From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Fri Sep 01 04:10:46 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GJ46w-0002Q9-KC for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 01 Sep 2006 04:10:46 -0400 Received: from mail.netbsd.org ([204.152.190.11]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GJ46v-0005GO-0N for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 01 Sep 2006 04:10:46 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 3A47A63B352; Fri, 1 Sep 2006 08:10:37 +0000 (UTC) X-Original-To: ietf-ssh@NetBSD.org Delivered-To: ietf-ssh@NetBSD.org Received: from mail.siliconcircus.com (mail.siliconcircus.com [62.141.33.102]) by mail.netbsd.org (Postfix) with ESMTP id AA99063B141 for ; Fri, 1 Sep 2006 08:10:32 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by mail.siliconcircus.com (Postfix) with ESMTP id B675B10A820; Fri, 1 Sep 2006 10:10:15 +0200 (CEST) Message-ID: <44F7EB3E.3070400@siliconcircus.com> Date: Fri, 01 Sep 2006 10:11:42 +0200 From: Jon Bright Organization: Silicon Circus Ltd. User-Agent: Thunderbird 1.5.0.5 (Windows/20060719) MIME-Version: 1.0 To: internet-drafts@ietf.org, ietf-ssh@NetBSD.org Subject: Submission: draft-ietf-secsh-publickey-subsystem-07.txt Content-Type: multipart/mixed; boundary="------------050806050506090103090902" Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.0 (/) X-Scan-Signature: f8016721885e9f48a0dd7262438d909a This is a multi-part message in MIME format. --------------050806050506090103090902 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hi, Please publish the attached draft-ietf-secsh-publickey-subsystem-07.txt Thanks, -- Jon Bright Silicon Circus Ltd. http://www.siliconcircus.com --------------050806050506090103090902 Content-Type: text/plain; name="draft-ietf-secsh-publickey-subsystem-07.txt" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="draft-ietf-secsh-publickey-subsystem-07.txt" Secure Shell Working Group J. Galbraith Internet-Draft J. Van Dyke Intended status: Informational B. McClure Expires: March 5, 2007 VanDyke Software J. Bright Silicon Circus September 1, 2006 Secure Shell Public-Key Subsystem draft-ietf-secsh-publickey-subsystem-07.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 March 5, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Galbraith, et al. Expires March 5, 2007 [Page 1] Internet-Draft Secure Shell Public-Key Subsystem September 2006 Abstract Secure Shell defines an authentication mechanism that is based on public keys, but does not define any mechanism for key distribution. No common key management solution exists in current implementations. This document describes a protocol that can be used to configure public keys in an implementation-independent fashion, allowing client software to take on the burden of this configuration. The public-key subsystem provides a server-independent mechanism for clients to add public keys, remove public keys, and list the current public keys known by the server. Rights to manage public keys are specific and limited to the authenticated user. A public key may also be associated with various restrictions, including a mandatory command or subsystem. Galbraith, et al. Expires March 5, 2007 [Page 2] Internet-Draft Secure Shell Public-Key Subsystem September 2006 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Public-Key Subsystem Overview . . . . . . . . . . . . . . . . 6 3.1. Opening the Public-Key Subsystem . . . . . . . . . . . . . 6 3.2. Requests and Responses . . . . . . . . . . . . . . . . . . 7 3.3. The Status Message . . . . . . . . . . . . . . . . . . . . 7 3.3.1. Status Codes . . . . . . . . . . . . . . . . . . . . . 7 3.4. The Version Packet . . . . . . . . . . . . . . . . . . . . 8 4. Public-Key Subsystem Operations . . . . . . . . . . . . . . . 9 4.1. Adding a Public Key . . . . . . . . . . . . . . . . . . . 9 4.2. Removing a Public Key . . . . . . . . . . . . . . . . . . 12 4.3. Listing Public Keys . . . . . . . . . . . . . . . . . . . 12 4.4. Listing Server Capabilities . . . . . . . . . . . . . . . 12 5. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 6.1. Registrations . . . . . . . . . . . . . . . . . . . . . . 15 6.2. Names . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.2.1. Conventions for Names . . . . . . . . . . . . . . . . 15 6.2.2. Future Assignments of Names . . . . . . . . . . . . . 16 6.3. Request Names . . . . . . . . . . . . . . . . . . . . . . 16 6.4. Response Names . . . . . . . . . . . . . . . . . . . . . . 16 6.5. Attribute Names . . . . . . . . . . . . . . . . . . . . . 16 6.6. Status Codes . . . . . . . . . . . . . . . . . . . . . . . 17 6.6.1. Conventions . . . . . . . . . . . . . . . . . . . . . 17 6.6.2. Initial Assignments . . . . . . . . . . . . . . . . . 17 6.6.3. Future Assignments . . . . . . . . . . . . . . . . . . 17 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 7.1. Normative References . . . . . . . . . . . . . . . . . . . 18 7.2. Informative References . . . . . . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 Intellectual Property and Copyright Statements . . . . . . . . . . 20 Galbraith, et al. Expires March 5, 2007 [Page 3] Internet-Draft Secure Shell Public-Key Subsystem September 2006 1. Introduction Secure Shell is a protocol for secure remote login and other secure network services over an insecure network. Secure Shell defines an authentication mechanism that is based on public keys, but does not define any mechanism for key distribution. Common practice is to authenticate once with password authentication and transfer the public key to the server. However, to date no two implementations use the same mechanism to configure a public key for use. This document describes a subsystem that can be used to configure public keys in an implementation-independent fashion. This approach allows client software to take on the burden of this configuration. The public-key subsystem protocol is designed for extreme simplicity in implementation. It is not intended as a PKIX replacement. The Secure Shell Public-Key subsystem has been designed to run on top of the Secure Shell transport layer [2] and user authentication protocols [3]. It provides a simple mechanism for the client to manage public keys on the server. This document should be read only after reading the Secure Shell architecture [1] and Secure Shell connection [4] documents. This protocol is intended to be used from the Secure Shell Connection Protocol [4] as a subsystem, as described in the section "Starting a Shell or a Command". The subsystem name used with this protocol is "publickey". This protocol requires that the user be able to authenticate in some fashion before it can be used. If password authentication is used, servers SHOULD provide a configuration option to disable the use of password authentication after the first public key is added. Galbraith, et al. Expires March 5, 2007 [Page 4] Internet-Draft Secure Shell Public-Key Subsystem September 2006 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC2119 [5]. Galbraith, et al. Expires March 5, 2007 [Page 5] Internet-Draft Secure Shell Public-Key Subsystem September 2006 3. Public-Key Subsystem Overview The public-key subsystem provides a server-independent mechanism for clients to add public keys, remove public keys, and list the current public keys known by the server. The subsystem name is "publickey". The public keys added, removed, and listed using this protocol are specific and limited to those of the authenticated user. The operations to add, remove, and list the authenticated user's public keys are performed as request packets sent to the server. The server sends response packets that indicate success or failure as well as provide specific response data. The format of public-key blobs are detailed in section 6.6, "Public Key Algorithms" of the SSH Transport Protocol document [2]. 