Draft Ident MIB Jul 92 Ident MIB Tue Jul 31 14:50:52 1992 Michael St. Johns U.S. Department of Defense stjohns@UMD5.UMD.EDU Marshall T. Rose Dover Beach Consulting, Inc. mrose@dbc.mtview.ca.us 1. Status of this Memo This document is an Internet Draft. 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. Internet Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet Drafts as reference material or to cite them other than as a "working draft" or "work in progress". Please check the 1id-abstracts.txt listing contained in the internet-drafts Shadow Directories on nic.ddn.mil, nnsc.nsf.net, nic.nordu.net, ftp.nisc.sri.com, or munnari.oz.au to learn the current status of any Internet Draft. 2. Abstract This memo defines a MIB for use with identifying the users associated with TCP connections. It provides functionality St. Johns, Rose Expires January 31, 1993 [Page 1]
Draft Ident MIB Jul 92 approximately equivalent to that provided by the protocol defined in RFC 931[1]. St. Johns, Rose Expires January 31, 1993 [Page 2]
Draft Ident MIB Jul 92 3. The Network Management Framework The Internet-standard Network Management Framework consists of three components. They are: RFC 1155[2] which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. RFC 1212[3] defines a more concise description mechanism, which is wholly consistent with the SMI. RFC 1213[4] which defines MIB-II, the core set of managed objects for the Internet suite of protocols. RFC 1157[5] which defines the SNMP, the protocol used for network access to managed objects. The Framework permits new objects to be defined for the purpose of experimentation and evaluation. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Within a given MIB module, objects are defined using RFC 1212's OBJECT-TYPE macro. At a minimum, each object has a name, a syntax, an access-level, and an implementation-status. The name is an object identifier, an administratively assigned name, which specifies an object type. The object type together with an object instance serves to uniquely identify a specific instantiation of the object. For human convenience, we often use a textual string, termed the object descriptor, to also refer to the object type. The syntax of an object type defines the abstract data structure corresponding to that object type. The ASN.1[6] language is used for this purpose. However, RFC 1155 purposely restricts the ASN.1 constructs which may be used. These restrictions are explicitly made for simplicity. The access-level of an object type defines whether it makes "protocol sense" to read and/or write the value of an instance of the object type. (This access-level is independent of any administrative authorization policy.) The implementation-status of an object type indicates whether the object is mandatory, optional, obsolete, or deprecated. St. Johns, Rose Expires January 31, 1993 [Page 3]
Draft Ident MIB Jul 92 4. Ident MIB The Ident MIB defines a uniform set of objects useful for identifying users associated with TCP connections. End- systems which support TCP may, at their option, implement this MIB. However, administrators should read Section 6 ("Security Considerations") before enabling these MIB objects. St. Johns, Rose Expires January 31, 1993 [Page 4]
Draft Ident MIB Jul 92 5. Definitions RFC-ident-MIB DEFINITIONS ::= BEGIN IMPORTS experimental FROM RFC-1155 OBJECT-TYPE FROM RFC-1212 tcpConnLocalAddress, tcpConnLocalPort, tcpConnRemAddress, tcpConnRemPort FROM RFC1213-MIB; ident OBJECT IDENTIFIER ::= { experimental 33 } -- conformance groups identInfo OBJECT IDENTIFIER ::= { ident 1 } -- textual conventions -- none St. Johns, Rose Expires January 31, 1993 [Page 5]
Draft Ident MIB Jul 92 -- the ident information system group -- -- implementation of this group is mandatory identTable OBJECT-TYPE SYNTAX SEQUENCE OF IdentEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "A table containing user information for TCP connections. Note that this table contains entries for all TCP connections on a managed system. The corresponding instance of tcpConnState (defined in MIB-II) indicates the state of a particular connection." ::= { identInfo 1 } identEntry OBJECT-TYPE SYNTAX IdentEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "User information about a particular TCP connection." INDEX { tcpConnLocalAddress, tcpConnLocalPort, tcpConnRemAddress, tcpConnRemPort } ::= { identTable 1 } IdentEntry ::= SEQUENCE { identStatus INTEGER, identOpSys OBJECT IDENTIFIER, identCharset OBJECT IDENTIFIER, identUserid OCTET STRING, identMisc OCTET STRING } identStatus OBJECT-TYPE SYNTAX INTEGER { noError(1), unknownError(2) } ACCESS read-only St. Johns, Rose Expires January 31, 1993 [Page 6]
Draft Ident MIB Jul 92 STATUS mandatory DESCRIPTION "Indicates whether user information for the associated TCP connection can be determined. A value of `noError(1)' indicates that user information is available. A value of `unknownError(2)' indicates that user information is not available." ::= { identEntry 1 } identOpSys OBJECT-TYPE SYNTAX OBJECT IDENTIFIER ACCESS read-only STATUS mandatory DESCRIPTION "Indicates the type of operating system in use. In addition to identifying an operating system, each assignment made for this purpose also (implicitly) identifies the textual format and maximum size of the corresponding identUserid and identMisc objects. The `identSystems' subtree may be used by the IANA for assignments." ::= { identEntry 2 } identCharset OBJECT-TYPE SYNTAX OBJECT IDENTIFIER ACCESS read-only STATUS mandatory DESCRIPTION "Indicates the repertoire of the corresponding identUserid and identMisc objects. The `identCharsets' subtree may be used by the IANA for assignments." ::= { identEntry 3 } identUserid OBJECT-TYPE SYNTAX OCTET STRING (SIZE (0..255)) ACCESS read-only STATUS mandatory DESCRIPTION "Indicates the user's identity. Interpretation of this object requires examination of the St. Johns, Rose Expires January 31, 1993 [Page 7]
