1 SNMP-USM-DH-OBJECTS-MIB DEFINITIONS ::= BEGIN
4 MODULE-IDENTITY, OBJECT-TYPE,
6 experimental, Integer32
10 MODULE-COMPLIANCE, OBJECT-GROUP
13 FROM SNMP-USER-BASED-SM-MIB
15 FROM SNMP-FRAMEWORK-MIB;
17 snmpUsmDHObjectsMIB MODULE-IDENTITY
18 LAST-UPDATED "200003060000Z" -- 6 March 2000, Midnight
19 ORGANIZATION "Excite@Home"
20 CONTACT-INFO "Author: Mike StJohns
23 Redwood City, CA 94063
24 Email: stjohns@corp.home.net
25 Phone: +1-650-556-5368"
28 "The management information definitions for providing forward
29 secrecy for key changes for the usmUserTable, and for providing a
30 method for 'kickstarting' access to the agent via a Diffie-Helman
33 REVISION "200003060000Z"
35 "Initial version published as RFC 2786."
38 ::= { experimental 101 } -- IANA DHKEY-CHANGE 101
40 -- Administrative assignments
42 usmDHKeyObjects OBJECT IDENTIFIER ::= { snmpUsmDHObjectsMIB 1 }
43 usmDHKeyConformance OBJECT IDENTIFIER ::= { snmpUsmDHObjectsMIB 2 }
45 -- Textual conventions
47 DHKeyChange ::= TEXTUAL-CONVENTION
50 "Upon initialization, or upon creation of a row containing an
51 object of this type, and after any successful SET of this value, a
52 GET of this value returns 'y' where y = g^xa MOD p, and where g is
53 the base from usmDHParameters, p is the prime from
54 usmDHParameters, and xa is a new random integer selected by the
55 agent in the interval 2^(l-1) <= xa < 2^l < p-1. 'l' is the
56 optional privateValueLength from usmDHParameters in bits. If 'l'
57 is omitted, then xa (and xr below) is selected in the interval 0
58 <= xa < p-1. y is expressed as an OCTET STRING 'PV' of length 'k'
62 y = SUM 2^(8(k-i)) PV'i
65 where PV1,...,PVk are the octets of PV from first to last, and
68 A successful SET consists of the value 'y' expressed as an OCTET
69 STRING as above concatenated with the value 'z'(expressed as an
70 OCTET STRING in the same manner as y) where z = g^xr MOD p, where
71 g, p and l are as above, and where xr is a new random integer
72 selected by the manager in the interval 2^(l-1) <= xr < 2^l <
73 p-1. A SET to an object of this type will fail with the error
74 wrongValue if the current 'y' does not match the 'y' portion of
75 the value of the varbind for the object. (E.g. GET yout, SET
76 concat(yin, z), yout <> yin).
78 Note that the private values xa and xr are never transmitted from
79 manager to device or vice versa, only the values y and z.
80 Obviously, these values must be retained until a successful SET on
81 the associated object.
83 The shared secret 'sk' is calculated at the agent as sk = z^xa MOD
84 p, and at the manager as sk = y^xr MOD p.
86 Each object definition of this type MUST describe how to map from
87 the shared secret 'sk' to the operational key value used by the
88 protocols and operations related to the object. In general, if n
89 bits of key are required, the author suggests using the n
90 right-most bits of the shared secret as the operational key value."
92 "-- Diffie-Hellman Key-Agreement Standard, PKCS #3;
