idnits 2.17.1 draft-ietf-precis-problem-statement-02.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to contain a disclaimer for pre-RFC5378 work, but was first submitted on or after 10 November 2008. The disclaimer is usually necessary only for documents that revise or obsolete older RFCs, and that take significant amounts of text from those RFCs. If you can contact all authors of the source material and they are willing to grant the BCP78 rights to the IETF Trust, you can and should remove the disclaimer. Otherwise, the disclaimer is needed and you can ignore this comment. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (March 31, 2011) is 4765 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-05) exists of draft-faltstrom-5892bis-04 -- Obsolete informational reference (is this intentional?): RFC 3454 (Obsoleted by RFC 7564) -- Obsolete informational reference (is this intentional?): RFC 3490 (Obsoleted by RFC 5890, RFC 5891) -- Obsolete informational reference (is this intentional?): RFC 3491 (Obsoleted by RFC 5891) -- Obsolete informational reference (is this intentional?): RFC 3530 (Obsoleted by RFC 7530) -- Obsolete informational reference (is this intentional?): RFC 3920 (Obsoleted by RFC 6120) -- Obsolete informational reference (is this intentional?): RFC 4013 (Obsoleted by RFC 7613) -- Obsolete informational reference (is this intentional?): RFC 5661 (Obsoleted by RFC 8881) Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 8 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group M. Blanchet 3 Internet-Draft Viagenie 4 Intended status: Informational A. Sullivan 5 Expires: October 2, 2011 March 31, 2011 7 Stringprep Revision Problem Statement 8 draft-ietf-precis-problem-statement-02.txt 10 Abstract 12 Using Unicode codepoints in protocol strings that expect comparison 13 with other strings requires preparation of the string that contains 14 the Unicode codepoints. Internationalizing Domain Names in 15 Applications (IDNA2003) defined and used Stringprep and Nameprep. 16 Other protocols subsequently defined Stringprep profiles. A new 17 approach different from Stringprep and Nameprep is used for a 18 revision of IDNA2003 (called IDNA2008). Other Stringprep profiles 19 need to be similarly updated or a replacement of Stringprep needs to 20 be designed. This document outlines the issues to be faced by those 21 designing a Stringprep replacement. 23 Status of this Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at http://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on October 2, 2011. 40 Copyright Notice 42 Copyright (c) 2011 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (http://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 This document may contain material from IETF Documents or IETF 56 Contributions published or made publicly available before November 57 10, 2008. The person(s) controlling the copyright in some of this 58 material may not have granted the IETF Trust the right to allow 59 modifications of such material outside the IETF Standards Process. 60 Without obtaining an adequate license from the person(s) controlling 61 the copyright in such materials, this document may not be modified 62 outside the IETF Standards Process, and derivative works of it may 63 not be created outside the IETF Standards Process, except to format 64 it for publication as an RFC or to translate it into languages other 65 than English. 67 Table of Contents 69 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 70 2. Issues raised during newprep BOF . . . . . . . . . . . . . . . 5 71 3. Major Topics for Consideration . . . . . . . . . . . . . . . . 6 72 3.1. Comparison . . . . . . . . . . . . . . . . . . . . . . . . 6 73 3.1.1. Comparison methods . . . . . . . . . . . . . . . . . . 6 74 3.1.2. Effect of comparison . . . . . . . . . . . . . . . . . 7 75 3.2. Dealing with characters . . . . . . . . . . . . . . . . . 7 76 3.2.1. Case folding, case sensitivity, and case 77 preservation . . . . . . . . . . . . . . . . . . . . . 7 78 3.2.2. Stringprep and NFKC . . . . . . . . . . . . . . . . . 