3.1. Opening the Public-Key Subsystem The public-key subsystem is started by a client sending an SSH_MSG_CHANNEL_REQUEST over an existing session's channel. The details of how a session is opened are described in the SSH Connection Protocol document [4] in the section "Opening a Session". To open the public-key subsystem, the client sends: byte SSH_MSG_CHANNEL_REQUEST uint32 recipient channel string "subsystem" boolean want reply string "publickey" Client implementations SHOULD reject this request; it is normally sent only by the client. If want reply is TRUE, the server MUST respond with SSH_MSG_CHANNEL_SUCCESS if the public-key subsystem was successfully started or SSH_MSG_CHANNEL_FAILURE if the server failed to start or does not support the public-key subsystem. The server SHOULD respond with SSH_MSG_CHANNEL_FAILURE if the user is not allowed access to the public-key subsystem (for example, because the user authenticated with a restricted public key). It is RECOMMENDED that clients request and check the reply for this request. Galbraith, et al. Expires March 5, 2007 [Page 6] Internet-Draft Secure Shell Public-Key Subsystem September 2006 3.2. Requests and Responses All public-key subsystem requests and responses are sent in the following form: uint32 length string name ... request/response specific data follows The length field describes the length of the name field and of the request/response-specific data, but does not include the length of the length field itself. The client MUST receive acknowledgement of each request prior to sending a new request. The version packet, as well as all requests and responses described in Section 4, are a description of the 'name' field and the data part of the packet. 3.3. The Status Message A request is acknowledged by sending a status packet. If there is data in response to the request, the status packet is sent after all data has been sent. string "status" uint32 status code string description [RFC-3629] string language tag [RFC-3066] A status message MUST be sent for any unrecognized packets, and the request SHOULD NOT close the subsystem. 3.3.1. Status Codes The status code gives the status in a more machine-readable format (suitable for localization), and can have the following values: SSH_PUBLICKEY_SUCCESS 0 SSH_PUBLICKEY_ACCESS_DENIED 1 SSH_PUBLICKEY_STORAGE_EXCEEDED 2 SSH_PUBLICKEY_VERSION_NOT_SUPPORTED 3 SSH_PUBLICKEY_KEY_NOT_FOUND 4 SSH_PUBLICKEY_KEY_NOT_SUPPORTED 5 SSH_PUBLICKEY_KEY_ALREADY_PRESENT 6 SSH_PUBLICKEY_GENERAL_FAILURE 7 SSH_PUBLICKEY_REQUEST_NOT_SUPPORTED 8 SSH_PUBLICKEY_ATTRIBUTE_NOT_SUPPORTED 9 Galbraith, et al. Expires March 5, 2007 [Page 7] Internet-Draft Secure Shell Public-Key Subsystem September 2006 If a request completed successfully, the server MUST send the status code SSH_PUBLICKEY_SUCCESS. The meaning of the failure codes is as implied by their names. 3.4. The Version Packet Both sides MUST start by sending a version packet that indicates the version of the protocol they are using. string "version" uint32 protocol-version-number This document describes version 2 of the protocol. Both sides send the highest version that they implement. The lower of the version numbers is the version of the protocol to use. If either side can't support the lower version, it should close the subsystem and notify the other side by sending an SSH_MSG_CHANNEL_CLOSE message. Before closing the subsystem, a status message with the status SSH_PUBLICKEY_VERSION_NOT_SUPPORTED SHOULD be sent. Note that, normally, status messages are only sent by the server (in response to requests from the client). This is the only occasion on which the client sends a status message. Both sides MUST wait to receive this version before continuing. The "version" packet MUST NOT be sent again after this initial exchange. The SSH_PUBLICKEY_VERSION_NOT_SUPPORTED status code must not be sent in response to any other request. Implementations MAY use the first 15 bytes of the version packet as a "magic cookie" to avoid processing spurious output from the user's shell (as described in section 6.5 of [4]). These bytes will always be: 0x00 0x00 0x00 0x0F 0x00 0x00 0x00 0x07 0x76 0x65 0x72 0x73 0x69 0x6F 0x6E Galbraith, et al. Expires March 5, 2007 [Page 8] Internet-Draft Secure Shell Public-Key Subsystem September 2006 4. Public-Key Subsystem Operations The public-key subsystem currently defines four operations: add, remove, list, and listattributes. 4.1. Adding a Public Key If the client wishes to add a public key, the client sends: string "add" string public-key algorithm name string public-key blob boolean overwrite uint32 attribute-count string attrib-name string attrib-value bool critical repeated attribute-count times The server MUST attempt to store the public key for the user in the appropriate location so the public key can be used for subsequent public-key authentications. If the overwrite field is false and the specified key already exists, the server MUST return SSH_PUBLICKEY_KEY_ALREADY_PRESENT. If the server returns this, the client SHOULD provide an option to the user to overwrite the key. If the overwrite field is true and the specified key already exists, but cannot be overwritten, the server MUST return SSH_PUBLICKEY_ACCESS_DENIED. Attribute names are defined following the same scheme laid out for algorithm names in [1]. If the server does not implement a critical attribute, it MUST fail the add, with the status code SSH_PUBLICKEY_ATTRIBUTE_NOT_SUPPORTED. For the purposes of a critical attribute, mere storage of the attribute is not sufficient -- rather, the server must understand and implement the intent of the attribute. The following attributes are currently defined: "comment" The value of the comment attribute contains user-specified text about the public key. The server SHOULD make every effort to preserve this value and return it with the key during any subsequent list operation. The server MUST NOT attempt to interpret or act upon the content of the comment field in any way. The comment attribute must be specified in UTF-8 format [7]. Galbraith, et al. Expires March 5, 2007 [Page 9] Internet-Draft Secure Shell Public-Key Subsystem September 2006 The comment field is useful so the user can identify the key without resorting to comparing its fingerprint. This attribute SHOULD NOT be critical. "comment-language" If this attribute is specified, it MUST immediately follow a "comment" attribute and specify the language for that attribute [6]. The client MAY specify more than one comment if it additionally specifies a different language for each of those comments. The server SHOULD attempt to store each comment with its language attribute. This attribute SHOULD NOT be critical. "command-override" "command-override" specifies a command to be executed when this key is in use. The command should be executed by the server when it receives an "exec" or "shell" request from the client, in place of the command or shell which would otherwise have been executed as a result of that request. If the command string is empty, both "exec" and "shell" requests should be denied. If no "command-override" attribute is specified, all "exec" and "shell" requests should be permitted (as long as they satisfy other security or authorization checks the server may perform). This attribute SHOULD be critical. "subsystem" "subsystem" specifies a comma-separated list of subsystems that may be started (using a "subsystem" request) when this key is in use. This attribute SHOULD be critical. If the value is empty, no subsystems may be started. If the "subsystem" attribute is not specified, no restrictions are placed on which subsystems may be started when authenticated using this key. "x11" "x11" specifies that X11 forwarding may not be performed when this key is in use. The attribute-value field SHOULD be empty for this attribute. This attribute SHOULD be critical. "shell" "shell" specifies that session channel "shell" requests should be denied when this key is in use. The attribute-value field SHOULD be empty for this attribute. This attribute SHOULD be critical. "exec" Galbraith, et al. Expires March 5, 2007 [Page 10] Internet-Draft Secure Shell Public-Key Subsystem September 2006 "exec" specifies that session channel "exec" requests should be denied when this key is in use. The attribute-value field SHOULD be empty for this attribute. This attribute SHOULD be critical. "agent" "agent" specifies that session channel "auth-agent-req" requests should be denied when this key is in use. The attribute-value field SHOULD be empty for this attribute. This attribute SHOULD be critical. "env" "env" specifies that session channel "env" requests should be denied when this key is in use. The attribute-value field SHOULD be empty for this attribute. This attribute SHOULD be critical. "from" "from" specifies a comma-separated list of hosts from which the key may be used. If a host not in this list attempts to use this key for authorization purposes, the authorization attempt MUST be denied. The server SHOULD make a log entry regarding this. The server MAY provide a method for administrators to disallow the appearance of a host in this list. The server should use whatever method is appropriate for its platform to identify the host - e.g. for IP-based networks, checking the IP address or performing a reverse DNS lookup. "port-forward" "port-forward" specifies that no "direct-tcpip" requests should be accepted, except those to hosts specified in the comma-separated list supplied as a value to this attribute. If the value of this attribute is empty, all "direct-tcpip" requests should be refused when using this key. This attribute SHOULD be critical. "reverse-forward" "reverse-forward" specifies that no "tcpip-forward" requests should be accepted, except for the port numbers in the comma-separated list supplied as a value to this attribute. If the value of this attribute is empty, all "tcpip-forward" requests should be refused when using this key. This attribute SHOULD be critical. In addition to the attributes specified by the client, the server MAY provide a method for administrators to enforce certain attributes compulsorily. Galbraith, et al. Expires March 5, 2007 [Page 11] Internet-Draft Secure Shell Public-Key Subsystem September 2006 4.2. Removing a Public Key If the client wishes to remove a public key, the client sends: string "remove" string public-key algorithm name string public-key blob The server MUST attempt to remove the public key for the user from the appropriate location, so that the public key cannot be used for subsequent authentications. 