Network Working Group                                      H. Tschofenig
Request for Comments: 4230                                       Siemens
Category: Informational                                      R. Graveman
                                                            RFG Security
                                                           December 2005
                        RSVP Security Properties

Status of This Memo


This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.


Copyright Notice


Copyright (C) The Internet Society (2005).




This document summarizes the security properties of RSVP. The goal of this analysis is to benefit from previous work done on RSVP and to capture knowledge about past activities.


Table of Contents


   1.   Introduction . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.   Terminology and Architectural Assumptions  . . . . . . . . .   3
   3.   Overview . . . . . . . . . . . . . . . . . . . . . . . . . .   5
        3.1.  The RSVP INTEGRITY Object  . . . . . . . . . . . . . .   5
        3.2.  Security Associations  . . . . . . . . . . . . . . . .   8
        3.3.  RSVP Key Management Assumptions  . . . . . . . . . . .   8
        3.4.  Identity Representation  . . . . . . . . . . . . . . .   9
        3.5.  RSVP Integrity Handshake   . . . . . . . . . . . . . .  13
   4.   Detailed Security Property Discussion  . . . . . . . . . . .  15
        4.1.  Network Topology   . . . . . . . . . . . . . . . . . .  15
        4.2.  Host/Router  . . . . . . . . . . . . . . . . . . . . .  15
        4.3.  User to PEP/PDP  . . . . . . . . . . . . . . . . . . .  19
        4.4.  Communication between RSVP-Aware Routers . . . . . . .  28
   5.   Miscellaneous Issues . . . . . . . . . . . . . . . . . . . .  29
        5.1.  First-Hop Issue  . . . . . . . . . . . . . . . . . . .  30
        5.2.  Next-Hop Problem . . . . . . . . . . . . . . . . . . .  30
        5.3.  Last-Hop Issue   . . . . . . . . . . . . . . . . . . .  33
        5.4.  RSVP- and IPsec-protected data traffic . . . . . . . .  34
        5.5.  End-to-End Security Issues and RSVP  . . . . . . . . .  36
        5.6.  IPsec protection of RSVP signaling messages  . . . . .  36
        5.7.  Authorization  . . . . . . . . . . . . . . . . . . . .  37
   6.   Conclusions  . . . . . . . . . . . . . . . . . . . . . . . .  38
   7.   Security Considerations  . . . . . . . . . . . . . . . . . .  40
   8.   Acknowledgements . . . . . . . . . . . . . . . . . . . . . .  40
   9.   References . . . . . . . . . . . . . . . . . . . . . . . . .  40
        9.1.  Normative References . . . . . . . . . . . . . . . . .  40
        9.2.  Informative References . . . . . . . . . . . . . . . .  41
   A.   Dictionary Attacks and Kerberos  . . . . . . . . . . . . . .  45
   B.   Example of User-to-PDP Authentication  . . . . . . . . . . .  45
   C.   Literature on RSVP Security  . . . . . . . . . . . . . . . .  46
1. Introduction
1. はじめに

As the work of the NSIS working group began, concerns about security and its implications for the design of a signaling protocol were raised. In order to understand the security properties and available options of RSVP, a number of documents have to be read. This document summarizes the security properties of RSVP and is part of the overall process of analyzing other signaling protocols and learning from their design considerations. This document should also provide a starting point for further discussions.


The content of this document is organized as follows. Section 2 introduces the terminology used throughout the document. Section 3 provides an overview of the security mechanisms provided by RSVP including the INTEGRITY object, a description of the identity representation within the POLICY_DATA object (i.e., user authentication), and the RSVP Integrity Handshake mechanism. Section 4 provides a more detailed discussion of the mechanisms used and tries to describe in detail the mechanisms provided. Several miscellaneous issues are covered in Section 5.


RSVP also supports multicast, but this document does not address security aspects for supporting multicast QoS signaling. Multicast is currently outside the scope of the NSIS working group.


Although a variation of RSVP, namely RSVP-TE, is used in the context of MPLS to distribute labels for a label switched path, its usage is different from the usage scenarios envisioned for NSIS. Hence, this document does not address RSVP-TE or its security properties.


2. Terminology and Architectural Assumptions

This section describes some important terms and explains some architectural assumptions.


o Chain-of-Trust:


The security mechanisms supported by RSVP [1] heavily rely on optional hop-by-hop protection, using the built-in INTEGRITY object. Hop-by-hop security with the INTEGRITY object inside the RSVP message thereby refers to the protection between RSVP-supporting network elements. Additionally, there is the notion of policy-aware nodes that understand the POLICY_DATA element within the RSVP message. Because this element also includes an INTEGRITY object, there is an additional hop-by-hop security mechanism that provides security between policy-aware nodes. Policy-ignorant nodes are not affected by the inclusion of this object in the POLICY_DATA element, because they do not try to interpret it.

RSVPによってサポートされるセキュリティメカニズム[1]重く内蔵のINTEGRITYオブジェクトを使用して、オプションのホップバイホップの保護に頼っています。 RSVPメッセージ内のINTEGRITYオブジェクトとホップバイホップセキュリティこれによりRSVP-サポートするネットワーク要素との間の保護を意味します。また、RSVPメッセージ内POLICY_DATA要素を理解してポリシーを意識したノードの概念があります。この要素はまたINTEGRITYオブジェクトを含むため、ポリシー対応ノード間のセキュリティを提供する付加的なホップバイホップセキュリティメカニズムが存在します。彼らはそれを解釈しようとしないため、ポリシー無知なノードは、POLICY_DATA要素で、このオブジェクトを含めることによって影響を受けません。

To protect signaling messages that are possibly modified by each RSVP router along the path, it must be assumed that each incoming request is authenticated, integrity protected, and replay protected. This provides protection against bogus messages injected by unauthorized nodes. Furthermore, each RSVP-aware router is assumed to behave in the expected manner. Outgoing messages transmitted to the next-hop network element receive new protection according to RSVP security processing.


Using the mechanisms described above, a chain-of-trust is created whereby a signaling message that is transmitted by router A via router B and received by router C is supposed to be secure if routers A and B and routers B and C share security associations and all routers behave as expected. Hence, router C trusts router A although router C does not have a direct security association with router A. We can therefore conclude that the protection achieved with this hop-by-hop security for the chain-of-trust is no better than the weakest link in the chain.


If one router is malicious (for example, because an adversary has control over this router), then it can arbitrarily modify messages, cause unexpected behavior, and mount a number of attacks that are not limited to QoS signaling. Additionally, it must be mentioned that some protocols demand more protection than others (which depends, in part, on which nodes are executing these protocols). For example, edge devices, where end-users are attached, may be more likely to be attacked in comparison with the more secure core network of a service provider. In some cases, a network service provider may choose not to use the RSVP-provided security mechanisms inside the core network because a different security protection is deployed.

(敵対者がこのルータを制御しているので、例えば)1つのルータが悪質な場合には、それは任意に、メッセージを変更する予期しない動作を引き起こす、およびQoSシグナリングに限定されるものではなく、攻撃の数をマウントすることができます。 (ノードは、これらのプロトコルを実行されている、部分的に依存する)さらに、いくつかのプロトコルが他よりも多くの保護を求めていることを言及しなければなりません。例えば、エンドユーザが接続されているエッジデバイスは、サービスプロバイダのより安全なコアネットワークと比較して攻撃されやすいかもしれません。いくつかのケースでは、ネットワークサービスプロバイダは、さまざまなセキュリティ保護が展開されているため、コアネットワーク内にRSVP-提供するセキュリティ・メカニズムを使用しないことも選択できます。

Section 6 of [2] mentions the term chain-of-trust in the context of RSVP integrity protection. In Section 6 of [14] the same term is used in the context of user authentication with the INTEGRITY object inside the POLICY_DATA element. Unfortunately, the term is not explained in detail and the assumptions behind it are not clearly specified.

[2]のセクション6は、用語チェーン・オブ・信頼RSVPの完全性保護の文脈で言及しています。 [14]のセクション6で同じ用語はPOLICY_DATA要素内INTEGRITYオブジェクトとユーザ認証の文脈で使用されます。残念ながら、この用語は詳細に説明されていないと、その背後にある仮定は明確に指定されていません。

o Host and User Authentication:


The presence of RSVP protection and a separate user identity representation leads to the fact that both user-identity and host-identity are used for RSVP protection. Therefore, user-based security and host-based security are covered separately, because of the different authentication mechanisms provided. To avoid confusion about the different concepts, Section 3.4 describes the concept of user authentication in more detail.


o Key Management:


It is assumed that most of the security associations required for the protection of RSVP signaling messages are already available, and hence key management was done in advance. There is, however, an exception with respect to support for Kerberos. Using Kerberos, an entity is able to distribute a session key used for RSVP signaling protection.

RSVPシグナリングメッセージの保護のために必要なセキュリティアソシエーションのほとんどはすでに利用可能であると想定されるため、鍵の管理は、事前に行われました。ケルベロスのサポートに関しては例外は、しかし、があります。 Kerberosを使用して、エンティティは、RSVPシグナリングの保護のために使用されるセッション鍵を配布することができます。



RSVP uses an INTEGRITY object in two places in a message. The first is in the RSVP message itself and covers the entire RSVP message as defined in [1]. The second is included in the POLICY_DATA object and defined in [2]. To differentiate the two objects by their scope of protection, the two terms RSVP INTEGRITY and POLICY_DATA INTEGRITY object are used, respectively. The data structure of the two objects, however, is the same.

RSVPは、メッセージ中の2つの場所でINTEGRITYオブジェクトを使用しています。最初は、RSVPメッセージ自体であり、[1]で定義されるように全体のRSVPメッセージをカバーします。第二は、POLICY_DATAオブジェクトに含ま及び[2]で定義されています。保護の彼らの範囲によって2つのオブジェクトを区別するために、2つの用語はINTEGRITYとPOLICY_DATA INTEGRITYオブジェクトをRSVPそれぞれ、使用されています。二つのオブジェクトのデータ構造は、しかしながら、同じです。

o Hop versus Peer:


In the past, the terminology for nodes addressed by RSVP has been discussed considerably. In particular, two favorite terms have been used: hop and peer. This document uses the term hop, which is different from an IP hop. Two neighboring RSVP nodes communicating with each other are not necessarily neighboring IP nodes (i.e., they may be more than one IP hop away).


3. Overview

This section describes the security mechanisms provided by RSVP. Although use of IPsec is mentioned in Section 10 of [1], the other security mechanisms primarily envisioned for RSVP are described.

このセクションでは、RSVPによって提供されるセキュリティメカニズムについて説明します。 IPsecの使用は、[1]のセクション10に記載されているが、主にRSVPのために想定される他のセキュリティ機構が記載されています。

3.1. The RSVP INTEGRITY Object

The RSVP INTEGRITY object is the major component of RSVP security protection. This object is used to provide integrity and replay protection for the content of the signaling message between two RSVP participating routers or between an RSVP router and host. Furthermore, the RSVP INTEGRITY object provides data origin authentication. The attributes of the object are briefly described:


o Flags field:


       The Handshake Flag is the only defined flag.  It is used to
       synchronize sequence numbers if the communication gets out of
       sync (e.g., it allows a restarting host to recover the most recent sequence number).  Setting this flag to one indicates that
       the sender is willing to respond to an Integrity Challenge
       message.  This flag can therefore be seen as a negotiation
       capability transmitted within each INTEGRITY object.

o Key Identifier:


       The Key Identifier selects the key used for verification of the
       Keyed Message Digest field and, hence, must be unique for the
       sender.  It has a fixed 48-bit length.  The generation of this
       Key Identifier field is mostly a decision of the local host. [1]
       describes this field as a combination of an address, sending
       interface, and key number.  We assume that the Key Identifier is
       simply a (keyed) hash value computed over a number of fields,
       with the requirement to be unique if more than one security
       association is used in parallel between two hosts (e.g., as is
       the case with security associations having overlapping
       lifetimes).  A receiving system uniquely identifies a security
       association based on the Key Identifier and the sender's IP
       address.  The sender's IP address may be obtained from the
       RSVP_HOP object or from the source IP address of the packet if
       the RSVP_HOP object is not present.  The sender uses the outgoing
       interface to determine which security association to use.  The
       term "outgoing interface" may be confusing.  The sender selects
       the security association based on the receiver's IP address
       (i.e., the address of the next RSVP-capable router).  The process
       of determining which node is the next RSVP-capable router is not
       further specified and is likely to be statically configured.

o Sequence Number:


       The sequence number used by the INTEGRITY object is 64 bits in
       length, and the starting value can be selected arbitrarily.  The
       length of the sequence number field was chosen to avoid
       exhaustion during the lifetime of a security association as
       stated in Section 3 of [1].  In order for the receiver to
       distinguish between a new and a replayed message, the sequence
       number must be monotonically incremented (modulo 2^64) for each
       message.  We assume that the first sequence number seen (i.e.,
       the starting sequence number) is stored somewhere.  The modulo-
       operation is required because the starting sequence number may be
       an arbitrary number.  The receiver therefore only accepts packets
       with a sequence number larger (modulo 2^64) than the previous
       packet.  As explained in [1] this process is started by
       handshaking and agreeing on an initial sequence number.  If no
       such handshaking is available then the initial sequence number
       must be part of the establishment of the security association.

The generation and storage of sequence numbers is an important step in preventing replay attacks and is largely determined by the capabilities of the system in the presence of system crashes, failures, and restarts. Section 3 of [1] explains some of the most important considerations. However, the description of how the receiver distinguishes proper from improper sequence numbers is incomplete: it implicitly assumes that gaps large enough to cause the sequence number to wrap around cannot occur.

シーケンス番号の生成と貯蔵は、リプレイ攻撃を防止するのに重要なステップであり、主にシステムがクラッシュした、障害、および再起動の存在下でのシステムの能力によって決定されます。 [1]の第3節では、最も重要な検討事項のいくつかを説明します。しかし、受信機が不適切なシーケンス番号から適切な区別方法の説明が不完全である:それは暗黙的にラップアラウンドするシーケンス番号を起こすのに十分な大きさのギャップが生じないことを前提としています。

If delivery in order were guaranteed, the following procedure would work: the receiver keeps track of the first sequence number received, INIT-SEQ, and the most recent sequence number received, LAST-SEQ, for each key identifier in a security association. When the first message is received, set INIT-SEQ = LAST-SEQ = value received and accept. When a subsequent message is received, if its sequence number is strictly between LAST-SEQ and INIT-SEQ, (modulo 2^64), accept and update LAST-SEQ with the value just received. If it is between INIT-SEQ and LAST-SEQ, inclusive, (modulo 2^64), reject and leave the value of LAST-SEQ unchanged. Because delivery in order is not guaranteed, the above rules need to be combined with a method of allowing a fixed sized window in the neighborhood of LAST-SEQ for out-of-order delivery, for example, as described in Appendix C of [3].

受信機は、最初のシーケンス番号のトラック受け、INIT-SEQを保持し、最新のシーケンス番号は、セキュリティアソシエーションの各キー識別子のために、LAST-SEQを受けた:順序で配信が保証された場合は、以下の手順が動作します。最初のメッセージを受信したとき、INIT-SEQ = LAST-SEQ =値が受信され受け入れセット。後続のメッセージが受信されると、そのシーケンス番号は厳密LAST-SEQとINIT-配列、(モジュロ2 ^ 64)の間にある場合、受信したばかりの値とLAST-配列を受け入れ、更新。それが(モジュロ2 ^ 64)、包括的、INIT-SEQとLAST-配列の間にある場合、拒否し不変LAST-SEQの値を残します。順番に配信が保証されないので、上記の規則は、[3付録Cに記載されているように、例えば、アウトオブオーダ送達のためLAST-配列の近傍に固定されたサイズのウィンドウを可能にする方法と組み合わせることが必要]。

o Keyed Message Digest:


       The Keyed Message Digest is a security mechanism built into RSVP
       that used to provide integrity protection of a signaling message
       (including its sequence number).  Prior to computing the value
       for the Keyed Message Digest field, the Keyed Message Digest
       field itself must be set to zero and a keyed hash computed over
       the entire RSVP packet.  The Keyed Message Digest field is
       variable in length but must be a multiple of four octets.  If
       HMAC-MD5 is used, then the output value is 16 bytes long.  The
       keyed hash function HMAC-MD5 [4] is required for an RSVP
       implementation, as noted in Section 1 of [1].  Hash algorithms
       other than MD5 [5], like SHA-1 [15], may also be supported.