7 79 3.2.3. Character mapping . . . . . . . . . . . . . . . . . . 8 80 3.2.4. Prohibited characters . . . . . . . . . . . . . . . . 8 81 3.2.5. Internal structure, delimiters, and special 82 characters . . . . . . . . . . . . . . . . . . . . . . 9 83 3.3. Where the data comes from and where it goes . . . . . . . 9 84 3.3.1. User input and the source of protocol elements . . . . 9 85 3.3.2. User output . . . . . . . . . . . . . . . . . . . . . 10 86 3.3.3. Operations . . . . . . . . . . . . . . . . . . . . . . 10 87 4. Considerations for Stringprep replacement . . . . . . . . . . 11 88 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12 89 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 90 7. Discussion home for this draft . . . . . . . . . . . . . . . . 12 91 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12 92 9. Informative References . . . . . . . . . . . . . . . . . . . . 12 93 Appendix A. Protocols known to be using Stringprep . . . . . . . 15 94 Appendix B. Changes between versions . . . . . . . . . . . . . . 16 95 B.1. 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 96 B.2. 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 97 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 99 1. Introduction 101 Internationalizing Domain Names in Applications (IDNA2003) [RFC3490], 102 [RFC3491], [RFC3492], [RFC3454] described a mechanism for encoding 103 Unicode labels making up Internationalized Domain Names (IDNs) as 104 standard DNS labels. The labels were processed using a method called 105 Nameprep [RFC3491] and Punycode [RFC3492]. That method was specific 106 to IDNA2003, but is generalized as Stringprep [RFC3454]. The general 107 mechanism can be used to help other protocols with similar needs, but 108 with different constraints than IDNA2003. 110 Stringprep defines a framework within which protocols define their 111 Stringprep profiles. Known IETF specifications using Stringprep are 112 listed below: 113 o The Nameprep profile [RFC3490] for use in Internationalized Domain 114 Names (IDNs); 115 o NFSv4 [RFC3530] and NFSv4.1 [RFC5661]; 116 o The iSCSI profile [RFC3722] for use in Internet Small Computer 117 Systems Interface (iSCSI) Names; 118 o EAP [RFC3748]; 119 o The Nodeprep and Resourceprep profiles [RFC3920] for use in the 120 Extensible Messaging and Presence Protocol (XMPP), and the XMPP to 121 CPIM mapping [RFC3922]; 122 o The Policy MIB profile [RFC4011] for use in the Simple Network 123 Management Protocol (SNMP); 124 o The SASLprep profile [RFC4013] for use in the Simple 125 Authentication and Security Layer (SASL), and SASL itself 126 [RFC4422]; 127 o TLS [RFC4279]; 128 o IMAP4 using SASLprep [RFC4314]; 129 o The trace profile [RFC4505] for use with the SASL ANONYMOUS 130 mechanism; 131 o The LDAP profile [RFC4518] for use with LDAP [RFC4511] and its 132 authentication methods [RFC4513]; 133 o Plain SASL using SASLprep [RFC4616]; 134 o NNTP using SASLprep [RFC4643]; 135 o PKIX subject identification using LDAPprep [RFC4683]; 136 o Internet Application Protocol Collation Registry [RFC4790]; 137 o SMTP Auth using SASLprep [RFC4954]; 138 o POP3 Auth using SASLprep [RFC5034]; 139 o TLS SRP using SASLprep [RFC5054]; 140 o IRI and URI in XMPP [RFC5122]; 141 o PKIX CRL using LDAPprep [RFC5280]; 142 o IAX using Nameprep [RFC5456]; 143 o SASL SCRAM using SASLprep [RFC5802]; 144 o Remote management of Sieve using SASLprep [RFC5804]; 145 o The i;unicode-casemap Unicode Collation [RFC5051]. 147 There turned out to be some difficulties with IDNA2003, documented in 148 [RFC4690]. These difficulties led to a new IDN specification, called 149 IDNA2008 [RFC5890], [RFC5891], [RFC5892], [RFC5893]. Additional 150 background and explanations of the decisions embodied in IDNA2008 is 151 presented in [RFC5894]. One of the effects of IDNA2008 is that 152 Nameprep and Stringprep are not used at all. Instead, an algorithm 153 based on Unicode properties of codepoints is defined. That algorithm 154 generates a stable and complete table of the supported Unicode 155 codepoints. This algorithm is based on an inclusion-based approach, 156 instead of the exclusion-based approach of Stringprep/Nameprep. 