the connection to the server (if a connection
exists) being closed.
A client identifier and initial password MUST be created on the
server before a client can successfully complete a <login> command.
The client identifier and initial password MUST be delivered to the
client using an out-of-band method that protects the identifier and
password from inadvertent disclosure.
In addition to the standard EPP command elements, the <login> command
contains the following child elements:
- A <clID> element that contains the client identifier assigned to
the client by the server.
- A <pw> element that contains the client's plain text password.
The value of this element is case sensitive.
- An OPTIONAL <newPW> element that contains a new plain text
password to be assigned to the client for use with subsequent
<login> commands. The value of this element is case sensitive.
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- An <options> element that contains the following child elements:
- A <version> element that contains the protocol version to be
used for the command or ongoing server session.
- A <lang> element that contains the text response language to be
used for the command or ongoing server session commands.
The values of the <version> and <lang> elements MUST exactly match
one of the values presented in the EPP greeting.
- A <svcs> element that contains one or more <objURI> elements that
contain namespace URIs representing the objects to be managed
during the session. The <svcs> element MAY contain an OPTIONAL
<svcExtension> element that contains one or more <extURI> elements
that identify object extensions to be used during the session.
The PLAIN Simple Authentication and Security Layer (SASL) mechanism
presented in [RFC2595] describes a format for providing a user
identifier, an authorization identifier, and a password as part of a
single plain text string. The EPP authentication mechanism is
similar, though EPP does not require a session-level authorization
identifier and the user identifier and password are separated into
distinct XML elements. Additional identification and authorization
schemes MUST be provided at other protocol layers to provide more
robust security services.
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Example <login> 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: <login>
C: <clID>ClientX</clID>
C: <pw>foo-BAR2</pw>
C: <newPW>bar-FOO2</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>http://custom/obj1ext-1.0</extURI>
C: </svcExtension>
C: </svcs>
C: </login>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
When a <login> command has been processed successfully, a server MUST
respond with an EPP response with no <resData> element. If
successful, the server will respond by creating and maintaining a new
session that SHOULD be terminated by a future <logout> command.
Example <login> response:
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: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
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The EPP <login> command is used to establish a session with an EPP
server. A <login> command MUST be rejected if received within the
bounds of an existing session. This action MUST be open to all
authorized clients.
2.9.1.2. EPP <logout> Command
The EPP <logout> command is used to end a session with an EPP server.
The <logout> command MUST be represented as an empty element with no
child elements.
A server MAY end a session due to client inactivity or excessive
client session longevity. The parameters for determining excessive
client inactivity or session longevity are a matter of server policy
and are not specified by this protocol.
Transport mappings MUST explicitly describe any connection-oriented
processing that takes place after processing a <logout> command and
ending a session.
Example <logout> 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: <logout/>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
When a <logout> command has been processed successfully, a server
MUST respond with an EPP response with no <resData> element. If
successful, the server MUST also end the current session.
Example <logout> response:
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="1500">
S: <msg>Command completed successfully; ending session</msg>
S: </result>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
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The EPP <logout> command is used to end a session with an EPP server.
A <logout> command MUST be rejected if the command has not been
preceded by a successful <login> command. This action MUST be open
to all authorized clients.
2.9.2. Query Commands
2.9.2.1. EPP <check> Command
The EPP <check> command is used to determine if an object can be
provisioned within a repository. It provides a hint that allows a
client to anticipate the success or failure of provisioning an object
using the <create> command as object provisioning requirements are
ultimately a matter of server policy.
The elements needed to identify an object are object-specific, so the
child elements of the <check> command are specified using the EPP
extension framework. In addition to the standard EPP command
elements, the <check> command contains the following child elements:
- An object-specific <obj:check> element that identifies the objects
to be queried. Multiple objects of the same type MAY be queried
within a single <check> command.
Example <check> 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: <check>
C: <obj:check xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <obj:name>example1</obj:name>
C: <obj:name>example2</obj:name>
C: <obj:name>example3</obj:name>
C: </obj:check>
C: </check>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
When a <check> command has been processed successfully, a server MUST
respond with an EPP <resData> element that MUST contain a child
element that identifies the object namespace. The child elements of
the <resData> element are object-specific, though the EPP <resData>
element MUST contain a child <obj:chkData> element that contains one
or more <obj:cd> (check data) elements. Each <obj:cd> element
contains the following child elements:
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- An object-specific element that identifies the queried object.
This element MUST contain an "avail" attribute whose value
indicates object availability (can it be provisioned or not) at
the moment the <check> command was completed. A value of "1" or
"true" means that the object can be provisioned. A value of "0"
or "false" means that the object cannot be provisioned.
- An OPTIONAL <obj:reason> element that MAY be provided when an
object cannot be provisioned. If present, this element contains
server-specific text to help explain why the object cannot be
provisioned. This text MUST be represented in the response
language previously negotiated with the client; an OPTIONAL "lang"
attribute MAY be present to identify the language if the
negotiated value is something other than the default value of "en"
(English).
Example <check> response:
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: <obj:chkData xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:cd>
S: <obj:name avail="1">example1</obj:name>
S: </obj:cd>
S: <obj:cd>
S: <obj:name avail="0">example2</obj:name>
S: <obj:reason>In use</obj:reason>
S: </obj:cd>
S: <obj:cd>
S: <obj:name avail="1">example3</obj:name>
S: </obj:cd>
S: </obj:chkData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <check> command is used to determine if an object can be
provisioned within a repository. This action MUST be open to all
authorized clients.
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2.9.2.2. EPP <info> Command
The EPP <info> command is used to retrieve information associated
with an existing object. The elements needed to identify an object
and the type of information associated with an object are both
object-specific, so the child elements of the <info> command are
specified using the EPP extension framework. In addition to the
standard EPP command elements, the <info> command contains the
following child elements:
- An object-specific <obj:info> element that identifies the object
to be queried.
Example <info> 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: <info>
C: <obj:info xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <!-- Object-specific elements. -->
C: </obj:info>
C: </info>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
When an <info> command has been processed successfully, a server MUST
respond with an EPP <resData> element that MUST contain a child
element that identifies the object namespace and the Repository
Object IDentifier (ROID) that was assigned to the object when the
object was created. Other child elements of the <resData> element
are object-specific.
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Example <info> response:
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: <obj:infData xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:roid>EXAMPLE1-REP</obj:roid>
S: <!-- Object-specific elements. -->
S: </obj:infData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <info> command is used to retrieve information associated
with an existing object. This action SHOULD be limited to authorized
clients; restricting this action to the sponsoring client is
RECOMMENDED.
2.9.2.3. EPP <poll> Command
The EPP <poll> command is used to discover and retrieve service
messages queued by a server for individual clients. If the message
queue is not empty, a successful response to a <poll> command MUST
return the first message from the message queue. Each response
returned from the server includes a server-unique message identifier
that MUST be provided to acknowledge receipt of the message, and a
counter that indicates the number of messages in the queue. After a
message has been received by the client, the client MUST respond to
the message with an explicit acknowledgement to confirm that the
message has been received. A server MUST dequeue the message and
decrement the queue counter after receiving acknowledgement from the
client, making the next message in the queue (if any) available for
retrieval.