93 RSA Laboratories, November 1993"
96 -- Diffie Hellman public values
98 usmDHPublicObjects OBJECT IDENTIFIER ::= { usmDHKeyObjects 1 }
100 usmDHParameters OBJECT-TYPE
102 MAX-ACCESS read-write
105 "The public Diffie-Hellman parameters for doing a Diffie-Hellman
106 key agreement for this device. This is encoded as an ASN.1
107 DHParameter per PKCS #3, section 9. E.g.
109 DHParameter ::= SEQUENCE {
112 privateValueLength INTEGER OPTIONAL }
115 Implementors are encouraged to use either the values from
116 Oakley Group 1 or the values of from Oakley Group 2 as specified
117 in RFC-2409, The Internet Key Exchange, Section 6.1, 6.2 as the
118 default for this object. Other values may be used, but the
119 security properties of those values MUST be well understood and
120 MUST meet the requirements of PKCS #3 for the selection of
121 Diffie-Hellman primes.
123 In addition, any time usmDHParameters changes, all values of
124 type DHKeyChange will change and new random numbers MUST be
125 generated by the agent for each DHKeyChange object."
127 "-- Diffie-Hellman Key-Agreement Standard, PKCS #3,
128 RSA Laboratories, November 1993
129 -- The Internet Key Exchange, RFC 2409, November 1998,
131 ::= { usmDHPublicObjects 1 }
133 usmDHUserKeyTable OBJECT-TYPE
134 SYNTAX SEQUENCE OF UsmDHUserKeyEntry
135 MAX-ACCESS not-accessible
138 "This table augments and extends the usmUserTable and provides
139 4 objects which exactly mirror the objects in that table with the
140 textual convention of 'KeyChange'. This extension allows key
141 changes to be done in a manner where the knowledge of the current
142 secret plus knowledge of the key change data exchanges (e.g. via
143 wiretapping) will not reveal the new key."
144 ::= { usmDHPublicObjects 2 }
146 usmDHUserKeyEntry OBJECT-TYPE
147 SYNTAX UsmDHUserKeyEntry
148 MAX-ACCESS not-accessible
151 "A row of DHKeyChange objects which augment or replace the
152 functionality of the KeyChange objects in the base table row."
153 AUGMENTS { usmUserEntry }
154 ::= {usmDHUserKeyTable 1 }
156 UsmDHUserKeyEntry ::= SEQUENCE {
157 usmDHUserAuthKeyChange DHKeyChange,
158 usmDHUserOwnAuthKeyChange DHKeyChange,
159 usmDHUserPrivKeyChange DHKeyChange,
160 usmDHUserOwnPrivKeyChange DHKeyChange
163 usmDHUserAuthKeyChange OBJECT-TYPE
165 MAX-ACCESS read-create
168 "The object used to change any given user's Authentication Key
169 using a Diffie-Hellman key exchange.
171 The right-most n bits of the shared secret 'sk', where 'n' is the
172 number of bits required for the protocol defined by
173 usmUserAuthProtocol, are installed as the operational
174 authentication key for this row after a successful SET."
175 ::= { usmDHUserKeyEntry 1 }
177 usmDHUserOwnAuthKeyChange OBJECT-TYPE
179 MAX-ACCESS read-create
182 "The object used to change the agents own Authentication Key
183 using a Diffie-Hellman key exchange.
185 The right-most n bits of the shared secret 'sk', where 'n' is the
186 number of bits required for the protocol defined by
187 usmUserAuthProtocol, are installed as the operational
188 authentication key for this row after a successful SET."
189 ::= { usmDHUserKeyEntry 2 }
191 usmDHUserPrivKeyChange OBJECT-TYPE
193 MAX-ACCESS read-create
196 "The object used to change any given user's Privacy Key using
197 a Diffie-Hellman key exchange.
199 The right-most n bits of the shared secret 'sk', where 'n' is the
200 number of bits required for the protocol defined by
201 usmUserPrivProtocol, are installed as the operational privacy key
202 for this row after a successful SET."
203 ::= { usmDHUserKeyEntry 3 }
205 usmDHUserOwnPrivKeyChange OBJECT-TYPE
207 MAX-ACCESS read-create
210 "The object used to change the agent's own Privacy Key using a
211 Diffie-Hellman key exchange.
213 The right-most n bits of the shared secret 'sk', where 'n' is the
214 number of bits required for the protocol defined by
215 usmUserPrivProtocol, are installed as the operational privacy key
216 for this row after a successful SET."