158 This document lists the shortcomings and issues found by protocols 159 listed above that defined Stringprep profiles. It also lists some 160 early conclusions and requirements for a potential replacement of 161 Stringprep. 163 2. Issues raised during newprep BOF 165 During IETF 77, a BOF discussed the current state of the protocols 166 that have defined Stringprep profiles [NEWPREP]. The main 167 conclusions from that discussion were as follows: 168 o Stringprep is bound to a specific version of Unicode: 3.2. 169 Stringprep has not been updated to new versions of Unicode. 170 Therefore, the protocols using Stringprep are stuck to Unicode 171 3.2. 172 o The protocols need to be updated to support new versions of 173 Unicode. The protocols would like to not be bound to a specific 174 version of Unicode, but rather have better Unicode agility in the 175 way of IDNA2008. This is important partly because it is usually 176 impossible for an application to require Unicode 3.2; the 177 application gets whatever version of Unicode is available on the 178 host. 179 o The protocols require better bidirectional support (bidi) than 180 currently offered by Stringprep. 181 o If the protocols are updated to use a new version of Stringprep or 182 another framework, then backward compatibility is an important 183 requirement. For example, Stringprep is based on and may use NFKC 184 [UAX15], while IDNA2008 mostly uses NFC [UAX15]. 185 o Protocols use each other; for example, a protocol can use user 186 identifiers that are later passed to SASL, LDAP or another 187 authentication mechanism. Therefore, common set of rules or 188 classes of strings are preferred over specific rules for each 189 protocol. 191 Protocols that use Stringprep profiles use strings for different 192 purposes: 193 o XMPP uses a different Stringprep profile for each part of the XMPP 194 address (JID): a localpart which is similar to a username and used 195 for authentication, a domainpart which is a domain name and a 196 resource part which is less restrictive than the localpart. 197 o iSCSI uses a Stringprep profile for the IQN, which is very similar 198 to (often is) a DNS domain name. 199 o SASL and LDAP uses a Stringprep profile for usernames. 200 o LDAP uses a set of Stringprep profiles. 202 During the newprep BOF, it was the consensus of the attendees that it 203 would be highly desirable to have a replacement of Stringprep, with 204 similar characteristics to IDNA2008. That replacement should be 205 defined so that the protocols could use internationalized strings 206 without a lot of specialized internationalization work, since 207 internationalization expertise is not available in the respective 208 protocols or working groups. 210 3. Major Topics for Consideration 212 This section provides an overview of major topics that a Stringprep 213 replacement needs to address. The headings correspond roughly with 214 categories under which known Stringprep-using protocol RFCs have been 215 evaluated. For the details of those evaluations, see Appendix A. 217 3.1. Comparison 219 3.1.1. Comparison methods 221 Identifiers can be conveniently organized into three classes or 222 "buckets": 224 1. Identifiers that must compare equally byte for byte. 225 2. Identifiers that do not compare equally byte for byte, but that 226 can always be compared for equality based on an algorithm 227 everyone can agree on. (This includes cases like comparison of 228 Unicode codepoints that are in different encodings: two different 229 encodings do not match byte for byte, but can all be recoded to a 230 single encoding which then does match bye for byte.) 231 3. Identifiers for which there is no single comparison algorithm on 232 which everyone can agree. (For instance, there may be locale- 233 sensitive comparison rules for identifiers.) 