idnits 2.17.1 draft-reschke-basicauth-enc-03.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 : ---------------------------------------------------------------------------- ** The abstract seems to contain references ([2], [1]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. -- The draft header indicates that this document updates RFC2617, but the abstract doesn't seem to directly say this. It does mention RFC2617 though, so this could be OK. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year (Using the creation date from RFC2617, updated by this document, for RFC5378 checks: 1997-12-01) -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (January 25, 2012) is 4474 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Possible downref: Non-RFC (?) normative reference: ref. 'ISO-8859-1' ** Obsolete normative reference: RFC 2617 (Obsoleted by RFC 7235, RFC 7615, RFC 7616, RFC 7617) -- Possible downref: Non-RFC (?) normative reference: ref. 'USASCII' Summary: 2 errors (**), 0 flaws (~~), 1 warning (==), 5 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group J. Reschke 3 Internet-Draft greenbytes 4 Updates: 2617 (if approved) January 25, 2012 5 Intended status: Standards Track 6 Expires: July 28, 2012 8 An Encoding Parameter for HTTP Basic Authentication 9 draft-reschke-basicauth-enc-03 11 Abstract 13 The "Basic" authentication scheme defined in RFC 2617 does not 14 properly define how to treat non-ASCII characters. This has lead to 15 a situation where user agent implementations disagree, and servers 16 make different assumptions based on the locales they are running in. 17 There is little interoperability for characters in the ISO-8859-1 18 character set, and even less interoperability for any characters 19 beyond that. 21 This document defines a backwards-compatible extension to "Basic", 22 specifying the server's character encoding expectation, using a new 23 authentication scheme parameter. 25 Editorial Note (To be removed by RFC Editor before publication) 27 Distribution of this document is unlimited. Although this is not a 28 work item of the HTTPbis Working Group, comments should be sent to 29 the Hypertext Transfer Protocol (HTTP) mailing list at 30 ietf-http-wg@w3.org [1], which may be joined by sending a message 31 with subject "subscribe" to ietf-http-wg-request@w3.org [2]. 33 Discussions of the HTTPbis Working Group are archived at 34 . 36 XML versions, latest edits and the issues list for this document are 37 available from 38 . 40 Status of This Memo 42 This Internet-Draft is submitted in full conformance with the 43 provisions of BCP 78 and BCP 79. 45 Internet-Drafts are working documents of the Internet Engineering 46 Task Force (IETF). Note that other groups may also distribute 47 working documents as Internet-Drafts. The list of current Internet- 48 Drafts is at http://datatracker.ietf.org/drafts/current/. 50 Internet-Drafts are draft documents valid for a maximum of six months 51 and may be updated, replaced, or obsoleted by other documents at any 52 time. It is inappropriate to use Internet-Drafts as reference 53 material or to cite them other than as "work in progress." 55 This Internet-Draft will expire on July 28, 2012. 57 Copyright Notice 59 Copyright (c) 2012 IETF Trust and the persons identified as the 60 document authors. All rights reserved. 62 This document is subject to BCP 78 and the IETF Trust's Legal 63 Provisions Relating to IETF Documents 64 (http://trustee.ietf.org/license-info) in effect on the date of 65 publication of this document. Please review these documents 66 carefully, as they describe your rights and restrictions with respect 67 to this document. Code Components extracted from this document must 68 include Simplified BSD License text as described in Section 4.e of 69 the Trust Legal Provisions and are provided without warranty as 70 described in the Simplified BSD License. 72 Table of Contents 74 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 75 2. Notational Conventions . . . . . . . . . . . . . . . . . . . . 4 76 3. The 'encoding' auth-param . . . . . . . . . . . . . . . . . . . 4 77 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 78 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 79 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 80 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 81 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 82 8.1. Normative References . . . . . . . . . . . . . . . . . . . 6 83 8.2. Informative References . . . . . . . . . . . . . . . . . . 6 84 Appendix A. Deployment Considerations . . . . . . . . . . . . . . 