Servers can occasionally perform actions on objects that are not in
direct response to a client request, or an action taken by one client
can indirectly involve a second client. Examples of such actions
include deletion upon expiration, automatic renewal upon expiration,
and transfer coordination; other types of service information MAY be
defined as a matter of server policy. Service messages SHOULD be
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created for passive clients affected by an action on an object.
Service messages MAY also be created for active clients that request
an action on an object, though such messages MUST NOT replace the
normal protocol response to the request. For example, <transfer>
actions SHOULD be reported to the client that has the authority to
approve or reject a transfer request. Other methods of server-client
action notification, such as offline reporting, are also possible and
are beyond the scope of this specification.
Message queues can consume server resources if clients do not
retrieve and acknowledge messages on a regular basis. Servers MAY
implement other mechanisms to dequeue and deliver messages if queue
maintenance needs exceed server resource consumption limits. Server
operators SHOULD consider time-sensitivity and resource management
factors when selecting a delivery method for service information
because some message types can be reasonably delivered using non-
protocol methods that require fewer server resources.
Some of the information returned in response to a <poll> command can
be object-specific, so some child elements of the <poll> response MAY
be specified using the EPP extension framework. The <poll> command
MUST be represented as an empty element with no child elements. An
"op" attribute with value "req" is REQUIRED to retrieve the first
message from the server message queue. An "op" attribute (with value
"ack") and a "msgID" attribute (whose value corresponds to the value
of the "id" attribute copied from the <msg> element in the message
being acknowledged) are REQUIRED to acknowledge receipt of a message.
Example <poll> 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: <poll op="req"/>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
The returned result code notes that a message has been dequeued and
returned in response to a <poll> command.
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Example <poll> response with object-specific information:
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="1301">
S: <msg>Command completed successfully; ack to dequeue</msg>
S: </result>
S: <msgQ count="5" id="12345">
S: <qDate>2000-06-08T22:00:00.0Z</qDate>
S: <msg>Transfer requested.</msg>
S: </msgQ>
S: <resData>
S: <obj:trnData
S: xmlns:obj="urn:ietf:params:xml:ns:obj-1.0">
S: <obj:name>example.com</obj:name>
S: <obj:trStatus>pending</obj:trStatus>
S: <obj:reID>ClientX</obj:reID>
S: <obj:reDate>2000-06-08T22:00:00.0Z</obj:reDate>
S: <obj:acID>ClientY</obj:acID>
S: <obj:acDate>2000-06-13T22:00:00.0Z</obj:acDate>
S: <obj:exDate>2002-09-08T22:00:00.0Z</obj:exDate>
S: </obj:trnData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
A client MUST acknowledge each response to dequeue the message and
make subsequent messages available for retrieval.
Example <poll> acknowledgement 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: <poll op="ack" msgID="12345"/>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
A <poll> acknowledgement response notes the ID of the message that
has been acknowledged and the number of messages remaining in the
queue.
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Example <poll> acknowledgement response:
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: <msgQ count="4" id="12345"/>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Service messages can also be returned without object information.
Example <poll> response with mixed message content and without
object-specific information:
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="1301">
S: <msg>Command completed successfully; ack to dequeue</msg>
S: </result>
S: <msgQ count="4" id="12346">
S: <qDate>2000-06-08T22:10:00.0Z</qDate>
S: <msg lang="en">Credit balance low.
S: <limit>100</limit><bal>5</bal>
S: </msg>
S: </msgQ>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The returned result code and message is used to note an empty server
message queue.
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Example <poll> response to note an empty message queue:
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="1300">
S: <msg>Command completed successfully; no messages</msg>
S: </result>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <poll> command is used to discover and retrieve client
service messages from a server. This action SHOULD be limited to
authorized clients; queuing service messages and limiting queue
access on a per-client basis is RECOMMENDED.
2.9.2.4. EPP <transfer> Query Command
The EPP <transfer> command provides a query operation that allows a
client to determine real-time status of pending and completed
transfer requests. The elements needed to identify an object that is
the subject of a transfer request are object-specific, so the child
elements of the <transfer> query command are specified using the EPP
extension framework. In addition to the standard EPP command
elements, the <transfer> command contains an "op" attribute with
value "query", and the following child elements:
- An object-specific <obj:transfer> element that identifies the
object whose transfer status is requested.
Transfer status is typically considered sensitive information by the
clients involved in the operation. Object mappings MUST provide
features to restrict transfer queries to authorized clients, such as
by requiring authorization information as part of the request.
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Example <transfer> query 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: <transfer op="query">
C: <obj:transfer xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <!-- Object-specific elements. -->
C: </obj:transfer>
C: </transfer>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
When a <transfer> query command has been processed successfully, a
server MUST respond with an EPP <resData> element that MUST contain a
child element that identifies the object namespace. The child
elements of the <resData> element are object-specific, but they MUST
include elements that identify the object, the status of the
transfer, the identifier of the client that requested the transfer,
the date and time that the request was made, the identifier of the
client that is authorized to act on the request, the date and time by
which an action is expected, and an OPTIONAL date and time noting
changes in the object's validity period (if applicable) that occur as
a result of the transfer.
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Example <transfer> query response:
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: <obj:trnData xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:name>example</obj:name>
S: <obj:trStatus>pending</obj:trStatus>
S: <obj:reID>ClientX</obj:reID>
S: <obj:reDate>2000-06-08T22:00:00.0Z</obj:reDate>
S: <obj:acID>ClientY</obj:acID>
S: <obj:acDate>2000-06-13T22:00:00.0Z</obj:acDate>
S: <obj:exDate>2002-09-08T22:00:00.0Z</obj:exDate>
S: </obj:trnData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <transfer> command provides a query operation that allows a
client to determine real-time status of pending and completed
transfer requests. This action SHOULD be limited to authorized
clients; restricting queries to the requesting and responding clients
is RECOMMENDED. Object transfer MAY be unavailable or limited by
object-specific policies.
2.9.3. Object Transform Commands
EPP provides five commands to transform objects: <create> to create
an instance of an object with a server, <delete> to remove an
instance of an object from a server, <renew> to extend the validity
period of an object, <transfer> to manage changes in client
sponsorship of an object, and <update> to change information
associated with an object.
2.9.3.1. EPP <create> Command
The EPP <create> command is used to create an instance of an object.
An object can be created for an indefinite period of time, or an
object can be created for a specific validity period. The EPP
mapping for an object MUST describe the status of an object with
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respect to time, to include expected client and server behavior if a
validity period is used.
The elements needed to identify an object and associated attributes
are object-specific, so the child elements of the <create> command
are specified using the EPP extension framework. In addition to the
standard EPP command elements, the <create> command contains the
following child elements:
- An object-specific <obj:create> element that identifies the object
to be created and the elements that are required to create the
object.
Example <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: <obj:create xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <!-- Object-specific elements. -->
C: </obj:create>
C: </create>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
When a <create> command has been processed successfully, a server MAY
respond with an EPP <resData> element that MUST contain a child
element that identifies the object namespace. The child elements of
the <resData> element are object-specific.
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Example <create> response with <resData>:
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: <obj:creData xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <!-- Object-specific elements. -->
S: </obj:creData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <create> command is used to create an instance of an object.