The key used for computing this Keyed Message Digest may be obtained from the pre-shared secret, which is either manually distributed or the result of a key management protocol. No key management protocol, however, is specified to create the desired security associations. Also, no guidelines for key length are given. It should be recommended that HMAC-MD5 keys be 128 bits and SHA-1 keys 160 bits, as in IPsec AH [16] and ESP [17].

このキー付きメッセージダイジェストを計算するために使用されるキーは、手動で分散されるか、事前共有秘密、または鍵管理プロトコルの結果から得ることができます。いいえ鍵管理プロトコルは、しかし、必要なセキュリティ関連付けを作成するために指定されていません。また、キーの長さのためのガイドラインが示されていません。 IPsec AH [16]およびESP [17]のように、HMAC-MD5キーは128ビット、SHA-1鍵160ビットであることが推奨されるべきです。

3.2. Security Associations
3.2. セキュリティアソシエーション

Different attributes are stored for security associations of sending and receiving systems (i.e., unidirectional security associations). The sending system needs to maintain the following attributes in such a security association [1]:


o Authentication algorithm and algorithm mode


o Key


o Key Lifetime


o Sending Interface


o Latest sequence number (received with this key identifier)


The receiving system has to store the following fields:


o Authentication algorithm and algorithm mode


o Key


o Key Lifetime


o Source address of the sending system


o List of last n sequence numbers (received with this key identifier)


Note that the security associations need to have additional fields to indicate their state. It is necessary to have overlapping lifetimes of security associations to avoid interrupting an ongoing communication because of expired security associations. During such a period of overlapping lifetime it is necessary to authenticate with either one or both active keys. As mentioned in [1], a sender and a receiver may have multiple active keys simultaneously. If more than one algorithm is supported, then the algorithm used must be specified for a security association.

セキュリティアソシエーションは、自分の状態を示すために追加のフィールドを持っている必要があることに注意してください。これは、有効期限が切れているため、セキュリティアソシエーションの進行中の通信を中断を避けるためにセキュリティアソシエーションのライフタイムをオーバーラップしていることが必要です。寿命を重複ような期間には、一方または両方の活性のキーのいずれかを使用して認証する必要があります。 [1]で述べたように、送信側と受信側は、同時に複数のアクティブなキーを有していてもよいです。複数のアルゴリズムがサポートされている場合、使用されるアルゴリズムは、セキュリティアソシエーションを指定する必要があります。

3.3. RSVP Key Management Assumptions
3.3. RSVPキー管理前提条件

RFC 2205 [6] assumes that security associations are already available. An implementation must support manual key distribution as noted in Section 5.2 of [1]. Manual key distribution, however, has different requirements for key storage; a simple plaintext ASCII file may be sufficient in some cases. If multiple security associations with different lifetimes need to be supported at the same time, then a key engine would be more appropriate. Further security requirements listed in Section 5.2 of [1] are the following:

RFC 2205 [6]セキュリティアソシエーションがすでに利用可能であることを前提としています。 [1]のセクション5.2で述べたように、実装は、手動鍵配布をサポートしなければなりません。手動鍵配布は、しかし、鍵保管のためのさまざまな要件があります。シンプルなプレーンテキストASCIIファイルには、いくつかのケースで十分かもしれません。異なる寿命を持つ複数のセキュリティアソシエーションを同時にサポートする必要がある場合には、キーエンジンは、より適切であろう。 5.2節に記載されているさらなるセキュリティ要件[1]次のとおりです。

o The manual deletion of security associations must be supported.


o The key storage should persist during a system restart.


o Each key must be assigned a specific lifetime and a specific Key Identifier.


3.4. Identity Representation
3.4. アイデンティティ表現

In addition to host-based authentication with the INTEGRITY object inside the RSVP message, user-based authentication is available as introduced in [2]. Section 2 of [7] states that "Providing policy based admission control mechanism based on user identities or application is one of the prime requirements." To identify the user or the application, a policy element called AUTH_DATA, which is contained in the POLICY_DATA object, is created by the RSVP daemon at the user's host and transmitted inside the RSVP message. The structure of the POLICY_DATA element is described in [2]. Network nodes acting as policy decision points (PDPs) then use the information contained in the AUTH_DATA element to authenticate the user and to allow policy-based admission control to be executed. As mentioned in [7], the policy element is processed and the PDP replaces the old element with a new one for forwarding to the next hop router.

導入されるように加えてRSVPメッセージ内のINTEGRITYオブジェクトと認証をホストベース、ユーザベースの認証が利用可能である[2]。 [7]の第2節では、「ユーザーIDまたはアプリケーションに基づいて提供するポリシーベースのアドミッション制御メカニズムが素数要件の一つである。」と述べていますユーザまたはPOLICY_DATAオブジェクトに含まれるアプリケーション、AUTH_DATAというポリシーの要素を識別するために、ユーザのホストでRSVPデーモンによって作成され、RSVPメッセージ内で伝送されます。 POLICY_DATA素子の構造は、[2]に記載されています。ポリシー決定ポイント(PDPの)として働くネットワークノードは、ユーザを認証するために、ポリシーベースのアドミッション制御を実行できるようにAUTH_DATA要素に含まれる情報を使用します。で述べたように、[7]、ポリシー要素が処理され、PDPは、ネクストホップルータに転送するために新しいものと古い要素を置き換えています。

A detailed description of the POLICY_DATA element can be found in [2]. The attributes contained in the authentication data policy element AUTH_DATA, which is defined in [7], are briefly explained in this Section. Figure 1 shows the abstract structure of the RSVP message with its security-relevant objects and the scope of protection. The RSVP INTEGRITY object (outer object) covers the entire RSVP message, whereas the POLICY_DATA INTEGRITY object only covers objects within the POLICY_DATA element.

POLICY_DATA要素の詳細な説明は、[2]に見出すことができます。 [7]で定義されている認証データポリシーエレメントAUTH_DATAに含まれる属性は、簡単に、このセクションで説明されています。図1は、セキュリティ関連オブジェクトとRSVPメッセージ及び保護の範囲の抽象的構造を示しています。 POLICY_DATA INTEGRITYオブジェクトのみPOLICY_DATA要素内のオブジェクトを覆う一方、RSVPのINTEGRITYオブジェクト(外部オブジェクト)は、全体のRSVPメッセージをカバーします。

   | RSVP Message                                           |
   | Object    |POLICY_DATA Object                         ||
   |           +-------------------------------------------+|
   |           | INTEGRITY +------------------------------+||
   |           | Object    | AUTH_DATA Object             |||
   |           |           +------------------------------+||
   |           |           | Various Authentication       |||
   |           |           | Attributes                   |||
   |           |           +------------------------------+||
   |           +-------------------------------------------+|
               Figure 1: Security Relevant Objects and Elements
                         within the RSVP Message.

The AUTH_DATA object contains information for identifying users and applications together with credentials for those identities. The main purpose of these identities seems to be usage for policy-based admission control and not authentication and key management. As noted in Section 6.1 of [7], an RSVP message may contain more than one POLICY_DATA object and each of them may contain more than one AUTH_DATA object. As indicated in Figure 1 and in [7], one AUTH_DATA object may contain more than one authentication attribute. A typical configuration for Kerberos-based user authentication includes at least the Policy Locator and an attribute containing the Kerberos session ticket.

AUTH_DATAオブジェクトは、それらのアイデンティティの資格情報と一緒に、ユーザーとアプリケーションを識別するための情報が含まれています。これらのIDの主な目的は、ポリシーベースのアドミッション制御ではなく、認証およびキー管理の使用方法のようです。セクション6.1で述べたように[7]、RSVPメッセージは、複数のPOLICY_DATAオブジェクトを含んでいてもよく、それらの各々は、複数のAUTH_DATAオブジェクトを含んでいてもよいです。図1及び[7]に示されているように、一個のAUTH_DATAオブジェクトが複数の認証属性を含んでいてもよいです。 Kerberosベースのユーザ認証のための代表的な構成は、少なくともポリシーロケータとKerberosセッションチケットを含む属性を含んでいます。

Successful user authentication is the basis for executing policy-based admission control. Additionally, other information such as time-of-day, application type, location information, group membership, etc. may be relevant to the implementation of an access control policy.


The following attributes are defined for use in the AUTH_DATA object:


o Policy Locator










The policy locator string is an X.500 distinguished name (DN) used to locate user or application-specific policy information. The four types of X.500 DNs are listed above. The first two types are the ASCII and the Unicode representation of the user or application DN identity. The two "encrypted" distinguished name types are either encrypted with the Kerberos session key or with the private key of the user's digital certificate (i.e., digitally signed). The term "encrypted together with a digital signature" is easy to misconceive. If user identity confidentiality is provided, then the policy locator has to be encrypted with the public key of the recipient. How to obtain this public key is not described in the document. This detail may be specified in a concrete architecture in which RSVP is used.

ポリシーロケータ文字列が識別名(DN)は、ユーザーまたはアプリケーション固有のポリシー情報を検索するために使用されるX.500です。 X.500 DNの4種類が、上に列挙されています。最初の2つのタイプは、ASCII、ユーザまたはアプリケーションDN同一のUnicode表現です。 2「暗号化された」識別名のタイプは、どちらかのKerberosセッションキーでか(すなわち、デジタル署名された)ユーザーのデジタル証明書の秘密鍵で暗号化されています。 「デジタル署名と一緒に暗号化された」という用語は、誤解しやすいです。ユーザ識別情報の機密性が提供されている場合、ポリシーロケータは、受信者の公開鍵で暗号化する必要があります。この公開鍵は、文書に記述されていない入手する方法。この詳細は、RSVPが使用される具体的なアーキテクチャで指定されてもよいです。

o Credentials


Two cryptographic credentials are currently defined for a user: authentication with Kerberos V5 [8], and authentication with the help of digital signatures based on X.509 [18] and PGP [19]. The following list contains all defined credential types currently available and defined in [7]:

二つの暗号資格情報は、現在のユーザのために定義されている:認証ケルベロスV5 [8]、および認証とX.509 [18]およびPGP [19]に基づいて、デジタル署名の助けを借りて。以下のリストは、現在利用可能と[7]で定義されたすべての定義されたクレデンシャルタイプが含まれています。

         | Credential   |  Description                   |
         |    Type      |                                |
         | ASCII_ID     |  User or application identity  |
         |              |  encoded as an ASCII string    |
         | UNICODE_ID   |  User or application identity  |
         |              |  encoded as a Unicode string   |
         | KERBEROS_TKT |  Kerberos V5 session ticket    |
         | X509_V3_CERT |  X.509 V3 certificate          |
         | PGP_CERT     |  PGP certificate               |

Figure 2: Credentials Supported in RSVP.


The first two credentials contain only a plaintext string, and therefore they do not provide cryptographic user authentication. These plaintext strings may be used to identify applications, that are included for policy-based admission control. Note that these plain-text identifiers may, however, be protected if either the RSVP INTEGRITY or the

最初の二つの資格情報はプレーンテキスト文字列を含むので、彼らは、暗号化、ユーザー認証を提供しません。これら平文文字列は、ポリシーベースのアドミッション制御のために含まれているアプリケーションを識別するために使用されてもよいです。 RSVPのINTEGRITYかのいずれか場合は、これらのプレーンテキスト識別子が、しかし、保護されていてもよいことに注意してください

INTEGRITY object of the POLICY_DATA element is present. Note that the two INTEGRITY objects can terminate at different entities depending on the network structure. The digital signature may also provide protection of application identifiers. A protected application identity (and the entire content of the POLICY_DATA element) cannot be modified as long as no policy-ignorant nodes are encountered in between.

POLICY_DATA要素のINTEGRITYオブジェクトが存在しています。 2つのINTEGRITYオブジェクトは、ネットワーク構成に応じて、異なるエンティティで終端することができることに留意されたいです。デジタル署名は、アプリケーション識別子の保護を提供することができます。保護されたアプリケーションID(及びPOLICY_DATA素子の全体の内容は)限りないポリシー無知ノードが間に遭遇されないように変更することができません。

A Kerberos session ticket, as previously mentioned, is the ticket of a Kerberos AP_REQ message [8] without the Authenticator. Normally, the AP_REQ message is used by a client to authenticate to a server. The INTEGRITY object (e.g., of the POLICY_DATA element) provides the functionality of the Kerberos Authenticator, namely protecting against replay and showing that the user was able to retrieve the session key following the Kerberos protocol. This is, however, only the case if the Kerberos session was used for the keyed message digest field of the INTEGRITY object. Section 7 of [1] discusses some issues for establishment of keys for the INTEGRITY object. The establishment of the security association for the RSVP INTEGRITY object with the inclusion of the Kerberos Ticket within the AUTH_DATA element may be complicated by the fact that the ticket can be decrypted by node B, whereas the RSVP INTEGRITY object terminates at a different host C.

ケルベロスセッションチケットは、前述したように、認証なしのケルベロスAP_REQメッセージ[8]のチケットです。通常、AP_REQメッセージがサーバーに認証するためにクライアントによって使用されます。 INTEGRITYオブジェクトは(例えば、POLICY_DATA素子)すなわちリプレイに対する保護とユーザがKerberosプロトコルに従ってセッションキーを取得することができたことを示し、ケルベロス認証の機能を提供します。ケルベロスセッションがINTEGRITYオブジェクトの鍵付きメッセージダイジェストフィールドに使用された場合、これは、しかし、唯一の場合です。 [1] INTEGRITYオブジェクトのキーの確立のためにいくつかの問題について説明するセクション7。 RSVPのINTEGRITYオブジェクトは異なるホスト℃で終端する一方、AUTH_DATA要素内のKerberosチケットを含めてRSVPのINTEGRITYオブジェクトのセキュリティ・アソシエーションの確立は、チケットがノードBによって復号化することができるという事実によって複雑にされてもよいです

The Kerberos session ticket contains, among many other fields, the session key. The Policy Locator may also be encrypted with the same session key. The protocol steps that need to be executed to obtain such a Kerberos service ticket are not described in [7] and may involve several roundtrips, depending on many Kerberos-related factors. As an optimization, the Kerberos ticket does not need to be included in every RSVP message, as described in Section 7.1 of [1]. Thus, the receiver must store the received service ticket. If the lifetime of the ticket has expired, then a new service ticket must be sent. If the receiver lost its state information (because of a crash or restart) then it may transmit an Integrity Challenge message to force the sender to re-transmit a new service ticket.

ケルベロスセッションチケットは、他の多くの分野、セッションキーの間で、含まれています。ポリシーロケータは、同じセッション鍵で暗号化することができます。そのようなKerberosのサービスチケットを取得するために実行する必要のあるプロトコルのステップが[7]に記載されておらず、多くのKerberos関連要因に応じて、いくつかのラウンドトリップを含むことができます。 [1]のセクション7.1で説明したように最適化として、Kerberosチケットは、すべてのRSVPメッセージに含まれている必要はありません。このように、受信機は、受信したサービスチケットを格納する必要があります。チケットの有効期間が満了している場合、新しいサービスチケットを送信する必要があります。受信機は、(理由はクラッシュまたは再起動の)その状態情報を失った場合、それは新しいサービスチケットを再送信するために送信者を強制的に整合性チャレンジメッセージを送信してもよいです。

If either the X.509 V3 or the PGP certificate is included in the policy element, then a digital signature must be added. The digital signature computed over the entire AUTH_DATA object provides authentication and integrity protection. The SubType of the digital signature authentication attribute is set to zero before computing the digital signature. Whether or not a guarantee of freshness with replay protection (either timestamps or sequence numbers) is provided by the digital signature is an open issue as discussed in Section 4.3.