4.3. Listing Public Keys If the client wishes to list the known public keys, the client sends: string "list" The server will respond with zero or more of the following responses: string "publickey" string public-key algorithm name string public-key blob uint32 attribute-count string attrib-name string attrib-value repeated attribute-count times Following the last "publickey" response, a status packet MUST be sent. An implementation MAY choose not to support this request. 4.4. Listing Server Capabilities If the client wishes to know which key attributes the server supports, it sends: string "listattributes" The server will respond with zero or more of the following responses: string "attribute" string attribute name boolean compulsory The "compulsory" field indicates whether this attribute will be compulsorily applied to any added keys (irrespective of whether the Galbraith, et al. Expires March 5, 2007 [Page 12] Internet-Draft Secure Shell Public-Key Subsystem September 2006 attribute has been specified by the client) due to administrative settings on the server. If the server does not support administrative settings of this nature, it MUST return false in the compulsory field. An example of use of the "compulsory" attribute would be a server with a configuration file specifying that the user is not permitted shell access. Given this, the server would return the "shell" attribute, with "compulsory" marked true. Whatever attributes the user subsequently asked the server to apply to their key, the server would also apply the "shell" attribute, rendering it impossible for the user to use a shell. Following the last "attribute" response, a status packet MUST be sent. An implementation MAY choose not to support this request. Galbraith, et al. Expires March 5, 2007 [Page 13] Internet-Draft Secure Shell Public-Key Subsystem September 2006 5. Security Considerations This protocol assumes that it is run over a secure channel and that the endpoints of the channel have been authenticated. Thus, this protocol assumes that it is externally protected from network-level attacks. This protocol provides a mechanism that allows client authentication data to be uploaded and manipulated. It is the responsibility of the server implementation to enforce any access controls that may be required to limit the access allowed for any particular user (the user being authenticated externally to this protocol, typically using the SSH User Authentication Protocol [3]). In particular, it is possible for users to overwrite an existing key on the server with this protocol, whilst at the same time specifying fewer restrictions for the new key than were previously present. Servers should take care that when doing this, clients are not able to override presets from the server's administrator. This protocol requires the client to assume that the server will correctly implement and observe attributes applied to keys. Implementation errors in the server could cause clients to authorize keys for access they were not intended to have, or to apply fewer restrictions than were intended. Galbraith, et al. Expires March 5, 2007 [Page 14] Internet-Draft Secure Shell Public-Key Subsystem September 2006 6. IANA Considerations This section contains conventions used in naming the namespaces, the initial state of the registry, and instructions for future assignments. 6.1. Registrations Consistent with Section 7 of [1], this document makes the following registration: The subsystem name "publickey". 6.2. Names In the following sections, the values for the namespaces are textual. The conventions and instructions to the IANA for future assignments are given in this section. The initial assignments are given in their respective sections. 6.2.1. Conventions for Names All names registered by the IANA in the following sections MUST be printable US-ASCII strings, and MUST NOT contain the characters at- sign ("@"), comma (","), or whitespace or control characters (ASCII codes 32 or less). Names are case-sensitive, and MUST NOT be longer than 64 characters. A provision is made here for locally extensible names. The IANA will not register, and will not control names with the at-sign in them. Names with the at-sign in them will have the format of "name@domainname" (without the double quotes) where the part preceeding the at-sign is the name. The format of the part preceding the at-sign is not specified, however these names MUST be printable US-ASCII strings, and MUST NOT contain the comma character (","), or whitespace, or control characters (ASCII codes 32 or less). The part following the at-sign MUST be a valid, fully qualified Internet domain name [9] controlled by the person or organization defining the name. Names are case-sensitive, and MUST NOT be longer than 64 characters. It is up to each domain how it manages its local namespace. It has been noted that these names resemble STD 11 [8] email addresses. This is purely coincidental and actually has nothing to do with STD 11 [8]. An example of a locally defined name is "ourcipher-cbc@example.com" (without the double quotes). Galbraith, et al. Expires March 5, 2007 [Page 15] Internet-Draft Secure Shell Public-Key Subsystem September 2006 6.2.2. Future Assignments of Names Requests for assignments of new Names MUST be done through the IETF Consensus method as described in [10]. 6.3. Request Names The following table lists the initial assignments of Request names. Request Name ------------- version add remove list listattributes 6.4. Response Names The following table lists the initial assignments of Response names. Response Name -------------- version status publickey attribute 6.5. Attribute Names Attributes are used to define properties or restrictions for public keys. The following table lists the initial assignments of Attribute names. Attribute Name --------------- comment comment-language command-override subsystem x11 shell exec agent env from port-forward reverse-forward Galbraith, et al. Expires March 5, 2007 [Page 16] Internet-Draft Secure Shell Public-Key Subsystem September 2006 6.6. Status Codes The status code is a byte value, describing the status of a request. 6.6.1. Conventions Status responses have status codes in the range 0 to 255. These numbers are allocated as follows. Of these, the range 192 to 255 is reserved for use by local, private extensions. 6.6.2. Initial Assignments The following table identifies the initial assignments of the status code values. Status code Value Reference ------------ ----- --------- SSH_PUBLICKEY_SUCCESS 0 SSH_PUBLICKEY_ACCESS_DENIED 1 SSH_PUBLICKEY_STORAGE_EXCEEDED 2 SSH_PUBLICKEY_VERSION_NOT_SUPPORTED 3 SSH_PUBLICKEY_KEY_NOT_FOUND 4 SSH_PUBLICKEY_KEY_NOT_SUPPORTED 5 SSH_PUBLICKEY_KEY_ALREADY_PRESENT 6 SSH_PUBLICKEY_GENERAL_FAILURE 7 SSH_PUBLICKEY_REQUEST_NOT_SUPPORTED 8 SSH_PUBLICKEY_ATTRIBUTE_NOT_SUPPORTED 9 6.6.3. Future Assignments Requests for assignments of new message numbers in the range of 0 to 191 MUST be done through the Standards Action method as described in [10]. The IANA will not control the message numbers range of 192 through 255. This range will be left for private use. Galbraith, et al. Expires March 5, 2007 [Page 17] Internet-Draft Secure Shell Public-Key Subsystem September 2006 7. References 7.1. Normative References [1] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH) Protocol Architecture", RFC 4251, January 2006. [2] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH) Transport Layer Protocol", RFC 4253, January 2006. [3] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH) Authentication Protocol", RFC 4252, January 2006. [4] Ylonen, T. and C. Lonvick, "The Secure Shell (SSH) Connection Protocol", RFC 4254, January 2006. [5] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [6] Alvestrand, H., "Tags for the Identification of Languages", BCP 47, RFC 3066, January 2001. [7] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, November 2003. 