This action SHOULD be limited to authorized clients and MAY be
restricted on a per-client basis.
2.9.3.2. EPP <delete> Command
The EPP <delete> command is used to remove an instance of an existing
object. The elements needed to identify an object are object-
specific, so the child elements of the <delete> command are specified
using the EPP extension framework. In addition to the standard EPP
command elements, the <delete> command contains the following child
elements:
- An object-specific <obj:delete> element that identifies the object
to be deleted.
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Example <delete> 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: <delete>
C: <obj:delete xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <!-- Object-specific elements. -->
C: </obj:delete>
C: </delete>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
When a <delete> command has been processed successfully, a server MAY
respond with an EPP <resData> element that MUST contain a child
element that identifies the object namespace. The child elements of
the <resData> element are object-specific.
Example <delete> response without <resData>:
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: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <delete> command is used to remove an instance of an existing
object. This action SHOULD be limited to authorized clients;
restricting this action to the sponsoring client is RECOMMENDED.
2.9.3.3. EPP <renew> Command
The EPP <renew> command is used to extend the validity period of an
existing object. The elements needed to identify and extend the
validity period of an object are object-specific, so the child
elements of the <renew> command are specified using the EPP extension
framework. In addition to the standard EPP command elements, the
<renew> command contains the following child elements:
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- An object-specific <obj:renew> element that identifies the object
to be renewed and the elements that are required to extend the
validity period of the object.
Example <renew> 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: <renew>
C: <obj:renew xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <!-- Object-specific elements. -->
C: </obj:renew>
C: </renew>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
When a <renew> command has been processed successfully, a server MAY
respond with an EPP <resData> element that MUST contain a child
element that identifies the object namespace. The child elements of
the <resData> element are object-specific.
Example <renew> response with <resData>:
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: <obj:renData xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <!-- Object-specific elements. -->
S: </obj:renData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <renew> command is used to extend the validity period of an
existing object. This action SHOULD be limited to authorized
clients; restricting this action to the sponsoring client is
RECOMMENDED. Object renewal MAY be unavailable or limited by object-
specific policies.
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2.9.3.4. EPP <transfer> Command
The EPP <transfer> command is used to manage changes in client
sponsorship of an existing object. Clients can initiate a transfer
request, cancel a transfer request, approve a transfer request, and
reject a transfer request using the "op" command attribute.
A client who wishes to assume sponsorship of a known object from
another client uses the <transfer> command with the value of the "op"
attribute set to "request". Once a transfer has been requested, the
same client can cancel the request using a <transfer> command with
the value of the "op" attribute set to "cancel". A request to cancel
the transfer MUST be sent to the server before the current sponsoring
client either approves or rejects the transfer request and before the
server automatically processes the request due to responding client
inactivity.
Once a transfer request has been received by the server, the server
MUST notify the current sponsoring client of the requested transfer
either by queuing a service message for retrieval via the <poll>
command or by using an out-of-band mechanism to inform the client of
the request. The current status of a pending <transfer> command for
any object can be found using the <transfer> query command. Transfer
service messages MUST include the object-specific elements specified
for <transfer> command responses.
The current sponsoring client MAY explicitly approve or reject the
transfer request. The client can approve the request using a
<transfer> command with the value of the "op" attribute set to
"approve". The client can reject the request using a <transfer>
command with the value of the "op" attribute set to "reject".
A server MAY automatically approve or reject all transfer requests
that are not explicitly approved or rejected by the current
sponsoring client within a fixed amount of time. The amount of time
to wait for explicit action and the default server behavior are local
matters not specified by EPP, but they SHOULD be documented in a
server-specific profile document that describes default server
behavior for client information.
Objects eligible for transfer MUST have associated authorization
information that MUST be provided to complete a <transfer> command.
The type of authorization information required is object-specific;
passwords or more complex mechanisms based on public key cryptography
are typical.
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The elements needed to identify and complete the transfer of an
object are object-specific, so the child elements of the <transfer>
command are specified using the EPP extension framework. In addition
to the standard EPP command elements, the <transfer> command contains
the following child elements:
- An object-specific <obj:transfer> element that identifies the
object to be transferred and the elements that are required to
process the transfer command.
Example <transfer> 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: <transfer op="request">
C: <obj:transfer xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <!-- Object-specific elements. -->
C: </obj:transfer>
C: </transfer>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
When a <transfer> command has been processed successfully, a server
MUST respond with an EPP <resData> element that MUST contain a child
element that identifies the object namespace. The child elements of
the <resData> element are object-specific, but they MUST include
elements that identify the object, the status of the transfer, the
identifier of the client that requested the transfer, the date and
time that the request was made, the identifier of the client that is
authorized to act on the request, the date and time by which an
action is expected, and an OPTIONAL date and time noting changes in
the object's validity period (if applicable) that occur as a result
of the transfer.
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Example <transfer> response with <resData>:
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="1001">
S: <msg>Command completed successfully; action pending</msg>
S: </result>
S: <resData>
S: <obj:trnData xmlns:obj="urn:ietf:params:xml:ns:obj">
S: <obj:name>example</obj:name>
S: <obj:trStatus>pending</obj:trStatus>
S: <obj:reID>ClientX</obj:reID>
S: <obj:reDate>2000-06-08T22:00:00.0Z</obj:reDate>
S: <obj:acID>ClientY</obj:acID>
S: <obj:acDate>2000-06-13T22:00:00.0Z</obj:acDate>
S: <obj:exDate>2002-09-08T22:00:00.0Z</obj:exDate>
S: </obj:trnData>
S: </resData>
S: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <transfer> command is used to manage changes in client
sponsorship of an existing object. This action SHOULD be limited to
authorized clients; restricting <transfer> requests to a client other
than the current sponsoring client, <transfer> approval requests to
the current sponsoring client, and <transfer> cancellation requests
to the original requesting client is RECOMMENDED. Object transfer
MAY be unavailable or limited by object-specific policies.
2.9.3.5. EPP <update> Command
The EPP <update> command is used to change information associated
with an existing object. The elements needed to identify and modify
an object are object-specific, so the child elements of the <update>
command are specified using the EPP extension framework. In addition
to the standard EPP command elements, the <update> command contains
the following child elements:
- An object-specific <obj:update> element that identifies the object
to be updated and the elements that are required to modify the
object. Object-specific elements MUST identify values to be
added, values to be removed, or values to be changed.
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Example <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: <obj:update xmlns:obj="urn:ietf:params:xml:ns:obj">
C: <!-- Object-specific elements. -->
C: </obj:update>
C: </update>
C: <clTRID>ABC-12346</clTRID>
C: </command>
C:</epp>
When an <update> command has been processed successfully, a server
MAY respond with an EPP <resData> element that MUST contain a child
element that identifies the object namespace. The child elements of
the <resData> element are object-specific.
Example <update> response without <resData>:
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: <trID>
S: <clTRID>ABC-12346</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
The EPP <update> command is used to change information associated
with an existing object. This action SHOULD be limited to authorized
clients; restricting this action to the sponsoring client is
RECOMMENDED.