235 A subclass of case (3) is one in which, within some constrained 236 population, the comparison rules are clear even though such rules are 237 not universally applicable. So, for instance, users of US-ASCII may 238 all agree on a comparison function, but the set of US-ASCII users and 239 Turkish users may not all agree about the same comparison function. 240 For the purposes of the present work, it is not plain whether this 241 subclass case is relevant, so categorization will include it. 243 In the section treating the existing known cases, Appendix A, these 244 "buckets" will be called Type 1, Type 2, Type 3, and Type 3a. 246 3.1.2. Effect of comparison 248 The comparisons outlined in Section 3.1.1 may have different effects 249 when applied. It is necessary to evaluate the effects if a 250 comparison results in a false positive, and what the effects are if a 251 comparison results in a false negative, especially in terms of the 252 consequences to security and usability. 254 3.2. Dealing with characters 256 This section outlines a range of issues having to do with characters 257 in the target protocols, and spends some effort to outline the ways 258 in which IDNA2008 might be a good analogy to other protocols, and 259 ways in which it might be a poor one. 261 3.2.1. Case folding, case sensitivity, and case preservation 263 In IDNA2003, labels are always mapped to lower case before the 264 Punycode transformation. In IDNA2008, there is no mapping at all: 265 input is either a valid U-label or it is not. At the same time, 266 upper-case characters are by definition not valid U-labels, because 267 they fall into the Unstable category (category B) of [RFC5892]. 269 If there are protocols that require upper and lower cases be 270 preserved, then the analogy with IDNA2008 will break down. 271 Accordingly, existing protocols are to be evaluated according to the 272 following criteria: 274 1. Does the protocol use case folding? For all blocks of code 275 points, or just for certain subsets? 276 2. Is the system or protocol case sensitive? 277 3. Does the system or protocol preserve case? 279 3.2.2. Stringprep and NFKC 281 Stringprep profiles may use normalization. If they do, they use NFKC 282 [UAX15]. It is not clear that NFKC is the right normalization to use 283 in all cases. In [UAX15], there is the following observation 284 regarding Normalization Forms KC and KD: "It is best to think of 285 these Normalization Forms as being like uppercase or lowercase 286 mappings: useful in certain contexts for identifying core meanings, 287 but also performing modifications to the text that may not always be 288 appropriate." For things like the spelling of users' names, then, 289 NFKC may not be the best form to use. At the same time, one of the 290 nice things about NFKC is that it deals with the width of characters 291 that are otherwise similar, by canonicalizing half-width to full- 292 width. This mapping step can be crucial in practice. The WG will 293 need to analyze the different use profiles and consider whether NFKC 294 or NFC is a better normalization for each profile. 296 For the purposes of evaluating an existing example of Stringprep use, 297 it is helpful to know whether it uses no normalization, NFKC, or NFC. 299 3.2.3. Character mapping 301 Along with the case mapping issues raised in Section 3.2.1, there is 302 the question of whether some characters are mapped either to other 303 characters or to nothing during Stringprep. [RFC3454], Section 3, 304 outlines a number of characters that are mapped to nothing, and also 305 permits Stringprep profiles to define their own mappings. 307 3.2.4. Prohibited characters 309 Along with case folding and other character mappings, many protocols 310 have characters that are simply disallowed. For example, control 311 characters and special characters such as "@" or "/" may be 312 prohibited in a protocol. 314 One of the primary changes of IDNA2008 is in the way it approaches 315 Unicode code points. IDNA2003 created an explicit list of excluded 316 or mapped-away characters; anything in Unicode 3.2 that was not so 317 listed could be assumed to be allowed under the protocol. IDNA2008 318 begins instead from the assumption that code points are disallowed, 319 and then relies on Unicode properties to derive whether a given code 320 point actually is allowed in the protocol. 