Draft Ident MIB Jul 92 corresponding value of the identOpSys and identCharset objects." ::= { identEntry 4 } identMisc OBJECT-TYPE SYNTAX OCTET STRING (SIZE (0..255)) ACCESS read-only STATUS mandatory DESCRIPTION "Indicates miscellaneous information about the user. Interpretation of this object requires examination of the corresponding value of the identOpSys and identCharset objects." ::= { identEntry 5 } St. Johns, Rose Expires January 31, 1993 [Page 8]
Draft Ident MIB Jul 92 -- operating system assignments, used for identOpSys identSystems OBJECT IDENTIFIER ::= { ident 2 } -- when the Assigned Numbers "system name" is UNIX identSysUnix OBJECT IDENTIFIER ::= { identSystems 1 } -- when identOpSys has the value identSysUnix: -- -- identUserid corresponds to the UNIX username (pw_name) -- of length 1 to 8 octets -- -- the syntax (and length) of identMisc is a local matter St. Johns, Rose Expires January 31, 1993 [Page 9]
Draft Ident MIB Jul 92 -- character set assignments, used for identCharset identCharsets OBJECT IDENTIFIER ::= { ident 3 } -- the NVT ASCII repertoire charsetNvtAscii OBJECT IDENTIFIER ::= { identCharsets 1 } END St. Johns, Rose Expires January 31, 1993 [Page 10]
Draft Ident MIB Jul 92 6. Security Considerations The information available through this MIB is at most as trustworthy as the host providing it OR the organization operating the host. For example, a PC in an open lab has few if any controls on it to prevent a user from having an SNMP query return any identifier the user wants. Likewise, if the host has been compromised the information returned may be completely erroneous and misleading. This portion of the MIB space should only be used to gain hints as to who "owns" a particular TCP connection -- information returned should NOT be considered authoritative for at least the reasons described above. At best, this MIB provides some additional auditing information with respect to TCP connections. At worse it can provide misleading, incorrect or maliciously incorrect information. The use of the information contained in this MIB for other than auditing or normal network management functions is strongly discouraged. Specifically, using information from this MIB space to make access control decisions - either as the primary method (i.e no other checks) or as an adjunct to other methods may result in a weakening of normal system security. This MIB provides access to information about users, entities, objects or processes which some systems might normally consider private. The information accessible through this MIB is a rough analog of the CallerID services provided by some phone companies and many of the same privacy consideration and arguments that apply to CallerID service apply to this MIB space. If you wouldn't run a "finger" server[7] due to privacy considerations, you might not want to provide access to this MIB space on a general basis. Access to this portion of the MIB tree may be controlled under the normal methods available through SNMP agent implementations. St. Johns, Rose Expires January 31, 1993 [Page 11]
Draft Ident MIB Jul 92 7. References [1] M. St. Johns, Authentication Server. Request for Comments 931, (May, 1990). [2] M.T. Rose and K. McCloghrie, Structure and Identification of Management Information for TCP/IP-based internets. Request for Comments 1155, (May, 1990). [3] M.T. Rose and K. McCloghrie, Concise MIB Definitions. Request for Comments 1212, (March, 1991). [4] K. McCloghrie and M.T. Rose, Management Information Base for Network Management of TCP/IP-based internets: MIB-II. Request for Comments 1213, (March, 1991). [5] J.D. Case, M.S. Fedor, M.L. Schoffstall, and J.R. Davin, Simple Network Management Protocol. Request for Comments 1157, (May, 1990). [6] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization. International Standard 8824, (December, 1987). [7] D.P. Zimmerman, Finger User Information Protocol. Request for Comments 1288, (December, 1991). St. Johns, Rose Expires January 31, 1993 [Page 12]
Draft Ident MIB Jul 92 Table of Contents 1 Status of this Memo ................................... 1 2 Abstract .............................................. 1 3 The Network Management Framework ...................... 3 4 Ident MIB ............................................. 4 5 Definitions ........................................... 5 5.1 Conformance Groups .................................. 5 5.2 Textual Conventions ................................. 5 5.3 The Ident information Group ......................... 6 5.4 Operating System Assignments ........................ 9 5.4.1 identSysUnix ...................................... 9 5.5 Character Set Assignments ........................... 10 5.5.1 charsetNvtAscii ................................... 10 6 Security Considerations ............................... 11 7 References ............................................ 12 St. Johns, Rose Expires January 31, 1993 [Page 13]