7 85 A.1. User Agents . . . . . . . . . . . . . . . . . . . . . . . . 7 86 A.1.1. Alternative approach . . . . . . . . . . . . . . . . . 7 87 A.2. Origin Servers . . . . . . . . . . . . . . . . . . . . . . 7 88 Appendix B. FAQ (to be removed by RFC Editor before 89 publication) . . . . . . . . . . . . . . . . . . . . . 8 90 B.1. Why not simply switch the default encoding to UTF-8? . . . 8 91 B.2. What about Digest? . . . . . . . . . . . . . . . . . . . . 8 92 B.3. Will existing UAs ignore the parameter? . . . . . . . . . . 8 93 Appendix C. Change Log (to be removed by RFC Editor before 94 publication) . . . . . . . . . . . . . . . . . . . . . 8 95 C.1. Since draft-reschke-basicauth-enc-00 . . . . . . . . . . . 8 96 C.2. Since draft-reschke-basicauth-enc-01 . . . . . . . . . . . 8 97 C.3. Since draft-reschke-basicauth-enc-02 . . . . . . . . . . . 8 99 Appendix D. Open issues (to be removed by RFC Editor prior to 100 publication) . . . . . . . . . . . . . . . . . . . . . 8 101 D.1. edit . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 103 1. Introduction 105 The "Basic" authentication scheme defined in Section 2 of [RFC2617] 106 does not properly define how to treat non-ASCII characters 107 ([USASCII]): it uses the Base64 ([RFC4648], Section 4) encoding of 108 the concatenation of username, separator character, and password 109 without stating which character encoding to use. 111 This has lead to a situation where user agent implementations 112 disagree, and servers make different assumptions based on the locales 113 they are running in. There is little interoperability for characters 114 in the ISO-8859-1 character set ([ISO-8859-1]), and even less 115 interoperability for any characters beyond that. 117 This document defines a backwards-compatible extension to "Basic", 118 specifying the server's character encoding expectation, using a new 119 auth-param as defined in Section 1.2 of [RFC2617]. 121 2. Notational Conventions 123 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 124 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 125 document are to be interpreted as described in [RFC2119]. 127 3. The 'encoding' auth-param 129 In challenges, servers MAY use the "encoding" authentication 130 parameter (case-insensitive) to express the character encoding they 131 expect the user agent to use. 133 The only allowed value is "UTF-8", to be matched case-insensitively 134 (see [RFC2978], Section 2.3), indicating that the server expects the 135 UTF-8 character encoding to be used ([RFC3629]). 137 Other values are reserved for future use. 139 For credentials sent by the user agent, the "encoding" parameter is 140 reserved for future use and MUST NOT be sent. 142 The reason for this is that the information that could be included 143 does not seem to be useful to the server, but the additional 144 complexity of parsing and processing the additional parameter might 145 make this extension harder to deploy. 147 4. Examples 149 In the example below, the server prompts for authentication in the 150 "foo" realm, using Basic authentication, with a preference for the 151 UTF-8 character encoding: 153 WWW-Authenticate: Basic realm="foo", encoding="UTF-8" 155 Note that the parameter value can be either a token or a quoted 156 string; in this case the server chose to use the quoted-string 157 notation. 159 The user's name is "test", and his password is the string "123" 160 followed by the Unicode character U+00A3 (POUND SIGN). Following 161 Section 1.2 of [RFC2617], but using the character encoding UTF-8, the 162 user-pass, converted to a sequence of octets, is: 164 't' 'e' 's' 't' ':' '1' '2' '3' pound 165 74 65 73 74 3A 31 32 33 C2 A3 167 Encoding this octet sequence in Base64 ([RFC4648], Section 4) yields: 169 dGVzdDoxMjPCow== 171 Thus the Authorization header field would be: 173 Authorization: Basic dGVzdDoxMjPCow== 175 5. Security Considerations 177 This document does not introduce any new security considerations 178 beyond those defined for the "Basic" authentication scheme 179 ([RFC2617], Section 4), and those applicable to the handling of UTF-8 180 ([RFC3629], Section 10). 182 6. IANA Considerations 184 There are no IANA Considerations related to this specification. 186 7. Acknowledgements 188 The internationalisation problem has been reported as a Mozilla bug 189 back in the year 2000 (see 190 and also the 191 more recent ). 192 It was Andrew Clover's idea to address it using a new auth-param. 194 Thanks to Martin Thomson for providing feedback on this document. 