322 Moreover, there is more than one class of "allowed in the protocol". 323 While some code points are disallowed outright, some are allowed only 324 in certain contexts. The reasons for the context-dependent rules 325 have to do with the way some characters are used. For instance, the 326 ZERO WIDTH JOINER and ZERO WIDTH NON-JOINER (ZWJ, U+200D and ZWNJ, 327 U+200C) are allowed with contextual rules because they are required 328 in some circumstances, yet are considered punctuation by Unicode and 329 would therefore be DISALLOWED under the usual IDNA2008 derivation 330 rules. The goal is to provide the widest possible repetoire of code 331 points possible and consistent with the traditional DNS, trusting to 332 the operators of individual zones to make sensible (and usually more 333 restrictive) policies for their zones. 335 IDNA2008 may be a poor model for what other protocols ought to do in 336 this case, because it is designed to support an old protocol that is 337 designed to operate on the scale of the entire Internet. Moreover, 338 IDNA2008 is intended to be deployed without any change to the base 339 DNS protocol. Other protocols may aim at deployment in more local 340 environments, or may have protocol version negotiation built in. 342 3.2.5. Internal structure, delimiters, and special characters 344 IDNA2008 has a special problem with delimiters, because the delimiter 345 "character" in the DNS wire format is not really part of the data. 346 In DNS, labels are not separated exactly; instead, a label carries 347 with it an indicator that says how long the label is. When the label 348 is presented in presentation format as part of a fully qualified 349 domain name, the label separator FULL STOP, U+002E (.) is used to 350 break up the labels. But because that label separator does not 351 travel with the wire format of the domain name, there is no way to 352 encode a different, "internationalized" separator in IDNA2008. 354 Other protocols may include characters with similar special meaning 355 within the protocol. Common characters for these purposes include 356 FULL STOP, U+002E (.); COMMERCIAL AT, U+0040 (@); HYPHEN-MINUS, 357 U+002D (-); SOLIDUS, U+002F (/); and LOW LINE, U+005F (_). The mere 358 inclusion of such a character in the protocol is not enough for it to 359 be considered similar to another protocol using the same character; 360 instead, handling of the character must be taken into consideration 361 as well. 363 An important issue to tackle here is whether it is valuable to map to 364 or from these special characters as part of the Stringprep 365 replacement. In some locales, the analogue to FULL STOP, U+002E is 366 some other character, and users may expect to be able to substitute 367 their normal stop for FULL STOP, U+002E. At the same time, there are 368 predcitability arguments in favour of treating names with FULL STOP, 369 U+002E in them just the way they are treated under IDNA2008. 371 3.3. Where the data comes from and where it goes 373 3.3.1. User input and the source of protocol elements 375 Some protocol elements are provided by users, and others are not. 376 Those that are not may presumably be subject to greater restrictions, 377 whereas those that users provide likely need to permit the broadest 378 range of code points. The following questions are helpful: 380 1. Do users input the strings directly? 381 2. If so, how? (keyboard, stylus, voice, copy-paste, etc.) 382 3. Where do we place the dividing line between user interface and 383 protocol? (see [RFC5895]) 385 3.3.2. User output 387 Just as only some protocol elements are expected to be entered 388 directly by users, only some protocol elements are intended to be 389 consumed directly by users. It is important to know how users are 390 expected to be able to consume the protocol elements, because 391 different environments present different challenges. An element that 392 is only ever delivered as part of a vCard remains in machine-readable 393 format, so the problem of visual confusion is not a great one. Is 394 the protocol element published as part of a vCard, a web directory, 395 on a business card, or on "the side of a bus"? Do users use the 396 protocol element as an identifier (which means that they might enter 397 it again in some other context)? 