509 V3またはPGP証明書のいずれかがポリシー要素に含まれている場合、デジタル署名が追加されなければなりません。全体AUTH_DATAオブジェクト上に計算されたデジタル署名は、認証と完全性保護を提供します。デジタル署名の認証属性のサブタイプは、デジタル署名を計算する前にゼロに設定されています。 4.3節で述べたように、デジタル署名によって提供されるリプレイ保護(いずれかのタイムスタンプやシーケンス番号)と新鮮さを保証するかどうかは、未解決の問題です。

o Digital Signature


The digital signature computed over the contents of the AUTH_DATA object must be the last attribute. The algorithm used to compute the digital signature depends on the authentication mode listed in the credential. This is only partially true, because, for example, PGP again allows different algorithms to be used for computing a digital signature. The algorithm identifier used for computing the digital signature is not included in the certificate itself. The algorithm identifier included in the certificate only serves the purpose of allowing the verification of the signature computed by the certificate authority (except for the case of self-signed certificates).


o Policy Error Object


The Policy Error Object is used in the case of a failure of policy-based admission control or other credential verification. Currently available error messages allow notification if the credentials are expired (EXPIRED_CREDENTIALS), if the authorization process disallowed the resource request (INSUFFICIENT_PRIVILEGES), or if the given set of credentials is not supported (UNSUPPORTED_CREDENTIAL_TYPE). The last error message returned by the network allows the user's host to discover the type of credentials supported. Particularly for mobile environments this might be quite inefficient. Furthermore, it is unlikely that a user supports different types of credentials. The purpose of the error message IDENTITY_CHANGED is unclear. Also, the protection of the error message is not discussed in [7].


3.5. RSVP Integrity Handshake
3.5. RSVPの整合性握手

The Integrity Handshake protocol was designed to allow a crashed or restarted host to obtain the latest valid challenge value stored at the receiving host. Due to the absence of key management, it must be guaranteed that two messages do not use the same sequence number with the same key. A host stores the latest sequence number of a cryptographically verified message. An adversary can replay eavesdropped packets if the crashed host has lost its sequence numbers. A signaling message from the real sender with a new sequence number would therefore allow the crashed host to update the sequence number field and prevent further replays. Hence, if there is a steady flow of RSVP-protected messages between the two hosts, an attacker may find it difficult to inject old messages, because new, authenticated messages with higher sequence numbers arrive and get stored immediately.

完全性ハンドシェークプロトコルがクラッシュしたり再起動し、ホストが受信ホストに格納された最新の有効なチャレンジ値を得ることができるように設計されました。鍵管理の欠如に起因する、2つのメッセージが同じキーで同じシーケンス番号を使用しないことを保証しなければなりません。ホストは、暗号検証メッセージの最新のシーケンス番号を格納します。クラッシュしたホストは、そのシーケンス番号を失った場合、敵は盗聴パケットを再生することができます。新しいシーケンス番号と実際の送信者からのシグナリングメッセージは、したがって、クラッシュしたホストがシーケンス番号フィールドを更新し、さらにリプレイを防ぐことができるようになります。 2つのホスト間のRSVP-保護されたメッセージの安定した流れがある場合はそのため、攻撃者は、より高いシーケンス番号を持つ新しい、認証済みのメッセージが到着し、すぐに格納されますので、それは難しい、古いメッセージを注入するかもしれません。

The following description explains the details of an RSVP Integrity Handshake that is started by Node A after recovering from a synchronization failure:


Integrity Challenge


                  (1) Message (including
    +----------+      a Cookie)            +----------+
    |          |-------------------------->|          |
    |  Node A  |                           |  Node B  |
    |          |<--------------------------|          |
    +----------+      Integrity Response   +----------+
                  (2) Message (including
                      the Cookie and the
                      INTEGRITY object)

Figure 3: RSVP Integrity Handshake.


The details of the messages are as follows:


CHALLENGE:=(Key Identifier, Challenge Cookie)


Integrity Challenge Message:=(Common Header, CHALLENGE)


Integrity Response Message:=(Common Header, INTEGRITY, CHALLENGE)


The "Challenge Cookie" is suggested to be a MD5 hash of a local secret and a timestamp [1].


The Integrity Challenge message is not protected with an INTEGRITY object as shown in the protocol flow above. As explained in Section 10 of [1] this was done to avoid problems in situations where both communicating parties do not have a valid starting sequence number.


Using the RSVP Integrity Handshake protocol is recommended although it is not mandatory (because it may not be needed in all network environments).


4. Detailed Security Property Discussion

This section describes the protection of the RSVP-provided mechanisms for authentication, authorization, integrity and replay protection individually, user identity confidentiality, and confidentiality of the signaling messages,


4.1. Network Topology
4.1. ネットワークトポロジー

This paragraph shows the basic interfaces in a simple RSVP network architecture. The architecture below assumes that there is only a single domain and that the two routers are RSVP- and policy-aware. These assumptions are relaxed in the individual paragraphs, as necessary. Layer 2 devices between the clients and their corresponding first-hop routers are not shown. Other network elements like a Kerberos Key Distribution Center and, for example, an LDAP server from which the PDP retrieves its policies are also omitted. The security of various interfaces to the individual servers (KDC, PDP, etc.) depends very much on the security policy of a specific network service provider.


                            | Policy |
                       |    | Point  +---+
                       |    +--------+   |
                       |                 |
                       |                 |
     +------+       +-+----+        +---+--+          +------+
     |Client|       |Router|        |Router|          |Client|
     |  A   +-------+  1   +--------+  2   +----------+  B   |
     +------+       +------+        +------+          +------+

Figure 4: Simple RSVP Architecture.


4.2. Host/Router
4.2. ホスト/ルータ

When considering authentication in RSVP, it is important to make a distinction between user and host authentication of the signaling messages. The host is authenticated using the RSVP INTEGRITY object, whereas credentials inside the AUTH_DATA object can be used to authenticate the user. In this section, the focus is on host authentication, whereas the next section covers user authentication.

RSVPでの認証を考えるとき、シグナリングメッセージのユーザーとホスト認証を区別することが重要です。 AUTH_DATAオブジェクト内の証明書がユーザを認証するために使用することができる一方、ホストは、RSVPのINTEGRITYオブジェクトを使用して認証されます。次のセクションでは、ユーザ認証を覆う一方、このセクションでは、焦点は、ホスト認証です。

(1) Authentication


       The term "host authentication" is used above, because the
       selection of the security association is bound to the host's IP address, as mentioned in Section 3.1 and Section 3.2.  Depending
       on the key management protocol used to create this security
       association and the identity used, it is also possible to bind a
       user identity to this security association.  Because the key
       management protocol is not specified, it is difficult to evaluate
       this part, and hence we speak about data-origin authentication
       based on the host's identity for RSVP INTEGRITY objects.  The
       fact that the host identity is used for selecting the security
       association has already been described in Section 3.1.

Data-origin authentication is provided with a keyed hash value computed over the entire RSVP message, excluding the keyed message digest field itself. The security association used between the user's host and the first-hop router is, as previously mentioned, not established by RSVP, and it must therefore be available before signaling is started.


* Kerberos for the RSVP INTEGRITY object

RSVP INTEGRITYオブジェクトの*ケルベロス

As described in Section 7 of [1], Kerberos may be used to create the key for the RSVP INTEGRITY object. How to learn the principal name (and realm information) of the other node is outside the scope of [1]. [20] describes a way to distribute principal and realm information via DNS, which can be used for this purpose (assuming that the FQDN or the IP address of the other node for which this information is desired is known). All that is required is to encapsulate the Kerberos ticket inside the policy element. It is furthermore mentioned that Kerberos tickets with expired lifetime must not be used, and the initiator is responsible for requesting and exchanging a new service ticket before expiration.

[1]のセクション7で説明したように、ケルベロスは、RSVP INTEGRITYオブジェクトのキーを作成するために使用されてもよいです。他のノードのプリンシパル名(およびレルム情報)を学習する方法[1]の範囲外です。 [20](この情報が所望される他のノードのFQDNまたはIPアドレスが既知であると仮定して)は、この目的のために使用することができるDNSを介して、プリンシパルとレルム情報を配布する方法を記載しています。必要とされるすべてのポリシー要素内のKerberosチケットをカプセル化することです。さらに、期限切れの寿命のKerberosチケットを使用してはならないと述べられている、とイニシエータは要求し、満了前に新しいサービスチケットを交換するための責任があります。

RSVP multicast processing in combination with Kerberos involves additional considerations. Section 7 of [1] states that in the multicast case all receivers must share a single key with the Kerberos Authentication Server (i.e., a single principal used for all receivers). From a personal discussion with Rodney Hess, it seems that there is currently no other solution available in the context of Kerberos. Multicast handling therefore leaves some open questions in this context.

ケルベロスとの組み合わせでRSVPマルチキャスト処理は、追加の考慮事項が含まれます。 [1]のセクション7は、マルチキャストの場合にすべての受信機は、Kerberos認証サーバー(すなわち、すべての受信機に使用される単一の主)を有する単一の鍵を共有しなければならないと述べています。ロドニー・ヘスとの個人的な議論から、ケルベロスのコンテキストで使用可能な他のソリューションが現在存在しないようです。したがって、取り扱いマルチキャストは、この文脈では、いくつかの未解決の問題を残します。

In the case where one entity crashed, the established security association is lost and therefore the other node must retransmit the service ticket. The crashed entity can use an Integrity Challenge message to request a new Kerberos ticket to be retransmitted by the other node. If a node receives such a request, then a reply message must be returned.


(2) Integrity protection


       Integrity protection between the user's host and the first-hop
       router is based on the RSVP INTEGRITY object.  HMAC-MD5 is
       preferred, although other keyed hash functions may also be used
       within the RSVP INTEGRITY object.  In any case, both
       communicating entities must have a security association that
       indicates the algorithm to use.  This may, however, be difficult,
       because no negotiation protocol is defined to agree on a specific
       algorithm.  Hence, if RSVP is used in a mobile environment, it is
       likely that HMAC-MD5 is the only usable algorithm for the RSVP
       INTEGRITY object.  Only in local environments may it be useful to
       switch to a different keyed hash algorithm.  The other possible
       alternative is that every implementation support the most
       important keyed hash algorithms. e.g., MD5, SHA-1, RIPEMD-160,
       etc.  HMAC-MD5 was chosen mainly because of its performance
       characteristics.  The weaknesses of MD5 [21] are known and were
       initially described in [22].  Other algorithms like SHA-1 [15]
       and RIPEMD-160 [21] have stronger security properties.

(3) Replay Protection


       The main mechanism used for replay protection in RSVP is based on
       sequence numbers, whereby the sequence number is included in the
       RSVP INTEGRITY object.  The properties of this sequence number
       mechanism are described in Section 3.1 of [1].  The fact that the
       receiver stores a list of sequence numbers is an indicator for a
       window mechanism.  This somehow conflicts with the requirement
       that the receiver only has to store the highest number given in
       Section 3 of [1].  We assume that this is an oversight.  Section
       4.2 of [1] gives a few comments about the out-of-order delivery
       and the ability of an implementation to specify the replay
       window.  Appendix C of [3] describes a window mechanism for
       handling out-of-sequence delivery.

(4) Integrity Handshake


       The mechanism of the Integrity Handshake is explained in Section
       3.5.  The Cookie value is suggested to be a hash of a local
       secret and a timestamp.  The Cookie value is not verified by the
       receiver.  The mechanism used by the Integrity Handshake is a
       simple Challenge/Response message, which assumes that the key
       shared between the two hosts survives the crash.  If, however,
       the security association is dynamically created, then this
       assumption may not be true.

In Section 10 of [1], the authors note that an adversary can create a faked Integrity Handshake message that includes challenge cookies. Subsequently, it could store the received response and later try to replay these responses while a responder recovers from a crash or restart. If this replayed Integrity Response value is valid and has a lower sequence number than actually used, then this value is stored at the recovering host. In order for this attack to be successful, the adversary must either have collected a large number of challenge/response value pairs or have "discovered" the cookie generation mechanism (for example by knowing the local secret). The collection of Challenge/Response pairs is even more difficult, because they depend on the Cookie value, the sequence number included in the response message, and the shared key used by the INTEGRITY object.


(5) Confidentiality


       Confidentiality is not considered to be a security requirement
       for RSVP.  Hence, it is not supported by RSVP, except as
       described in paragraph d) of Section 4.3.  This assumption may
       not hold, however, for enterprises or carriers who want to
       protect billing data, network usage patterns, or network
       configurations, in addition to users' identities, from
       eavesdropping and traffic analysis.  Confidentiality may also
       help make certain other attacks more difficult.  For example, the
       PathErr attack described in Section 5.2 is harder to carry out if
       the attacker cannot observe the Path message to which the PathErr

(6) Authorization


       The task of authorization consists of two subcategories: network
       access authorization and RSVP request authorization.  Access
       authorization is provided when a node is authenticated to the
       network, e.g., using EAP [23] in combination with AAA protocols
       (for example, RADIUS [24] or DIAMETER [9]).  Issues related to
       network access authentication and authorization are outside the
       scope of RSVP.

The second authorization refers to RSVP itself. Depending on the network configuration:


* the router either forwards the received RSVP request to the policy decision point (e.g., using COPS [10] and [11]) to request that an admission control procedure be executed, or


* the router supports the functionality of a PDP and, therefore, there is no need to forward the request, or


* the router may already be configured with the appropriate policy information to decide locally whether to grant this request.


Based on the result of the admission control, the request may be granted or rejected. Information about the resource-requesting entity must be available to provide policy-based admission control.


(7) Performance


       The computation of the keyed message digest for an RSVP INTEGRITY
       object does not represent a performance problem.  The protection
       of signaling messages is usually not a problem, because these
       messages are transmitted at a low rate.  Even a high volume of
       messages does not cause performance problems for an RSVP router
       due to the efficiency of the keyed message digest routine.

Dynamic key management, which is computationally more demanding, is more important for scalability. Because RSVP does not specify a particular key exchange protocol, it is difficult to estimate the effort needed to create the required security associations. Furthermore, the number of key exchanges to be triggered depends on security policy issues like lifetime of a security association, required security properties of the key exchange protocol, authentication mode used by the key exchange protocol, etc. In a stationary environment with a single administrative domain, manual security association establishment may be acceptable and may provide the best performance characteristics. In a mobile environment, asymmetric authentication methods are likely to be used with a key exchange protocol, and some sort of public key or certificate verification needs to be supported.

計算がより要求される動的な鍵管理は、スケーラビリティのためのより重要です。 RSVPは、特定の鍵交換プロトコルを指定していないので、必要なセキュリティアソシエーションを作成するために必要な労力を推定することは困難です。さらに、トリガされる鍵交換の数は、セキュリティアソシエーションの寿命のようなセキュリティポリシーの問題に依存して、鍵交換プロトコル、単一の管理静止環境において等鍵交換プロトコルによって使用される認証方式のセキュリティプロパティを必要ドメインは、手動セキュリティアソシエーションの確立には許容することができ、最高の性能特性を提供することができます。モバイル環境では、非対称認証方法は、鍵交換プロトコルで使用される可能性があり、公開鍵や証明書の検証のいくつかの並べ替えをサポートする必要があります。

4.3. User to PEP/PDP
4.3. PEP / PDPへのユーザー

As noted in the previous section, RSVP supports both user-based and host-based authentication. Using RSVP, a user may authenticate to the first hop router or to the PDP as specified in [1], depending on the infrastructure provided by the network domain or the architecture used (e.g., the integration of RSVP and Kerberos V5 into the Windows 2000 Operating System [25]). Another architecture in which RSVP is tightly integrated is the one specified by the PacketCable organization. The interested reader is referred to [26] for a discussion of their security architecture.