3. Result Codes
EPP result codes are based on the theory of reply codes described in
section 4.2.1 of [RFC2821]. EPP uses four decimal digits to describe
the success or failure of each EPP command. Each of the digits of
the reply have special significance.
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The first digit denotes command success or failure. The second digit
denotes the response category, such as command syntax or security.
The third and fourth digits provide explicit response detail within
each response category.
There are two values for the first digit of the reply code:
1yzz Positive completion reply. The command was accepted and
processed by the system without error.
2yzz Negative completion reply. The command was not accepted, and
the requested action did not occur.
The second digit groups responses into one of six specific
categories:
x0zz Protocol Syntax
x1zz Implementation-specific Rules
x2zz Security
x3zz Data Management
x4zz Server System
x5zz Connection Management
The third and fourth digits provide response detail within the
categories defined by the first and second digits. Specific result
codes are listed in the table below.
Every EPP response MUST include a result code and a human-readable
description of the result code. The language used to represent the
description MAY be identified using an instance of the "lang"
attribute within the <msg> element. If not specified, the default
language is English, identified as "en". A description of the
structure of valid values for the "lang" attribute is described in
[RFC3066].
Response text MAY be translated into other languages, though the
translation MUST preserve the meaning of the code as described here.
Response code values MUST NOT be changed when translating text.
Response text in the table below is enclosed in quotes to clearly
mark the beginning and ending of each response string. Quotes MUST
NOT be used to delimit these strings when returning response text via
the protocol.
Successful command completion responses:
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Code Response text in English
____ ________________________
1000 "Command completed successfully"
This is the usual response code for a successfully completed
command that is not addressed by any other 1xxx-series
response code.
1001 "Command completed successfully; action pending"
This response code MUST be returned when responding to a
command that requires offline activity before the requested
action can be completed. See Section 2 for a description of
other processing requirements.
1300 "Command completed successfully; no messages"
This response code MUST be returned when responding to a
<poll> request command and the server message queue is empty.
1301 "Command completed successfully; ack to dequeue"
This response code MUST be returned when responding to a
<poll> request command and a message has been retrieved from
the server message queue.
1500 "Command completed successfully; ending session"
This response code MUST be returned when responding to a
successful <logout> command.
Command error responses:
Code Response text in English
____ ________________________
2000 "Unknown command"
This response code MUST be returned when a server receives a
command element that is not defined by EPP.
2001 "Command syntax error"
This response code MUST be returned when a server receives an
improperly formed command element.
2002 "Command use error"
This response code MUST be returned when a server receives a
properly formed command element, but the command cannot be
executed due to a sequencing or context error. For example,
a <logout> command cannot be executed without having first
completed a <login> command.
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2003 "Required parameter missing"
This response code MUST be returned when a server receives a
command for which a required parameter value has not been
provided.
2004 "Parameter value range error"
This response code MUST be returned when a server receives a
command parameter whose value is outside the range of values
specified by the protocol. The error value SHOULD be
returned via a <value> element in the EPP response.
2005 "Parameter value syntax error"
This response code MUST be returned when a server receives a
command containing a parameter whose value is improperly
formed. The error value SHOULD be returned via a <value>
element in the EPP response.
2100 "Unimplemented protocol version"
This response code MUST be returned when a server receives a
command element specifying a protocol version that is not
implemented by the server.
2101 "Unimplemented command"
This response code MUST be returned when a server receives a
valid EPP command element that is not implemented by the
server. For example, a <transfer> command can be
unimplemented for certain object types.
2102 "Unimplemented option"
This response code MUST be returned when a server receives a
valid EPP command element that contains a protocol option
that is not implemented by the server.
2103 "Unimplemented extension"
This response code MUST be returned when a server receives a
valid EPP command element that contains a protocol command
extension that is not implemented by the server.
2104 "Billing failure"
This response code MUST be returned when a server attempts to
execute a billable operation and the command cannot be
completed due to a client billing failure.
2105 "Object is not eligible for renewal"
This response code MUST be returned when a client attempts to
<renew> an object that is not eligible for renewal in
accordance with server policy.
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2106 "Object is not eligible for transfer"
This response code MUST be returned when a client attempts to
<transfer> an object that is not eligible for transfer in
accordance with server policy.
2200 "Authentication error"
This response code MUST be returned when a server notes an
error when validating client credentials.
2201 "Authorization error"
This response code MUST be returned when a server notes a
client authorization error when executing a command. This
error is used to note that a client lacks privileges to
execute the requested command.
2202 "Invalid authorization information"
This response code MUST be returned when a server receives
invalid command authorization information required to confirm
authorization to execute a command. This error is used to
note that a client has the privileges required to execute the
requested command, but the authorization information provided
by the client does not match the authorization information
archived by the server.
2300 "Object pending transfer"
This response code MUST be returned when a server receives a
command to transfer of an object that is pending transfer due
to an earlier transfer request.
2301 "Object not pending transfer"
This response code MUST be returned when a server receives a
command to confirm, reject, or cancel the transfer an object
when no command has been made to transfer the object.
2302 "Object exists"
This response code MUST be returned when a server receives a
command to create an object that already exists in the
repository.
2303 "Object does not exist"
This response code MUST be returned when a server receives a
command to query or transform an object that does not exist
in the repository.
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2304 "Object status prohibits operation"
This response code MUST be returned when a server receives a
command to transform an object that cannot be completed due
to server policy or business practices. For example, a
server can disallow <transfer> commands under terms and
conditions that are matters of local policy, or the server
might have received a <delete> command for an object whose
status prohibits deletion.
2305 "Object association prohibits operation"
This response code MUST be returned when a server receives a
command to transform an object that cannot be completed due
to dependencies on other objects that are associated with the
target object. For example, a server can disallow <delete>
commands while an object has active associations with other
objects.
2306 "Parameter value policy error"
This response code MUST be returned when a server receives a
command containing a parameter value that is syntactically
valid, but semantically invalid due to local policy. For
example, the server can support a subset of a range of valid
protocol parameter values. The error value SHOULD be
returned via a <value> element in the EPP response.
2307 "Unimplemented object service"
This response code MUST be returned when a server receives a
command to operate on an object service that is not supported
by the server.
2308 "Data management policy violation"
This response code MUST be returned when a server receives a
command whose execution results in a violation of server data
management policies. For example, removing all attribute
values or object associations from an object might be a
violation of a server's data management policies.
2400 "Command failed"
This response code MUST be returned when a server is unable
to execute a command due to an internal server error that is
not related to the protocol. The failure can be transient.
The server MUST keep any ongoing session active.
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2500 "Command failed; server closing connection"
This response code MUST be returned when a server receives a
command that cannot be completed due to an internal server
error that is not related to the protocol. The failure is
not transient and will cause other commands to fail as well.
The server MUST end the active session and close the existing
connection.
2501 "Authentication error; server closing connection"
This response code MUST be returned when a server notes an
error when validating client credentials and a server-defined
limit on the number of allowable failures has been exceeded.
The server MUST close the existing connection.
2502 "Session limit exceeded; server closing connection"
This response code MUST be returned when a server receives a
<login> command, and the command cannot be completed because
the client has exceeded a system-defined limit on the number
of sessions that the client can establish. It might be
possible to establish a session by ending existing unused
sessions and closing inactive connections.
