ENTERASYS-ENCR-8021X-REKEYING-MIB ENTERASYS-ENCR-8021X-REKEYING-MIB DEFINITIONS ::= BEGIN -- enterasys-encr-8021x-rekeying-mib.txt -- -- Part Number: -- -- -- This module provides authoritative definitions for Enterasys -- Networks' encrypted IEEE 802.1x rapid rekeying MIB. -- -- This module will be extended, as needed. -- Enterasys Networks reserves the right to make changes in this -- specification and other information contained in this document -- without prior notice. The reader should consult Enterasys Networks -- to determine whether any such changes have been made. -- -- In no event shall Enterasys Networks be liable for any incidental, -- indirect, special, or consequential damages whatsoever (including -- but not limited to lost profits) arising out of or related to this -- document or the information contained in it, even if Enterasys -- Networks has been advised of, known, or should have known, the -- possibility of such damages. -- -- Enterasys Networks grants vendors, end-users, and other interested -- parties a non-exclusive license to use this Specification in -- connection with the management of Enterasys Networks products. -- Copyright March, 2002 Enterasys Networks, Inc. IMPORTS MODULE-IDENTITY, OBJECT-TYPE FROM SNMPv2-SMI -- TruthValue -- FROM SNMPv2-TC MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF dot1xPaePortNumber FROM IEEE8021-PAE-MIB etsysModules FROM ENTERASYS-MIB-NAMES; etsysEncr8021xRekeyingMIB MODULE-IDENTITY LAST-UPDATED "200203142049Z" -- Thu Mar 14 20:49 GMT 2002 ORGANIZATION "Enterasys Networks, Inc" CONTACT-INFO "Postal: Enterasys Networks 35 Industrial Way, P.O. Box 5005 Rochester, NH 03867-0505 Phone: +1 603 332 9400 E-mail: support@enterasys.com WWW: http://www.enterasys.com" -- This is the overall description of this MIB module DESCRIPTION "The Enterasys Networks MIB module for configuring rapid rekeying on SNMPv1-only platforms. This MIB includes encrypted variants of selected objects from the Enterasys 802.1x Rapid Rekeying MIB. ------------------ N O T I C E Use of this MIB in any product requires the approval of the Office of the CTO, Enterasys Networks, Inc. Permission to use this MIB will not be granted for products in which SNMPv3 is now, or will soon be, implemented. Permission to use this MIB in products that are never scheduled to implement SNMPv3 will be granted on a case-by-case basis, depending on what other suitable, secure means of configuration are available in the product. ------------------ The following is a discussion of the encoding/decoding and encryption/decryption methods that must be used to extract data from an encrypted OCTET STRING. (These methods are the same as for the Enterasys Networks encrypted RADIUS Client MIB.) The encryption/decryption methods make use of an agreed-upon Secret and an Authenticator shared between the SNMP network management system and the entity that implements the MIB. The encryption/decryption algorithm, as presented herein, is taken from the RADIUS protocol, and is the method specified for encryption of Tunnel-Password Attributes in RFC 2868. To permit plug-and-play remote installation, configuration, and management of the device, the device will algorithmically derive the initial shared secret and the initial authenticator. For security reasons, the network manager should change the authenticator portion of the management encryption key after initial configuration. The methods available for doing this are implementation-specific and subject to change. (On the RoamAbout AccessPoint 2000, the encrypted RADIUS client MIB contains an authenticator object used for both that MIB and this one.) All read-write and write-only access objects except the table index are encoded into fields in an OCTET STRING. Octet String Before encryption, the 'native' objects must be encoded into a formatted Octet String. After decryption, the Octet String must be decoded to obtain the 'native' objects. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Salt | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | String ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type The data type of the non-encrypted 'native' data: 1 = Integer32 2 = OCTET STRING Length The length in octets of the native object sub-field of the Octet String, exclusive of any optional padding. Note that the Integrity Check sub-fields (CRC, OID-tail, Time Stamp, Source IP Address) are not included in this length value, but since the IC sub-fields are always present and are of fixed length, there is no impediment to proper packet parsing. Salt The Salt field is two octets in length and is used to ensure the uniqueness of the encryption key used to encrypt each object. The most significant bit (leftmost) of the Salt field MUST be set (1). The contents of each Salt field in a given SNMP packet must be unique. String 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CRC (4 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OID-tail (4 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Time Stamp (4 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source IP Address (4 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Object/Padding ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The plain-text String field consists of six logical sub-fields: the