前のセクションで述べたように、RSVPは、ユーザベースおよびホスト・ベースの認証の両方をサポートします。で指定されるようにRSVPを使用して、ユーザは、PDP最初のホップルータにまたはに認証することができる[1]、ネットワークドメインまたは使用されるアーキテクチャによって提供されるインフラストラクチャに依存して(例えば、Windows 2000の中へのRSVPとKerberos V5の統合オペレーティングシステム[25])。 RSVPが緊密に統合されているもう一つのアーキテクチャでは、PacketCableの組織によって指定されたものです。興味のある読者は、それらのセキュリティアーキテクチャの議論については[26]と呼ばれます。

(1) Authentication


       When a user sends an RSVP PATH or RESV message, this message may
       include some information to authenticate the user. [7] describes
       how user and application information is embedded into the RSVP
       message (AUTH_DATA object) and how to protect it.  A router
       receiving such a message can use this information to authenticate
       the client and forward the user or application information to the
       policy decision point (PDP).  Optionally, the PDP itself can
       authenticate the user, which is described in the next section.
       To be able to authenticate the user, to verify the integrity, and
       to check for replays, the entire POLICY_DATA element has to be
       forwarded from the router to the PDP (e.g., by including the
       element into a COPS message).  It is assumed, although not
       clearly specified in [7], that the INTEGRITY object within the
       POLICY_DATA element is sent to the PDP along with all other

* Certificate Verification


Using the policy element as described in [7], it is not possible to provide a certificate revocation list or other information to prove the validity of the certificate inside the policy element. A specific mechanism for certificate verification is not discussed in [7] and hence a number of them can be used for this purpose. For certificate verification, the network element (a router or the policy decision point) that has to authenticate the user could frequently download certificate revocation lists or use a protocol like the Online Certificate Status Protocol (OCSP) [27] and the Simple Certificate Validation Protocol (SCVP) [28] to determine the current status of a digital certificate.


* User Authentication to the PDP


This alternative authentication procedure uses the PDP to authenticate the user instead of the first-hop router. In Section 4.2.1 of [7], the choice is given for the user to obtain a session ticket either for the next hop router or for the PDP. As noted in the same section, the identity of the PDP or the next hop router is statically configured or dynamically retrieved. Subsequently, user authentication to the PDP is considered.


* Kerberos-based Authentication to the PDP

PDPへ* Kerberosベースの認証

If Kerberos is used to authenticate the user, then a session ticket for the PDP must be requested first. A user who roams between different routers in the same administrative domain does not need to request a new service ticket, because the same PDP is likely to be used by most or all first-hop routers within the same administrative domain. This is different from the case in which a session ticket for a router has to be obtained and authentication to a router is required. The router therefore plays a passive role of simply forwarding the request to the PDP and executing the policy decision returned by the PDP. Appendix B describes one example of user-to-PDP authentication.


User authentication with the policy element provides only unilateral authentication, whereby the client authenticates to the router or to the PDP. If an RSVP message is sent to the user's host and public-key-based authentication is not used, then the message does not contain a certificate and digital signature. Hence, no mutual authentication can be assumed. In case of Kerberos, mutual authentication may be accomplished if the PDP or the router transmits a policy element with an INTEGRITY object computed with the session key retrieved from the Kerberos ticket, or if the Kerberos ticket included in the policy element is also used for the RSVP INTEGRITY object as described in Section 4.2. This procedure only works if a previous message was transmitted from the end host to the network and such key is already established. Reference [7] does not discuss this issue, and therefore there is no particular requirement for transmitting network-specific credentials back to the end-user's host.

ポリシー要素を持つユーザー認証は、クライアントがルータやPDPに認証することにより、唯一の一方的な認証を提供します。 RSVPメッセージは、ユーザのホストに送信され、公開鍵ベースの認証を使用しない場合、メッセージは、証明書とデジタル署名が含まれていません。したがって、何の相互認証を仮定することはできません。 PDPやルータがKerberosチケットから取り出されたセッション鍵を用いて計算INTEGRITYオブジェクトとポリシー要素を送信する場合のKerberosの場合には、相互認証が達成されてもよい、Kerberosチケットは、他にも使用されているポリシー要素または含まれている場合セクション4.2で説明したようにRSVP INTEGRITYオブジェクト。前のメッセージは、ネットワークへのエンドホストから送信されたと、そのようなキーが既に確立されている場合は、この手順はのみ動作します。参考文献[7]、この問題を議論していないので、バックエンド・ユーザーのホストへのネットワーク固有の資格情報を送信するための特別な要件はありません。

(2) Integrity Protection


          Integrity protection is applied separately to the RSVP message
          and the POLICY_DATA element, as shown in Figure 1.  In case of
          a policy-ignorant node along the path, the RSVP INTEGRITY
          object and the INTEGRITY object inside the policy element
          terminate at different nodes.  Basically, the same is true for
          the user credentials if they are verified at the policy
          decision point instead of the first hop router.

* Kerberos


If Kerberos is used to authenticate the user to the first hop router, then the session key included in the Kerberos ticket may be used to compute the INTEGRITY object of the policy element. It is the keyed message digest that provides the authentication. The existence of the Kerberos service ticket inside the AUTH_DATA object does not provide authentication or a guarantee of freshness for the receiving host.

Kerberosが最初のホップルータにユーザを認証するために使用されている場合は、Kerberosチケットに含まれたセッションキーは、ポリシー要素のINTEGRITYオブジェクトを計算するために使用することができます。これは、認証を提供するキー付きメッセージダイジェストです。 AUTH_DATAオブジェクト内のKerberosサービスチケットの存在は、認証または受信ホストの新鮮さの保証を提供していません。

Authentication and guarantee of freshness are provided by the keyed hash value of the INTEGRITY object inside the POLICY_DATA element. This shows that the user actively participated in the Kerberos protocol and was able to obtain the session key to compute the keyed message digest. The Authenticator used in the Kerberos V5 protocol provides similar functionality, but replay protection is based on timestamps (or on a sequence number if the optional seq-number field inside the Authenticator is used for KRB_PRIV/KRB_SAFE messages as described in Section 5.3.2 of [8]).

鮮度の認証及び保証はPOLICY_DATA要素内INTEGRITYオブジェクトの鍵付きハッシュ値によって提供されます。これは、ユーザが積極的にKerberosプロトコルに参加し、キー付きメッセージダイジェストを計算するためのセッション鍵を得ることができたことを示しています。 Kerberos V5プロトコルで使用されるオーセンティケータは、同様の機能を提供するが、セクション5.3.2で説明したように認証内部オプション配列番号フィールドはKRB_PRIV / KRB_SAFEメッセージのために使用された場合、リプレイ保護はタイムスタンプ(またはシーケンス番号に基づいています[8])。

* Digital Signature

* デジタル署名

If public-key-based authentication is provided, then user authentication is accomplished with a digital signature. As explained in Section 3.3.3 of [7], the DIGITAL_SIGNATURE attribute must be the last attribute in the AUTH_DATA object, and the digital signature covers the entire AUTH_DATA object. In the case of PGP, which hash algorithm and public key algorithm are used for the digital signature computation is described in [19]. In the case of X.509 credentials, the situation is more complex because different mechanisms like CMS [29] or PKCS#7 [30] may be used for digitally signing the message element. X.509 only provides the standard for the certificate layout, which seems to provide insufficient information for this purpose. Therefore, X.509 certificates are supported, for example, by CMS or PKCS#7. [7], however, does not make any statements about the usage of CMS or PKCS#7. Currently, there is no support for CMS or for PKCS#7 [7], which provides more than just public-key-based authentication (e.g., CRL distribution, key transport, key agreement, etc.). Furthermore, the use of PGP in RSVP is vaguely defined, because there are different versions of PGP (including OpenPGP [19]), and no indication is given as to which should be used.

公開鍵ベースの認証が提供されている場合、ユーザ認証は、デジタル署名を用いて達成されます。 [7]のセクション3.3.3で説明したように、DIGITAL_SIGNATURE属性はAUTH_DATAオブジェクト内の最後の属性でなければならず、デジタル署名全体AUTH_DATAオブジェクトを覆っています。ハッシュアルゴリズム及び公開鍵アルゴリズムは、デジタル署名の計算に使用されているPGPの場合、[19]に記載されています。 CMS [29]またはPKCS#7 [30]のような異なる機構がデジタルメッセージ要素に署名するために使用することができるので、X.509認証情報の場合には、状況はより複雑です。 X.509は、この目的のために十分な情報を提供するように思われ、証明書のレイアウトのための標準を提供します。したがって、X.509証明書は、CMSまたはPKCS#7によって、例えば、サポートされています。 [7]、しかし、CMSまたはPKCS#7の使用状況に関するすべてのステートメントを作成しません。現在、CMSまたは単に公開鍵ベースの認証(例えば、CRL分布、主要な輸送、鍵合意等)以上を提供するPKCS#7 [7]のためのサポートはありません。さらに、(OpenPGPの[19]を含む)PGPの異なるバージョンが存在するため、RSVPにPGPを使用することは漠然と定義され、かつ使用されるべきであるよう兆候が与えられていません。

Supporting public-key-based mechanisms in RSVP might increase the risks of denial-of-service attacks. The large processing, memory, and bandwidth requirements should also be considered. Fragmentation might also be an issue here.


If the INTEGRITY object is not included in the POLICY_DATA element or not sent to the PDP, then we have to make the following observations:


For the digital signature case, only the replay protection provided by the digital signature algorithm can be used. It is not clear, however, whether this usage was anticipated or not. Hence, we might assume that replay protection is based on the availability of the RSVP INTEGRITY object used with a security association that is established by other means.


Including only the Kerberos session ticket is insufficient, because freshness is not provided (because the Kerberos Authenticator is missing). Obviously there is no guarantee that the user actually followed the Kerberos protocol and was able to decrypt the received TGS_REP (or, in rare cases, the AS_REP if a session ticket is requested with the initial AS_REQ).


(3) Replay Protection


       Figure 5 shows the interfaces relevant for replay protection of
       signaling messages in a more complicated architecture.  In this
       case, the client uses the policy data element with PEP2, because
       PEP1 is not policy-aware.  The interfaces between the client and
       PEP1 and between PEP1 and PEP2 are protected with the RSVP
       INTEGRITY object.  The link between the PEP2 and the PDP is
       protected, for example, by using the COPS built-in INTEGRITY
       object.  The dotted line between the Client and the PDP indicates
       the protection provided by the AUTH_DATA element, which has no
       RSVP INTEGRITY object included.
                        AUTH_DATA                         +----+
      +---------------------------------------------------+PDP +-+
      |                                                   +----+ |
      |                                                          |
      |                                                          |
      |                                                 COPS     |
      |                                                 INTEGRITY|
      |                                                          |
      |                                                          |
      |                                                          |
   +--+---+   RSVP INTEGRITY  +----+    RSVP INTEGRITY    +----+ |
   +--+---+                   +----+                      +-+--+
      |                                                     |
                       POLICY_DATA INTEGRITY

Figure 5: Replay Protection.


Host authentication with the RSVP INTEGRITY object and user authentication with the INTEGRITY object inside the POLICY_DATA element both use the same anti-replay mechanism. The length of the Sequence Number field, sequence number rollover, and the Integrity Handshake have already been explained in Section 3.1.


Section 9 of [7] states: "RSVP INTEGRITY object is used to protect the policy object containing user identity information from security (replay) attacks." When using public-key-based authentication, RSVP-based replay protection is not supported, because the digital signature does not cover the POLICY_DATA INTEGRITY object with its Sequence Number field. The digital signature covers only the entire AUTH_DATA object.

[7]のセクション9の状態:「RSVPのINTEGRITYオブジェクトがセキュリティ(リプレイ)攻撃からユーザ識別情報を含むポリシー・オブジェクトを保護するために使用されます。」公開鍵ベースの認証を使用する場合は、デジタル署名は、そのシーケンス番号フィールドとPOLICY_DATA INTEGRITYオブジェクトをカバーしていないので、RSVPベースのリプレイ保護は、サポートされていません。デジタル署名は、全体AUTH_DATAオブジェクトを覆っています。

The use of public key cryptography within the AUTH_DATA object complicates replay protection. Digital signature computation with PGP is described in [31] and in [19]. The data structure preceding the signed message digest includes information about the message digest algorithm used and a 32-bit timestamp of when the signature was created ("Signature creation time"). The timestamp is included in the computation of the message digest. The IETF standardized version of OpenPGP [19] contains more information and describes the different hash algorithms (MD2, MD5, SHA-1, RIPEMD-160) supported. [7] does not make any statements as to whether the "Signature creation time" field is used for replay protection. Using timestamps for replay protection requires different synchronization mechanisms in the case of clock-skew. Traditionally, these cases assume "loosely synchronized" clocks but also require specifying a replay window.

AUTH_DATAオブジェクト内の公開鍵暗号の使用は、再生保護を複雑にします。 PGPでデジタル署名の計算は、[31]および[19]に記載されています。署名されたメッセージダイジェストを先行するデータ構造が使用されるアルゴリズム及び署名が作成されたときの32ビットのタイムスタンプ(「署名作成時間」)メッセージダイジェストに関する情報を含みます。タイムスタンプは、メッセージダイジェストの計算に含まれます。 OpenPGPの[19]のIETF標準化されたバージョンは、より多くの情報が含まれており、異なるハッシュアルゴリズム(MD2、MD5、SHA-1、RIPEMD-160)サポートを記述する。 [7]「署名の作成時間」フィールドはリプレイ保護のために使用されているかどうかのいずれかの書類を作成しません。リプレイ保護のためのタイムスタンプを使用してクロック・スキューの場合には、異なる同期メカニズムを必要とします。伝統的に、これらの例は、「緩やかに同期化」クロックを前提ともリプレイウィンドウを指定する必要があります。

If the "Signature creation time" is not used for replay protection, then a malicious, policy-ignorant node can use this weakness to replace the AUTH_DATA object without destroying the digital signature. If this was not simply an oversight, it is therefore assumed that replay protection of the user credentials was not considered an important security requirement, because the hop-by-hop processing of the RSVP message protects the message against modification by an adversary between two communicating nodes.


The lifetime of the Kerberos ticket is based on the fields starttime and endtime of the EncTicketPart structure in the ticket, as described in Section 5.3.1 of [8]. Because the ticket is created by the KDC located at the network of the verifying entity, it is not difficult to have the clocks roughly synchronized for the purpose of lifetime verification. Additional information about clock-synchronization and Kerberos can be found in [32].


If the lifetime of the Kerberos ticket expires, then a new ticket must be requested and used. Rekeying is implemented with this procedure.


(4) (User Identity) Confidentiality


       This section discusses privacy protection of identity information
       transmitted inside the policy element.  User identity
       confidentiality is of particular interest because there is no
       built-in RSVP mechanism for encrypting the POLICY_DATA object or
       the AUTH_DATA elements.  Encryption of one of the attributes
       inside the AUTH_DATA element, the POLICY_LOCATOR attribute, is

To protect the user's privacy, it is important not to reveal the user's identity to an adversary located between the user's host and the first-hop router (e.g., on a wireless link). Furthermore, user identities should not be transmitted outside the domain of the visited network provider. That is, the user identity information inside the policy data element should be removed or modified by the PDP to prevent revealing its contents to other (unauthorized) entities along the signaling path. It is not possible (with the offered mechanisms) to hide the user's identity in such a way that it is not visible to the first policy-aware RSVP node (or to the attached network in general).


The ASCII or Unicode distinguished name of the user or application inside the POLICY_LOCATOR attribute of the AUTH_DATA element may be encrypted as specified in Section 3.3.1 of [7]. The user (or application) identity is then encrypted with either the Kerberos session key or with the private key in case of public-key-based authentication. When the private key is used, we usually speak of a digital signature that can be verified by everyone possessing the public key. Because the certificate with the public key is included in the message itself, decryption is no obstacle. Furthermore, the included certificate together with the additional (unencrypted) information in the RSVP message provides enough identity information for an eavesdropper. Hence, the possibility of encrypting the policy locator in case of public-key-based authentication is problematic. To encrypt the identities using asymmetric cryptography, the user's host must be able somehow to retrieve the public key of the entity verifying the policy element (i.e., the first policy-aware router or the PDP). Then, this public key could be used to encrypt a symmetric key, which in turn encrypts the user's identity and certificate, as is done, e.g., by PGP. Currently, no such mechanism is defined in [7].