196 8. References 198 8.1. Normative References 200 [ISO-8859-1] International Organization for Standardization, 201 "Information technology -- 8-bit single-byte coded 202 graphic character sets -- Part 1: Latin alphabet No. 203 1", ISO/IEC 8859-1:1998, 1998. 205 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 206 Requirement Levels", BCP 14, RFC 2119, March 1997. 208 [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, 209 S., Leach, P., Luotonen, A., and L. Stewart, "HTTP 210 Authentication: Basic and Digest Access 211 Authentication", RFC 2617, June 1999. 213 [RFC2978] Freed, N. and J. Postel, "IANA Charset Registration 214 Procedures", BCP 19, RFC 2978, October 2000. 216 [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 217 10646", STD 63, RFC 3629, November 2003. 219 [USASCII] American National Standards Institute, "Coded Character 220 Set -- 7-bit American Standard Code for Information 221 Interchange", ANSI X3.4, 1986. 223 8.2. Informative References 225 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data 226 Encodings", RFC 4648, October 2006. 228 [XHR] van Kesteren, A., "XMLHttpRequest Level 2", W3C Working 229 Draft WD-XMLHttpRequest2-20110816, August 2011, . 232 Latest version available at 233 . 235 URIs 237 [1] 239 [2] 241 Appendix A. Deployment Considerations 243 A.1. User Agents 245 User agents not implementing this specifications should continue to 246 work as before, ignoring the new parameter. 248 User agents which already default to the UTF-8 encoding already 249 implement this specification by definition. Note that some user 250 agents already have different defaults depending on whether the 251 request originates from page navigation as opposed to a script-driven 252 request using XMLHttpRequest [XHR]. 254 Other user agents can keep their default behavior, and switch to 255 UTF-8 when seeing the new parameter. 257 A.1.1. Alternative approach 259 On the other hand, the strategy below may already improve the user- 260 visible behavior today: 262 o In the first authentication request, choose the character encoding 263 based on the user's credentials: if they do not need any 264 characters outside the ISO-8859-1 character set, default to ISO- 265 8859-1, otherwise use UTF-8. 267 o If the first attempt failed and the encoding used was ISO-8859-1, 268 retry once with UTF-8 encoding instead. 270 Note that there's a risk if the site blocks an account after multiple 271 login failures (for instance, when it doesn't reset the counter after 272 a successful login). 274 A.2. Origin Servers 276 Origin servers that do not support non-ASCII characters in 277 credentials do not require any changes. 279 Origin servers that need to support non-ASCII characters, but can't 280 use the UTF-8 encoding will not be affected; they will continue to 281 function as well as before. 283 Finally, origin servers that need to support non-ASCII characters and 284 can use the UTF-8 encoding can opt in as described above. In the 285 worst case, they'll continue to see either broken credentials or no 286 credentials at all (depending on how legacy clients handle characters 287 they can not encode). 289 Appendix B. FAQ (to be removed by RFC Editor before publication) 291 B.1. Why not simply switch the default encoding to UTF-8? 293 There are sites in use today that default to a locale encoding, such 294 as ISO-8859-1, and expect user agents to use that encoding. These 295 sites will break if the user agent uses a different encoding, such as 296 UTF-8. 298 B.2. What about Digest? 300 Although the solution proposed in this document may be applicable to 301 "Digest" as well, any attempt to update this scheme may be an uphill 302 battle hard to win. 304 B.3. Will existing UAs ignore the parameter? 306 It appears they will. See 307 and 308 . 310 Appendix C. Change Log (to be removed by RFC Editor before publication) 312 C.1. Since draft-reschke-basicauth-enc-00 314 Add and close issues "credparam" and "paramcase". Rewrite the 315 deployment considerations. 317 C.2. Since draft-reschke-basicauth-enc-01 319 Note more recent Mozilla bugzilla entry; add behavior of existing UAs 320 to FAQ (with pointer to test cases). 322 C.3. Since draft-reschke-basicauth-enc-02 324 Add and resolve issue "xhrutf8". 326 Appendix D. Open issues (to be removed by RFC Editor prior to 327 publication) 329 D.1. edit 331 Type: edit 333 julian.reschke@greenbytes.de (2010-08-11): Umbrella issue for 334 editorial fixes/enhancements. 336 Author's Address 338 Julian F. Reschke 339 greenbytes GmbH 340 Hafenweg 16 341 Muenster, NW 48155 342 Germany 344 EMail: julian.reschke@greenbytes.de 345 URI: http://greenbytes.de/tech/webdav/