217 ::= { usmDHUserKeyEntry 4 }
219 usmDHKickstartGroup OBJECT IDENTIFIER ::= { usmDHKeyObjects 2 }
221 usmDHKickstartTable OBJECT-TYPE
222 SYNTAX SEQUENCE OF UsmDHKickstartEntry
223 MAX-ACCESS not-accessible
226 "A table of mappings between zero or more Diffie-Helman key
227 agreement values and entries in the usmUserTable. Entries in this
228 table are created by providing the associated device with a
229 Diffie-Helman public value and a usmUserName/usmUserSecurityName
230 pair during initialization. How these values are provided is
231 outside the scope of this MIB, but could be provided manually, or
232 through a configuration file. Valid public value/name pairs
233 result in the creation of a row in this table as well as the
234 creation of an associated row (with keys derived as indicated) in
235 the usmUserTable. The actual access the related usmSecurityName
236 has is dependent on the entries in the VACM tables. In general,
237 an implementor will specify one or more standard security names
238 and will provide entries in the VACM tables granting various
239 levels of access to those names. The actual content of the VACM
240 table is beyond the scope of this MIB.
242 Note: This table is expected to be readable without authentication
243 using the usmUserSecurityName 'dhKickstart'. See the conformance
244 statements for details."
245 ::= { usmDHKickstartGroup 1 }
247 usmDHKickstartEntry OBJECT-TYPE
248 SYNTAX UsmDHKickstartEntry
249 MAX-ACCESS not-accessible
253 "An entry in the usmDHKickstartTable. The agent SHOULD either
254 delete this entry or mark it as inactive upon a successful SET of
255 any of the KeyChange-typed objects in the usmUserEntry or upon a
256 successful SET of any of the DHKeyChange-typed objects in the
257 usmDhKeyChangeEntry where the related usmSecurityName (e.g. row of
258 usmUserTable or row of ushDhKeyChangeTable) equals this entry's
259 usmDhKickstartSecurityName. In otherwords, once you've changed
260 one or more of the keys for a row in usmUserTable with a
261 particular security name, the row in this table with that same
262 security name is no longer useful or meaningful."
264 INDEX { usmDHKickstartIndex }
265 ::= {usmDHKickstartTable 1 }
267 UsmDHKickstartEntry ::= SEQUENCE {
268 usmDHKickstartIndex Integer32,
269 usmDHKickstartMyPublic OCTET STRING,
270 usmDHKickstartMgrPublic OCTET STRING,
271 usmDHKickstartSecurityName SnmpAdminString
274 usmDHKickstartIndex OBJECT-TYPE
275 SYNTAX Integer32 (1..2147483647)
276 MAX-ACCESS not-accessible
279 "Index value for this row."
280 ::= { usmDHKickstartEntry 1 }
282 usmDHKickstartMyPublic OBJECT-TYPE
287 "The agent's Diffie-Hellman public value for this row. At
288 initialization, the agent generates a random number and derives
289 its public value from that number. This public value is published
290 here. This public value 'y' equals g^r MOD p where g is the from
291 the set of Diffie-Hellman parameters, p is the prime from those
292 parameters, and r is a random integer selected by the agent in the
293 interval 2^(l-1) <= r < p-1 < 2^l. If l is unspecified, then r is
294 a random integer selected in the interval 0 <= r < p-1
296 The public value is expressed as an OCTET STRING 'PV' of length
300 y = SUM 2^(8(k-i)) PV'i
303 where PV1,...,PVk are the octets of PV from first to last, and
307 The following DH parameters (Oakley group #2, RFC 2409, sec 6.1,
308 6.2) are used for this object:
311 p = FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1
312 29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD
313 EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245
314 E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED
315 EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE65381
320 "-- Diffie-Hellman Key-Agreement Standard, PKCS#3v1.4;
321 RSA Laboratories, November 1993
322 -- The Internet Key Exchange, RFC2409;
323 Harkins, D., Carrel, D.; November 1998"
324 ::= { usmDHKickstartEntry 2 }
326 usmDHKickstartMgrPublic OBJECT-TYPE
332 "The manager's Diffie-Hellman public value for this row. Note
333 that this value is not set via the SNMP agent, but may be set via
334 some out of band method, such as the device's configuration file.