4. Formal Syntax
EPP is specified in XML Schema notation. The formal syntax presented
here is a complete schema representation of EPP suitable for
automated validation of EPP XML instances.
Two schemas are presented here. The first schema is the base EPP
schema. The second schema defines elements and structures that can
be used by both the base EPP schema and object mapping schemas. The
BEGIN and END tags are not part of the schema; they are used to note
the beginning and ending of the schema for URI registration purposes.
4.1. Base Schema
BEGIN
<?xml version="1.0" encoding="UTF-8"?>
<schema targetNamespace="urn:ietf:params:xml:ns:epp-1.0"
xmlns:epp="urn:ietf:params:xml:ns:epp-1.0"
xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
xmlns="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">
<!--
Import common element types.
-->
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<import namespace="urn:ietf:params:xml:ns:eppcom-1.0"/>
<annotation>
<documentation>
Extensible Provisioning Protocol v1.0 schema.
</documentation>
</annotation>
<!--
Every EPP XML instance must begin with this element.
-->
<element name="epp" type="epp:eppType"/>
<!--
An EPP XML instance must contain a greeting, hello, command,
response, or extension.
-->
<complexType name="eppType">
<choice>
<element name="greeting" type="epp:greetingType"/>
<element name="hello"/>
<element name="command" type="epp:commandType"/>
<element name="response" type="epp:responseType"/>
<element name="extension" type="epp:extAnyType"/>
</choice>
</complexType>
<!--
A greeting is sent by a server in response to a client connection
or <hello>.
-->
<complexType name="greetingType">
<sequence>
<element name="svID" type="epp:sIDType"/>
<element name="svDate" type="dateTime"/>
<element name="svcMenu" type="epp:svcMenuType"/>
<element name="dcp" type="epp:dcpType"/>
</sequence>
</complexType>
<!--
Server IDs are strings with minimum and maximum length restrictions.
-->
<simpleType name="sIDType">
<restriction base="normalizedString">
<minLength value="3"/>
<maxLength value="64"/>
</restriction>
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</simpleType>
<!--
A server greeting identifies available object services.
-->
<complexType name="svcMenuType">
<sequence>
<element name="version" type="epp:versionType"
maxOccurs="unbounded"/>
<element name="lang" type="language"
maxOccurs="unbounded"/>
<element name="objURI" type="anyURI"
maxOccurs="unbounded"/>
<element name="svcExtension" type="epp:extURIType"
minOccurs="0"/>
</sequence>
</complexType>
<!--
Data Collection Policy types.
-->
<complexType name="dcpType">
<sequence>
<element name="access" type="epp:dcpAccessType"/>
<element name="statement" type="epp:dcpStatementType"
maxOccurs="unbounded"/>
<element name="expiry" type="epp:dcpExpiryType"
minOccurs="0"/>
</sequence>
</complexType>
<complexType name="dcpAccessType">
<choice>
<element name="all"/>
<element name="none"/>
<element name="null"/>
<element name="other"/>
<element name="personal"/>
<element name="personalAndOther"/>
</choice>
</complexType>
<complexType name="dcpStatementType">
<sequence>
<element name="purpose" type="epp:dcpPurposeType"/>
<element name="recipient" type="epp:dcpRecipientType"/>
<element name="retention" type="epp:dcpRetentionType"/>
</sequence>
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</complexType>
<complexType name="dcpPurposeType">
<sequence>
<element name="admin"
minOccurs="0"/>
<element name="contact"
minOccurs="0"/>
<element name="other"
minOccurs="0"/>
<element name="prov"
minOccurs="0"/>
</sequence>
</complexType>
<complexType name="dcpRecipientType">
<sequence>
<element name="other"
minOccurs="0"/>
<element name="ours" type="epp:dcpOursType"
minOccurs="0" maxOccurs="unbounded"/>
<element name="public"
minOccurs="0"/>
<element name="same"
minOccurs="0"/>
<element name="unrelated"
minOccurs="0"/>
</sequence>
</complexType>
<complexType name="dcpOursType">
<sequence>
<element name="recDesc" type="epp:dcpRecDescType"
minOccurs="0"/>
</sequence>
</complexType>
<simpleType name="dcpRecDescType">
<restriction base="token">
<minLength value="1"/>
<maxLength value="255"/>
</restriction>
</simpleType>
<complexType name="dcpRetentionType">
<choice>
<element name="business"/>
<element name="indefinite"/>
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<element name="legal"/>
<element name="none"/>
<element name="stated"/>
</choice>
</complexType>
<complexType name="dcpExpiryType">
<choice>
<element name="absolute" type="dateTime"/>
<element name="relative" type="duration"/>
</choice>
</complexType>
<!--
Extension framework types.
-->
<complexType name="extAnyType">
<sequence>
<any namespace="##other"
maxOccurs="unbounded"/>
</sequence>
</complexType>
<complexType name="extURIType">
<sequence>
<element name="extURI" type="anyURI"
maxOccurs="unbounded"/>
</sequence>
</complexType>
<!--
An EPP version number is a dotted pair of decimal numbers.
-->
<simpleType name="versionType">
<restriction base="token">
<pattern value="[1-9]+\.[0-9]+"/>
<enumeration value="1.0"/>
</restriction>
</simpleType>
<!--
Command types.
-->
<complexType name="commandType">
<sequence>
<choice>
<element name="check" type="epp:readWriteType"/>
<element name="create" type="epp:readWriteType"/>
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<element name="delete" type="epp:readWriteType"/>
<element name="info" type="epp:readWriteType"/>
<element name="login" type="epp:loginType"/>
<element name="logout"/>
<element name="poll" type="epp:pollType"/>
<element name="renew" type="epp:readWriteType"/>
<element name="transfer" type="epp:transferType"/>
<element name="update" type="epp:readWriteType"/>
</choice>
<element name="extension" type="epp:extAnyType"
minOccurs="0"/>
<element name="clTRID" type="epp:trIDStringType"
minOccurs="0"/>
</sequence>
</complexType>
<!--
The <login> command.
-->
<complexType name="loginType">
<sequence>
<element name="clID" type="eppcom:clIDType"/>
<element name="pw" type="epp:pwType"/>
<element name="newPW" type="epp:pwType"
minOccurs="0"/>
<element name="options" type="epp:credsOptionsType"/>
<element name="svcs" type="epp:loginSvcType"/>
</sequence>
</complexType>
<complexType name="credsOptionsType">
<sequence>
<element name="version" type="epp:versionType"/>
<element name="lang" type="language"/>
</sequence>
</complexType>
<simpleType name="pwType">
<restriction base="token">
<minLength value="6"/>
<maxLength value="16"/>
</restriction>
</simpleType>
<complexType name="loginSvcType">
<sequence>
<element name="objURI" type="anyURI"
maxOccurs="unbounded"/>
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<element name="svcExtension" type="epp:extURIType"
minOccurs="0"/>
</sequence>
</complexType>
<!--
The <poll> command.
-->
<complexType name="pollType">
<attribute name="op" type="epp:pollOpType"
use="required"/>
<attribute name="msgID" type="token"/>
</complexType>
<simpleType name="pollOpType">
<restriction base="token">
<enumeration value="ack"/>
<enumeration value="req"/>
</restriction>
</simpleType>
<!--
The <transfer> command. This is object-specific, and uses attributes
to identify the requested operation.