The algorithm used to encrypt the POLICY_LOCATOR with the Kerberos session key is assumed to be the same as the one used for encrypting the service ticket. The information about the algorithm used is available in the etype field of the EncryptedData ASN.1 encoded message part. Section 6.3 of [8] lists the supported algorithms. [33] defines newer encryption algorithms (Rijndael, Serpent, and Twofish).

ケルベロスセッションキーとPOLICY_LOCATORを暗号化するために使用されるアルゴリズムは、サービスチケットの暗号化に使用したものと同じであると仮定されます。使用されるアルゴリズムについての情報は、はEncryptedData ASN.1符号化されたメッセージ部分のETYPE分野で利用可能です。 [8]サポートされているアルゴリズムを示していますのセクション6.3。 [33]新しい暗号化アルゴリズム(ラインダール、蛇、およびTwofishは)を定義します。

Evaluating user identity confidentiality also requires looking at protocols executed outside of RSVP (for example, the Kerberos protocol). The ticket included in the CREDENTIAL attribute may provide user identity protection by not including the optional cname attribute inside the unencrypted part of the Ticket. Because the Authenticator is not transmitted with the RSVP message, the cname and the crealm of the unencrypted part of the Authenticator are not revealed. In order for the user to request the Kerberos session ticket for inclusion in the CREDENTIAL attribute, the Kerberos protocol exchange must be executed. Then the Authenticator sent with the TGS_REQ reveals the identity of the user. The AS_REQ must also include the user's identity to allow the Kerberos Authentication Server to respond with an AS_REP message that is encrypted with the user's secret key. Using Kerberos, it is therefore only possible to hide the content of the encrypted policy locator, which is only useful if this value differs from the Kerberos principal name. Hence, using Kerberos it is not "entirely" possible to provide user identity confidentiality.

ユーザ識別情報の機密性を評価することもRSVP(例えば、Kerberosプロトコル)の外で実行プロトコルを見て必要とします。 CREDENTIAL属性に含まれたチケットは、チケットの暗号化されていない部分内のオプションCNAME属性を含めないことで、ユーザのアイデンティティ保護を提供することができます。認証がRSVPメッセージで送信されないため、CNAMEと認証の暗号化されていない部分のcrealmが明らかにされていません。 CREDENTIAL属性に含めるためにケルベロスセッションチケットを要求するユーザーのために、Kerberosプロトコル交換が実行されなければなりません。そして、TGS_REQに送られた認証は、ユーザーの身元を明らかにする。 AS_REQはまた、Kerberos認証サーバーがユーザーの秘密鍵で暗号化されたAS_REPメッセージで応答することを可能にするユーザーのIDを含める必要があります。 Kerberosを使用して、この値は、Kerberosプリンシパル名と異なる場合にのみ有用である暗号化されたポリシーロケータの内容を非表示にするため、のみ可能です。したがって、Kerberosを使用すると、ユーザーIDの機密性を提供するために、「完全に」ことはできません。

It is important to note that information stored in the policy element may be changed by a policy-aware router or by the policy decision point. Which parts are changed depends upon whether multicast or unicast is used, how the policy server reacts, where the user is authenticated, whether the user needs to be re-authenticated in other network nodes, etc. Hence, user-specific and application-specific information can leak after the messages leave the first hop within the network where the user's host is attached. As mentioned at the beginning of this section, this information leakage is assumed to be intentional.


(5) Authorization


       In addition to the description of the authorization steps of the
       Host-to-Router interface, user-based authorization is performed
       with the policy element providing user credentials.  The
       inclusion of user and application specific information enables
       policy-based admission control with special user policies that
       are likely to be stored at a dedicated server.  Hence, a Policy
       Decision Point can query, for example, an LDAP server for a service level agreement that states the amount of resources a
       certain user is allowed to request.  In addition to the user
       identity information, group membership and other non-security-
       related information may contribute to the evaluation of the final
       policy decision.  If the user is not registered to the currently
       attached domain, then there is the question of how much
       information the home domain of the user is willing to exchange.
       This also impacts the user's privacy policy.

In general, the user may not want to distribute much of this policy information. Furthermore, the lack of a standardized authorization data format may create interoperability problems when exchanging policy information. Hence, we can assume that the policy decision point may use information from an initial authentication and key agreement protocol (which may have already required cross-realm communication with the user's home domain, if only to show that the home domain knows the user and that the user is entitled to roam), to forward accounting messages to this domain. This represents the traditional subscriber-based accounting scenario. Non-traditional or alternative means of access might be deployed in the near future that do not require any type of inter-domain communication.


Additional discussions are required to determine the expected authorization procedures. [34] and [35] discuss authorization issues for QoS signaling protocols. Furthermore, a number of mobility implications for policy handling in RSVP are described in [36].

追加の議論が予想されるの認可手続きを決定するために必要とされます。 [34]と[35]のQoSシグナリングプロトコルの認可の問題を議論します。また、RSVPのポリシー処理のためのモビリティの影響の数は[36]に記載されています。

(6) Performance


       If Kerberos is used for user authentication, then a Kerberos
       ticket must be included in the CREDENTIAL Section of the
       AUTH_DATA element.  The Kerberos ticket has a size larger than
       500 bytes, but it only needs to be sent once because a
       performance optimization allows the session key to be cached as
       noted in Section 7.1 of [1].  It is assumed that subsequent RSVP
       messages only include the POLICY_DATA INTEGRITY object with a
       keyed message digest that uses the Kerberos session key.
       However, this assumes that the security association required for
       the POLICY_DATA INTEGRITY object is created (or modified) to
       allow the selection of the correct key.  Otherwise, it difficult
       to say which identifier is used to index the security

If Kerberos is used as an authentication system then, from a performance perspective, the message exchange to obtain the session key needs to be considered, although the exchange only needs to be done once in the lifetime of the session ticket. This is particularly true in a mobile environment with a fast roaming user's host.


Public-key-based authentication usually provides the best scalability characteristics for key distribution, but the protocols are performance demanding. A major disadvantage of the public-key-based user authentication in RSVP is the lack of a method to derive a session key. Hence, every RSVP PATH or RESV message includes the certificate and a digital signature, which is a huge performance and bandwidth penalty. For a mobile environment with low power devices, high latency, channel noise, and low-bandwidth links, this seems to be less encouraging. Note that a public key infrastructure is required to allow the PDP (or the first-hop router) to verify the digital signature and the certificate. To check for revoked certificates, certificate revocation lists or protocols like the Online Certificate Status Protocol [27] and the Simple Certificate Validation Protocol [28] are needed. Then the integrity of the AUTH_DATA object can be verified via the digital signature.

公開鍵ベースの認証は、通常、鍵の配布のための最高のスケーラビリティ特性を提供しますが、プロトコルは、性能要求されています。 RSVPにおける公開鍵ベースのユーザー認証の主な欠点は、セッション鍵を導出する方法の欠如です。したがって、すべてのRSVP PATHまたはRESVメッセージは、証明書と巨大なパフォーマンスと帯域幅ペナルティであるデジタル署名を含みます。低電力デバイス、高遅延、チャネルノイズ、低帯域幅リンクでのモバイル環境では、これはあまり有望であると思われます。公開鍵インフラストラクチャがPDP(又は第1のホップ・ルータ)は、デジタル署名と証明書を検証できるようにするために必要であることに留意されたいです。失効した証明書、オンライン証明書状態プロトコルのような証明書失効リストまたはプロトコル[27]とシンプルな証明書の検証議定書[28]をチェックするために必要とされています。次いで、AUTH_DATAオブジェクトの整合性は、デジタル署名を介して確認することができます。

4.4. Communication between RSVP-Aware Routers
4.4. RSVP-Awareのルータ間の通信

(1) Authentication


       RSVP signaling messages have data origin authentication and are
       protected against modification and replay with the RSVP INTEGRITY
       object.  The RSVP message flow between routers is protected based
       on the chain of trust, and hence each router needs only a
       security association with its neighboring routers.  This
       assumption was made because of performance advantages and because
       of special security characteristics of the core network to which
       no user hosts are directly attached.  In the core network the
       network structure does not change frequently and the manual
       distribution of shared secrets for the RSVP INTEGRITY object may
       be acceptable.  The shared secrets may be either manually
       configured or distributed by using appropriately secured network
       management protocols like SNMPv3.

Independent of the key distribution mechanism, host authentication with built-in RSVP mechanisms is accomplished using the keyed message digest in the RSVP INTEGRITY object, computed using the previously exchanged symmetric key.


(2) Integrity Protection


       Integrity protection is accomplished with the RSVP INTEGRITY
       object with the variable length Keyed Message Digest field.

(3) Replay Protection


       Replay protection with the RSVP INTEGRITY object is extensively
       described in previous sections.  To enable crashed hosts to learn
       the latest sequence number used, the Integrity Handshake
       mechanism is provided in RSVP.

(4) Confidentiality


Confidentiality is not provided by RSVP.


(5) Authorization


       Depending on the RSVP network, QoS resource authorization at
       different routers may need to contact the PDP again.  Because the
       PDP is allowed to modify the policy element, a token may be added
       to the policy element to increase the efficiency of the re-
       authorization procedure.  This token is used to refer to an
       already computed policy decision.  The communications interface
       from the PEP to the PDP must be properly secured.

(6) Performance


       The performance characteristics for the protection of the RSVP
       signaling messages is largely determined by the key exchange
       protocol, because the RSVP INTEGRITY object is only used to
       compute a keyed message digest of the transmitted signaling

The security associations within the core network, that is, between individual routers (in comparison with the security association between the user's host and the first-hop router or with the attached network in general), can be established more easily because of the normally strong trust assumptions. Furthermore, it is possible to use security associations with an increased lifetime to avoid frequent rekeying. Hence, there is less impact on the performance compared with the user-to-network interface. The security association storage requirements are also less problematic.


5. Miscellaneous Issues

This section describes a number of issues that illustrate some of the shortcomings of RSVP with respect to security.


5.1. First-Hop Issue
5.1. 最初のホップの問題

In case of end-to-end signaling, an end host starts signaling to its attached network. The first-hop communication is often more difficult to secure because of the different requirements and a missing trust relationship. An end host must therefore obtain some information to start RSVP signaling:


o Does this network support RSVP signaling?


o Which node supports RSVP signaling?


o To which node is authentication required?


o Which security mechanisms are used for authentication?


o Which algorithms are required?


o Where should the keys and security associations come from?


o Should a security association be established?


RSVP, as specified today, is used as a building block. Hence, these questions have to be answered as part of overall architectural considerations. Without answers to these questions, ad hoc RSVP communication by an end host roaming to an unknown network is not possible. A negotiation of security mechanisms and algorithms is not supported for RSVP.


5.2. Next-Hop Problem
5.2. 次ホップの問題

Throughout the document it was assumed that the next RSVP node along the path is always known. Knowing the next hop is important to be able to select the correct key for the RSVP Integrity object and to apply the proper protection. In the case in which an RSVP node assumes it knows which node is the next hop, the following protocol exchange can occur:

文書全体それは経路に沿った次のRSVPノードが常に既知であると仮定しました。ネクストホップを知ることは、RSVPのIntegrityオブジェクトのための正しいキーを選択できるように、適切な保護を適用することが重要です。 RSVPノードは、それが次のホップであるノードを知っている前提としていた場合には、以下のプロトコル交換が発生する可能性があります。

                          (A<->C)               +------+
                                      (3)       | RSVP |
                                 +------------->+ Node |
                                 |              |  B   |
                    Integrity    |              +--+---+
                     (A<->C)     |                 |
          +------+    (2)     +--+----+            |
     (1)  | RSVP +----------->+Router |            |  Error
    ----->| Node |            | or    +<-----------+ (I am B)
          |  A   +<-----------+Network|       (4)
          +------+    (5)     +--+----+
                     Error       .
                    (I am B)     .              +------+
                                 .              | RSVP |
                                 ...............+ Node |
                                                |  C   |

Figure 6: Next-Hop Issue.


When RSVP node A in Figure 6 receives an incoming RSVP Path message, standard RSVP message processing takes place. Node A then has to decide which key to select to protect the signaling message. We assume that some unspecified mechanism is used to make this decision. In this example, node A assumes that the message will travel to RSVP node C. However, for some reasons (e.g., a route change, inability to learn the next RSVP hop along the path, etc.) the message travels to node B via a non-RSVP supporting router that cannot verify the integrity of the message (or cannot decrypt the Kerberos service ticket). The processing failure causes a PathErr message to be returned to the originating sender of the Path message. This error message also contains information about the node that recognized the error. In many cases, a security association might not be available. Node A receiving the PathErr message might use the information returned with the PathErr message to select a different security association (or to establish one).

図6のRSVPノードAが着信RSVP Pathメッセージを受信した場合、標準のRSVPメッセージの処理が行われます。ノードAは、シグナリングメッセージを保護するために、選択するキーを決定する必要があります。我々はいくつかの不特定のメカニズムは、この決定を行うために使用されていることを前提としています。この例では、ノードAは、メッセージがいくつかの理由で、しかしノードCをRSVPに移動すると仮定(例えば、経路変更等の経路に沿って次のRSVPホップを学習することができない)メッセージを介してノードBに移動しますメッセージの整合性を検証することはできません(またはKerberosサービスチケットを解読することはできません)非RSVPサポートするルータ。処理の失敗はのPathErrメッセージは、Pathメッセージの元の送信者に返されるようにします。このエラーメッセージは、エラーを認識したノードに関する情報が含まれています。多くの場合、セキュリティアソシエーションが使用できない場合があります。たPathErrメッセージを受信したノードAは、異なるセキュリティアソシエーションを選択する(または1つを確立する)のPathErrメッセージで返された情報を使用することがあります。

Figure 6 describes a behavior that might help node A learn that an error occurred. However, the description in Section 4.2 of [1] states in step (5) that a signaling message is silently discarded if the receiving host cannot properly verify the message: "If the calculated digest does not match the received digest, the message is discarded without further processing." For RSVP Path and similar messages, this functionality is not really helpful.

図6は、ノードAは、エラーが発生したことを学ぶのを助けるかもしれない動作について説明します。しかし、[1]ステップにおける状態のセクション4.2で説明が(5)受信ホストが正しくメッセージを確認できない場合、シグナリングメッセージは黙って破棄されること:「計算されたダイジェストは、受信したダイジェストと一致しない場合、メッセージは破棄されますさらに処理せずに。」 RSVPのパスと類似したメッセージの場合、この機能は本当に便利ではありません。

The RSVP Path message therefore provides a number of functions: path discovery, detecting route changes, discovery of QoS capabilities along the path using the Adspec object (with some interpretation), next-hop discovery, and possibly security association establishment (for example, in the case of Kerberos).

で、ルート変更、(いくつかの解釈を伴う)ADSPECオブジェクトを使用して、パスに沿ってQoS機能の発見、次ホップの発見、例えば、おそらくセキュリティ・アソシエーションの確立を(検出、パス検出:RSVP Pathメッセージは、したがって、多くの機能を提供しますケルベロスの場合)。

From a security point of view, there are conflicts between:


o Idempotent message delivery and efficiency


The RSVP Path message especially performs a number of functions. Supporting idempotent message delivery somehow contradicts with security association establishment, efficient message delivery, and message size. For example, a "real" idempotent signaling message would contain enough information to perform security processing without depending on a previously executed message exchange. Adding a Kerberos ticket with every signaling message is, however, inefficient. Using public-key-based mechanisms is even more inefficient when included in every signaling message. With public-key-based protection for idempotent messages, there is the additional risk of introducing denial-of-service attacks.

