Network Working Group B. Wellington
Request for Comments: 3655 O. Gudmundsson
Updates: 2535 November 2003
Category: Standards Track
Network Working Group B. Wellington
Request for Comments: 3655 O. Gudmundsson
Updates: 2535 November 2003
Category: Standards Track
Redefinition of DNS Authenticated Data (AD) bit
DNS身份验证数据（AD）位的重新定义
Status of this Memo
本备忘录的状况
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.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (C) The Internet Society (2003). All Rights Reserved.
版权所有（C）互联网协会（2003年）。版权所有。
Abstract
摘要
This document alters the specification defined in RFC 2535. Based on implementation experience, the Authenticated Data (AD) bit in the DNS header is not useful. This document redefines the AD bit such that it is only set if all answers or records proving that no answers exist in the response has been cryptographically verified or otherwise meets the server's local security policy.
本文件修改了RFC 2535中定义的规范。根据实施经验，DNS报头中的身份验证数据（AD）位没有用处。本文档重新定义AD位，以便仅当证明响应中不存在答案的所有答案或记录已通过加密验证或符合服务器的本地安全策略时，才设置AD位。
Familiarity with the DNS system [RFC1035] and DNS security extensions [RFC2535] is helpful but not necessary.
熟悉DNS系统[RFC1035]和DNS安全扩展[RFC2535]会有所帮助，但不是必需的。
As specified in RFC 2535 (section 6.1), the AD (Authenticated Data) bit indicates in a response that all data included in the answer and authority sections of the response have been authenticated by the server according to the policies of that server. This is not especially useful in practice, since a conformant server SHOULD never reply with data that failed its security policy.
如RFC 2535（第6.1节）所述，AD（认证数据）位在响应中表示响应的应答和授权部分中包含的所有数据已由服务器根据该服务器的策略进行认证。这在实践中并不特别有用，因为一致性服务器永远不应该使用未通过其安全策略的数据进行回复。
This document redefines the AD bit such that it is only set if all data in the response has been cryptographically verified or otherwise meets the server's local security policy. Thus, neither a response containing properly delegated insecure data, nor a server configured without DNSSEC keys, will have the AD set. As before, data that failed to verify will not be returned. An application running on a host that has a trust relationship with the server performing the
本文档重新定义AD位，使其仅在响应中的所有数据都经过加密验证或符合服务器的本地安全策略时设置。因此，无论是包含正确委派的不安全数据的响应，还是未配置DNSSEC密钥的服务器，都不会设置AD。与之前一样，将不会返回验证失败的数据。在主机上运行的应用程序，该主机与执行
recursive query can now use the value of the AD bit to determine whether the data is secure.
递归查询现在可以使用AD位的值来确定数据是否安全。
A full DNSSEC capable resolver called directly from an application can return to the application the security status of the RRsets in the answer. However, most applications use a limited stub resolver that relies on an external recursive name server which incorporates a full resolver. The recursive nameserver can use the AD bit in a response to indicate the security status of the data in the answer, and the local resolver can pass this information to the application. The application in this context can be either a human using a DNS tool or a software application.
直接从应用程序调用的支持DNSSEC的完整解析器可以将应答中RRSET的安全状态返回给应用程序。但是，大多数应用程序使用有限的存根解析器，它依赖于外部递归名称服务器，该服务器包含完整的解析器。递归名称服务器可以在响应中使用AD位来指示应答中数据的安全状态，本地解析器可以将此信息传递给应用程序。此上下文中的应用程序可以是使用DNS工具的人员，也可以是软件应用程序。
The AD bit SHOULD be used by the local resolver if and only if it has been explicitly configured to trust the remote resolver. The AD bit SHOULD be ignored when the recursive name server is not trusted.
当且仅当AD位已明确配置为信任远程冲突解决程序时，本地冲突解决程序才应使用AD位。当递归名称服务器不受信任时，应忽略AD位。
An alternate solution would be to embed a full DNSSEC resolver into every application, but this has several disadvantages.
另一种解决方案是在每个应用程序中嵌入完整的DNSSEC解析器，但这有几个缺点。
- DNSSEC validation is both CPU and network intensive, and caching SHOULD be used whenever possible.