7.2. Informative References [8] Crocker, D., "Standard for the format of ARPA Internet text messages", STD 11, RFC 822, August 1982. [9] Mockapetris, P., "Domain names - concepts and facilities", STD 13, RFC 1034, November 1987. [10] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. Galbraith, et al. Expires March 5, 2007 [Page 18] Internet-Draft Secure Shell Public-Key Subsystem September 2006 Authors' Addresses Joseph Galbraith VanDyke Software 4848 Tramway Ridge Blvd Suite 101 Albuquerque, NM 87111 US Phone: +1 505 332 5700 Email: galb-list@vandyke.com Jeff P. Van Dyke VanDyke Software 4848 Tramway Ridge Blvd Suite 101 Albuquerque, NM 87111 US Phone: +1 505 332 5700 Email: jpv@vandyke.com Brent McClure VanDyke Software 4848 Tramway Ridge Blvd Suite 101 Albuquerque, NM 87111 US Phone: +1 505 332 5700 Email: bdm@vandyke.com Jon Bright Silicon Circus 24 Jubilee Road Chichester, West Sussex PO19 7XB UK Phone: +49 172 524 0521 Email: jon@siliconcircus.com Galbraith, et al. Expires March 5, 2007 [Page 19] Internet-Draft Secure Shell Public-Key Subsystem September 2006 Full Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 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The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Galbraith, et al. Expires March 5, 2007 [Page 20] --------------050806050506090103090902-- From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Fri Sep 01 04:11:20 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GJ47U-0002Vv-OP for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 01 Sep 2006 04:11:20 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GJ47T-0005PZ-D0 for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 01 Sep 2006 04:11:20 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id C9D0563B356; Fri, 1 Sep 2006 08:11:07 +0000 (UTC) X-Original-To: ietf-ssh@NetBSD.org Delivered-To: ietf-ssh@NetBSD.org Received: from mail.siliconcircus.com (mail.siliconcircus.com [62.141.33.102]) by mail.netbsd.org (Postfix) with ESMTP id 2346A63B141 for ; Fri, 1 Sep 2006 08:11:07 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by mail.siliconcircus.com (Postfix) with ESMTP id 10AA110A820 for ; Fri, 1 Sep 2006 10:11:06 +0200 (CEST) Message-ID: <44F7EB71.6080803@siliconcircus.com> Date: Fri, 01 Sep 2006 10:12:33 +0200 From: Jon Bright Organization: Silicon Circus Ltd. User-Agent: Thunderbird 1.5.0.5 (Windows/20060719) MIME-Version: 1.0 To: ietf-ssh@NetBSD.org Subject: publickey-subsystem-07 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 1.1 (+) X-Scan-Signature: 7bac9cb154eb5790ae3b2913587a40de Hi, I've just resubmitted -07. The first submission didn't go through because I'd not bumped the version number - the resubmission includes all changes discussed here. -- Jon Bright Silicon Circus Ltd. http://www.siliconcircus.com From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Fri Sep 01 11:26:50 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GJAuw-0000XV-BB for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 01 Sep 2006 11:26:50 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GJAut-0003ua-JP for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 01 Sep 2006 11:26:50 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id DFDA063B77E; Fri, 1 Sep 2006 15:25:47 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from mail-gw3.sa.ew.hu (mail-gw3.sa.ew.hu [212.108.200.82]) by mail.netbsd.org (Postfix) with ESMTP id B5DC363B79F for ; Fri, 1 Sep 2006 15:25:45 +0000 (UTC) Received: from dorka.pomaz.szeredi.hu (245-051.dyn-fa.pool.ew.hu [193.226.245.51]) by mail-gw3.sa.ew.hu (mu) with ESMTP id k81FPT6L020498 for ; Fri, 1 Sep 2006 17:25:38 +0200 Received: from miko by dorka.pomaz.szeredi.hu with local (Exim 3.36 #1 (Debian)) id 1GJAtT-00024P-00; Fri, 01 Sep 2006 17:25:19 +0200 To: ietf-ssh@netbsd.org Subject: Comments on SFTP draft 13 Message-Id: From: Miklos Szeredi Date: Fri, 01 Sep 2006 17:25:19 +0200 Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.1 (/) X-Scan-Signature: 025f8c5000216988bfe31585db759250 First off, I'm new to the list, so apologies for any issues that have already been discussed. I have implemented an experimental sftp server that supports versions 6 (as well as 2 and 3) of the SFTP protocol and tries to conform fully to draft 13 of the specification. It works on Linux, and the source code (released under GPL) is available from: http://fuse.sourceforge.net/tmp/sftp-server.c See below for my comments accumulated during the implementation. Miklos -------------------------------------------------------------------------- |5.1. Client Initialization | | The SSH_FXP_INIT packet (from client to server) has the following | data: | | uint32 version | | 'version' is the version number of the client. If the client wishes | to interoperate with servers that support noncontiguous version | numbers it SHOULD send '3', and then use the 'version-select' | extension (see below.) This seems wrong. If the server doesn't send version-select, but supports versions > 3, then the negotiation will end up with version 3, even though both the client and server support a greater version. |5.4. Supported Features | max-read-size | This is the maximum read size that the server guarantees to | complete. For example, certain embedded server implementations | complete only the first 4K of a read, even if there is additional | data to be read from the file. | | If the server specifies a non-zero value for max-read-size, it | MUST return the requested number of bytes for reads that are less | than or equal to the value, unless it encounters EOF or an ERROR. | | The server MAY use this value to express that it is willing to | handle very large read requests, in excess of the standard 34000 | bytes specified in Section 4. Shouldn't this read ... very large WRITE requests ... or just ... very large requests ... Also "MAY" here makes client implementation difficult, since the client has to recover from a failed request for servers which don't handle large WRITE requests but set 'max-read-size' to a large value. |6. File Names | A server MAY include the following extension with it's version | packet. | | string "filename-charset" | string charset-name | A pointer to a standard should be included here. I've found this: http://www.iana.org/assignments/character-sets |8.1.1.3. flags | SSH_FXF_APPEND_DATA | Data is always written at the end of the file. The offset field | of SSH_FXP_WRITE requests is ignored. | | Data is not required to be appended atomically. This means that | if multiple writers attempt to append data simultaneously, data | from the first may be lost. However, data MAY be appended | atomically. | | SSH_FXF_APPEND_DATA_ATOMIC | Data is always written at the end of the file. The offset field | of the SSH_FXP_WRITE requests are ignored. | | Data MUST be written atomically so that there is no chance that | multiple appenders can collide and result in data being lost. | | If both append flags are specified, the server SHOULD use atomic | append if it is available, but SHOULD use non-atomic appends | otherwise. The server SHOULD NOT fail the request in this case. What is the relation of SSH_FXF_APPEND_DATA* to ACE4_APPEND_DATA? As I see it ACE4_APPEND_DATA is redundant. It is unlikely that a client would request APPEND access, while not actually wanting data to be appended. I think ACE4_APPEND_DATA should simply be ignored by servers. | The 'attrs' field specifies the initial attributes for the file. | Default values MUST be supplied by the server for those attributes | that are not specified. See Section ''File Attributes'' for more | information. It is not clear what should happen if the server doesn't support setting an attribute atomically with the create. For example POSIX create only supports setting the permission bits, and owner/group/ times/size/etc are not settable. The 'size' attribute semantics with OPEN are explicitly described in the spec, but others are not. The most sensible solution I think is to return SSH_FX_OP_UNSUPPORTED status. However this could pose a problem for clients, which would have to learn by trial and error which attributes are supported on file creation and which are not. The 'supported-attribute-mask' doesn't help, if the server supports setting less attributes on file creation than in a SETATTR operation. The easiest solution is probably to extend "supported2" extension with "supported-create-attribute-mask'. This would apply