RSVP Pathメッセージは、特に、多数の機能を実行します。何とか冪等メッセージの配信をサポートするセキュリティ・アソシエーションの確立、効率的なメッセージ配信、およびメッセージサイズと矛盾します。例えば、「真の」冪等のシグナリングメッセージは、以前に実行されたメッセージ交換に依存せずにセキュリティ処理を実行するための十分な情報を含むであろう。すべてのシグナリングメッセージでKerberosチケットを追加すると、しかし、非効率的です。すべてのシグナリングメッセージに含まれる公開鍵ベースのメカニズムを使用することも、より非効率的です。冪等メッセージのための公開鍵ベースの保護を使用すると、サービス拒否攻撃を導入する追加的なリスクがあります。

o RSVP Path message functionality and next-hop discovery

O RSVP Pathメッセージ機能およびネクストホップ発見

To protect an RSVP signaling message (and an RSVP Path message in particular) it is necessary to know the identity of the next RSVP-aware node (and some other parameters). Without a mechanism for next-hop discovery, an RSVP Path message is also responsible for this task. Without knowing the identity of the next hop, the Kerberos principal name is also unknown. The so-called Kerberos user-to-user authentication mechanism, which would allow the receiver to trigger the process of establishing Kerberos authentication, is not supported. This issue will again be discussed in relationship with the last-hop problem.

RSVPシグナリングメッセージ(特に、RSVP Pathメッセージ)を保護するためには、次のRSVPアウェアノードの識別(およびいくつかの他のパラメータ)を知る必要があります。ネクストホップ発見のためのメカニズムがなければ、RSVP Pathメッセージも、この作業を担当しています。次のホップのアイデンティティを知らずに、Kerberosプリンシパル名も不明です。受信機は、Kerberos認証を確立するプロセスをトリガすることを可能にするいわゆるケルベロスユーザ対ユーザ認証メカニズムは、サポートされていません。この問題は、再び最終ホップ問題との関係で議論されます。

It is fair to assume that an RSVP-supporting node might not have security associations with all immediately neighboring RSVP nodes. Especially for inter-domain signaling, IntServ over DiffServ, or some new applications such as firewall signaling, the next RSVP-aware node might not be known in advance. The number of next RSVP nodes might be considerably large if they are separated by a large number of non-RSVP aware nodes. Hence, a node transmitting an RSVP Path message might experience difficulties in properly protecting the message if it serves as a mechanism to detect both the next RSVP node (i.e., Router Alert Option added to the signaling message and addressed to the destination address) and to detect route changes. It is fair to note that, in the intra- domain case with a dense distribution of RSVP nodes, protection might be possible with manual configuration.

RSVP-サポートするノードはすべて、すぐ隣のRSVPノードとのセキュリティアソシエーションを持っていない可能性がありますと仮定することが公正です。特に、ドメイン間のシグナリング、DiffServのオーバーイントサーブ、または、ファイアウォールのシグナル伝達など、いくつかの新しいアプリケーションでは、次のRSVP対応ノードは、事前に知られていない可能性があります。彼らは非RSVP意識し、多数のノードで分離されている場合は、次のRSVPノードの数がかなり大きくなる可能性があります。したがって、それは次のRSVPノードの両方を検出するための機構としての場合は、RSVP Pathメッセージを送信するノードが適切にメッセージを保護する上で問題が発生する可能性がある(すなわち、ルータ警告オプションがシグナリングメッセージに追加され、宛先アドレス宛て)とのルート変更を検出します。 RSVPノードの密な分布とイントラドメインケースには、保護が手動設定で可能であるかもしれない、ということに注意することは公平です。

Nothing prevents an adversary from continuously flooding an RSVP node with bogus PathErr messages, although it might be possible to protect the PathErr message with an existing, available security association. A legitimate RSVP node would believe that a change in the path took place. Hence, this node might try to select a different security association or try to create one with the indicated node. If an adversary is located somewhere along the path, and either authentication or authorization is not performed with the necessary strength and accuracy, then it might also be possible to act as a man-in-the-middle. One method of reducing susceptibility to this attack is as follows: when a PathErr message is received from a node with which no security association exists, attempt to establish a security association and then repeat the action that led to the PathErr message.


5.3. Last-Hop Issue
5.3. 最終ホップ問題

This section tries to address practical difficulties when authentication and key establishment are accomplished with a two-party protocol that shows some asymmetry in message processing. Kerberos is such a protocol and also the only supported protocol that provides dynamic session key establishment for RSVP. For first-hop communication, authentication is typically done between a user and some router (for example the access router). Especially in a mobile environment, it is not feasible to authenticate end hosts based on their IP or MAC address. To illustrate this problem, the typical processing steps for Kerberos are shown for first-hop communication:

このセクションでは、認証及び鍵確立は、メッセージ処理中にいくつかの非対称性を示す二者のプロトコルを用いて達成されたときに実用的な問題に対処しようとします。 Kerberosは、このようなプロトコルともRSVPの動的セッション鍵確立を提供する唯一のサポートされているプロトコルです。最初のホップ通信のために、認証は通常、ユーザと、いくつかのルータ(例えばアクセスルータ)との間で行われます。特にモバイル環境では、彼らのIPまたはMACアドレスに基づいて、エンドホストを認証することは不可能です。この問題を示すために、ケルベロスのための典型的な処理工程は、第1ホップ通信のために示されています。

(1) The end host A learns the identity (i.e., Kerberos principal name) of some entity B. This entity B is either the next RSVP node, a PDP, or the next policy-aware RSVP node.


(2) Entity A then requests a ticket granting ticket for the network domain. This assumes that the identity of the network domain is known.


(3) Entity A then requests a service ticket for entity B, whose name was learned in step (1).


(4) Entity A includes the service ticket with the RSVP signaling message (inside the policy object). The Kerberos session key is used to protect the integrity of the entire RSVP signaling message.


For last-hop communication, this processing theoretically has to be reversed: entity A is then a node in the network (for example, the access router) and entity B is the other end host (under the assumption that RSVP signaling is accomplished between two end hosts and not between an end host and an application server). However, the access router in step (1) might not be able to learn the user's principal name because this information might not be available. Entity A could reverse the process by triggering an IAKERB exchange. This would cause entity B to request a service ticket for A as described above. However, IAKERB is not supported in RSVP.


5.4. RSVP- and IPsec-Protected Data Traffic
5.4. RSVP-とIPsecで保護されたデータトラフィック

QoS signaling requires flow information to be established at routers along a path. This flow identifier installed at each device tells the router which data packets should receive QoS treatment. RSVP typically establishes a flow identifier based on the 5-tuple (source IP address, destination IP address, transport protocol type, source port, and destination port). If this 5-tuple information is not available, then other identifiers have to be used. ESP-encrypted data traffic is such an example where the transport protocol and the port numbers are not accessible. Hence, the IPsec SPI is used as a substitute for them. [12] considers these IPsec implications for RSVP and is based on three assumptions:

QoSのシグナリングは、経路に沿ってルータで確立されるフロー情報を必要とします。各デバイスに設置このフロー識別子は、データパケットがQoS処理を受信するルータに伝えます。 RSVPは、典型的には、5タプル(送信元IPアドレス、宛先IPアドレス、トランスポートプロトコルタイプ、送信元ポート、および宛先ポート)に基づいて、フロー識別子を確立します。この5タプル情報が利用できない場合は、他の識別子を使用しなければなりません。 ESP暗号化データトラフィックは、トランスポートプロトコルとポート番号にアクセスできないような例です。したがって、IPsecのSPIは、それらの代替として使用されています。 [12] RSVPのためにこれらのIPsecの影響を考慮し、3つの仮定に基づいています。

(1) An end host that initiates the RSVP signaling message exchange has to be able to retrieve the SPI for a given flow. This requires some interaction with the IPsec security association database (SAD) and security policy database (SPD) [3]. An application usually does not know the SPI of the protected flow and cannot provide the desired values. It can provide the signaling protocol daemon with flow identifiers. The signaling daemon would then need to query the SAD by providing the flow identifiers as input parameters and receiving the SPI as an output parameter.


(2) [12] assumes end-to-end IPsec protection of the data traffic. If IPsec is applied in a nested fashion, then parts of the path do not experience QoS treatment. This can be treated as a problem of tunneling that is initiated by the end host. The following figure better illustrates the problem in the case of enforcing secure network access:

(2)[12]は、データトラフィックのエンドツーエンドのIPsec保護を想定しています。 IPsecは、ネストされた方式で適用されている場合は、パスの部分は、QoS処理は発生しません。これは、エンドホストによって開始されたトンネルの問題として扱うことができます。より良い次の図は、セキュアなネットワークアクセスを施行した場合の問題を示しています。

    +------+          +---------------+      +--------+          +-----+
    | Host |          | Security      |      | Router |          | Host|
    |  A   |          | Gateway (SGW) |      |   Rx   |          |  B  |
    +--+---+          +-------+-------+      +----+---+          +--+--+
       |                      |                   |                 |
       |IPsec-Data(           |                   |                 |
       | OuterSrc=A,          |                   |                 |
       | OuterDst=SGW,        |                   |                 |
       | SPI=SPI1,            |                   |                 |
       | InnerSrc=A,          |                   |                 |
       | InnerDst=B,          |                   |                 |
       | Protocol=X,          |IPsec-Data(        |                 |
       | SrcPort=Y,           | SrcIP=A,          |                 |
       | DstPort=Z)           | DstIP=B,          |                 |
       |=====================>| Protocol=X,       |IPsec-Data(      |
       |                      | SrcPort=Y,        | SrcIP=A,        |
       | --IPsec protected->  | DstPort=Z)        | DstIP=B,        |
       |    data traffic      |------------------>| Protocol=X,     |
       |                      |                   | SrcPort=Y,      |
       |                      |                   | DstPort=Z)      |
       |                      |                   |---------------->|
       |                      |                   |                 |
       |                      |     --Unprotected data traffic--->  |
       |                      |                   |                 |

Figure 7: RSVP and IPsec protected data traffic.


Host A, transmitting data traffic, would either indicate a 3- tuple <A, SGW, SPI1> or a 5-tuple <A, B, X, Y, Z>. In any case, it is not possible to make a QoS reservation for the entire path. Two similar examples are remote access using a VPN and protection of data traffic between a home agent (or a security gateway in the home network) and a mobile node. The same problem occurs with a nested application of IPsec (for example, IPsec between A and SGW and between A and B).


One possible solution to this problem is to change the flow identifier along the path to capture the new flow identifier after an IPsec endpoint.


IPsec tunnels that neither start nor terminate at one of the signaling end points (for example between two networks) should be addressed differently by recursively applying an RSVP signaling exchange for the IPsec tunnel. RSVP signaling within tunnels is addressed in [13].


(3) It is assumed that SPIs do not change during the lifetime of the established QoS reservation. If a new IPsec SA is created, then


       a new SPI is allocated for the security association.  To reflect
       this change, either a new reservation has to be established or
       the flow identifier of the existing reservation has to be
       updated.  Because IPsec SAs usually have a longer lifetime, this
       does not seem to be a major issue.  IPsec protection of SCTP data
       traffic might more often require an IPsec SA (and SPI) change to
       reflect added and removed IP addresses from an SCTP association.
5.5. End-to-End Security Issues and RSVP
5.5. エンドツーエンドのセキュリティ問題とRSVP

End-to-end security for RSVP has not been discussed throughout the document. In this context, end-to-end security refers to credentials transmitted between the two end hosts using RSVP. It is obvious that care must be taken to ensure that routers along the path are able to process and modify the signaling messages according to prescribed processing procedures. However, some objects or mechanisms could be used for end-to-end protection. The main question, however, is the benefit of such end-to-end security. First, there is the question of how to establish the required security association. Between two arbitrary hosts on the Internet, this might turn out to be quite difficult. Second, the usefulness of end-to-end security depends on the architecture in which RSVP is deployed. If RSVP is used only to signal QoS information into the network, and other protocols have to be executed beforehand to negotiate the parameters and to decide which entity is charged for the QoS reservation, then no end-to-end security is likely to be required. Introducing end-to-end security to RSVP would then cause problems with extensions like RSVP proxy [37], Localized RSVP [38], and others that terminate RSVP signaling somewhere along the path without reaching the destination end host. Such a behavior could then be interpreted as a man-in-the-middle attack.

RSVPのためのエンドツーエンドのセキュリティは、文書を通して議論されていません。この文脈では、エンドツーエンドのセキュリティは、RSVPを使用して、2台のエンドホストとの間で送信資格情報を指します。ケア経路に沿ったルータは、所定の処理手順に従って処理し、シグナリングメッセージを修正することが可能であることを保証するために注意しなければならないことは明らかです。しかし、いくつかのオブジェクトまたは機構は、エンドツーエンドの保護のために使用することができます。主な問題は、しかし、そのようなエンドツーエンドのセキュリティの利点です。まず、必要なセキュリティアソシエーションを確立する方法についての質問があります。インターネット上の任意の二つのホスト間で、これは非常に困難であることが判明するかもしれません。第二に、エンドツーエンドのセキュリティの有用性は、RSVPが展開されているアーキテクチャに依存します。 RSVPは、ネットワークにQoS情報を通知するためにのみ使用され、他のプロトコルパラメータをネゴシエートし、QoS予約のために充電されるエンティティを決定するように事前に実行されなければならない場合は、何のエンドツーエンドのセキュリティを必要とする可能性がありません。 RSVPへのエンドツーエンドのセキュリティを導入し、次いでRSVPプロキシ[37]、ローカライズされたRSVP [38]、および宛先エンドホストに到達することなく経路に沿ってどこかにRSVPシグナリングを終了などのような拡張機能の問題を引き起こします。このような行動は、man-in-the-middle攻撃と解釈できます。

5.6. IPsec Protection of RSVP Signaling Messages
5.6. RSVPシグナリングメッセージのIPsecの保護

It is assumed throughout that RSVP signaling messages can also be protected by IPsec [3] in a hop-by-hop fashion between two adjacent RSVP nodes. RSVP, however, uses special processing of signaling messages, which complicates IPsec protection. As explained in this section, IPsec should only be used for protection of RSVP signaling messages in a point-to-point communication environment (i.e., an RSVP message can only reach one RSVP router and not possibly more than one). This restriction is caused by the combination of signaling message delivery and discovery into a single message. Furthermore, end-to-end addressing complicates IPsec handling considerably. This section describes at least some of these complications.

それは、2つの隣接するRSVPノード間のホップバイホップ方式でのIPsec [3]によっても保護することができるシグナリングメッセージをそのRSVPを通して想定されます。 RSVPは、しかし、IPsec保護を複雑にシグナリングメッセージの特殊な処理を、使用しています。このセクションで説明したように、IPsecは唯一のポイント・ツー・ポイント通信環境でRSVPシグナリングメッセージを保護するために使用されるべきである(すなわち、RSVPメッセージは、唯一のRSVPルータとしない可能性が1つ以下に達することができます)。この制限は、単一のメッセージにメッセージ配信および発見シグナリングの組合せによって引き起こされます。さらに、エンド・ツー・エンドのアドレッシング複雑にIPsecはかなり扱い。このセクションでは、これらの合併症の少なくともいくつかを説明します。

RSVP messages are transmitted as raw IP packets with protocol number 46. It might be possible to encapsulate them in UDP as described in Appendix C of [6]. Some RSVP messages (Path, PathTear, and ResvConf) must have the Router Alert IP Option set in the IP header. These messages are addressed to the (unicast or multicast) destination address and not to the next RSVP node along the path. Hence, an IPsec traffic selector can only use these fields for IPsec SA selection. If there is only a single path (and possibly all traffic along it is protected) then there is no problem for IPsec protection of signaling messages. This type of protection is not common and might only be used to secure network access between an end host and its first-hop router. Because the described RSVP messages are addressed to the destination address instead of the next RSVP node, it is not possible to use IPsec ESP [17] or AH [16] in transport mode--only IPsec in tunnel mode is possible.