399 3.3.3. Operations 401 Some strings are useful as part of the protocol but are not used as 402 input to other operations (for instance, purely informative or 403 descriptive text). Other strings are used directly as input to other 404 operations (such as cryptographic hash functions), or are used 405 together with other strings to (such as concatenating a string with 406 some others to form a unique identifier). 408 3.3.3.1. String classes 410 Strings often have a similar function in different protocols. For 411 instance, many different protocols contain user identifiers or 412 passwords. A single profile for all such uses might be desirable. 414 Often, a string in a protocol is effectively a protocol element from 415 another protocol. For instance, different systems might use the same 416 credentials database for authentication. 418 3.3.3.2. Community considerations 420 A Stringprep replacement that does anything more than just update 421 Stringprep to the latest version of Unicode will probably entail some 422 changes. It is important to identify the willingness of the 423 protocol-using community to accept backwards-incompatible changes. 424 By the same token, it is important to evaluate the desire of the 425 community for features not available under Stringprep. 427 3.3.3.3. What to do about Unicode changes 429 IDNA2008 uses an algorithm to derive the validity of a Unicode code 430 point for use under IDNA2008. It does this by using the properties 431 of each code point to test its validity. 433 This approach depends crucially on the idea that code points, once 434 valid for a protocol profile, will not later be made invalid. That 435 is not a guarantee currently provided by Unicode. Properties of code 436 points may change between versions of Unicode. Rarely, such a change 437 could cause a given code point to become invalid under a protocol 438 profile, even though the code point would be valid with an earlier 439 version of Unicode. This is not merely a theoretical possibility, 440 because it has occurred ([I-D.faltstrom-5892bis]). 442 Accordingly, a Stringprep replacement that intends to be Unicode 443 version agnostic will need to work out a mechansism to address cases 444 where incompatible changes occur because of new Unicode versions. 446 4. Considerations for Stringprep replacement 448 The above suggests the following direction for the working group: 449 o A stringprep replacement should be defined. 450 o The replacement should take an approach similar to IDNA2008, in 451 that it enables Unicode agility. 452 o Protocols share similar characteristics of strings. Therefore, 453 defining i18n preparation algorithms for a (small) set of string 454 classes may be sufficient for most cases and provides the 455 coherence among a set of protocol friends. 456 o The sets of string classes need to be evaluated according to the 457 considerations that make up the headings in Section 3 458 o It is reasonable to limit scope to Unicode code points, and rule 459 the mapping of data from other character encodings outside the 460 scope of this effort. 461 o Recommendations for handling protocol incompatibilities resulting 462 from changes to Unicode are required. 464 Existing deployments already depend on Stringprep profiles. 465 Therefore, the working group will need to consider the effects of any 466 new strategy on existing deployments. By way of comparison, it is 467 worth noting that some characters were acceptable in IDNA labels 468 under IDNA2003, but are not protocol-valid under IDNA2008 (and 469 conversely). Different implementers may make different decisions 470 about what to do in such cases; this could have interoperability 471 effects. The working group will need to trade better support for 472 different linguistic environments against the potential side effects 473 of backward incompatibility. 