draft-ietf-idn-nameprep-03.txt

bind-3.2.

correct results from the authoritative name server.

6.3 Versions of applications and authoritative name servers

Another way to see that this versioning system works is to compare what
happens when an application uses a newer or older version of this
document.

Newer application -- Suppose that a application or intermediary DNS
server is using version newVersion and the authoritative name server is
using version oldVersion. This case is simple: there will be no names on
the server that cannot be accessed by the application because the
resolver uses a superset of the code points accepted by the server.

Newer server -- Suppose that an application or intermediary DNS server
is using oldVersion and the authoritative name server is using
newVersion. Because the application passed through any unassigned code
points, the user can access names on the server that use code points in
newVersion. No names on the site can have code points that are
unassigned in newVersion, since that is illegal. In this case, the
application has to enter the unassigned code points in the correct
order, and has to use unassigned code points that would make it through
both the mapping and the normalization steps.


7. Security Considerations

Much of the security of the Internet relies on the DNS. Thus, any change
to the characteristics of the DNS can change the security of much of the
Internet.

Host names are used by users to connect to Internet servers. The
security of the Internet would be compromised if a user entering a
single internationalized name could be connected to different servers
based on different interpretations of the internationalized host name.

Current applications may assume that the characters allowed in host
names will always be the same as they are in [STD13]. This document
vastly increases the number of characters available in host names. Every
program that uses "special" characters in conjunction with host names
may be vulnerable to attack based on the new characters allowed by this
specification.


8. References

[CharModel] Unicode Technical Report;17, Character Model.
<http://www.unicode.org/unicode/reports/tr17/>.

[Glossary] Unicode Glossary, <http://www.unicode.org/glossary/>.

[IDNReq] Zita Wenzel and James Seng, "Requirements of Internationalized
Domain Names", draft-ietf-idn-requirements

[IDNRev] Marc Blanchet, "Handling versions of internationalized domain
names protocols", draft-ietf-idn-version

[ISO10646] ISO/IEC 10646-1:2000. International Standard -- Information
technology -- Universal Multiple-Octet Coded Character Set (UCS) -- Part
1: Architecture and Basic Multilingual Plane.

[Normalize] Character Normalization in IETF Protocols,
draft-duerst-i18n-norm-03

[RFC2119] Scott Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", March 1997, RFC 2119.

[RFC2396] Tim Berners-Lee, et. al., "Uniform Resource Identifiers (URI):
Generic Syntax", August 1998, RFC 2396.

[RFC2732] Robert Hinden, et. al., Format for Literal IPv6 Addresses in
URL's, December 1999, RFC 2732.

[STD13] Paul Mockapetris, "Domain names - concepts and facilities" (RFC
1034) and "Domain names - implementation and specification" (RFC 1035,
STD 13, November 1987.

[Unicode3] The Unicode Consortium, "The Unicode Standard -- Version
3.0", ISBN 0-201-61633-5. Described at
<http://www.unicode.org/unicode/standard/versions/Unicode3.0.html>.

[URIs] For example: Roy Fielding et. al., "Uniform Resource Identifiers:
Generic Syntax", August 1998, RFC 2396; Robert Hinden et. al, "IPv6
Literal Addresses in URL's", December 1999, RFC 2732.

[UTR15] Mark Davis and Martin Duerst. Unicode Normalization Forms.
Unicode Technical Report;15.
<http://www.unicode.org/unicode/reports/tr15/>.

[UTR21] Mark Davis. Case Mappings. Unicode Technical Report;21.
<http://www.unicode.org/unicode/reports/tr21/>.


A. Acknowledgements

Many people from the IETF IDN Working Group and the Unicode Technical
Committee contributed ideas that went into the first draft of this
document. Mark Davis and Patrik Faltstrom were particularly helpful in
some of the ideas, such as the versioning description.

The IDN namprep design team made many useful changes to the first
draft. That team and its advisors include:

Asmus Freytag
Cathy Wissink
Francois Yergeau
James Seng
Marc Blanchet
Mark Davis
Martin Duerst
Patrik Faltstrom
Paul Hoffman

Additional significant improvements were proposed by:

Jonathan Rosenne
Kent Karlsson
Scott Hollenbeck


B. Differences Between -02 and -03 Drafts

Throughout: Changed "ISO 10646" to "ISO/IEC 10646". Changed "codepoint"
to "code point".

Abstract: Added last sentence.

1: Removed the sentence about [IDNComp] in the first paragraph.
Clarified the design goals in the third paragraph. Added new last
paragraph about processing name parts.

3: Added sentence at the end of the second paragraph about accepting
shorter or longer responses. Changed "Design note" to "Rationale".

3.1: Revised the first paragraph to make it clearer that the mapping is
not simple lowercasing. Changed "Design note" to "Rationale".

3.2: Made it clearer that the normalization is with form KC.

5: Removed the previous third paragraph, which discussed the DNS service
interface.

5.1: Added references for URIs.

5.4: Changed the sentence about the replacement character to read
"...and is often displayed by renderers to indicate...".

5.10: Added this section, which prohibits U+3002.

6: Removed "yet" from the first sentence.

8: Fixed the reference for [IDNReq] and [STD13]. Removed the reference
to [IDNComp]. Added the reference for [URIs].

C: Changed wording of the section.

E, F, G: Added tags to the beginning and end of the tables.

F: Added 3002 (from section 5.10). Added FDD0-FDEF, which were omitted
in error.


C. IANA Considerations

None.