-->
<complexType name="transferType">
<sequence>
<any namespace="##other"/>
</sequence>
<attribute name="op" type="epp:transferOpType"
use="required"/>
</complexType>
<simpleType name="transferOpType">
<restriction base="token">
<enumeration value="approve"/>
<enumeration value="cancel"/>
<enumeration value="query"/>
<enumeration value="reject"/>
<enumeration value="request"/>
</restriction>
</simpleType>
<!--
All other object-centric commands. EPP doesn't specify the syntax or
semantics of object-centric command elements. The elements MUST be
described in detail in another schema specific to the object.
-->
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<complexType name="readWriteType">
<sequence>
<any namespace="##other"/>
</sequence>
</complexType>
<complexType name="trIDType">
<sequence>
<element name="clTRID" type="epp:trIDStringType"
minOccurs="0"/>
<element name="svTRID" type="epp:trIDStringType"/>
</sequence>
</complexType>
<simpleType name="trIDStringType">
<restriction base="token">
<minLength value="3"/>
<maxLength value="64"/>
</restriction>
</simpleType>
<!--
Response types.
-->
<complexType name="responseType">
<sequence>
<element name="result" type="epp:resultType"
maxOccurs="unbounded"/>
<element name="msgQ" type="epp:msgQType"
minOccurs="0"/>
<element name="resData" type="epp:extAnyType"
minOccurs="0"/>
<element name="extension" type="epp:extAnyType"
minOccurs="0"/>
<element name="trID" type="epp:trIDType"/>
</sequence>
</complexType>
<complexType name="resultType">
<sequence>
<element name="msg" type="epp:msgType"/>
<choice minOccurs="0" maxOccurs="unbounded">
<element name="value" type="epp:errValueType"/>
<element name="extValue" type="epp:extErrValueType"/>
</choice>
</sequence>
<attribute name="code" type="epp:resultCodeType"
use="required"/>
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</complexType>
<complexType name="errValueType" mixed="true">
<sequence>
<any namespace="##any" processContents="skip"/>
</sequence>
<anyAttribute namespace="##any" processContents="skip"/>
</complexType>
<complexType name="extErrValueType">
<sequence>
<element name="value" type="epp:errValueType"/>
<element name="reason" type="epp:msgType"/>
</sequence>
</complexType>
<complexType name="msgQType">
<sequence>
<element name="qDate" type="dateTime"
minOccurs="0"/>
<element name="msg" type="epp:mixedMsgType"
minOccurs="0"/>
</sequence>
<attribute name="count" type="unsignedLong"
use="required"/>
<attribute name="id" type="eppcom:minTokenType"
use="required"/>
</complexType>
<complexType name="mixedMsgType" mixed="true">
<sequence>
<any processContents="skip"
minOccurs="0" maxOccurs="unbounded"/>
</sequence>
<attribute name="lang" type="language"
default="en"/>
</complexType>
<!--
Human-readable text may be expressed in languages other than English.
-->
<complexType name="msgType">
<simpleContent>
<extension base="normalizedString">
<attribute name="lang" type="language"
default="en"/>
</extension>
</simpleContent>
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</complexType>
<!--
EPP result codes.
-->
<simpleType name="resultCodeType">
<restriction base="unsignedShort">
<enumeration value="1000"/>
<enumeration value="1001"/>
<enumeration value="1300"/>
<enumeration value="1301"/>
<enumeration value="1500"/>
<enumeration value="2000"/>
<enumeration value="2001"/>
<enumeration value="2002"/>
<enumeration value="2003"/>
<enumeration value="2004"/>
<enumeration value="2005"/>
<enumeration value="2100"/>
<enumeration value="2101"/>
<enumeration value="2102"/>
<enumeration value="2103"/>
<enumeration value="2104"/>
<enumeration value="2105"/>
<enumeration value="2106"/>
<enumeration value="2200"/>
<enumeration value="2201"/>
<enumeration value="2202"/>
<enumeration value="2300"/>
<enumeration value="2301"/>
<enumeration value="2302"/>
<enumeration value="2303"/>
<enumeration value="2304"/>
<enumeration value="2305"/>
<enumeration value="2306"/>
<enumeration value="2307"/>
<enumeration value="2308"/>
<enumeration value="2400"/>
<enumeration value="2500"/>
<enumeration value="2501"/>
<enumeration value="2502"/>
</restriction>
</simpleType>
<!--
End of schema.
-->
</schema>
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END
4.2. Shared Structure Schema
BEGIN
<?xml version="1.0" encoding="UTF-8"?>
<schema targetNamespace="urn:ietf:params:xml:ns:eppcom-1.0"
xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
xmlns="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">
<annotation>
<documentation>
Extensible Provisioning Protocol v1.0
shared structures schema.
</documentation>
</annotation>
<!--
Object authorization information types.
-->
<complexType name="pwAuthInfoType">
<simpleContent>
<extension base="normalizedString">
<attribute name="roid" type="eppcom:roidType"/>
</extension>
</simpleContent>
</complexType>
<complexType name="extAuthInfoType">
<sequence>
<any namespace="##other"/>
</sequence>
</complexType>
<!--
<check> response types.
-->
<complexType name="reasonType">
<simpleContent>
<extension base="eppcom:reasonBaseType">
<attribute name="lang" type="language"/>
</extension>
</simpleContent>
</complexType>
<simpleType name="reasonBaseType">
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<restriction base="token">
<minLength value="1"/>
<maxLength value="32"/>
</restriction>
</simpleType>
<!--
Abstract client and object identifier type.
-->
<simpleType name="clIDType">
<restriction base="token">
<minLength value="3"/>
<maxLength value="16"/>
</restriction>
</simpleType>
<!--
DNS label type.
-->
<simpleType name="labelType">
<restriction base="token">
<minLength value="1"/>
<maxLength value="255"/>
</restriction>
</simpleType>
<!--
Non-empty token type.
-->
<simpleType name="minTokenType">
<restriction base="token">
<minLength value="1"/>
</restriction>
</simpleType>
<!--
Repository Object IDentifier type.
-->
<simpleType name="roidType">
<restriction base="token">
<pattern value="(\w|_){1,80}-\w{1,8}"/>
</restriction>
</simpleType>
<!--
Transfer status identifiers.
-->
<simpleType name="trStatusType">
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<restriction base="token">
<enumeration value="clientApproved"/>
<enumeration value="clientCancelled"/>
<enumeration value="clientRejected"/>
<enumeration value="pending"/>
<enumeration value="serverApproved"/>
<enumeration value="serverCancelled"/>
</restriction>
</simpleType>
<!--
End of schema.
-->
</schema>
END
5. Internationalization Considerations
EPP is represented in XML, which provides native support for encoding
information using the Unicode character set and its more compact
representations including UTF-8. Conformant XML processors recognize
both UTF-8 and UTF-16. Though XML includes provisions to identify
and use other character encodings through use of an "encoding"
attribute in an <?xml?> declaration, use of UTF-8 is RECOMMENDED in
environments where parser encoding support incompatibility exists.
