1 2 3 4 5 6 7Network Working Group K. Zeilenga 8Request for Comments: 3062 OpenLDAP Foundation 9Category: Standards Track February 2001 10 11 12 LDAP Password Modify Extended Operation 13 14Status of this Memo 15 16 This document specifies an Internet standards track protocol for the 17 Internet community, and requests discussion and suggestions for 18 improvements. Please refer to the current edition of the "Internet 19 Official Protocol Standards" (STD 1) for the standardization state 20 and status of this protocol. Distribution of this memo is unlimited. 21 22Copyright Notice 23 24 Copyright (C) The Internet Society (2001). All Rights Reserved. 25 26Abstract 27 28 The integration of the Lightweight Directory Access Protocol (LDAP) 29 and external authentication services has introduced non-DN 30 authentication identities and allowed for non-directory storage of 31 passwords. As such, mechanisms which update the directory (e.g., 32 Modify) cannot be used to change a user's password. This document 33 describes an LDAP extended operation to allow modification of user 34 passwords which is not dependent upon the form of the authentication 35 identity nor the password storage mechanism used. 36 37 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 38 "SHOULD", "SHOULD NOT", "RECOMMENDED", and "MAY" in this document are 39 to be interpreted as described in RFC 2119. 40 411. Background and Intent of Use 42 43 Lightweight Directory Access Protocol (LDAP) [RFC2251] is designed to 44 support an number of authentication mechanisms including simple user 45 name/password pairs. Traditionally, LDAP users where identified by 46 the Distinguished Name [RFC2253] of a directory entry and this entry 47 contained a userPassword [RFC2256] attribute containing one or more 48 passwords. 49 50 The protocol does not mandate that passwords associated with a user 51 be stored in the directory server. The server may use any attribute 52 suitable for password storage (e.g., userPassword), or use non- 53 directory storage. 54 55 56 57 58Zeilenga Standards Track [Page 1] 59 60RFC 3062 LDAP Password Modify Extended Operation February 2001 61 62 63 The integration [RFC2829] of application neutral SASL [RFC2222] 64 services which support simple username/password mechanisms (such as 65 DIGEST-MD5) has introduced non-LDAP DN authentication identity forms 66 and made storage of passwords the responsibility of the SASL service 67 provider. 68 69 LDAP update operations are designed to act upon attributes of an 70 entry within the directory. LDAP update operations cannot be used to 71 modify a user's password when the user is not represented by a DN, 72 does not have a entry, or when that password used by the server is 73 not stored as an attribute of an entry. An alternative mechanism is 74 needed. 75 76 This document describes an LDAP Extended Operation intended to allow 77 directory clients to update user passwords. The user may or may not 78 be associated with a directory entry. The user may or may not be 79 represented as an LDAP DN. The user's password may or may not be 80 stored in the directory. 81 82 The operation SHOULD NOT be used without adequate security protection 83 as the operation affords no privacy or integrity protect itself. 84 This operation SHALL NOT be used anonymously. 85 862. Password Modify Request and Response 87 88 The Password Modify operation is an LDAPv3 Extended Operation 89 [RFC2251, Section 4.12] and is identified by the OBJECT IDENTIFIER 90 passwdModifyOID. This section details the syntax of the protocol 91 request and response. 92 93 passwdModifyOID OBJECT IDENTIFIER ::= 1.3.6.1.4.1.4203.1.11.1 94 95 PasswdModifyRequestValue ::= SEQUENCE { 96 userIdentity [0] OCTET STRING OPTIONAL 97 oldPasswd [1] OCTET STRING OPTIONAL 98 newPasswd [2] OCTET STRING OPTIONAL } 99 100 PasswdModifyResponseValue ::= SEQUENCE { 101 genPasswd [0] OCTET STRING OPTIONAL } 102 1032.1. Password Modify Request 104 105 A Password Modify request is an ExtendedRequest with the requestName 106 field containing passwdModifyOID OID and optionally provides a 107 requestValue field. If the requestValue field is provided, it SHALL 108 contain a PasswdModifyRequestValue with one or more fields present. 109 110 111 112 113 114Zeilenga Standards Track [Page 2] 115 116RFC 3062 LDAP Password Modify Extended Operation February 2001 117 118 119 The userIdentity field, if present, SHALL contain an octet string 120 representation of the user associated with the request. This string 121 may or may not be an LDAPDN [RFC2253]. If no userIdentity field is 122 present, the request acts up upon the password of the user currently 123 associated with the LDAP session. 124 125 The oldPasswd field, if present, SHALL contain the user's current 126 password. 127 128 The newPasswd field, if present, SHALL contain the desired password 129 for this user. 130 1312.2. Password Modify Response 132 133 A Password Modify response is an ExtendedResponse where the 134 responseName field is absent and the response field is optional. The 135 response field, if present, SHALL contain a PasswdModifyResponseValue 136 with genPasswd field present. 137 138 The genPasswd field, if present, SHALL contain a generated password 139 for the user. 140 141 If an resultCode other than success (0) is indicated in the response, 142 the response field MUST be absent. 143 1443. Operation Requirements 145 146 Clients SHOULD NOT submit a Password Modification request without 147 ensuring adequate security safeguards are in place. Servers SHOULD 148 return a non-success resultCode if sufficient security protection are 149 not in place. 