- DNSSEC验证是CPU和网络密集型验证，应尽可能使用缓存。
- DNSSEC requires non-trivial configuration - the root key must be configured, as well as keys for any "islands of security" that will exist until DNSSEC is fully deployed. The number of configuration points should be minimized.
- DNSSEC需要非常重要的配置—必须配置根密钥以及在DNSSEC完全部署之前存在的任何“安全孤岛”的密钥。应尽量减少配置点的数量。
The key words "MAY", "MAY NOT" "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", in this document are to be interpreted as described in BCP 14, RFC 2119 [RFC2119].
本文件中的关键词“可能”、“不可能”、“必须”、“不得”、“应该”、“不应该”、“建议”应按照BCP 14、RFC 2119[RFC2119]中的说明进行解释。
The definition of the AD bit in RFC 2535, Section 6.1, is changed.
RFC 2535第6.1节中AD位的定义已更改。
The presence of the CD (Checking Disabled) bit in a query does not affect the setting of the AD bit in the response. If the CD bit is set, the server will not perform checking, but SHOULD still set the AD bit if the data has already been cryptographically verified or
查询中存在CD（检查禁用）位不会影响响应中AD位的设置。如果设置了CD位，服务器将不执行检查，但如果数据已通过加密验证或验证，则仍应设置AD位
complies with local policy. The AD bit MUST only be set if DNSSEC records have been requested via the DO bit [RFC3225] and relevant SIG records are returned.
遵守当地政策。只有通过DO位[RFC3225]请求DNSSEC记录并返回相关SIG记录时，才能设置AD位。
Section 6.1 of RFC 2535 says:
RFC 2535第6.1节规定：
"The AD bit MUST NOT be set on a response unless all of the RRs in the answer and authority sections of the response are either Authenticated or Insecure."
“除非响应的应答和授权部分中的所有RRs都经过身份验证或不安全，否则不得在响应上设置AD位。”
The replacement text reads:
替换案文如下：
"The AD bit MUST NOT be set on a response unless all of the RRsets in the answer and authority sections of the response are Authenticated."
“除非响应的应答和授权部分中的所有RRSET都经过身份验证，否则不得在响应上设置AD位。”
"The AD bit SHOULD be set if and only if all RRs in the answer section and any relevant negative response RRs in the authority section are Authenticated."
“当且仅当应答部分中的所有RRs和授权部分中的任何相关否定响应RRs都经过身份验证时，才应设置AD位。”
A recursive DNS server following this modified specification will only set the AD bit when it has cryptographically verified the data in the answer.
遵循此修改规范的递归DNS服务器只有在对应答中的数据进行加密验证后才会设置AD位。
A primary server for a secure zone MAY have the policy of treating authoritative secure zones as Authenticated. Secondary servers MAY have the same policy, but SHOULD NOT consider zone data Authenticated unless the zone was transferred securely and/or the data was verified. An authoritative server MUST only set the AD bit for authoritative answers from a secure zone if it has been explicitly configured to do so. The default for this behavior SHOULD be off.
安全区域的主服务器可以具有将权威安全区域视为已认证的策略。辅助服务器可能具有相同的策略，但不应考虑区域数据经过验证，除非安全区域被传输和/或数据被验证。权威服务器必须仅为来自安全区域的权威应答设置AD位（如果已明确配置为这样做）。此行为的默认值应为“关闭”。
Note that having the AD bit clear on an authoritative answer is normal and expected behavior.
请注意，在权威答案上明确广告位是正常和预期的行为。
The setting of the AD bit by authoritative servers affects only the small set of resolvers that are configured to directly query and trust authoritative servers. This only affects servers that function as both recursive and authoritative. Iterative resolvers SHOULD ignore the AD bit.
权威服务器对AD位的设置仅影响配置为直接查询和信任权威服务器的一小部分解析程序。这只影响同时具有递归和权威功能的服务器。迭代解析器应该忽略AD位。
The cost of verifying all signatures on load by an authoritative server can be high and increases the delay before it can begin
权威服务器在加载时验证所有签名的成本可能很高，并且会增加开始之前的延迟
answering queries. Verifying signatures at query time is also expensive and could lead to resolvers timing out on many queries after the server reloads zones.
