7 INTERNET-DRAFT Kurt D. Zeilenga
8 Intended Category: Standards Track OpenLDAP Foundation
9 Expires in six months 26 May 2003
12 SASLprep: Stringprep profile for user names and passwords
13 <draft-ietf-sasl-saslprep-02.txt>
18 This document is an Internet-Draft and is in full conformance with all
19 provisions of Section 10 of RFC 2026.
21 This document is intended to be, after appropriate review and
22 revision, submitted to the RFC Editor as a Standards Track document.
23 Distribution of this memo is unlimited. Technical discussion of this
24 document will take place on the IETF SASL mailing list
25 <ietf-sasl@imc.org>. Please send editorial comments directly to the
26 document editor <Kurt@OpenLDAP.org>.
28 Internet-Drafts are working documents of the Internet Engineering Task
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31 Internet-Drafts are draft documents valid for a maximum of six months
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41 Copyright (C) The Internet Society (2003). All Rights Reserved.
43 Please see the Full Copyright section near the end of this document
49 This document describes how to prepare Unicode strings representing
50 user names and passwords for comparison. The document defines the
51 "SASLprep" "stringprep" profile to be used for both user names and
52 passwords. This profile is intended to be used by Simple
53 Authentication and Security Layer (SASL) mechanisms (such as PLAIN,
54 CRAM-MD5, and DIGEST-MD5) as well as other protocols exchanging user
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63 names and/or passwords.
68 The use of simple user names and passwords in authentication and
69 authorization is pervasive on the Internet. To increase the
70 likelihood that user name and password input and comparison work in
71 ways that make sense for typical users throughout the world, this
72 document defines rules for preparing internationalized user names and
73 passwords for comparison. For simplicity and implementation ease, a
74 single algorithm is defined for both user names and passwords.
76 This document defines the "SASLprep" profile of the "stringprep"
77 protocol [StringPrep].
79 The profile is designed for use in Simple Authentication and Security
80 Layer ([SASL]) mechanisms such as [PLAIN]. It may be applicable
81 elsewhere simple user names and passwords are used. This profile is
82 not intended to be used for arbitrary text. This profile is also not
83 intended to be used to prepare identity strings which are not simple
84 user names (e.g., e-mail addresses, domain names, distinguished
88 2. The SASLprep profile
90 This section defines the "SASLprep" profile. This profile is intended
91 to be used to prepare strings representing simple user names and
94 This profile uses Unicode 3.2, as defined in [StringPrep, A.1].
96 Character names in this document use the notation for code points and
97 names from the Unicode Standard [Unicode]. For example, the letter
98 "a" may be represented as either <U+0061> or <LATIN SMALL LETTER A>.
99 In the lists of mappings and the prohibited characters, the "U+" is
100 left off to make the lists easier to read. The comments for character
101 ranges are shown in square brackets (such as "[CONTROL CHARACTERS]")
102 and do not come from the standard.
104 Note: a glossary of terms used in Unicode can be found in [Glossary].
105 Information on the Unicode character encoding model can be found in
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119 This profile specifies:
120 - non-ASCII space characters [StringPrep, C.1.2] be mapped to SPACE
123 - the "commonly mapped to nothing" characters [StringPrep, B.1] be
130 This profile specifies using Unicode normalization form KC, as
131 described in Section 4 of [StringPrep].
134 2.3. Prohibited Output
136 This profile specifies the following characters:
138 - Non-ASCII space characters [StringPrep, C.1.2],
139 - ASCII control characters [StringPrep, C.2.1],
140 - Non-ASCII control characters [StringPrep, C.2.2],
141 - Private Use [StringPrep, C.3],
142 - Non-character code points [StringPrep, C.4],
143 - Surrogate code points [StringPrep, C.5],
144 - Inappropriate for plain text [StringPrep, C.6],
145 - Inappropriate for canonical representation [StringPrep, C.7],
146 - Change display properties or are deprecated [StringPrep, C.8], and
147 - Tagging characters [StringPrep, C.9].
149 are prohibited output.
152 2.4. Bidirectional characters
154 This profile specifies checking bidirectional strings as described in
155 [StringPrep, Section 6].
158 2.5. Unassigned Code Points
160 This profile specifies [StringPrep, A.1] table as its list of
161 unassigned code points.
164 3. Security Considerations
166 This profile is intended to used to prepare simple user names and
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175 passwords for comparison. It is not intended to be used for to
176 prepare identities which are not simple user names (e.g.,
177 distinguished names and domain names). Nor is the profile intended to
178 be used for simple user names which require different handling.
179 Protocols (or applications of those protocols) which have
180 application-specific identity forms and/or comparison algorithms
181 should use mechanisms specifically designed for these forms and
184 User names and passwords should be protected from eavesdropping.
186 General "stringprep" and Unicode security considerations apply. Both
187 are discused in [StringPrep].
190 4. IANA Considerations
192 This document details the "SASLprep" profile of [StringPrep] protocol.
193 Upon Standards Action the profile should be registered in the
194 stringprep profile registry.
196 Name of this profile: SASLprep
197 RFC in which the profile is defined: This RFC
198 Indicator whether or not this is the newest version of the
199 profile: This is the first version of the SASPprep profile.
204 This document borrows text from "Preparation of Internationalized
205 Strings ('stringprep')" and "Nameprep: A Stringprep Profile for
206 Internationalized Domain Names", both by Paul Hoffman and Marc
210 6. Normative References
212 [StringPrep] Hoffman P. and M. Blanchet, "Preparation of
213 Internationalized Strings ('stringprep')", RFC 3454,
216 [SASL] Myers, J., "Simple Authentication and Security Layer
217 (SASL)", draft-myers-saslrev-xx.txt, a work in progress.
219 [Unicode] The Unicode Consortium, "The Unicode Standard, Version
220 3.2.0" is defined by "The Unicode Standard, Version 3.0"
221 (Reading, MA, Addison-Wesley, 2000. ISBN 0-201-61633-5),
222 as amended by the "Unicode Standard Annex #27: Unicode
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231 3.1" (http://www.unicode.org/reports/tr27/) and by the
232 "Unicode Standard Annex #28: Unicode 3.2"
233 (http://www.unicode.org/reports/tr28/).
237 7. Informative References
239 [Glossary] The Unicode Consortium, "Unicode Glossary",
240 <http://www.unicode.org/glossary/>.
242 [CharModel] Whistler, K. and M. Davis, "Unicode Technical Report
243 #17, Character Encoding Model", UTR17,
244 <http://www.unicode.org/unicode/reports/tr17/>, August
247 [CRAM-MD5] Nerenberg, L., "The CRAM-MD5 SASL Mechanism",
248 draft-nerenberg-sasl-crammd5-xx.txt, a work in progress.
250 [DIGEST-MD5] Leach, P., C. Newman, and A. Melnikov, "Using Digest
251 Authentication as a SASL Mechanism",
252 draft-ietf-sasl-rfc2831bis-xx.txt, a work in progress.
254 [PLAIN] Zeilenga, K., "The Plain SASL Mechanism",
255 draft-ietf-sasl-plain-xx.txt, a work in progress.
264 Email: kurt@OpenLDAP.org
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338 Zeilenga SASLprep [Page 6]