to OPEN and MKDIR. | O_CREAT | flags = SSH_FXF_OPEN_OR_CREATE | | O_TRUNC | flags = SSH_FXF_TRUNCATE_EXISTING | | O_TRUNC|O_CREATE | flags = SSH_FXF_CREATE_TRUNCATE should be "O_TRUNC|O_CREAT" And for completeness sake: O_CREAT|O_EXCL flags = SSH_FXF_CREATE_NEW |8.5. Retrieving File Attributes | The flags field specify the attribute flags in which the client has | particular interest. This is a hint to the server. For example, | because retrieving owner / group and acl information can be an | expensive operation under some operating systems, the server may | choose not to retrieve this information unless the client expresses a | specific interest in it. I think this should be more than a hint: the server SHOULD mask the attribute flags field with this, before composing the ATTRS data. This saves bandwidth (both network and CPU) in case the client doesn't need some of the attributes, even if the attribute itself is not expensive to compute. |8.7. Dealing with Links | The SSH_FXP_LINK request creates a link (either hard or symbolic) on | the server. | | byte SSH_FXP_LINK | uint32 request-id | string new-link-path [UTF-8] | string existing-path [UTF-8] 'existing-path' should be 'target-path', as in the description. |8.9. Canonicalizing the Server-Side Path Name | control-byte | | SSH_FXP_REALPATH_NO_CHECK 0x00000001 | SSH_FXP_REALPATH_STAT_IF 0x00000002 | SSH_FXP_REALPATH_STAT_ALWAYS 0x00000003 | | This field is optional, and if it is not present in the packet, it | is assumed to be SSH_FXP_REALPATH_NO_CHECK. | | If SSH_FXP_REALPATH_NO_CHECK is specified, the server MUST NOT | fail the request if the path does not exist, is hidden, or the | user does not have access to the path or some component thereof. It is impossible to canonicalize a non-existent path. E.g. "x/../z" is NOT equivalent to "z" if "x" does not exist (or not a directory, etc). It is possible to partially canonicalize a non-existent or erroneous path, but that doesn't make much sense, and it makes the implementation difficult. My implementation does not even try to canonicalize the path for SSH_FXP_REALPATH_NO_CHECK, and only canonicalizes the path for SSH_FXP_REALPATH_STAT_IF if stat returns success. | In addition, the path MUST NOT resolve symbolic links. This | allows paths to be composed for the SSH_FXP_REMOVE command to | remove symbolic links. This only requires that the last component be not resolved, and the client can do this by omitting the last component before supplying it to REALPATH. |8.9.1. Best Practice for Dealing with Paths | The client SHOULD treat the results of SSH_FXP_REALPATH as a | canonical absolute path, even if the path does not appear to be | absolute. A client that uses REALPATH(".", "") and treats the result | as absolute, even if there is no leading slash, will continue to | function correctly, even when talking to a Windows NT or VMS style | system, where absolute paths may not begin with a slash. This contradicts section 6: * File names starting with a slash are "absolute", and are relative to * the root of the file system. Names starting with any other character * are relative to the user's default directory (home directory). | The client SHOULD also use SSH_FXP_REALPATH call to compose paths so | that it does not need to know when a path is absolute or relative. This is unnecessary if servers _do_ follow the "absolute begins with a slash" rule. So I think it should rather be up to the server to always convert any local path representations into one which follow the rules outlined in section 6. E.g. "c:/x/y/z" could become "/c$/x/y/z". Hence all the added complexity of REALPATH and it's optional fields become unnecessary. In addition path composition normally wouldn't require a round-trip to the server. |9.4. Name Response | end-of-list | If this field is present and true, there are no more entries to be | read. This field should either be omitted or be true unless the | request is SSH_FXP_READDIR. This last sentence is not clear to me. Should this field be always specified for READDIR? Should it be omitted for other requests? Does omitting it imply a TRUE or a FALSE value? -------------------------------------------------------------------------- Here are some features that I miss from the current protocol. These could be added as extensions, but the core protocol might benefit from standardizing some of them. SSH_FXP_READDIR, SSH_FXP_REALPATH: SSH_FXP_STAT and friends have a 'flags' field for indicating which attributes the client is interested in. This field should be equally applicable to a READDIR request. Extension to the ATTRS data: - numeric owner/group. The client may want to display numeric or named values in directory listings on a request by request basis (e.g. depending on the '-n' option of 'ls'). - device number (st_dev), inode number (st_ino) fields. The client can use this to identify directory entries which are hard links to the same file. - device type (st_rdev) for device files. New requests: MKNOD: Create file node (FIFO or other special file types). Same format as MKDIR. The type field in ATTR is used to determine the file type. Exclude directory creation, but possibly include regular file creation, which can be used to create an empty file with a single request, instead of having to do OPEN/CLOSE. STATFS: Return file system statistics for the given path. A good starting point would be the fields of POSIX struct statvfs. From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Tue Sep 05 11:55:18 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GKdGg-0003iF-T4 for secsh-tyoxbijeg7-archive@lists.ietf.org; Tue, 05 Sep 2006 11:55:18 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GKdGf-0005tL-Fg for secsh-tyoxbijeg7-archive@lists.ietf.org; Tue, 05 Sep 2006 11:55:18 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 7B16863B2AD; Tue, 5 Sep 2006 15:55:04 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from ns1.neustar.com (ns1.neustar.com [156.154.16.138]) by mail.netbsd.org (Postfix) with ESMTP id 7844463B2EF for ; Tue, 5 Sep 2006 15:55:03 +0000 (UTC) Received: from stiedprstage1.ietf.org (stiedprstage1.va.neustar.com [10.31.47.10]) by ns1.neustar.com (Postfix) with ESMTP id CE7F82AB69; Tue, 5 Sep 2006 14:50:01 +0000 (GMT) Received: from ietf by stiedprstage1.ietf.org with local (Exim 4.43) id 1GKcFV-0008OI-Lz; Tue, 05 Sep 2006 10:50:01 -0400 Content-Type: Multipart/Mixed; Boundary="NextPart" Mime-Version: 1.0 To: i-d-announce@ietf.org Cc: ietf-ssh@netbsd.org From: Internet-Drafts@ietf.org Subject: I-D ACTION:draft-ietf-secsh-publickey-subsystem-07.txt Message-Id: Date: Tue, 05 Sep 2006 10:50:01 -0400 Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.3 (/) X-Scan-Signature: b5d20af10c334b36874c0264b10f59f1 --NextPart A New Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the Secure Shell Working Group of the IETF. Title : Secure Shell Public-Key Subsystem Author(s) : J. Galbraith, et al. Filename : draft-ietf-secsh-publickey-subsystem-07.txt Pages : 20 Date : 2006-9-5 Secure Shell defines an authentication mechanism that is based on public keys, but does not define any mechanism for key distribution. No common key management solution exists in current implementations. This document describes a protocol that can be used to configure public keys in an implementation-independent fashion, allowing client software to take on the burden of this configuration. The public-key subsystem provides a server-independent mechanism for clients to add public keys, remove public keys, and list the current public keys known by the server. Rights to manage public keys are specific and limited to the authenticated user. A public key may also be associated with various restrictions, including a mandatory command or subsystem. A URL for this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-secsh-publickey-subsystem-07.txt To remove yourself from the I-D Announcement list, send a message to i-d-announce-request@ietf.org with the word unsubscribe in the body of the message. You can also visit https://www1.ietf.org/mailman/listinfo/I-D-announce to change your subscription settings. Internet-Drafts are also available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-secsh-publickey-subsystem-07.txt". A list of Internet-Drafts directories can be found in http://www.ietf.org/shadow.html or ftp://ftp.ietf.org/ietf/1shadow-sites.txt Internet-Drafts can also be obtained by e-mail. Send a message to: mailserv@ietf.org. In the body type: "FILE /internet-drafts/draft-ietf-secsh-publickey-subsystem-07.txt". NOTE: The mail server at ietf.org can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e. documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ietf.org" Content-Type: text/plain Content-ID: <2006-9-5025317.I-D@ietf.org> ENCODING mime FILE /internet-drafts/draft-ietf-secsh-publickey-subsystem-07.