RSVPメッセージは、付録Cに記載されているようにUDPでそれらをカプセル化することが可能であるかもしれないプロトコル番号46と生のIPパケットとして送信される[6]。いくつかのRSVPメッセージ(パス、PathTear、およびResvConf)は、IPヘッダに設定ルータアラートIPオプションを持っている必要があります。これらのメッセージは、(ユニキャストまたはマルチキャスト)宛先アドレスとしないパスに沿って次のRSVPノードにアドレス指定されます。したがって、IPsecトラフィックセレクタは、IPsec SAの選択のためにこれらのフィールドを使用することができます。単一パスのみ(そしておそらく、それに沿ってすべてのトラフィックが保護されています)がある場合は、シグナリングメッセージのIPsec保護のためには問題ありません。このタイプの保護は一般的ではありませんとだけエンドホストとその最初のホップルータ間のネットワークアクセスを保護するために使用される可能性があります。説明RSVPメッセージは代わりに、次のRSVPノードの宛先アドレスにアドレス指定されるので、それはトランスポート・モードのIPsec ESP [17]またはAH [16]を使用することはできません - のみのIPsecトンネルモードにすることが可能です。

If an RSVP message can taket more than one possible path, then the IPsec engine will experience difficulties protecting the message. Even if the RSVP daemon installs a traffic selector with the destination IP address, still, no distinguishing element allows selection of the correct security association for one of the possible RSVP nodes along the path. Even if it possible to apply IPsec protection (in tunnel mode) for RSVP signaling messages by incorporating some additional information, there is still the possibility that the tunneled messages do not recognize a path change in a non-RSVP router. In this case the signaling messages would simply follow a different path than the data.

RSVPメッセージは複数の可能なパスをTAKETことができた場合は、IPsecのエンジンは、メッセージを保護する難しさを経験します。 RSVPデーモンは宛先IPアドレスを持つトラフィックセレクタをインストールした場合でも、依然として、全く区別要素が経路に沿って可能なRSVPノードのいずれかの適切なセキュリティアソシエーションを選択することができません。でも、いくつかの追加情報を組み込むことによって、RSVPシグナリングメッセージのために(トンネルモードで)IPsec保護を適用することが可能な場合は、トンネリングされたメッセージが非RSVPルータにパスの変更を認識しない可能性がまだあります。この場合、シグナリングメッセージは、単にデータとは別の道をたどるだろう。

RSVP messages like RESV can be protected by IPsec, because they contain enough information to create IPsec traffic selectors that allow differentiation between various next RSVP nodes. The traffic selector would then contain the protocol number and the source and destination address pair of the two communicating RSVP nodes.


One benefit of using IPsec is the availability of key management using either IKE [39], KINK [40] or IKEv2 [41].

IPsecを使用することの1つの利点は、IKE [39]、KINK [40]またはIKEv2の[41]のいずれかを使用して鍵管理の利用可能性です。

5.7. Authorization
5.7. 認定

[34] describes two trust models (NJ Turnpike and NJ Parkway) and two authorization models (per-session and per-channel financial settlement). The NJ Turnpike model gives a justification for hop-by-hop security protection. RSVP focuses on the NJ Turnpike model, although the different trust models are not described in detail. RSVP supports the NJ Parkway model and per-channel financial settlement only to a certain extent. Authentication of the user (or end host) can be provided with the user identity representation mechanism, but authentication might, in many cases, be insufficient for authorization. The communication procedures defined for policy

[34](セッションごとのチャンネルごとの金融決済)2つの信頼モデル(NJターンパイクとNJパークウェイ)と2つの認証モデルについて簡単に説明します。 NJターンパイクモデルは、ホップバイホップのセキュリティ保護のための正当化を提供します。異なる信頼モデルが詳細に記載されていないが、RSVPは、NJターンパイクモデルに焦点を当てています。 RSVPは、ある程度までしかNJパークウェイモデルとチャンネルごとの決算をサポートしています。ユーザー(またはエンドホスト)の認証は、ユーザーのアイデンティティの表現機構を備えることができますが、認証は、多くの場合、認証には不十分かもしれません。ポリシーに定義された通信手順

objects [42] can be improved to support the more efficient per-channel financial settlement model by avoiding policy handling between inter-domain networks at a signaling message granularity. Additional information about expected behavior of policy handling in RSVP can also be obtained from [43].

オブジェクト[42]は、シグナリングメッセージの単位でドメイン間のネットワーク間のポリシーの取り扱いを避けることによって、より効率的なチャネルごとの金融決済モデルをサポートするように改善することができます。 RSVPの取り扱いポリシーの予想される動作についての追加情報は、[43]から得ることができます。

[35] and [36] provide additional information on authorization. No good and agreed mechanism for dealing with authorization of QoS reservations in roaming environments is provided. Price distribution mechanisms are only described in papers and never made their way through standardization. RSVP focuses on receiver-initiated reservations with authorization for the QoS reservation by the data receiver, which introduces a fair amount of complexity for mobility handling as described, for example, in [36].

[35]及び[36]認可に関する追加情報を提供します。ローミング環境でのQoS予約の承認を扱うには良いと合意されたメカニズムが提供されていません。価格配布メカニズムはのみの論文に記載されており、標準化を介して自分の道を作ったことはありません。 RSVPは、[36]において、例えば、記載されているようにモビリティ処理のための複雑さのかなりの量を導入し、データ受信機によってQoS予約のために許可して受信器で開始予約に焦点を当てています。

6. Conclusions

RSVP was the first QoS signaling protocol that provided some security protection. Whether RSVP provides appropriate security protection heavily depends on the environment where it is deployed. RSVP as specified today should be viewed as a building block that has to be adapted to a given architecture.

RSVPは、いくつかのセキュリティ保護を提供するシグナリングプロトコル最初のQoSでした。 RSVPは、適切なセキュリティ保護を提供するかどうかを頻繁にそれが展開されている環境に依存します。今日指定されたRSVPは、与えられたアーキテクチャに適合させなければならないビルディングブロックとして表示する必要があります。

This document aims to provide more insight into the security of RSVP. It cannot be interpreted as a pass or fail evaluation of the security provided by RSVP.


Certainly this document is not a complete description of all security issues related to RSVP. Some issues that require further consideration are RSVP extensions (for example [12]), multicast issues, and other security properties like traffic analysis. Additionally, the interaction with mobility protocols (micro- and macro-mobility) demands further investigation from a security point of view.


What can be learned from practical protocol experience and from the increased awareness regarding security is that some of the available credential types have received more acceptance than others. Kerberos is a system that is integrated into many IETF protocols today. Public-key-based authentication techniques are, however, still considered to be too heavy-weight (computationally and from a bandwidth perspective) to be used for per-flow signaling. The increased focus on denial of service attacks puts additional demands on the design of public-key-based authentication.

どのような実用的なプロトコルの経験からして、セキュリティに関する意識向上から学ぶことができると、使用可能なクレデンシャルタイプのいくつかは他のものより承認を受けているということです。 Kerberosは、今日、多くのIETFプロトコルに統合されたシステムです。公開鍵ベースの認証技術は、しかしながら、依然としてあまりにも重い(計算及び帯域幅の観点から)あたりフローシグナリングのために使用することがあると考えられます。サービス拒否攻撃の増加焦点は、公開鍵ベースの認証の設計上の追加の要求を置きます。

The following list briefly summarizes a few security or architectural issues that deserve improvement:


o Discovery and signaling message delivery should be separated.


o For some applications and scenarios, it cannot be assumed that neighboring RSVP-aware nodes know each other. Hence, some in-path discovery mechanism should be provided.


o Addressing for signaling messages should be done in a hop-by-hop fashion.


o Standard security protocols (IPsec, TLS, or CMS) should be used whenever possible. Authentication and key exchange should be separated from signaling message protection. In general, it is necessary to provide key management to establish security associations dynamically for signaling message protection. Relying on manually configured keys between neighboring RSVP nodes is insufficient. A separate, less frequently executed key management and security association establishment protocol is a good place to perform entity authentication, security service negotiation and selection, and agreement on mechanisms, transforms, and options.


o The use of public key cryptography in authorization tokens, identity representations, selective object protection, etc. is likely to cause fragmentation, the need to protect against denial of service attacks, and other problems.


o Public key authentication and user identity confidentiality provided with RSVP require some improvement.

O RSVPを提供する公開鍵認証とユーザー識別情報の機密性は、いくつかの改善が必要です。

o Public-key-based user authentication only provides entity authentication. An additional security association is required to protect signaling messages.


o Data origin authentication should not be provided by non-RSVP nodes (such as the PDP). Such a procedure could be accomplished by entity authentication during the authentication and key exchange phase.


o Authorization and charging should be better integrated into the base protocol.


o Selective message protection should be provided. A protected message should be recognizable from a flag in the header.


o Confidentiality protection is missing and should therefore be added to the protocol. The general principle is that protocol designers can seldom foresee all of the environments in which protocols will be run, so they should allow users to select from a full range of security services, as the needs of different user communities vary.


o Parameter and mechanism negotiation should be provided.


7. Security Considerations

This document discusses security properties of RSVP and, as such, it is concerned entirely with security.


8. Acknowledgements

We would like to thank Jorge Cuellar, Robert Hancock, Xiaoming Fu, Guenther Schaefer, Marc De Vuyst, Bob Grillo, and Jukka Manner for their comments. Additionally, Hannes would like to thank Robert and Jorge for their time discussing various issues.


Finally, we would like to thank Allison Mankin and John Loughney for their guidance and input.


9. References
9.1. Normative References
9.1. 引用規格

[1] Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic Authentication", RFC 2747, January 2000.

[1]ベーカー、F.、リンデル、B.、およびM. Talwar、 "RSVP暗号化認証"、RFC 2747、2000年1月。

[2] Herzog, S., "RSVP Extensions for Policy Control", RFC 2750, January 2000.

[2]ヘルツォーク、S.、 "ポリシー制御のためのRSVP拡張機能"、RFC 2750、2000年1月。

[3] Kent, S. and R. Atkinson, "Security Architecture for the Internet Protocol", RFC 2401, November 1998.

[3]ケント、S.とR.アトキンソン、 "インターネットプロトコルのためのセキュリティー体系"、RFC 2401、1998年11月。

[4] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-Hashing for Message Authentication", RFC 2104, February 1997.

[4] Krawczyk、H.、ベラー、M.、およびR.カネッティ、 "HMAC:メッセージ認証のための鍵付きハッシュ化"、RFC 2104、1997年2月。

[5] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, April 1992.

[5]のRivest、R.、 "MD5メッセージダイジェストアルゴリズム"、RFC 1321、1992年4月。

[6] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997.

[6]ブレーデン、B.、チャン、L.、Berson氏、S.、ハーツォグ、S.、およびS.ヤミン、 "リソース予約プロトコル(RSVP) - バージョン1機能仕様"、RFC 2205、1997年9月。

[7] Yadav, S., Yavatkar, R., Pabbati, R., Ford, P., Moore, T., Herzog, S., and R. Hess, "Identity Representation for RSVP", RFC 3182, October 2001.

[7] Yadavが、S.、Yavatkar、R.、Pabbati、R.、フォード、P.、ムーア、T.、ヘルツォーク、S.、およびR.ヘス、 "RSVPのID表現"、RFC 3182、2001年10月。

[8] Kohl, J. and C. Neuman, "The Kerberos Network Authentication Service (V5)", RFC 1510, September 1993. Obsoleted by RFC 4120.

[8]コールズ、J.及びC.ノイマン、 "ケルベロスネットワーク認証サービス(V5)"、RFC 1510、1993年9月は、RFC 4120によって時代遅れ。

[9] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003.

[9]カルフーン、P.、Loughney、J.、ガットマン、E.、ゾルン、G.、およびJ. Arkko、 "直径ベースプロトコル"、RFC 3588、2003年9月。

[10] Durham, D., Boyle, J., Cohen, R., Herzog, S., Rajan, R., and A. Sastry, "The COPS (Common Open Policy Service) Protocol", RFC 2748, January 2000.

[10]ダラム、D.、ボイル、J.、コーエン、R.、ヘルツォーク、S.、ラジャン、R.、およびA. Sastry、 "COPS(共通オープンポリシーサービス)プロトコル"、RFC 2748、2000年1月。

[11] Herzog, S., Boyle, J., Cohen, R., Durham, D., Rajan, R., and A. Sastry, "COPS usage for RSVP", RFC 2749, January 2000.

[11]ヘルツォーク、S.、ボイル、J.、コーエン、R.、ダラム、D.、ラジャン、R.、およびA. Sastry、RFC 2749、2000年1月 "RSVPの使用は、COPS"。

[12] Berger, L. and T. O'Malley, "RSVP Extensions for IPSEC Data Flows", RFC 2207, September 1997.

[12]バーガー、L.とT.オマリー、 "IPSECデータフローのためのRSVP拡張機能"、RFC 2207、1997年9月。

[13] Terzis, A., Krawczyk, J., Wroclawski, J., and L. Zhang, "RSVP Operation Over IP Tunnels", RFC 2746, January 2000.

[13] Terzis、A.、Krawczyk、J.、Wroclawski、J.、およびL.チャン、 "RSVP操作オーバーIPトンネル"、RFC 2746、2000年1月。

9.2. Informative References
9.2. 参考文献

[14] Hess, R. and S. Herzog, "RSVP Extensions for Policy Control", Work in Progress, June 2001.

[14]ヘス、R.とS.ヘルツォーク、 "ポリシー制御のためのRSVP拡張機能"、進歩、2001年6月での作業。

[15] "Secure Hash Standard, NIST, FIPS PUB 180-1", Federal Information Processing Society, April 1995.

[15] "セキュアハッシュ標準、NIST、FIPS PUB 180-1の"、連邦情報処理学会、1995年4月。

[16] Kent, S. and R. Atkinson, "IP Authentication Header", RFC 2402, November 1998.

[16]ケント、S.とR.アトキンソン、 "IP認証ヘッダー"、RFC 2402、1998年11月。

[17] Kent, S. and R. Atkinson, "IP Encapsulating Security Payload (ESP)", RFC 2406, November 1998.

[17]ケント、S.とR.アトキンソン、 "IPカプセル化セキュリティペイロード(ESP)"、RFC 2406、1998年11月。

[18] Fowler, D., "Definitions of Managed Objects for the DS1, E1, DS2 and E2 Interface Types", RFC 2495, January 1999.

[18]ファウラー、D.、RFC 2495、1999年1月 "DS1、E1、DS2およびE2インターフェイスのタイプのための管理オブジェクトの定義"。

[19] Callas, J., Donnerhacke, L., Finney, H., and R. Thayer, "OpenPGP Message Format", RFC 2440, November 1998.

[19]カラス、J.、Donnerhacke、L.、フィニー、H.、およびR.セイヤー、 "OpenPGPのメッセージフォーマット"、RFC 2440、1998年11月。

[20] Hornstein, K. and J. Altman, "Distributing Kerberos KDC and Realm Information with DNS", Work in Progress, July 2002.

[20] Hornstein、K.とJ.アルトマン、 "DNSと配布のKerberos KDCとレルム情報"、進歩、2002年7月の作業。

[21] Dobbertin, H., Bosselaers, A., and B. Preneel, "RIPEMD-160: A strengthened version of RIPEMD in Fast Software Encryption", LNCS vol. 1039, pp. 71-82, 1996.

[21] Dobbertin、H.、Bosselaers、A.およびB. Preneel、 "RIPEMD-160:高速ソフトウェア暗号化にRIPEMDの強化バージョン"、LNCS体積。 1039年、頁71-82、1996。

[22] Dobbertin, H., "The Status of MD5 After a Recent Attack", RSA Laboratories CryptoBytes, vol. 2, no. 2, 1996.

[22] Dobbertin、H.、 "最近の攻撃の後MD5の状況"、RSA研究所CryptoBytes、巻。 2、ありません。 2、1996。

[23] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H. Levkowetz, "Extensible Authentication Protocol (EAP)", RFC 3748, June 2004.

[23] Aboba、B.、ブルンク、L.、Vollbrecht、J.、カールソン、J.、およびH. Levkowetz、 "拡張認証プロトコル(EAP)"、RFC 3748、2004年6月。

[24] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000.

、RFC 2865、2000年6月 "ユーザーサービス(RADIUS)においてリモート認証ダイヤルイン" [24] Rigney、C.、ウィレンス、S.、ルーベン、A.、およびW.シンプソン。

[25] "Microsoft Authorization Data Specification v. 1.0 for Microsoft Windows 2000 Operating Systems", April 2000.

[25]の "Microsoft Windows 2000オペレーティングシステム用のMicrosoft認証データ仕様V 1.0"、2000年4月。

[26] Cable Television Laboratories, Inc., "PacketCable Security Specification, PKT-SP-SEC-I01-991201", website:, June 2003.