回答问题。在查询时验证签名也很昂贵，并且可能导致解析程序在服务器重新加载区域后在许多查询上超时。
Organizations requiring that all DNS responses contain cryptographically verified data will need to separate the authoritative name server and signature verification functions, since name servers are not required to validate signatures of data for which they are authoritative.
要求所有DNS响应包含加密验证数据的组织将需要分离权威名称服务器和签名验证功能，因为名称服务器不需要验证其权威数据的签名。
A response containing data marked Insecure in the answer or authority section MUST never have the AD bit set. In this case, the resolver SHOULD treat the data as Insecure whether or not SIG records are present.
包含应答或授权部分中标记为不安全数据的响应不得设置AD位。在这种情况下，无论是否存在SIG记录，解析器都应将数据视为不安全的。
A resolver MUST NOT blindly trust the AD bit unless it communicates with a recursive nameserver over a secure transport mechanism or using a message authentication such as TSIG [RFC2845] or SIG(0) [RFC2931] and is explicitly configured to trust this recursive name server.
解析程序不得盲目信任AD位，除非它通过安全传输机制或使用诸如TSIG[RFC2845]或SIG（0）[RFC2931]等消息身份验证与递归名称服务器通信，并明确配置为信任此递归名称服务器。
The AD bit is intended to allow the transmission of the indication that a resolver has verified the DNSSEC signatures accompanying the records in the Answer and Authority section. The AD bit MUST only be trusted when the end consumer of the DNS data has confidence that the intermediary resolver setting the AD bit is trustworthy. This can only be accomplished via an out of band mechanism such as:
AD位用于允许传输解析程序已验证应答和授权部分记录附带的DNSSEC签名的指示。只有当DNS数据的最终使用者确信设置AD位的中间解析程序是可信的时，才必须信任AD位。这只能通过带外机制实现，例如：
- Fiat: An organization that can dictate whether it is OK to trust certain DNS servers.
- Fiat：一个可以决定是否可以信任某些DNS服务器的组织。
- Personal: Because of a personal relationship or the reputation of a recursive nameserver operator, a DNS consumer can decide to trust that recursive nameserver.
- 个人：由于个人关系或递归名称服务器操作员的声誉，DNS使用者可以决定信任该递归名称服务器。
- Knowledge: If a recursive nameserver operator posts the configured policy of a recursive nameserver, a consumer can decide that recursive nameserver is trustworthy.
- 知识：如果递归名称服务器操作员发布递归名称服务器的配置策略，则使用者可以确定递归名称服务器是可信的。
In the absence of one or more of these factors AD bit from a recursive name server SHOULD NOT be trusted. For example, home users frequently depend on their ISP to provide recursive DNS service; it
在缺少上述一个或多个因素的情况下，不应信任递归名称服务器的AD位。例如，家庭用户经常依赖其ISP提供递归DNS服务；信息技术
is not advisable to trust these recursive nameservers. A roaming/traveling host SHOULD not use recursive DNS servers offered by DHCP when looking up information where security status matters.
不建议信任这些递归名称服务器。漫游/移动主机在查找安全状态重要的信息时，不应使用DHCP提供的递归DNS服务器。
In the latter two cases, the end consumer must also completely trust the path to the trusted recursive name servers, or a secure transport must be employed to protect the traffic.
在后两种情况下，最终使用者还必须完全信任到受信任的递归名称服务器的路径，或者必须使用安全传输来保护流量。
When faced with a situation where there are no satisfactory recursive nameservers available, running one locally is RECOMMENDED. This has the advantage that it can be trusted, and the AD bit can still be used to allow applications to use stub resolvers.
当遇到没有令人满意的递归名称服务器可用的情况时，建议在本地运行一个。它的优点是可以信任，并且AD位仍然可以用于允许应用程序使用存根解析器。
This document redefines a bit in the DNS header. If a resolver trusts the value of the AD bit, it must be sure that the responder is using the updated definition, which is any DNS server/resolver supporting the DO bit [RFC3225].