EPP includes a provision for returning a human-readable message with
every result code. This document describes result codes in English,
but the actual text returned with a result MAY be provided in a
language negotiated when a session is established. Languages other
than English MUST be noted through specification of a "lang"
attribute for each message. Valid values for the "lang" attribute
and "lang" negotiation elements are described in [RFC3066].
All date-time values presented via EPP MUST be expressed in Universal
Coordinated Time using the Gregorian calendar. XML Schema allows use
of time zone identifiers to indicate offsets from the zero meridian,
but this option MUST NOT be used with EPP. 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.
Hollenbeck Standards Track [Page 60]
RFC 4930 EPP May 2007
6. IANA Considerations
This document uses URNs to describe XML namespaces and XML schemas
conforming to a registry mechanism described in [RFC3688]. Four URI
assignments have been registered by the IANA.
Registration request for the EPP namespace:
URI: urn:ietf:params:xml:ns:epp-1.0
Registrant Contact: See the "Author's Address" section of this
document.
XML: None. Namespace URIs do not represent an XML specification.
Registration request for the EPP XML schema:
URI: urn:ietf:params:xml:schema:epp-1.0
Registrant Contact: See the "Author's Address" section of this
document.
XML: See the "Base Schema" section of this document.
Registration request for the EPP shared structure namespace:
URI: urn:ietf:params:xml:ns:eppcom-1.0
Registrant Contact: See the "Author's Address" section of this
document.
XML: None. Namespace URIs do not represent an XML specification.
Registration request for the EPP shared structure XML schema:
URI: urn:ietf:params:xml:schema:eppcom-1.0
Registrant Contact: See the "Author's Address" section of this
document.
XML: See the "Shared Structure Schema" section of this document.
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7. Security Considerations
EPP provides only simple client authentication services. A passive
attack is sufficient to recover client identifiers and passwords,
allowing trivial command forgery. Protection against most common
attacks and more robust security services MUST be provided by other
protocol layers. Specifically, EPP instances MUST be protected using
a transport mechanism or application protocol that provides
integrity, confidentiality, and mutual strong client-server
authentication.
EPP uses a variant of the PLAIN SASL mechanism described in [RFC2595]
to provide a simple application-layer authentication service that
augments or supplements authentication and identification services
that might be available at other protocol layers. Where the PLAIN
SASL mechanism specifies provision of an authorization identifier,
authentication identifier, and password as a single string separated
by ASCII NUL characters, EPP specifies use of a combined
authorization and authentication identifier and a password provided
as distinct XML elements.
Repeated password guessing attempts can be discouraged by limiting
the number of <login> attempts that can be attempted on an open
connection. A server MAY close an open connection if multiple
<login> attempts are made with either an invalid client identifier,
an invalid password, or both an invalid client identifier and an
invalid password.
EPP uses authentication information associated with objects to
confirm object transfer authority. Authentication information
exchanged between EPP clients and third-party entities MUST be
exchanged using a facility that provides privacy and integrity
services to protect against unintended disclosure and modification
while in transit.
EPP instances SHOULD be protected using a transport mechanism or
application protocol that provides anti-replay protection. EPP
provides some protection against replay attacks through command
idempotency and client-initiated transaction identification.
Consecutive command replays will not change the state of an object in
any way. There is, however, a chance of unintended or malicious
consequence if a command is replayed after intervening commands have
changed the object state and client identifiers are not used to
detect replays. For example, a replayed <create> command that
follows a <delete> command might succeed without additional
facilities to prevent or detect the replay.
Hollenbeck Standards Track [Page 62]
RFC 4930 EPP May 2007
8. Acknowledgements
This document was originally written as an individual submission
Internet-Draft. The PROVREG working group later adopted it as a
working group document and provided many invaluable comments and
suggested improvements. The author wishes to acknowledge the efforts
of WG chairs Edward Lewis and Jaap Akkerhuis for their process and
editorial contributions.
Specific suggestions that have been incorporated into this document
were provided by Chris Bason, Eric Brunner-Williams, Jordyn Buchanan,
Roger Castillo Cortazar, Dave Crocker, Ayesha Damaraju, Sheer El-
Showk, Patrik Faltstrom, James Gould, John Immordino, Dan Kohn, Hong
Liu, Klaus Malorny, Dan Manley, Michael Mealling, Patrick Mevzek,
Andrew Newton, Budi Rahardjo, Asbjorn Steira, Rick Wesson, and Jay
Westerdal.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2277] Alvestrand, H., "IETF Policy on Character Sets and
Languages", BCP 18, RFC 2277, January 1998.
[RFC2914] Floyd, S., "Congestion Control Principles", BCP 41,
RFC 2914, September 2000.
[RFC3066] Alvestrand, H., "Tags for the Identification of
Languages", RFC 3066, January 2001.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[W3C.REC-xml-20040204]
Yergeau, F., Maler, E., Sperberg-McQueen, C., Bray, T.,
and J. Paoli, "Extensible Markup Language (XML) 1.0 (Third
Edition)", World Wide Web Consortium FirstEdition REC-xml-
20040204, February 2004,
<http://www.w3.org/TR/2004/REC-xml-20040204>.
Hollenbeck Standards Track [Page 63]
RFC 4930 EPP May 2007
[W3C.REC-xmlschema-1-20041028]
Thompson, H., Maloney, M., Mendelsohn, N., and D. Beech,
"XML Schema Part 1: Structures Second Edition", World Wide
Web Consortium Recommendation REC-xmlschema-1-20041028,
October 2004,
<http://www.w3.org/TR/2004/REC-xmlschema-1-20041028>.
[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,
<http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.
9.2. Informative References
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, September 1981.
[RFC2595] Newman, C., "Using TLS with IMAP, POP3 and ACAP",
RFC 2595, June 1999.
[RFC2781] Hoffman, P. and F. Yergeau, "UTF-16, an encoding of ISO
10646", RFC 2781, February 2000.
[RFC2821] Klensin, J., "Simple Mail Transfer Protocol", RFC 2821,
April 2001.
[RFC2960] Stewart, R., Xie, Q., Morneault, K., Sharp, C.,
Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M.,
Zhang, L., and V. Paxson, "Stream Control Transmission
Protocol", RFC 2960, October 2000.
[RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media
Types", RFC 3023, January 2001.
[RFC3080] Rose, M., "The Blocks Extensible Exchange Protocol Core",
RFC 3080, March 2001.
[RFC3375] Hollenbeck, S., "Generic Registry-Registrar Protocol
Requirements", RFC 3375, September 2002.
[RFC3730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
RFC 3730, March 2004.
Hollenbeck Standards Track [Page 64]
RFC 4930 EPP May 2007
[W3C.REC-P3P-20020416]
Marchiori, M., "The Platform for Privacy Preferences 1.0
(P3P1.0) Specification", World Wide Web Consortium
Recommendation REC-P3P-20020416, April 2002,
<http://www.w3.org/TR/2002/REC-P3P-20020416>.
Hollenbeck Standards Track [Page 65]
RFC 4930 EPP May 2007
Appendix A. Object Mapping Template
This appendix describes a recommended outline for documenting the EPP
mapping of an object. Documents that describe EPP object mappings
SHOULD describe the mapping in a format similar to the one used here.