[26]ケーブルテレビラボラトリーズ社、 "PacketCableのセキュリティ仕様、PKT-SP-SEC-I01-991201"、ウェブサイト:、2003年6月。

[27] Myers, M., Ankney, R., Malpani, A., Galperin, S., and C. Adams, "X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP", RFC 2560, June 1999.

[27]マイヤーズ、M.、Ankney、R.、Malpani、A.、Galperin、S.、およびC.アダムス、 "X.509のインターネット公開鍵暗号基盤のオンライン証明書状態プロトコル - OCSP"、RFC 2560、1999年6月。

[28] Malpani, A., Housley, R., and T. Freeman, "Simple Certificate Validation Protocol (SCVP)", Work in Progress, October 2005.

[28] Malpani、A.、Housley氏、R.、およびT.フリーマン、 "簡単な証明書の検証プロトコル(SCVP)"、進歩、2005年10月に作業。

[29] Housley, R., "Cryptographic Message Syntax (CMS)", RFC 3369, August 2002.

[29] Housley氏、R.、 "暗号メッセージ構文(CMS)"、RFC 3369、2002年8月。

[30] Kaliski, B., "PKCS #7: Cryptographic Message Syntax Version 1.5", RFC 2315, March 1998.

[30] Kaliski、B.、 "PKCS#7:暗号メッセージ構文バージョン1.5"、RFC 2315、1998年3月。

[31] "Specifications and standard documents", website:, March 2002.

[31] "仕様と標準文書"、ウェブサイト:、2002年3月。

[32] Davis, D. and D. Geer, "Kerberos With Clocks Adrift: History, Protocols and Implementation", USENIX Computing Systems, vol 9 no. 1, Winter 1996.

[32]デイビス、D.およびD.ギヤー、「ケルベロスとクロック漂流:歴史、プロトコル及び実装」、USENIXコンピューティングシステム、巻9ありません。 1、冬1996。

[33] Raeburn, K., "Encryption and Checksum Specifications for Kerberos 5", RFC 3961, February 2005.

[33]レイバーン、K.、 "暗号化とケルベロス5チェックサムの仕様"、RFC 3961、2005年2月。

[34] Tschofenig, H., Buechli, M., Van den Bosch, S., and H. Schulzrinne, "NSIS Authentication, Authorization and Accounting Issues", Work in Progress, March 2003.

[34] Tschofenig、H.、Buechli、M.、ヴァン・デン・ボッシュ、S.、およびH. Schulzrinneと、 "NSIS認証、認可および会計問題"、進歩、2003年3月での作業。

[35] Tschofenig, H., Buechli, M., Van den Bosch, S., Schulzrinne, H., and T. Chen, "QoS NSLP Authorization Issues", Work in Progress, June 2003.

[35] Tschofenig、H.、Buechli、M.、ヴァン・デン・ボッシュ、S.、Schulzrinneと、H.、およびT.チェン、 "QoSのNSLP認可の問題"、進歩、2003年6月に作業。

[36] Thomas, M., "Analysis of Mobile IP and RSVP Interactions", Work in Progress, October 2002.

、進歩、2002年10月に作業[36]トーマス、M.、 "モバイルIPおよびRSVP相互作用の分析"。

[37] Gai, S., Gaitonde, S., Elfassy, N., and Y. Bernet, "RSVP Proxy", Work in Progress, March 2002.

[37]ガイ、S.、Gaitonde、S.、Elfassy、N.、およびY. Bernet、 "プロキシをRSVP"、進歩、2002年3月での作業。

[38] Manner, J., Suihko, T., Kojo, M., Liljeberg, M., and K. Raatikainen, "Localized RSVP", Work in Progress, September 2004.

[38]ようにして、J.、Suihko、T.、古城、M.、Liljeberg、M.、およびK. Raatikainen、 "ローカライズRSVP"、進歩、2004年9月ワーク。

[39] Harkins, D. and D. Carrel, "The Internet Key Exchange (IKE)", RFC 2409, November 1998.

[39]ハーキンズ、D.とD.カレル、 "インターネットキー交換(IKE)"、RFC 2409、1998年11月。

[40] Thomas, M., "Kerberized Internet Negotiation of Keys (KINK)", Work in Progress, October 2005.

[40]トーマス、M.、 "キーのKerberos対応インターネット交渉(KINK)"、進歩、2005年10月に作業。

[41] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", RFC 4306, November 2005.

[41]カウフマン、C.、 "インターネットキーエクスチェンジ(IKEv2の)プロトコル"、RFC 4306、2005年11月。

[42] Herzog, S., "Accounting and Access Control in RSVP", PhD Dissertation, USC, Work in Progress, November 1995.

[42]ヘルツォーク、S.、 "会計とRSVPでのアクセス制御"、博士論文、USC、進歩、1995年11月での作業。

[43] Herzog, S., "Accounting and Access Control for Multicast Distributions: Models and Mechanisms", June 1996.


[44] Pato, J., "Using Pre-Authentication to Avoid Password Guessing Attacks", Open Software Foundation DCE Request for Comments, December 1992.


[45] Tung, B. and L. Zhu, "Public Key Cryptography for Initial Authentication in Kerberos", Work in Progress, November 2005.


[46] Wu, T., "A Real-World Analysis of Kerberos Password Security", in Proceedings of the 1999 Internet Society Network and Distributed System Security Symposium, San Diego, February 1999.

[46] 1999インターネット協会ネットワークと分散システムセキュリティシンポジウム、サンディエゴ、1999年2月の議事録では呉、T.、「ケルベロスパスワードセキュリティの実世界の解析」、。

[47] Wu, T., Wu, F., and F. Gong, "Securing QoS: Threats to RSVP Messages and Their Countermeasures", IEEE IWQoS, pp. 62-64, 1999.

[47]呉、T.、ウー、F.、及びF.ゴング、 "QoSの確保:メッセージのRSVPへの脅威とその対策"、IEEE IWQoS、PPの62-64、1999。

[48] Talwar, V., Nahrstedt, K., and F. Gong, "Securing RSVP For Multimedia Applications", Proc ACM Multimedia 2000 (Multimedia Security Workshop), November 2000.

[48] Talwar、V.、Nahrstedt、K.、およびF.ゴング、 "マルチメディアアプリケーションのために確保RSVP"、PROC ACMマルチメディア2000(マルチメディアセキュリティワークショップ)、2000年11月。

[49] Talwar, V., Nahrstedt, K., and S. Nath, "RSVP-SQoS: A Secure RSVP Protocol", International Conf on Multimedia and Exposition, Tokyo, Japan, August 2001.

[49] Talwar、V.、Nahrstedt、K.、およびS.ナス、 "RSVP-SQoS:セキュアRSVPプロトコル"、マルチメディアおよび博覧会、東京、日本、2001年8月に国際コンファレンス。

[50] Jablon, D., "Strong Password-only Authenticated Key Exchange", ACM Computer Communication Review, 26(5), pp. 5-26, October 1996.

[50] Jablon、D.、 "強力なパスワードのみの認証鍵交換"、ACMコンピュータコミュニケーションレビュー、26(5)、頁5-26、1996年10月。

Appendix A. Dictionary Attacks and Kerberos


Kerberos might be used with RSVP as described in this document. Because dictionary attacks are often mentioned in relationship with Kerberos, a few issues are addressed here.


The initial Kerberos AS_REQ request (without pre-authentication, without various extensions, and without PKINIT) is unprotected. The response message AS_REP is encrypted with the client's long-term key. An adversary can take advantage of this fact by requesting AS_REP messages to mount an off-line dictionary attack. Pre-authentication ([44]) can be used to reduce this problem. However, pre-authentication does not entirely prevent dictionary attacks by an adversary who can still eavesdrop on Kerberos messages along the path between a mobile node and a KDC. With mandatory pre-authentication for the initial request, an adversary cannot request a Ticket Granting Ticket for an arbitrary user. On-line password guessing attacks are still possible by choosing a password (e.g., from a dictionary) and then transmitting an initial request that includes a pre-authentication data field. An unsuccessful authentication by the KDC results in an error message and thus gives the adversary a hint to restart the protocol and try a new password.

(事前認証なし、様々な拡張せず、そしてPKINITなし)初期のKerberos AS_REQ要求が保護されていません。応答メッセージAS_REPは、クライアントの長期的な鍵で暗号化されています。敵はオフライン辞書攻撃を仕掛けるためにAS_REPメッセージを要求することで、この事実を利用することができます。事前認証([44])は、この問題を軽減するために使用することができます。しかし、事前認証は完全にまだ移動ノードとKDCとの間の経路に沿ってケルベロスメッセージを盗聴することができます敵で辞書攻撃を防ぐことはできません。最初の要求のための必須事前認証では、敵対者は、任意のユーザーのチケット許可チケットを要求することはできません。オンラインでパスワード推測攻撃が(辞書から、例えば)パスワードを選択した後、事前認証データフィールドを含む最初の要求を送信することは可能です。 KDCによって認証失敗は、エラーメッセージになり、したがって、敵にプロトコルを再起動し、新しいパスワードをしようとするヒントを提供します。

There are, however, some proposals that prevent dictionary attacks. The use of Public Key Cryptography for initial authentication [45] (PKINIT) is one such solution. Other proposals use strong-password-based authenticated key agreement protocols to protect the user's password during the initial Kerberos exchange. [46] discusses the security of Kerberos and also discusses mechanisms to prevent dictionary attacks.

辞書攻撃を防ぐため、いくつかの提案は、しかし、があります。初期認証[45](PKINIT)の公開鍵暗号の使用は、そのような解決策です。他の提案は、最初のKerberos交換中にユーザーのパスワードを保護するために、強力なパスワードベースの認証済み鍵合意プロトコルを使用します。 [46]ケルベロスのセキュリティについて説明し、また、辞書攻撃を防止するための機構を議論します。

Appendix B. Example of User-to-PDP Authentication


The following Section describes an example of user-to-PDP authentication. Note that the description below is not fully covered by the RSVP specification and hence it should only be viewed as an example.


Windows 2000, which integrates Kerberos into RSVP, uses a configuration with the user authentication to the PDP as described in [25]. The steps for authenticating the user to the PDP in an intra-realm scenario are the following:

RSVPにKerberosを統合Windows 2000は、[25]に記載のようにPDPにユーザー認証とコンフィギュレーションを使用します。イントラ領域シナリオでPDPにユーザを認証するための手順は以下の通りであります:

o Windows 2000 requires the user to contact the KDC and to request a Kerberos service ticket for the PDP account AcsService in the local realm.

O Windows 2000はKDCに連絡し、地元の分野におけるPDPアカウントAcsServiceのKerberosサービスチケットを要求するユーザーが必要です。

o This ticket is then embedded into the AUTH_DATA element and included in either the PATH or the RESV message. In the case of Microsoft's implementation, the user identity encoded as a distinguished name is encrypted with the session key provided with the Kerberos ticket. The Kerberos ticket is sent without the Kerberos authdata element that contains authorization information, as explained in [25].

Oこのチケットは次に、AUTH_DATA要素に埋め込まれ、PATHまたはRESVメッセージのいずれかに含まれています。 Microsoftの実装の場合は、識別名として符号化されたユーザーIDは、Kerberosチケットを提供したセッション鍵で暗号化されています。 [25]で説明したように、Kerberosチケットは、認証情報が含まれているケルベロスauthdata要素なしで送信されます。

o The RSVP message is then intercepted by the PEP, which forwards it to the PDP. [25] does not state which protocol is used to forward the RSVP message to the PDP.

O RSVPメッセージは、次いでPDPに転送PEPによってインターセプトされます。 [25] PDPにRSVPメッセージを転送するために使用されるプロトコルステートありません。

o The PDP that finally receives the message and decrypts the received service ticket. The ticket contains the session key used by the user's host to

最後にメッセージを受信し、受信したサービスチケットを復号化PDP O。チケットは、ユーザへのホストによって使用されるセッションキーが含まれています

* Encrypt the principal name inside the policy locator field of the AUTH_DATA object and to

* AUTH_DATAオブジェクトのポリシーロケータフィールド内とするプリンシパル名を暗号化

* Create the integrity-protected Keyed Message Digest field in the INTEGRITY object of the POLICY_DATA element. The protection described here is between the user's host and the PDP. The RSVP INTEGRITY object on the other hand is used to protect the path between the user's host and the first-hop router, because the two message parts terminate at different nodes, and different security associations must be used. The interface between the message-intercepting, first-hop router and the PDP must be protected as well.

* POLICY_DATA要素のINTEGRITYオブジェクトに整合性が保護キー付きメッセージダイジェストフィールドを作成します。ここで説明した保護は、ユーザーのホストとPDPの間です。一方、RSVPのINTEGRITYオブジェクトは、2つのメッセージ部分は異なるノードで終端しているため、ユーザのホストと第一ホップルータとの間のパスを保護するために使用され、異なるセキュリティアソシエーションを使用しなければなりません。メッセージインターセプト、最初のホップルータとPDPとの間のインターフェースは、同様に保護されなければなりません。

* The PDP does not maintain a user database, and [25] describes how the PDP may query the Active Directory (a LDAP based directory service) for user policy information.

* PDPは、ユーザーのデータベースを維持しないと、[25]はPDPがユーザーポリシー情報をActive Directory(LDAPベースのディレクトリサービス)を照会することができる方法を説明します。

Appendix C. Literature on RSVP Security


Few documents address the security of RSVP signaling. This section briefly describes some important documents.


Improvements to RSVP are proposed in [47] to deal with insider attacks. Insider attacks are caused by malicious RSVP routers that modify RSVP signaling messages in such a way that they cause harm to the nodes participating in the signaling message exchange.


As a solution, non-mutable RSVP objects are digitally signed by the sender. This digital signature is added to the RSVP PATH message. Additionally, the receiver attaches an object to the RSVP RESV message containing a "signed" history. This value allows intermediate RSVP routers (by examining the previously signed value) to detect a malicious RSVP node.

解決策として、非可変のRSVPオブジェクトは、デジタル送信者によって署名されています。このデジタル署名は、RSVP PATHメッセージに付加されます。また、受信機は、「署名済み」履歴を含むRSVP RESVメッセージにオブジェクトを添付する。この値は、悪意のあるRSVPノードを検出するために(以前に符号付きの値を調べることによって)、中間RSVPルータを可能にします。

A few issues are, however, left open in this document. Replay attacks are not covered, and it is therefore assumed that timestamp-based replay protection is used. To identify a malicious node, it is necessary that all routers along the path are able to verify the digital signature. This may require a global public key infrastructure and also client-side certificates. Furthermore, the bandwidth and computational requirements to compute, transmit, and verify digital signatures for each signaling message might place a burden on a real-world deployment.


Authorization is not considered in the document, which might have an influence on the implications of signaling message modification. Hence, the chain-of-trust relationship (or this step in a different direction) should be considered in relationship with authorization.


In [48], the above-described idea of detecting malicious RSVP nodes is improved by addressing performance aspects. The proposed solution is somewhere between hop-by-hop security and the approach in [47], insofar as it separates the end-to-end path into individual networks. Furthermore, some additional RSVP messages (e.g., feedback messages) are introduced to implement a mechanism called "delayed integrity checking." In [49], the approach presented in [48] is enhanced.

[48]において、悪意のあるRSVPノードを検出する上述の考え方は、性能面をアドレス指定することによって改善されます。提案された解決策は、それが個々のネットワークへのエンドツーエンドパスを分離する限り、ホップバイホップセキュリティおよび[47]におけるアプローチの間のどこかです。さらに、いくつかの追加のRSVPメッセージが(例えば、フィードバックメッセージ)と呼ばれるメカニズムを実装するために導入されている「遅延の整合性チェックを。」 [49]では、[48]に提示アプローチが強化されています。

Authors' Addresses


Hannes Tschofenig Siemens Otto-Hahn-Ring 6 Munich, Bavaria 81739 Germany




Richard Graveman RFG Security 15 Park Avenue Morristown, NJ 07960 USA

リチャードGraveman RFGセキュリティ15パークアベニューモリスタウン、NJ 07960 USA



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