475 5. Security Considerations 477 This document merely states what problems are to be solved, and does 478 not define a protocol. There are undoubtedly security implications 479 of the particular results that will come from the work to be 480 completed. 482 6. IANA Considerations 484 This document has no actions for IANA. 486 7. Discussion home for this draft 488 This document is intended to define the problem space discussed on 489 the precis@ietf.org mailing list. 491 8. Acknowledgements 493 This document is the product of the PRECIS IETF Working Group, and 494 participants in that Working Group were helpful in addressing issues 495 with the text. 497 Specific contributions came from Alan DeKok, Alexey Melnikov, Peter 498 Saint-Andre, Dave Thaler, and Yoshiro Yoneya. 500 Dave Thaler provided the "buckets" insight in Section 3.1.1, central 501 to the organization of the problem. 503 9. Informative References 505 [I-D.faltstrom-5892bis] 506 Faltstrom, P. and P. Hoffman, "The Unicode code points and 507 IDNA - Unicode 6.0", draft-faltstrom-5892bis-04 (work in 508 progress), March 2011. 510 [NEWPREP] "Newprep BoF Meeting Minutes", March 2010. 512 [RFC3454] Hoffman, P. and M. Blanchet, "Preparation of 513 Internationalized Strings ("stringprep")", RFC 3454, 514 December 2002. 516 [RFC3490] Faltstrom, P., Hoffman, P., and A. Costello, 517 "Internationalizing Domain Names in Applications (IDNA)", 518 RFC 3490, March 2003. 520 [RFC3491] Hoffman, P. and M. Blanchet, "Nameprep: A Stringprep 521 Profile for Internationalized Domain Names (IDN)", 522 RFC 3491, March 2003. 524 [RFC3492] Costello, A., "Punycode: A Bootstring encoding of Unicode 525 for Internationalized Domain Names in Applications 526 (IDNA)", RFC 3492, March 2003. 528 [RFC3530] Shepler, S., Callaghan, B., Robinson, D., Thurlow, R., 529 Beame, C., Eisler, M., and D. Noveck, "Network File System 530 (NFS) version 4 Protocol", RFC 3530, April 2003. 532 [RFC3722] Bakke, M., "String Profile for Internet Small Computer 533 Systems Interface (iSCSI) Names", RFC 3722, April 2004. 535 [RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H. 536 Levkowetz, "Extensible Authentication Protocol (EAP)", 537 RFC 3748, June 2004. 539 [RFC3920] Saint-Andre, P., Ed., "Extensible Messaging and Presence 540 Protocol (XMPP): Core", RFC 3920, October 2004. 542 [RFC3922] Saint-Andre, P., "Mapping the Extensible Messaging and 543 Presence Protocol (XMPP) to Common Presence and Instant 544 Messaging (CPIM)", RFC 3922, October 2004. 546 [RFC4011] Waldbusser, S., Saperia, J., and T. Hongal, "Policy Based 547 Management MIB", RFC 4011, March 2005. 549 [RFC4013] Zeilenga, K., "SASLprep: Stringprep Profile for User Names 550 and Passwords", RFC 4013, February 2005. 552 [RFC4279] Eronen, P. and H. Tschofenig, "Pre-Shared Key Ciphersuites 553 for Transport Layer Security (TLS)", RFC 4279, 554 December 2005. 556 [RFC4314] Melnikov, A., "IMAP4 Access Control List (ACL) Extension", 557 RFC 4314, December 2005. 559 [RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and 560 Security Layer (SASL)", RFC 4422, June 2006. 562 [RFC4505] Zeilenga, K., "Anonymous Simple Authentication and 563 Security Layer (SASL) Mechanism", RFC 4505, June 2006. 565 [RFC4511] Sermersheim, J., "Lightweight Directory Access Protocol 566 (LDAP): The Protocol", RFC 4511, June 2006. 568 [RFC4513] Harrison, R., "Lightweight Directory Access Protocol 569 (LDAP): Authentication Methods and Security Mechanisms", 570 RFC 4513, June 2006. 572 [RFC4518] Zeilenga, K., "Lightweight Directory Access Protocol 573 (LDAP): Internationalized String Preparation", RFC 4518, 574 June 2006. 576 [RFC4616] Zeilenga, K., "The PLAIN Simple Authentication and 577 Security Layer (SASL) Mechanism", RFC 4616, August 2006. 579 [RFC4643] Vinocur, J. and K. Murchison, "Network News Transfer 580 Protocol (NNTP) Extension for Authentication", RFC 4643, 581 October 2006. 