335 The manager calculates this value in the same manner and using the
336 same parameter set as the agent does. E.g. it selects a random
337 number 'r', calculates y = g^r mod p and provides 'y' as the
338 public number expressed as an OCTET STRING. See
339 usmDHKickstartMyPublic for details.
341 When this object is set with a valid value during initialization,
342 a row is created in the usmUserTable with the following values:
344 usmUserEngineID localEngineID
345 usmUserName [value of usmDHKickstartSecurityName]
346 usmUserSecurityName [value of usmDHKickstartSecurityName]
347 usmUserCloneFrom ZeroDotZero
348 usmUserAuthProtocol usmHMACMD5AuthProtocol
349 usmUserAuthKeyChange -- derived from set value
350 usmUserOwnAuthKeyChange -- derived from set value
351 usmUserPrivProtocol usmDESPrivProtocol
352 usmUserPrivKeyChange -- derived from set value
353 usmUserOwnPrivKeyChange -- derived from set value
355 usmUserStorageType permanent
358 A shared secret 'sk' is calculated at the agent as sk =
359 mgrPublic^r mod p where r is the agents random number and p is the
360 DH prime from the common parameters. The underlying privacy key
361 for this row is derived from sk by applying the key derivation
362 function PBKDF2 defined in PKCS#5v2.0 with a salt of 0xd1310ba6,
363 and iterationCount of 500, a keyLength of 16 (for
364 usmDESPrivProtocol), and a prf (pseudo random function) of
365 'id-hmacWithSHA1'. The underlying authentication key for this row
366 is derived from sk by applying the key derivation function PBKDF2
367 with a salt of 0x98dfb5ac , an interation count of 500, a
368 keyLength of 16 (for usmHMAC5AuthProtocol), and a prf of
369 'id-hmacWithSHA1'. Note: The salts are the first two words in the
370 ks0 [key schedule 0] of the BLOWFISH cipher from 'Applied
371 Cryptography' by Bruce Schnier - they could be any relatively
372 random string of bits.
374 The manager can use its knowledge of its own random number and the
375 agent's public value to kickstart its access to the agent in a
376 secure manner. Note that the security of this approach is
377 directly related to the strength of the authorization security of
378 the out of band provisioning of the managers public value
379 (e.g. the configuration file), but is not dependent at all on the
380 strength of the confidentiality of the out of band provisioning
383 "-- Password-Based Cryptography Standard, PKCS#5v2.0;
384 RSA Laboratories, March 1999
385 -- Applied Cryptography, 2nd Ed.; B. Schneier,
386 Counterpane Systems; John Wiley & Sons, 1996"
387 ::= { usmDHKickstartEntry 3 }
389 usmDHKickstartSecurityName OBJECT-TYPE
390 SYNTAX SnmpAdminString
394 "The usmUserName and usmUserSecurityName in the usmUserTable
395 associated with this row. This is provided in the same manner and
396 at the same time as the usmDHKickstartMgrPublic value -
397 e.g. possibly manually, or via the device's configuration file."
398 ::= { usmDHKickstartEntry 4 }
400 -- Conformance Information
402 usmDHKeyMIBCompliances OBJECT IDENTIFIER ::= { usmDHKeyConformance 1 }
403 usmDHKeyMIBGroups OBJECT IDENTIFIER ::= { usmDHKeyConformance 2 }
405 -- Compliance statements
407 usmDHKeyMIBCompliance MODULE-COMPLIANCE
410 "The compliance statement for this module."
412 GROUP usmDHKeyMIBBasicGroup
414 "This group MAY be implemented by any agent which
415 implements the usmUserTable and which wishes to provide the
416 ability to change user and agent authentication and privacy
417 keys via Diffie-Hellman key exchanges."