CRC, OID-tail, Time Stamp, Source IP address and native Object sub-fields (all of which are required), and the optional Padding sub-field. The String field MUST be treated as a counted-string of undistinguished octets, and not as a standard C/UNIX-style null-terminated, printable ASCII string. CRC Sub-field The CRC sub-field contains a 32-bit CRC (CRC-32) calculated over the following concatentated sub-fields of the String: the OID-tail, Time Stamp, Source IP Address and unpadded native Object fields. The CRC sub-field acts as an integrity check on the decrypted data. OID-tail Sub-field The OID-tail sub-field contains the least significant four octets of the Object ID of the varbind. This field is included as an integrity check on the OID of the varbind. Time Stamp Sub-field The Time Stamp sub-field contains a 32-bit unsigned integer value representing the time the encrypted message was assembled. This field acts as an integrity check by facilitating the disposal of stale or replayed messages. The time window of acceptance is implementation dependant, and may be the subject of local (i.e. managed entity) policy configuration. The Time Stamp is relative time, in units of seconds, referenced to the sysUpTime object of the managed entity. Source IP Address Sub-field The Source IP Address sub-field contains an unsigned 32-bit representation of the IPv4 address of the source of the encrypted message. This is an added check to allow verification of the source of the varbind. The CRC, OID-tail, Time Stamp, and Source IP Address sub-fields are collectively hereinafter refered to as the Integrity Check (IC) sub-fields. Object/Padding Sub-field Object The Object sub-field contains the actual or native object data followed by padding, if necessary. Padding If the combined length (in octets) of the non-encrypted CRC, OID-tail, Time Stamp, Source IP Address, and native Object sub-fields is not an even multiple of 16, then the Padding sub-field MUST be present. If it is present, the length of the Padding sub-field is variable, between 1 and 15 octets. The value of the pad octets SHOULD be zero. Encrypting/Decrypting the String Field The entire String field MUST be encrypted as follows, prior to transmission: Construct a plain-text version of the String field by concatenating the CRC, OID-tail, Time Stamp, Source IP address, and native Object sub-fields. If necessary, pad the resulting string until its length (in octets) is an even multiple of 16. It is recommended that zero octets (0x00) be used for padding. Call this plain-text P. Shared Secret The shared secret is formed from the MAC (hardware) address of the primary management interface of the managed device (containing the RADIUS Client). The MAC address is represented as up-cased, dashed-ASCII, e.g. 08-00-2B-11-22-33. Authenticator The 128-bit authenticator is a pre-defined constant. The default value of the authenticator is an Enterasys Networks trade secret. This value is settable and the user is advised to change it from the default value after initial configuration of the system. Contact the MIB author for additional information on the default value. Call the shared secret S, the [pseudo-random] 128-bit Authenticator R, and the contents of the Salt field A. Break P into 16 octet chunks p(1), p(2)...p(i), where i = len(P)/16. Call the cipher-text blocks c(1), c(2)...c(i) and the final cipher-text C. Intermediate values b(1), b(2)...c(i) are required. Encryption is performed in the following manner ('+' indicates concatenation): b(1) = MD5(S + R + A) c(1) = p(1) xor b(1) C = c(1) b(2) = MD5(S + c(1)) c(2) = p(2) xor b(2) C = C + c(2) . . . . . . b(i) = MD5(S + c(i-1)) c(i) = p(i) xor b(i) C = C + c(i) The resulting encrypted String field will contain c(1)+c(2)+...+c(i). On receipt, the process is reversed to yield the plain-text String." REVISION "200203142049Z" -- Thu Mar 14 20:49 GMT 2002 DESCRIPTION "The initial version of this MIB module." ::= { etsysModules 20 } etsysEncrDot1xRekeyingObjects OBJECT IDENTIFIER ::= { etsysEncr8021xRekeyingMIB 1 } -- ---------------------------------------------------------- -- -- Textual Conventions -- ---------------------------------------------------------- -- -- ---------------------------------------------------------- -- -- Branches of the Enterasys IEEE 802.1x Rapid Rekeying MIB -- ---------------------------------------------------------- -- etsysEncrDot1xRekeyBaseBranch OBJECT IDENTIFIER ::= { etsysEncrDot1xRekeyingObjects 1 } -- ---------------------------------------------------------- -- -- The Rapid Rekeying Configuration Table -- ---------------------------------------------------------- -- etsysEncrDot1xRekeyConfigTable OBJECT-TYPE SYNTAX SEQUENCE OF EtsysEncrDot1xRekeyConfigEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A table that contains encryption-key-related configuration objects for ports on which Authenticator PAEs can run." ::= { etsysEncrDot1xRekeyBaseBranch 1 } etsysEncrDot1xRekeyConfigEntry OBJECT-TYPE SYNTAX EtsysEncrDot1xRekeyConfigEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Each conceptual row holds encryption key configuration information for the Authenticator PAEs associated with one port." INDEX { dot1xPaePortNumber } ::= { etsysEncrDot1xRekeyConfigTable 1 } EtsysEncrDot1xRekeyConfigEntry ::= SEQUENCE { etsysEncrDot1xRekeyEnabled OCTET STRING, etsysEncrDot1xRekeyPeriod OCTET STRING, etsysEncrDot1xRekeyLength OCTET STRING, etsysEncrDot1xRekeyAsymmetric OCTET STRING } etsysEncrDot1xRekeyEnabled OBJECT-TYPE SYNTAX OCTET STRING (SIZE(0..255)) -- encrypted TruthValue MAX-ACCESS read-write STATUS current DESCRIPTION "An encrypted version of etsysDot1xRekeyEnabled. Determines how an access point selects radio encryption keys. If the selected port does not support the EAPOL-Key feature (e.g., because radio keys are not applicable to Ethernet ports), this object will have a value of FALSE and attempts to write TRUE will fail. Normally, if radio keys are present, the manager enters them into the access point through some manual process. The manager or the users may also need to configure the keys into each laptop (access points can distribute the keys automatically to 802.1x EAP-TLS clients). However laptops get keys, the keys remain static until somebody goes to the trouble of changing them. If the keys stay unchanged for long periods, this can make it easier for a determined attacker to launch a cryptographic attack. When rapid rekeying is enabled, an access point ignores its manually-set keys. It generates pseudo-random keys on a periodic basis, using IEEE 802.1x key distribution to deliver the keys to new and current clients. Do not enable rapid rekeying unless ALL of your clients support IEEE 802.1x and an authentication method (e.g., EAP-TLS) that supports key distribution. Before enabling rapid rekeying, make sure that you have set 'dot1xAuthKeyTxEnabled' to TRUE. Changing the keys without telling any of the clients about the changes is not a very useful mode of operation. The data type is 1, Integer32." -- DEFVAL { encrypt(false) } ::= { etsysEncrDot1xRekeyConfigEntry 1 } etsysEncrDot1xRekeyPeriod OBJECT-TYPE SYNTAX OCTET STRING (SIZE(0..255)) -- encrypted Unsigned32 MAX-ACCESS read-write STATUS current DESCRIPTION "An encrypted version of etsysDot1xRekeyPeriod. When rapid rekeying (periodic changing of radio keys) is enabled, the value of this object determines the period, in seconds, between key changes. The data type is 1, Integer32." -- DEFVAL { encrypt(1800) } ::= { etsysEncrDot1xRekeyConfigEntry 2 } etsysEncrDot1xRekeyLength OBJECT-TYPE SYNTAX OCTET STRING (SIZE(0..255)) -- encrypted enumeration MAX-ACCESS read-write STATUS current DESCRIPTION "An encrypted version of etsysDot1xRekeyLength. SYNTAX INTEGER { keylen40 (1), keylen128 (2) } Determines the number of bits/bytes used in the encryption keys. Currently supports either 128-bit (16-octet) encryption keys or 40-bit (5-octet) encryption keys. The data type is 1, Integer32." -- DEFVAL { encrypt(keylen128) } ::= { etsysEncrDot1xRekeyConfigEntry 3 } etsysEncrDot1xRekeyAsymmetric OBJECT-TYPE SYNTAX OCTET STRING (SIZE(0..255)) -- encrypted TruthValue MAX-ACCESS read-write STATUS current DESCRIPTION "An encrypted version of etsysDot1xRekeyAsymmetric. Determines the association between the supplicant and authenticator transmit keys. If true(1), the authenticator and supplicant will use different encryption keys in order to transmit data. If false(2), the authenticator and supplicant will use a single key pattern to encrypt the transmitted data. The data type is 1, Integer32." -- DEFVAL { encrypt(true) } ::= { etsysEncrDot1xRekeyConfigEntry 4 } -- ---------------------------------------------------------- -- -- Enterasys 802.1X Rekeying MIB - Conformance Information -- ---------------------------------------------------------- -- etsysEncrDot1xRekeyingConformance OBJECT IDENTIFIER ::= { etsysEncr8021xRekeyingMIB 2 } etsysEncrDot1xRekeyingGroups OBJECT IDENTIFIER ::= { etsysEncrDot1xRekeyingConformance 1 } etsysEncrDot1xRekeyingCompliances OBJECT IDENTIFIER ::= { etsysEncrDot1xRekeyingConformance 2 } -- ---------------------------------------------------------- -- -- Units of conformance -- ---------------------------------------------------------- -- etsysEncrDot1xRekeyingBaseGroup OBJECT-GROUP OBJECTS { etsysEncrDot1xRekeyPeriod, etsysEncrDot1xRekeyEnabled, etsysEncrDot1xRekeyLength, etsysEncrDot1xRekeyAsymmetric } STATUS current DESCRIPTION "A collection of objects providing rekeying configuration information about a port on which Authenticator PAEs can run." ::= { etsysEncrDot1xRekeyingGroups 1 } -- ---------------------------------------------------------- -- -- Compliance statements -- ---------------------------------------------------------- -- etsysEncrDot1xRekeyingCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "The compliance statement for devices that support the Enterasys IEEE 802.1x extensions MIB." MODULE MANDATORY-GROUPS { etsysEncrDot1xRekeyingBaseGroup } OBJECT etsysEncrDot1xRekeyEnabled MIN-ACCESS read-only DESCRIPTION "Write access is not required." OBJECT etsysEncrDot1xRekeyPeriod MIN-ACCESS read-only DESCRIPTION "Write access is not required." OBJECT etsysEncrDot1xRekeyLength MIN-ACCESS read-only DESCRIPTION "Write access is not required. Depending upon product capabilities (and export restrictions, if applicable), some systems may not implement all key lengths." OBJECT etsysEncrDot1xRekeyAsymmetric MIN-ACCESS read-only DESCRIPTION "Write access is not required." ::= { etsysEncrDot1xRekeyingCompliances 1 } END