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-secsh-publickey-subsystem-07.txt"; site="ftp.ietf.org"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <2006-9-5025317.I-D@ietf.org> --OtherAccess-- --NextPart-- From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Tue Sep 05 13:44:13 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GKey5-0003oI-Ba for secsh-tyoxbijeg7-archive@lists.ietf.org; Tue, 05 Sep 2006 13:44:13 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GKey4-0004ry-3W for secsh-tyoxbijeg7-archive@lists.ietf.org; Tue, 05 Sep 2006 13:44:13 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id D195463B2B1; Tue, 5 Sep 2006 17:44:08 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from carter-zimmerman.mit.edu (carter-zimmerman.dyn.mit.edu [18.188.3.148]) by mail.netbsd.org (Postfix) with ESMTP id 2FC6663B11F for ; Tue, 5 Sep 2006 17:44:08 +0000 (UTC) Received: by carter-zimmerman.mit.edu (Postfix, from userid 8042) id 32BEAE0127; Tue, 5 Sep 2006 13:44:03 -0400 (EDT) To: ietf-ssh@netbsd.org Subject: Sending publickey subsystem to last call From: Sam Hartman Message-Id: <20060905174403.32BEAE0127@carter-zimmerman.mit.edu> Date: Tue, 5 Sep 2006 13:44:03 -0400 (EDT) Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.0 (/) X-Scan-Signature: 9182cfff02fae4f1b6e9349e01d62f32 Hi. I found one minor problem in the newest version of the pbulickey subsystem draft. The text added to deal with spurious garbage is inadequate because it is optional for client implementations. To guarantee interoperability this needs to be mandatory. + Implementations MAY use the first 15 bytes of the version packet as a + "magic cookie" to avoid processing spurious output from the user's + shell (as described in section 6.5 of [4]). These bytes will always + be: + + 0x00 0x00 0x00 0x0F 0x00 0x00 0x00 0x07 0x76 0x65 0x72 0x73 0x69 0x6F + 0x6E + +4. Public-Key Subsystem Operations Please s/MAY/MUST/. Don't submit a new version now; I'll let you know if/when I want a new version. If this is the only change, I'll handle it in an rfc-editor note in the protocol action message. From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Tue Sep 05 13:56:48 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GKfAG-0008KN-2f for secsh-tyoxbijeg7-archive@lists.ietf.org; Tue, 05 Sep 2006 13:56:48 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GKfAE-0006h4-Po for secsh-tyoxbijeg7-archive@lists.ietf.org; Tue, 05 Sep 2006 13:56:48 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 48AFF63B1BD; Tue, 5 Sep 2006 17:56:34 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from ns1.neustar.com (ns1.neustar.com [156.154.16.138]) by mail.netbsd.org (Postfix) with ESMTP id 9D41463B10C for ; Tue, 5 Sep 2006 17:56:33 +0000 (UTC) Received: from stiedprstage1.ietf.org (stiedprstage1.va.neustar.com [10.31.47.10]) by ns1.neustar.com (Postfix) with ESMTP id CAB5726E02; Tue, 5 Sep 2006 17:56:02 +0000 (GMT) Received: from ietf by stiedprstage1.ietf.org with local (Exim 4.43) id 1GKf9W-00070h-NI; Tue, 05 Sep 2006 13:56:02 -0400 X-test-idtracker: no To: IETF-Announce From: The IESG Subject: Last Call: 'Secure Shell Public-Key Subsystem' to Proposed Standard (draft-ietf-secsh-publickey-subsystem) Reply-To: iesg@ietf.org Cc: Message-Id: Date: Tue, 05 Sep 2006 13:56:02 -0400 Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.1 (/) X-Scan-Signature: 7a6398bf8aaeabc7a7bb696b6b0a2aad The IESG has received a request from the Secure Shell WG to consider the following document: - 'Secure Shell Public-Key Subsystem ' as a Proposed Standard The IESG plans to make a decision in the next few weeks, and solicits final comments on this action. Please send any comments to the iesg@ietf.org or ietf@ietf.org mailing lists by 2006-09-19. The file can be obtained via http://www.ietf.org/internet-drafts/draft-ietf-secsh-publickey-subsystem-07.txt From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Fri Sep 15 21:42:08 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GOPC4-0000YB-EE for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 15 Sep 2006 21:42:08 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GOPC3-0008Ix-5U for secsh-tyoxbijeg7-archive@lists.ietf.org; Fri, 15 Sep 2006 21:42:08 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 6F93163B179; Sat, 16 Sep 2006 01:41:45 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from Sparkle.Rodents.Montreal.QC.CA (Sparkle.Rodents.Montreal.QC.CA [216.46.5.7]) by mail.netbsd.org (Postfix) with ESMTP id 93C2763B130 for ; Sat, 16 Sep 2006 01:41:42 +0000 (UTC) Received: (from mouse@localhost) by Sparkle.Rodents.Montreal.QC.CA (8.8.8/8.8.8) id SAA01822; Fri, 15 Sep 2006 18:07:51 -0400 (EDT) From: der Mouse Message-Id: <200609152207.SAA01822@Sparkle.Rodents.Montreal.QC.CA> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Erik-Conspiracy: There is no Conspiracy - and if there were I wouldn't be part of it anyway. X-Message-Flag: Microsoft: the company who gave us the botnet zombies. Date: Fri, 15 Sep 2006 18:01:42 -0400 (EDT) To: ietf-ssh@netbsd.org Subject: What's "maximum packet size"? Sender: ietf-ssh-owner@NetBSD.org Precedence: list Content-Transfer-Encoding: quoted-printable X-Spam-Score: 0.0 (/) X-Scan-Signature: 79899194edc4f33a41f49410777972f8 There's a "maximum packet size" in CHANNEL_OPEN and CHANNEL_OPEN_CONFIRMATION messages. 4254 says that this is "the maximum size of an individual data packet that can be sent to the sender". I've interpreted this to mean that I should send, there, the maximum payload length I support, where "paylaod" is as in section 6 of 4253 - the part of a binary-protocol packet after MAC and padding are stripped and decryption and uncompression are done. My value for this is 35000. But when talking to other implementations, I not uncommonly get crashes where my code complains about a payload overflow, getting a 35009-byte payload from the peer. Have I misinterpreted 4254? If so, what *is* that the maximum size of? The only other thing that makes any sense to me is that it's the "data" field of CHANNEL_DATA packets (see 4254 5.2); is that what it's supposed to be? /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse@rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Sat Sep 16 07:21:37 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GOYEr-00066V-Qe for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 07:21:37 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GOYEp-0000cI-Hv for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 07:21:37 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id DEB3B63B253; Sat, 16 Sep 2006 11:21:20 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from chiark.greenend.org.uk (chiark.greenend.org.uk [193.201.200.170]) by mail.netbsd.org (Postfix) with ESMTP id 2490263B23D for ; Sat, 16 Sep 2006 11:21:20 +0000 (UTC) Received: by chiark.greenend.org.uk (Debian Exim 3.36 #1) with local (return-path jacobn@chiark.greenend.org.uk) id 1GOYEY-0007Eo-00 for ietf-ssh@netbsd.org; Sat, 16 Sep 2006 12:21:18 +0100 Date: Sat, 16 Sep 2006 12:21:18 +0100 From: Jacob Nevins To: ietf-ssh@netbsd.org Subject: Re: What's "maximum packet size"? Message-ID: <20060916112118.GA10228@chiark.greenend.org.uk> Reply-To: ietf-ssh@netbsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200609152207.SAA01822@Sparkle.Rodents.Montreal.QC.CA> User-Agent: Mutt/1.5.9i Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.0 (/) X-Scan-Signature: 7655788c23eb79e336f5f8ba8bce7906 der Mouse writes: > There's a "maximum packet size" in CHANNEL_OPEN and > CHANNEL_OPEN_CONFIRMATION messages. [...] > Have I misinterpreted 4254? If so, what *is* that the maximum size of? > The only other thing that makes any sense to me is that it's the "data" > field of CHANNEL_DATA packets (see 4254 5.2); is that what it's > supposed to be? I believe that this (maximum length of channel data) is the correct interpretation. (FWIW, it's what both PuTTY and OpenSSH used, last time I looked.) This was discussed at least once before, in Oct-Nov 2005 (subject 'Definition of "packet"'), and that seemed to be the consensus. Language was added to what became section 5.2 of 4254 in an attempt to clarify this. However, perhaps unfortunately, it still does not spell out the precise relationship between the "maximum packet size" and the number of bytes of channel data; it just says that "The maximum amount of data allowed is *determined* by the maximum packet size for the channel [...]" (my emphasis). The relationship with the transport layer is discussed in the next paragraphs, but again it's not entirely