Network Working Group D. Moffat Internet-Draft Sun Microsystems Expires: June 10, 2002 December 10, 2001 SSH Agent Forwarding draft-ietf-secsh-agent-00.txt # 訳者 春山征吾 haruyama@unixuser.org Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on June 10, 2002. Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. Abstract 概要 SSH is a protocol for secure remote login and other secure network services over an insecure network. One of the common authentication mechanisms used with SSH is public key. This document describes the authentication agent forwarding protocol, which runs as a channel over [SSH-TRANS] it is designed to ensure that the sensitive private keys never leave the users control even when using SSH to login over multiple hops. SSH は, 安全ではないネットワーク越しの, 安全なリモートログイン及び他の 安全なネットワークサービスのためのプロトコルだ. SSH で用いられる 共通の認証メカニズムの 1 つが公開鍵だ. この文書では [SSH-TRANS] の上のチャンネルとして働く認証エージェントの 転送プロトコルを記述する. これは, SSH を用いた複数のホップ越しのログインをしているときでさえ センシティブな秘密鍵が ユーザの制御から決して離れないことを 保証するよう設計されている. Moffat Expires June 10, 2002 [Page 1] Internet-Draft SSH Agent Forwarding December 2001 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 Agent Operations . . . . . . . . . . . . . . . . . . . . . . . 3 2. Security Considerations . . . . . . . . . . . . . . . . . . . 3 3. Additional Information . . . . . . . . . . . . . . . . . . . . 4 References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 4 Full Copyright Statement . . . . . . . . . . . . . . . . . . . 5 Moffat Expires June 10, 2002 [Page 2] Internet-Draft SSH Agent Forwarding December 2001 1. Introduction 1. イントロダクション This protocol is designed to facilitate an ad hoc secure single sign on mechanism using the SSH protocol. A typical scenario is that a user has their private keys stored on their laptop (host A) and uses the SSH protocol to remotely connect to their corporate VPN (host B) access point. Then uses further SSH connections to reach a specific host (host C) within the enterprise network. このプロトコルは SSH プロトコルを使ったメカニズムにおいての アドホックな安全な一回のサインを楽にするように設計されている. 典型的なシナリオは, ユーザがラップトップマシン (ホスト A) に 秘密鍵を格納していて, 共同の VPN アクセスポイント (ホスト B) に SSH プロトコルを使ってリモート接続することだ. そして, 会社のネットワークの中の特定のホスト (ホスト C) に 繋ぐのにさらなる SSH 接続を使う. Without agent forwarding the user is required to have a copy of their private key on host A and host B so that the connection to host C can be made using public key authentication. The key pairs used for the host A to B and the host B to C connection maybe the same but this is not always the case. エージェントの転送なしでは, ユーザは 公開鍵認証を使って hostC と接続するために ホスト A と ホスト B に秘密鍵のコピーを置く必要がある. ホスト A から B へと ホスト B から C への接続で使われる鍵のペアは おそらく同じだ. いつもそうではないが. This presents a security risk since the users private key (s) must be stored on host B which is likely to be a host the end user is not in control of even though they do trust it. It is likely that the private keys on host A and host B are stored in an encrypted format, this means the user has at least two passwords to enter to make the connection from A to C. これはセキュリティの危険を招く. たとえエンドユーザが信頼していてもそれを管理下にはおいていない と思われるホスト B にユーザの秘密鍵を格納しなけれ ばならないからだ. ホスト A と B に置かれる秘密鍵は 暗号化された形式で格納されるだろう. だから, ユーザは, A から C に接続するために少なくとも 2 回パスワード (パスフレーズ) を を入力することになる. Ideally the private keys should remain on a device in the direct control of the end user (host A in this example) and all encryption and signing operations involving the private key should be performed on this device, regardless of the location of the entity requesting the operation. 理想的には, 秘密鍵はエンドユーザの直接の管理下にあるデバイス (この例では ホスト A) だけにあるべきで, その秘密鍵によるすべての暗号化と署名の操作 は, その操作を実際に要求する場所にかかわらず, このデバイス上で行なわれるべきである. 1.1 Agent Operations 1.1 エージェントの操作 The following interactions with the agent are requried: ADD, DELETE, LIST, SIGN. エージェントとの次の相互作用が必要とされる: ADD, DELETE, LIST, SIGN. An agent implementation MUST support requests to forward operations using all public key types, defined in [SSH-USERAUTH] even those that the implementation doesn't support natively. エージェントの実装は, [SSH-USERAUTH] で定義されているすべての公開鍵の 種類を使った操作の転送要求をサポートしなければならない. たとえそれらが実装でネイティヴにサポートされていなくても. 2. Security Considerations 2. セキュリティに関する考察 This protocol is designed only to run as a channel of the SSH protocol. このプロトコルは SSH プロトコルのチャンネルとして動かすため だけに設計されている. The goal of this extension is to ensure that the users private keys never leave the machine they are physically at. Ideally the private keys should be stored on a password protected removable media such as a smartcard. この拡張の目標は, ユーザの秘密鍵が, 決して マシンに物理的に存在しないようにすることを保証することだ. 理想的には, 秘密鍵はスマートカードのようなパスワードで保護された リムーバブルメディアに格納されるべきだ. Moffat Expires June 10, 2002 [Page 3] Internet-Draft SSH Agent Forwarding December 2001 3. Additional Information The current document editor is: Darren.Moffat@Sun.COM. Comments on this internet draft should be sent to the IETF SECSH working group, details at: http://ietf.org/html.charters/secsh-charter.html References [FIPS-186] Federal Information Processing Standards Publication, ., "FIPS PUB 186, Digital Signature Standard", May 1994. [SSH-ARCH] Ylonen, T., "SSH Protocol Architecture", I-D draft- ietf-architecture-11.txt, July 2001. [SSH-TRANS] Ylonen, T., "SSH Transport Layer Protocol", I-D draft-ietf-transport-11.txt, July 2001. [SSH-USERAUTH] Ylonen, T., "SSH Authentication Protocol", I-D draft- ietf-userauth-13.txt, July 2001. [SSH-CONNECT] Ylonen, T., "SSH Connection Protocol", I-D draft- ietf-connect-14.txt, July 2001. Author's Address Darren J Moffat Sun Microsystems 901 San Antonio Road Palo Alto 94303 USA EMail: Darren.Moffat@Sun.COM Moffat Expires June 10, 2002 [Page 4] Internet-Draft SSH Agent Forwarding December 2001 Full Copyright Statement Copyright (C) The Internet Society (2001). All Rights Reserved. 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