583 [RFC4683] Park, J., Lee, J., Lee, H., Park, S., and T. Polk, 584 "Internet X.509 Public Key Infrastructure Subject 585 Identification Method (SIM)", RFC 4683, October 2006. 587 [RFC4690] Klensin, J., Faltstrom, P., Karp, C., and IAB, "Review and 588 Recommendations for Internationalized Domain Names 589 (IDNs)", RFC 4690, September 2006. 591 [RFC4790] Newman, C., Duerst, M., and A. Gulbrandsen, "Internet 592 Application Protocol Collation Registry", RFC 4790, 593 March 2007. 595 [RFC4954] Siemborski, R. and A. Melnikov, "SMTP Service Extension 596 for Authentication", RFC 4954, July 2007. 598 [RFC5034] Siemborski, R. and A. Menon-Sen, "The Post Office Protocol 599 (POP3) Simple Authentication and Security Layer (SASL) 600 Authentication Mechanism", RFC 5034, July 2007. 602 [RFC5051] Crispin, M., "i;unicode-casemap - Simple Unicode Collation 603 Algorithm", RFC 5051, October 2007. 605 [RFC5054] Taylor, D., Wu, T., Mavrogiannopoulos, N., and T. Perrin, 606 "Using the Secure Remote Password (SRP) Protocol for TLS 607 Authentication", RFC 5054, November 2007. 609 [RFC5122] Saint-Andre, P., "Internationalized Resource Identifiers 610 (IRIs) and Uniform Resource Identifiers (URIs) for the 611 Extensible Messaging and Presence Protocol (XMPP)", 612 RFC 5122, February 2008. 614 [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., 615 Housley, R., and W. Polk, "Internet X.509 Public Key 616 Infrastructure Certificate and Certificate Revocation List 617 (CRL) Profile", RFC 5280, May 2008. 619 [RFC5456] Spencer, M., Capouch, B., Guy, E., Miller, F., and K. 620 Shumard, "IAX: Inter-Asterisk eXchange Version 2", 621 RFC 5456, February 2010. 623 [RFC5661] Shepler, S., Eisler, M., and D. Noveck, "Network File 624 System (NFS) Version 4 Minor Version 1 Protocol", 625 RFC 5661, January 2010. 627 [RFC5802] Newman, C., Menon-Sen, A., Melnikov, A., and N. Williams, 628 "Salted Challenge Response Authentication Mechanism 629 (SCRAM) SASL and GSS-API Mechanisms", RFC 5802, July 2010. 631 [RFC5804] Melnikov, A. and T. Martin, "A Protocol for Remotely 632 Managing Sieve Scripts", RFC 5804, July 2010. 634 [RFC5890] Klensin, J., "Internationalized Domain Names for 635 Applications (IDNA): Definitions and Document Framework", 636 RFC 5890, August 2010. 638 [RFC5891] Klensin, J., "Internationalized Domain Names in 639 Applications (IDNA): Protocol", RFC 5891, August 2010. 641 [RFC5892] Faltstrom, P., "The Unicode Code Points and 642 Internationalized Domain Names for Applications (IDNA)", 643 RFC 5892, August 2010. 645 [RFC5893] Alvestrand, H. and C. Karp, "Right-to-Left Scripts for 646 Internationalized Domain Names for Applications (IDNA)", 647 RFC 5893, August 2010. 649 [RFC5894] Klensin, J., "Internationalized Domain Names for 650 Applications (IDNA): Background, Explanation, and 651 Rationale", RFC 5894, August 2010. 653 [RFC5895] Resnick, P. and P. Hoffman, "Mapping Characters for 654 Internationalized Domain Names in Applications (IDNA) 655 2008", RFC 5895, September 2010. 657 [UAX15] "Unicode Standard Annex #15: Unicode Normalization Forms", 658 UAX 15, September 2009. 660 Appendix A. Protocols known to be using Stringprep 662 [[anchor21: This is where I'm supposed to have put the stuff already 663 in trac. --ajs@crankycanuck.ca]] 665 Appendix B. Changes between versions 667 Note to RFC Editor: This section should be removed prior to 668 publication. 670 B.1. 00 672 First WG version. Based on 673 draft-blanchet-precis-problem-statement-00. 675 B.2. 01 677 o Made clear that the document is talking only about Unicode code 678 points, and not any particular encoding. 679 o Substantially reorganized the document along the lines of the 680 review template at . 682 o Included specific questions for each topic for consideration. 683 o Moved spot for individual protocol review to appendix. Not 684 populated yet. 686 Authors' Addresses 688 Marc Blanchet 689 Viagenie 690 2600 boul. Laurier, suite 625 691 Quebec, QC G1V 4W1 692 Canada 694 Email: Marc.Blanchet@viagenie.ca 695 URI: http://viagenie.ca 697 Andrew Sullivan 698 519 Maitland St. 699 London, ON N6B 2Z5 700 Canada 702 Email: ajs@crankycanuck.ca