419 GROUP usmDHKeyParamGroup
421 "This group MUST be implemented by any agent which
422 implements a MIB containing the DHKeyChange Textual
423 Convention defined in this module."
425 GROUP usmDHKeyKickstartGroup
427 "This group MAY be implemented by any agent which
428 implements the usmUserTable and which wishes the ability to
429 populate the USM table based on out-of-band provided DH
431 Any agent implementing this group is expected to provide
432 preinstalled entries in the vacm tables as follows:
434 In the usmUserTable: This entry allows access to the
435 system and dhKickstart groups
437 usmUserEngineID localEngineID
438 usmUserName 'dhKickstart'
439 usmUserSecurityName 'dhKickstart'
440 usmUserCloneFrom ZeroDotZero
441 usmUserAuthProtocol none
442 usmUserAuthKeyChange ''
443 usmUserOwnAuthKeyChange ''
444 usmUserPrivProtocol none
445 usmUserPrivKeyChange ''
446 usmUserOwnPrivKeyChange ''
448 usmUserStorageType permanent
451 In the vacmSecurityToGroupTable: This maps the initial
452 user into the accessible objects.
454 vacmSecurityModel 3 (USM)
455 vacmSecurityName 'dhKickstart'
456 vacmGroupName 'dhKickstart'
457 vacmSecurityToGroupStorageType permanent
458 vacmSecurityToGroupStatus active
460 In the vacmAccessTable: Group name to view name translation.
462 vacmGroupName 'dhKickstart'
463 vacmAccessContextPrefix ''
464 vacmAccessSecurityModel 3 (USM)
465 vacmAccessSecurityLevel noAuthNoPriv
466 vacmAccessContextMatch exact
467 vacmAccessReadViewName 'dhKickRestricted'
468 vacmAccessWriteViewName ''
469 vacmAccessNotifyViewName 'dhKickRestricted'
470 vacmAccessStorageType permanent
471 vacmAccessStatus active
473 In the vacmViewTreeFamilyTable: Two entries to allow the
474 initial entry to access the system and kickstart groups.
476 vacmViewTreeFamilyViewName 'dhKickRestricted'
477 vacmViewTreeFamilySubtree 1.3.6.1.2.1.1 (system)
478 vacmViewTreeFamilyMask ''
479 vacmViewTreeFamilyType 1
480 vacmViewTreeFamilyStorageType permanent
481 vacmViewTreeFamilyStatus active
483 vacmViewTreeFamilyViewName 'dhKickRestricted'
484 vacmViewTreeFamilySubtree (usmDHKickstartTable OID)
485 vacmViewTreeFamilyMask ''
486 vacmViewTreeFamilyType 1
487 vacmViewTreeFamilyStorageType permanent
488 vacmViewTreeFamilyStatus active
491 OBJECT usmDHParameters
494 "It is compliant to implement this object as read-only for
497 ::= { usmDHKeyMIBCompliances 1 }
499 -- Units of Compliance
501 usmDHKeyMIBBasicGroup OBJECT-GROUP
503 usmDHUserAuthKeyChange,
504 usmDHUserOwnAuthKeyChange,
505 usmDHUserPrivKeyChange,
506 usmDHUserOwnPrivKeyChange
511 ::= { usmDHKeyMIBGroups 1 }
513 usmDHKeyParamGroup OBJECT-GROUP
519 "The mandatory object for all MIBs which use the DHKeyChange
521 ::= { usmDHKeyMIBGroups 2 }
523 usmDHKeyKickstartGroup OBJECT-GROUP
525 usmDHKickstartMyPublic,
526 usmDHKickstartMgrPublic,
527 usmDHKickstartSecurityName
531 "The objects used for kickstarting one or more SNMPv3 USM
532 associations via a configuration file or other out of band,
533 non-confidential access."
534 ::= { usmDHKeyMIBGroups 3 }