此文档重新定义DNS标头中的一个位。如果解析程序信任AD位的值，则必须确保响应程序使用更新的定义，即任何支持DO位的DNS服务器/解析程序[RFC3225]。
Authoritative servers can be explicitly configured to set the AD bit on answers without doing cryptographic checks. This behavior MUST be off by default. The only affected resolvers are those that directly query and trust the authoritative server, and this functionality SHOULD only be used on servers that act both as authoritative and recursive name servers.
权威服务器可以显式配置为在应答上设置AD位，而无需进行加密检查。默认情况下，此行为必须处于禁用状态。唯一受影响的解析程序是那些直接查询和信任权威服务器的解析程序，此功能应仅在同时充当权威和递归名称服务器的服务器上使用。
Resolvers (full or stub) that blindly trust the AD bit without knowing the security policy of the server generating the answer can not be considered security aware.
盲目信任AD位而不知道生成答案的服务器的安全策略的解析程序（完整或存根）不能被视为具有安全意识。
A resolver MUST NOT blindly trust the AD bit unless it communicates such as IPsec, or using message authentication such as TSIG [RFC2845] or SIG(0) [RFC2931]. In addition, the resolver must have been explicitly configured to trust this recursive name server.
解析程序不得盲目信任AD位，除非它进行IPsec等通信，或使用TSIG[RFC2845]或SIG（0）[RFC2931]等消息身份验证。此外，解析程序必须已显式配置为信任此递归名称服务器。
None.
没有一个
None. This document does not change any textual data in any protocol.
没有一个本文档不会更改任何协议中的任何文本数据。
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The following people have provided input on this document: Robert Elz, Andreas Gustafsson, Bob Halley, Steven Jacob, Erik Nordmark, Edward Lewis, Jakob Schlyter, Roy Arends, Ted Lindgreen.
以下人员为本文件提供了意见：罗伯特·埃尔兹、安德烈亚斯·古斯塔夫松、鲍勃·哈雷、史蒂文·雅各布、埃里克·诺德马克、爱德华·刘易斯、雅各布·施莱特、罗伊·阿伦兹、特德·林德格林。
[RFC1035] Mockapetris, P., "Domain Names - Implementation and Specification", STD 13, RFC 1035, November 1987.
[RFC1035]Mockapetris，P.，“域名-实现和规范”，STD 13，RFC 1035，1987年11月。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC2535] Eastlake, D., "Domain Name System Security Extensions", RFC 2535, March 1999.
[RFC2535]Eastlake，D.，“域名系统安全扩展”，RFC25351999年3月。
[RFC2845] Vixie, P., Gudmundsson, O., Eastlake 3rd, D. and B. Wellington, "Secret Key Transaction Authentication for DNS (TSIG)", RFC 2845, May 2000.
[RFC2845]Vixie，P.，Gudmundsson，O.，Eastlake 3rd，D.和B.Wellington，“DNS秘密密钥交易认证（TSIG）”，RFC 28452000年5月。
[RFC2931] Eastlake, D., "DNS Request and Transaction Signatures (SIG(0))", RFC 2931, September 2000.
[RFC2931]Eastlake，D.，“DNS请求和事务签名（SIG（0））”，RFC 29312000年9月。
[RFC3225] Conrad, D., "Indicating Resolver Support of DNSSEC", RFC 3225, December 2001.
[RFC3225]Conrad，D.“指示DNSSEC的分解器支持”，RFC 3225，2001年12月。
Brian Wellington Nominum Inc. 2385 Bay Road Redwood City, CA, 94063 USA
Brian Wellington Nominum Inc.美国加利福尼亚州红木市海湾路2385号，邮编94063
EMail: Brian.Wellington@nominum.com
EMail: Brian.Wellington@nominum.com
Olafur Gudmundsson 3821 Village Park Drive Chevy Chase, MD, 20815 USA
美国马里兰州雪佛兰蔡斯市奥拉弗尔·古德蒙松村公园路3821号，邮编：20815
EMail: ogud@ogud.com
EMail: ogud@ogud.com
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