unambiguous. From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Sat Sep 16 09:41:00 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GOaPk-0002w5-QE for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 09:41:00 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GOaPj-0006bG-GJ for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 09:41:00 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 9E5EF63B2C9; Sat, 16 Sep 2006 13:40:44 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) by mail.netbsd.org (Postfix) with ESMTP id 683B363B274 for ; Sat, 16 Sep 2006 13:40:43 +0000 (UTC) Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id DB5DB200A24E for ; Sat, 16 Sep 2006 15:40:36 +0200 (CEST) Received: from mail.lysator.liu.se ([127.0.0.1]) by localhost (lenin.lysator.liu.se [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 17457-01-80 for ; Sat, 16 Sep 2006 15:40:23 +0200 (CEST) Received: from sellafield.lysator.liu.se (sellafield.lysator.liu.se [130.236.254.103]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTP id 4B731200A25D for ; Sat, 16 Sep 2006 15:39:44 +0200 (CEST) Received: from sellafield.lysator.liu.se (localhost [127.0.0.1]) by sellafield.lysator.liu.se (8.13.4+Sun/8.13.4) with ESMTP id k8GDdhQ5012302 for ; Sat, 16 Sep 2006 15:39:43 +0200 (MEST) Received: (from nisse@localhost) by sellafield.lysator.liu.se (8.13.4+Sun/8.12.8/Submit) id k8GDdgPA012299; Sat, 16 Sep 2006 15:39:42 +0200 (MEST) X-Authentication-Warning: sellafield.lysator.liu.se: nisse set sender to nisse@lysator.liu.se using -f To: ietf-ssh@netbsd.org Subject: Re: What's "maximum packet size"? References: <20060916112118.GA10228@chiark.greenend.org.uk> Content-type: text/plain; charset=iso-8859-1 From: nisse@lysator.liu.se (=?iso-8859-1?q?Niels_M=F6ller?=) Date: 16 Sep 2006 15:39:42 +0200 In-Reply-To: <20060916112118.GA10228@chiark.greenend.org.uk> Message-ID: Lines: 46 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 X-Virus-Scanned: by amavisd-new-20030616-p10 (Debian) at lysator.liu.se Sender: ietf-ssh-owner@NetBSD.org Precedence: list Content-Transfer-Encoding: quoted-printable X-Spam-Score: 0.0 (/) X-Scan-Signature: 4adaf050708fb13be3316a9eee889caa Jacob Nevins writes: > I believe that this (maximum length of channel data) is the correct > interpretation. (FWIW, it's what both PuTTY and OpenSSH used, last time > I looked.) That's my recollection too (I haven't checked the archives, though). > The relationship with the transport layer is discussed in the next > paragraphs, but again it's not entirely unambiguous. If we accept that "maximum packet size" in the connection layer should be interpreted in the context of that layer (i.e. it's the size of the payload in CHANNEL_DATA / CHANNEL_EXTENDED_DATA), I don't think the relationship is terribly difficult. For receiving: When you advertise a maximum packet size for a new channel, that means you are prepared to receive channel packets up to that size. And it's your responsibility to ensure that your transport layer implementation is comfortable with the corresponding transport-layer packets, which may well be larger than the 32768/35000 limits. For sending: When the other side has advertized a large maximum packet size for a channel, feel free to generate packets of that size, even if it makes the transport packets larger than the 32768/35000 limit. And if your transport implementation is unwilling to generate packets of that size, just clamp down the advertised value you receive from the other end. If you want to honor the 32768 octet limit on the transport layer, to get the largest possible "maximum packet size" for a channel, you have to subtract the CHANNEL_EXTENDED_DATA overhead, which is 13 octets IIRC. For simplicity, and to have a little margin, my implementation restricts the maximum packet size in the connection layer to 32768 - 100. Regards, /Niels From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Sat Sep 16 11:04:52 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GObiu-000399-OV for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 11:04:52 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GObit-0002hL-Ft for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 11:04:52 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id B5E4A63B2D3; Sat, 16 Sep 2006 15:04:47 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from chiark.greenend.org.uk (chiark.greenend.org.uk [193.201.200.170]) by mail.netbsd.org (Postfix) with ESMTP id E427E63B13E for ; Sat, 16 Sep 2006 15:04:46 +0000 (UTC) Received: by chiark.greenend.org.uk (Debian Exim 3.36 #1) with local (return-path jacobn@chiark.greenend.org.uk) id 1GObio-0002rw-00 for ietf-ssh@netbsd.org; Sat, 16 Sep 2006 16:04:46 +0100 Date: Sat, 16 Sep 2006 16:04:45 +0100 From: Jacob Nevins To: ietf-ssh@netbsd.org Subject: Ambiguity when forwarding port "0" Message-ID: <20060916150445.GA7700@chiark.greenend.org.uk> Reply-To: ietf-ssh@netbsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.9i Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.0 (/) X-Scan-Signature: ea4ac80f790299f943f0a53be7e1a21a RFC 4254 (ssh-connect) section 7.1 allows a party (client) to specify a port of 0 in a remote-to-local "tcpip-forward" request. This causes the other party (server) to unilaterally allocate a port, and optionally notify the client of that port. However, a port number is required to identify the tunnel in subsequent messages sent by the client -- "cancel-tcpip-forward" (7.1) and "forwarded-tcpip" (7.2). I can't find it explicitly stated anywhere whether the port number in these latter messages should be 0, or the port allocated by the server. Reading through the list archives, some of the original proposals for this feature (circa 2001) made it clear that port 0 was not to be used subsequently (and hence implied that the actually bound port should be used). This does seem to be the only interpretation that makes sense when you consider two such requests in a single session. Going with this interpretation, 7.1 implies that it is optional for a client to request notification of the bound port; however, if it does not do so, it can't meet the requirement of 7.2 that "Implementations MUST reject ["forwarded-tcpip"] messages unless they have previously requested a remote TCP/IP port forwarding with the given port number." (Although I don't see what unforeseeable trouble a client could get into by accepting all such requests, if it had originally sent a port of 0.) Does anyone's implementation disagree? From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Sat Sep 16 18:00:20 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GOiCy-00081t-UL for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 18:00:20 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GOiCx-00064U-H0 for secsh-tyoxbijeg7-archive@lists.ietf.org; Sat, 16 Sep 2006 18:00:20 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 7F4AA63B14B; Sat, 16 Sep 2006 22:00:09 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from chiark.greenend.org.uk (chiark.greenend.org.uk [193.201.200.170]) by mail.netbsd.org (Postfix) with ESMTP id 4BB0863B144 for ; Sat, 16 Sep 2006 22:00:08 +0000 (UTC) Received: by chiark.greenend.org.uk (Debian Exim 3.36 #1) with local (return-path jacobn@chiark.greenend.org.uk) id 1GOiCl-0002rO-00 for ietf-ssh@netbsd.org; Sat, 16 Sep 2006 23:00:07 +0100 Date: Sat, 16 Sep 2006 23:00:07 +0100 From: Jacob Nevins To: ietf-ssh@netbsd.org Subject: Last call comments for draft-ietf-secsh-publickey-subsystem-07 Message-ID: <20060916220007.GB2190@chiark.greenend.org.uk> Reply-To: ietf-ssh@netbsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.9i Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 1.1 (+) X-Scan-Signature: cd26b070c2577ac175cd3a6d878c6248 (Apologies for the lateness of these comments.) My main comment: 3: "Public key blob" specification is still too vague. It became clear when we were finishing off publickeyfile that the language that escaped to publication in 4253 is less than perfect, and has led to confusion in practice. The term "blob" is not explicitly defined in the reference, but where it is mentioned it seems to refer to something other than that which some people expect it to mean. Therefore, I think we should explicitly define what's required, as in publickeyfile-13. Assuming the same interpretation is required, the existing paragraph should be replaced with: In the following, "public-key blob" has the format specified in section 6.6, "Public Key Algorithms" of the SSH Transport Protocol document [2]: string certificate or public key format identifier byte[n] key/certificate data (Although in fact I'd rather we avoided the term "blob" entirely, as in publickeyfile, due to the conflict with 4253.) I believe that this interpretation matches at least one implementation (VanDyke's patch for OpenSSH) -- that implementation is rather old (it seems to correspond to the text circa draft-galb-secsh-publickey-subsystem-01), but this part of the protocol hasn't obviously changed. By way of example, I believe this is a well-formed "publickey" response according to this interpretation (although I haven't tested it): 00000000 00 00 00 B0 00 00 00 09 70 75 62 6C 69 63 6B 65 ........publicke 00000010 79 00 00 00 07 73 73 68 2D 64 73 73 00 00 00 90 y....ssh-dss.... 00000020 00 00 00 07 73 73 68 2D 64 73 73 00 00 00 20 73 ....ssh-dss... s 00000030 F9 F2 9C 4E 7A DD DF E0 17 49 92 73 75 1B 7C 0B ...Nz....I.su.