150 151 Servers SHOULD indicate their support for this extended operation by 152 providing PasswdModifyOID as a value of the supportedExtension 153 attribute type in their root DSE. A server MAY choose to advertise 154 this extension only when the client is authorized and/or has 155 established the necessary security protections to use this operation. 156 Clients SHOULD verify the server implements this extended operation 157 prior to attempting the operation by asserting the supportedExtension 158 attribute contains a value of PasswdModifyOID. 159 160 The server SHALL only return success upon successfully changing the 161 user's password. The server SHALL leave the password unmodified and 162 return a non-success resultCode otherwise. 163 164 If the server does not recognize provided fields or does not support 165 the combination of fields provided, it SHALL NOT change the user 166 password. 167 168 169 170Zeilenga Standards Track [Page 3] 171 172RFC 3062 LDAP Password Modify Extended Operation February 2001 173 174 175 If oldPasswd is present and the provided value cannot be verified or 176 is incorrect, the server SHALL NOT change the user password. If 177 oldPasswd is not present, the server MAY use other policy to 178 determine whether or not to change the password. 179 180 The server SHALL NOT generate a password on behalf of the client if 181 the client has provided a newPasswd. In absence of a client provided 182 newPasswd, the server SHALL either generate a password on behalf of 183 the client or return a non-success result code. The server MUST 184 provide the generated password upon success as the value of the 185 genPasswd field. 186 187 The server MAY return adminLimitExceeded, busy, 188 confidentialityRequired, operationsError, unavailable, 189 unwillingToPerform, or other non-success resultCode as appropriate to 190 indicate that it was unable to successfully complete the operation. 191 192 Servers MAY implement administrative policies which restrict this 193 operation. 194 1954. Security Considerations 196 197 This operation is used to modify user passwords. The operation 198 itself does not provide any security protection to ensure integrity 199 and/or confidentiality of the information. Use of this operation is 200 strongly discouraged when privacy protections are not in place to 201 guarantee confidentiality and may result in the disclosure of the 202 password to unauthorized parties. This extension MUST be used with 203 confidentiality protection, such as Start TLS [RFC 2830]. The NULL 204 cipher suite MUST NOT be used. 205 2065. Bibliography 207 208 [RFC2219] Bradner, S., "Key words for use in RFCs to Indicate 209 Requirement Levels", BCP 14, RFC 2119, March 1997. 210 211 [RFC2222] Myers, J., "Simple Authentication and Security Layer 212 (SASL)", RFC 2222, October 1997. 213 214 [RFC2251] Wahl, M., Howes, T. and S. Kille, "Lightweight Directory 215 Access Protocol (v3)", RFC 2251, December 1997. 216 217 [RFC2252] Wahl, M., Coulbeck, A., Howes, T. and S. Kille, 218 "Lightweight Directory Access Protocol (v3): Attribute 219 Syntax Definitions", RFC 2252, December 1997. 220 221 222 223 224 225 226Zeilenga Standards Track [Page 4] 227 228RFC 3062 LDAP Password Modify Extended Operation February 2001 229 230 231 [RFC2253] Wahl, M., Kille,S. and T. Howes, "Lightweight Directory 232 Access Protocol (v3): UTF-8 String Representation of 233 Distinguished Names", RFC 2253, December 1997. 234 235 [RFC2256] Wahl, M., "A Summary of the X.500(96) User Schema for use 236 with LDAPv3", RFC 2256, December 1997. 237 238 [RFC2829] Wahl, M., Alvestrand, H., Hodges, J. and R. Morgan, 239 "Authentication Methods for LDAP", RFC 2829, May 2000. 240 241 [RFC2830] Hodges, J., Morgan, R. and M. Wahl, "Lightweight Directory 242 Access Protocol (v3): Extension for Transport Layer 243 Security", RFC 2830, May 2000. 244 2456. Acknowledgment 246 247 This document borrows from a number of IETF documents and is based 248 upon input from the IETF LDAPext working group. 249 2507. Author's Address 251 252 Kurt D. Zeilenga 253 OpenLDAP Foundation 254 255 EMail: Kurt@OpenLDAP.org 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282Zeilenga Standards Track [Page 5] 283 284RFC 3062 LDAP Password Modify Extended Operation February 2001 285 286 2878. Full Copyright Statement 288 289 Copyright (C) The Internet Society (2001). All Rights Reserved. 290 291 This document and translations of it may be copied and furnished to 292 others, and derivative works that comment on or otherwise explain it 293 or assist in its implementation may be prepared, copied, published 294 and distributed, in whole or in part, without restriction of any 295 kind, provided that the above copyright notice and this paragraph are 296 included on all such copies and derivative works. However, this 297 document itself may not be modified in any way, such as by removing 298 the copyright notice or references to the Internet Society or other 299 Internet organizations, except as needed for the purpose of 300 developing Internet standards in which case the procedures for 301 copyrights defined in the Internet Standards process must be 302 followed, or as required to translate it into languages other than 303 English. 304 305 The limited permissions granted above are perpetual and will not be 306 revoked by the Internet Society or its successors or assigns. 307 308 This document and the information contained herein is provided on an 309 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 310 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING 311 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION 312 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF 313 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 314 315Acknowledgement 316 317 Funding for the RFC Editor function is currently provided by the 318 Internet Society. 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338Zeilenga Standards Track [Page 6] 339 340