Additional sections are required if the object mapping is written in
Internet-Draft or RFC format.
1. Introduction
Provide an introduction that describes the object and an overview
of the mapping to EPP.
2. Object Attributes
Describe the attributes associated with the object, including
references to syntax specifications as appropriate. Examples of
object attributes include a name or identifier and dates
associated with modification events.
3. EPP Command Mapping
3.1. EPP Query Commands
3.1.1. EPP <check> Command
Describe the object-specific mappings required to implement the
EPP <check> command. Include both sample commands and sample
responses.
3.1.2. EPP <info> Command
Describe the object-specific mappings required to implement the
EPP <info> command. Include both sample commands and sample
responses.
3.1.3. EPP <poll> Command
Describe the object-specific mappings required to implement the
EPP <poll> command. Include both sample commands and sample
responses.
3.1.4. EPP <transfer> Command
Describe the object-specific mappings required to implement the
EPP <transfer> query command. Include both sample commands and
sample responses.
Hollenbeck Standards Track [Page 66]
RFC 4930 EPP May 2007
3.2. EPP Transform Commands
3.2.1. EPP <create> Command
Describe the object-specific mappings required to implement the
EPP <create> command. Include both sample commands and sample
responses. Describe the status of the object with respect to
time, including expected client and server behavior if a validity
period is used.
3.2.2. EPP <delete> Command
Describe the object-specific mappings required to implement the
EPP <delete> command. Include both sample commands and sample
responses.
3.2.3. EPP <renew> Command
Describe the object-specific mappings required to implement the
EPP <renew> command. Include both sample commands and sample
responses.
3.2.4. EPP <transfer> Command
Describe the object-specific mappings required to implement the
EPP <transfer> command. Include both sample commands and sample
responses.
3.2.4. EPP <update> Command
Describe the object-specific mappings required to implement the
EPP <update> command. Include both sample commands and sample
responses.
4. Formal Syntax
Provide the XML schema for the object mapping. An XML DTD MUST
NOT be used as DTDs do not provide sufficient support for XML
namespaces and strong data typing.
Hollenbeck Standards Track [Page 67]
RFC 4930 EPP May 2007
Appendix B. Media Type Registration: application/epp+xml
MIME media type name: application
MIME subtype name: epp+xml
Required parameters: none
Optional parameters: Same as the charset parameter of application/xml
as specified in [RFC3023].
Encoding considerations: Same as the encoding considerations of
application/xml as specified in [RFC3023].
Security considerations: This type has all of the security
considerations described in [RFC3023] plus the considerations
specified in the Security Considerations section of this document.
Interoperability considerations: XML has proven to be interoperable
across WWW Distributed Authoring and Versioning (WebDAV) clients and
servers, and for import and export from multiple XML authoring tools.
For maximum interoperability, validating processors are recommended.
Although non-validating processors can be more efficient, they are
not required to handle all features of XML. For further information,
see Section 2.9, "Standalone Document Declaration", and Section 5,
"Conformance", of [W3C.REC-xml-20040204].
Published specification: This document.
Applications that use this media type: EPP is device-, platform-, and
vendor-neutral and is supported by multiple service providers.
Additional information: If used, magic numbers, fragment identifiers,
base URIs, and use of the BOM should be as specified in [RFC3023].
Magic number(s): None.
File extension(s): .xml
Macintosh file type code(s): "TEXT"
Person & email address for further information: See the "Author's
Address" section of this document.
Intended usage: COMMON
Author/Change controller: IETF
Hollenbeck Standards Track [Page 68]
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Appendix C. Changes from RFC 3730
1. Minor reformatting as a result of converting I-D source format
from nroff to XML.
2. Updated the state diagram in Section 2 to note that a <hello>
can be received and processed at any time that a server is
waiting for a command. The text correctly describes how this
works, but the state diagram was inconsistent with the text.
3. In Section 2, changed "The specific strings used to associate
URIs and namespaces (such as the string "foo" in "xmlns:foo") in
EPP are illustrative and are not needed for interoperability" to
"The XML namespace prefixes used in examples (such as the string
"foo" in "xmlns:foo") are solely for illustrative purposes. A
conforming implementation MUST NOT require the use of these or
any other specific namespace prefixes".
4. Removed the last paragraph from Section 2 that described an
error in the W3C XML reference specification. This was
corrected in a later edition. References in this specification
have been updated to cite the most current version. Preserved
the last sentence by appending it to the end of the previous
paragraph.
5. Updated the description of the <value> element in Section 2.6 to
add "or other information" to "a client-provided element
(including XML tag and value)".
6. Changed text in Section 2.9.2.3 from this:
"Service messages MUST be created for all clients affected by an
action on an object. For example, <transfer> actions MUST be
reported to both the client that requests an object transfer and
the client that has the authority to approve or reject the
transfer request."
to this:
"Service messages SHOULD be created for passive clients affected
by an action on an object. Service messages MAY also be created
for active clients that request an action on an object, though
such messages MUST NOT replace the normal protocol response to
the request. For example, <transfer> actions SHOULD be reported
to the client that has the authority to approve or reject a
transfer request. Other methods of server-client action
notification, such as offline reporting, are also possible and
are beyond the scope of this specification."
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RFC 4930 EPP May 2007
7. Changed text in Section 2.9.2.3 from this:
"A <poll> acknowledgement response notes the number of messages
remaining in the queue and the ID of the next message available
for retrieval."
to this:
"A <poll> acknowledgement response notes the ID of the message
that has been acknowledged and the number of messages remaining
in the queue."
Fixed the example to note the correct message ID. This was done
because the msgID isn't needed to retrieve a message, only to
ack and dequeue it, so it doesn't need to be returned in the
response. Implementations are known to implement this feature
as updated.
8. Changed text in Section 2.9.3.4 from this:
"Once a transfer request has been received by the server, the
server MUST notify the current sponsoring client of the
requested transfer by queuing a service message for retrieval
via the <poll> command."
to this:
"Once a transfer request has been received by the server, the
server MUST notify the current sponsoring client of the
requested transfer either by queuing a service message for
retrieval via the <poll> command or by using an out-of-band
mechanism to inform the client of the request."
9. Updated Security Considerations to note implemented required
practices for authentication and replay protection.
10. Updated XML references. Updated reference from RFC 2279 to RFC
3629.
11. Removed text describing use of the XML Schema schemaLocation
attribute. This is an optional attribute that doesn't need to
be mandated for use in EPP.
12. Moved RFCs 2781 and 3375 (Informational RFCs) from the normative
reference section to the informative reference section.
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RFC 4930 EPP May 2007
13. Moved RFC 3023 from the normative reference section to the
informative reference section. This reference is used only in
an informative appendix.
14. Removed references to RFC 3339 and replaced them with references
to the W3C XML Schema specification.
Author's Address
Scott Hollenbeck
VeriSign, Inc.
21345 Ridgetop Circle
Dulles, VA 20166-6503
US
EMail: shollenbeck@verisign.com
Hollenbeck Standards Track [Page 71]
RFC 4930 EPP May 2007
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Hollenbeck Standards Track [Page 72]
ERRATA