|. 00000040 28 77 A2 CB 12 AA 03 97 8C AA B8 9A FB D6 D3 00 (w.............. 00000050 00 00 15 00 86 6E 41 6C 0B 64 99 87 F5 8D A8 DD .....nAl.d...... 00000060 05 E7 E1 4D 85 A3 49 5F 00 00 00 20 2B 22 75 CF ...M..I_... +"u. 00000070 04 3E F0 28 69 8B 82 D1 ED 65 F5 23 D3 EE 8F 9C .>.(i....e.#.... 00000080 FC 64 41 B3 C2 D2 C5 25 2F 4C 9C 45 00 00 00 20 .dA....%/L.E... 00000090 07 67 23 4D A8 C0 3F 7F F2 50 1A C0 5F CF D1 A2 .g#M..?..P.._... 000000A0 4F 65 64 07 2A A7 CF 3C 8B 39 7A 38 59 B5 A2 F3 Oed.*..<.9z8Y... 000000B0 00 00 00 00 .... (Yes, the algorithm name does appear twice on the wire.) Other, minor comments: Section 4 "Requests and responses": I don't understand what the last paragraph means. Is it meant to imply that a version of other than 2 could change the semantics of any and all "name" and data parts? 4.1: attributes: "x11", "shell", "exec" etc: "The attribute-value field SHOULD be empty": why not MUST? (Nit, as this doesn't create any actual ambiguity.) "from" (etc): is it worth spelling out what a "host" is in the "comma-separated list of hosts"? (I presume FQDNs, and IP addresses -- IPv4, IPv6, whatever. No wildcards, suffix matching etc.) 6.2.1 "Conventions for names": Nit: To reduce confusion, it might be worth changing the example of a locally defined name from "ourcipher-cbc@example.com" to something more appropriate to the context, say "ourattr@example.com". Status codes duplicated in 3.3.1 and 6.6.2 (consistently). I reckon 3.3.1 should instead refer to 6.6.2. Nit: 6.6.3 says "message numbers" twice where it should say "status codes". From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Wed Sep 27 15:16:30 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GSetS-00086D-TY for secsh-tyoxbijeg7-archive@lists.ietf.org; Wed, 27 Sep 2006 15:16:30 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GSetR-0000kv-FC for secsh-tyoxbijeg7-archive@lists.ietf.org; Wed, 27 Sep 2006 15:16:30 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 8E56463B163; Wed, 27 Sep 2006 19:16:13 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from mail.siliconcircus.com (mail.siliconcircus.com [62.141.33.102]) by mail.netbsd.org (Postfix) with ESMTP id 616A563B117 for ; Wed, 27 Sep 2006 19:16:08 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by mail.siliconcircus.com (Postfix) with ESMTP id 5626D10C39E for ; Wed, 27 Sep 2006 21:15:58 +0200 (CEST) Message-ID: <451ACDF0.6080407@siliconcircus.com> Date: Wed, 27 Sep 2006 21:16:00 +0200 From: Jon Bright User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: ietf-ssh@netbsd.org Subject: Re: Last call comments for draft-ietf-secsh-publickey-subsystem-07 References: <20060916220007.GB2190@chiark.greenend.org.uk> In-Reply-To: <20060916220007.GB2190@chiark.greenend.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 1.1 (+) X-Scan-Signature: c3a18ef96977fc9bcc21a621cbf1174b Hi, Jacob Nevins wrote: > (Apologies for the lateness of these comments.) Apologies for the delay in replying. > > In the following, "public-key blob" has the format specified > in section 6.6, "Public Key Algorithms" of the SSH Transport > Protocol document [2]: > > string certificate or public key format identifier > byte[n] key/certificate data > > (Although in fact I'd rather we avoided the term "blob" entirely, as > in publickeyfile, due to the conflict with 4253.) The suggestion seems OK. I'm not sure what word other than "blob" we could use. "public key object"? "public key representation"? Since we're in IESG evaluation now, I'm not sure what the process is for integrating such a change. If I can issue another rev, I will (unless someone speaks up against it) include this change. > By way of example, I believe this is a well-formed "publickey" > response according to this interpretation (although I haven't tested > it): I agree that it's well formed. > (Yes, the algorithm name does appear twice on the wire.) Confused me when implementing 4253, too. > Other, minor comments: > > Section 4 "Requests and responses": > > I don't understand what the last paragraph means. > Is it meant to imply that a version of other than 2 could change the > semantics of any and all "name" and data parts? Assuming you meant the last paragraph of 3.2: No, it's just meant to clarify that we're not going to write out length every time. > 4.1: attributes: > > "x11", "shell", "exec" etc: "The attribute-value field SHOULD be > empty": why not MUST? (Nit, as this doesn't create any actual > ambiguity.) It's not necessary for interoperability (at least not with peers implementing version 2 between one another). It's not an absolute requirement that the attribute-value be empty, the presence or absence of the attribute is decisive. As such, I believe SHOULD to be the correct 2119ish. > "from" (etc): is it worth spelling out what a "host" is in the > "comma-separated list of hosts"? (I presume FQDNs, and IP addresses -- > IPv4, IPv6, whatever. No wildcards, suffix matching etc.) IESG review has turned up a similar comment. I guess a clarification that the from list are FQDNs or IP addresses would work. Again, if another rev happens, it'll include this. > 6.2.1 "Conventions for names": > Nit: To reduce confusion, it might be worth changing the example of a > locally defined name from "ourcipher-cbc@example.com" to something > more appropriate to the context, say "ourattr@example.com". Agreed. Ditto another-rev comment from above. > Status codes duplicated in 3.3.1 and 6.6.2 (consistently). > I reckon 3.3.1 should instead refer to 6.6.2. Hm, I think I disagree. 3.3.1 is defining stuff for the purposes of the protocol. Unless you happen to be IANA, I'm guessing you could pretty much cut off section 6... > Nit: 6.6.3 says "message numbers" twice where it should say "status codes". True, will change if possible. -- Jon Bright From bounces-ietf-ssh-owner-secsh-tyoxbijeg7-archive=lists.ietf.org@NetBSD.org Thu Sep 28 15:20:31 2006 Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1GT1Qt-0003OL-P9 for secsh-tyoxbijeg7-archive@lists.ietf.org; Thu, 28 Sep 2006 15:20:31 -0400 Received: from mail.netbsd.org ([2001:4f8:4:7:2e0:81ff:fe52:9ab6]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1GT1Qq-0003pm-TO for secsh-tyoxbijeg7-archive@lists.ietf.org; Thu, 28 Sep 2006 15:20:31 -0400 Received: by mail.netbsd.org (Postfix, from userid 0) id 4693D63B221; Thu, 28 Sep 2006 19:20:15 +0000 (UTC) X-Original-To: ietf-ssh@netbsd.org Delivered-To: ietf-ssh@netbsd.org Received: from carter-zimmerman.mit.edu (carter-zimmerman.suchdamage.org [69.25.196.178]) by mail.netbsd.org (Postfix) with ESMTP id 36FC963B21C for ; Thu, 28 Sep 2006 19:20:14 +0000 (UTC) Received: by carter-zimmerman.mit.edu (Postfix, from userid 8042) id 0A3A2E0127; Thu, 28 Sep 2006 15:19:57 -0400 (EDT) From: Sam Hartman To: ietf-ssh@netbsd.org Subject: IESG comments on draft-ietf-secsh-publickey-subsystem Date: Thu, 28 Sep 2006 15:19:57 -0400 Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: ietf-ssh-owner@NetBSD.org Precedence: list X-Spam-Score: 0.1 (/) X-Scan-Signature: ffa9dfbbe7cc58b3fa6b8ae3e57b0aa3 Hi, folks, the IESG evaluated the publickey subsystem draft today and approved it pending some edits. https://datatracker.ietf.org/public/pidtracker.cgi?command=print_ballot&ballot_id=2239&filename=draft-ietf-secsh-publickey-subsystem contains the IESG comments. Please make the following changes and submit a new version: * Update the IANA considerations section per my note to IANA on which the authors were copied. In particular, add Publickey Subsystem in front of the names of all the subregistries that are created. * Add text in accordance with the secdir review I comment I agreed with. * Consider the IESG comments referenced above and if appropriate add text to address them. If not, respond to the IESg member explaining why you chose not to address the comment. These are non-blocking comments; don't engage in a long dialogue as the IESG has already signed off, but do be responsive. Thanks, --Sam