D. Author Contact Information

Paul Hoffman
Internet Mail Consortium and VPN Consortium
127 Segre Place
Santa Cruz, CA  95060 USA
[e-mail] and [e-mail]

Marc Blanchet
Viagenie inc.
2875 boul. Laurier, bur. 300
Ste-Foy, Quebec, Canada, G1V 2M2
[e-mail]


E. Mapping Table

The following is the mapping table from Section 3. The table has three
columns:
- the character that is mapped from
- the zero or more characters that it is mapped to
- the reason for the mapping
The columns are separated by semicolons. Note that the second column may
be empty, or it may have one character, or it may have more than one
character, with each character separated by a space.

----- Start Mapping Table -----
0041; 0061; Case map
0042; 0062; Case map
0043; 0063; Case map
0044; 0064; Case map
0045; 0065; Case map
0046; 0066; Case map
0047; 0067; Case map
0048; 0068; Case map
0049; 0069; Case map
004A; 006A; Case map
004B; 006B; Case map
004C; 006C; Case map
004D; 006D; Case map
004E; 006E; Case map
004F; 006F; Case map
0050; 0070; Case map
0051; 0071; Case map
0052; 0072; Case map
0053; 0073; Case map
0054; 0074; Case map
0055; 0075; Case map
0056; 0076; Case map
0057; 0077; Case map
0058; 0078; Case map
0059; 0079; Case map
005A; 007A; Case map
00AD; ; Map out
00B5; 03BC; Case map
00C0; 00E0; Case map
00C1; 00E1; Case map
00C2; 00E2; Case map
00C3; 00E3; Case map
00C4; 00E4; Case map
00C5; 00E5; Case map
00C6; 00E6; Case map
00C7; 00E7; Case map
00C8; 00E8; Case map
00C9; 00E9; Case map
00CA; 00EA; Case map
00CB; 00EB; Case map
00CC; 00EC; Case map
00CD; 00ED; Case map
00CE; 00EE; Case map
00CF; 00EF; Case map
00D0; 00F0; Case map
00D1; 00F1; Case map
00D2; 00F2; Case map
00D3; 00F3; Case map
00D4; 00F4; Case map
00D5; 00F5; Case map
00D6; 00F6; Case map
00D8; 00F8; Case map
00D9; 00F9; Case map
00DA; 00FA; Case map
00DB; 00FB; Case map
00DC; 00FC; Case map
00DD; 00FD; Case map
00DE; 00FE; Case map
00DF; 0073 0073; Case map
0100; 0101; Case map
0102; 0103; Case map
0104; 0105; Case map
0106; 0107; Case map
0108; 0109; Case map
010A; 010B; Case map
010C; 010D; Case map
010E; 010F; Case map
0110; 0111; Case map
0112; 0113; Case map
0114; 0115; Case map
0116; 0117; Case map
0118; 0119; Case map
011A; 011B; Case map
011C; 011D; Case map
011E; 011F; Case map
0120; 0121; Case map
0122; 0123; Case map
0124; 0125; Case map
0126; 0127; Case map
0128; 0129; Case map
012A; 012B; Case map
012C; 012D; Case map
012E; 012F; Case map
0130; 0069; Case map
0131; 0069; Case map
0132; 0133; Case map
0134; 0135; Case map
0136; 0137; Case map
0139; 013A; Case map
013B; 013C; Case map
013D; 013E; Case map
013F; 0140; Case map
0141; 0142; Case map
0143; 0144; Case map
0145; 0146; Case map
0147; 0148; Case map
0149; 02BC 006E; Case map
014A; 014B; Case map
014C; 014D; Case map
014E; 014F; Case map
0150; 0151; Case map
0152; 0153; Case map
0154; 0155; Case map
0156; 0157; Case map
0158; 0159; Case map
015A; 015B; Case map
015C; 015D; Case map
015E; 015F; Case map
0160; 0161; Case map
0162; 0163; Case map
0164; 0165; Case map
0166; 0167; Case map
0168; 0169; Case map
016A; 016B; Case map
016C; 016D; Case map
016E; 016F; Case map
0170; 0171; Case map
0172; 0173; Case map
0174; 0175; Case map
0176; 0177; Case map
0178; 00FF; Case map
0179; 017A; Case map
017B; 017C; Case map
017D; 017E; Case map
017F; 0073; Case map
0181; 0253; Case map
0182; 0183; Case map
0184; 0185; Case map
0186; 0254; Case map
0187; 0188; Case map
0189; 0256; Case map
018A; 0257; Case map
018B; 018C; Case map
018E; 01DD; Case map
018F; 0259; Case map
0190; 025B; Case map
0191; 0192; Case map
0193; 0260; Case map
0194; 0263; Case map
0196; 0269; Case map
0197; 0268; Case map
0198; 0199; Case map
019C; 026F; Case map
019D; 0272; Case map
019F; 0275; Case map
01A0; 01A1; Case map
01A2; 01A3; Case map
01A4; 01A5; Case map
01A6; 0280; Case map
01A7; 01A8; Case map
01A9; 0283; Case map
01AC; 01AD; Case map
01AE; 0288; Case map
01AF; 01B0; Case map
01B1; 028A; Case map
01B2; 028B; Case map
01B3; 01B4; Case map
01B5; 01B6; Case map
01B7; 0292; Case map
01B8; 01B9; Case map
01BC; 01BD; Case map
01C4; 01C6; Case map
01C5; 01C6; Case map
01C7; 01C9; Case map
01C8; 01C9; Case map
01CA; 01CC; Case map
01CB; 01CC; Case map
01CD; 01CE; Case map
01CF; 01D0; Case map
01D1; 01D2; Case map
01D3; 01D4; Case map
01D5; 01D6; Case map
01D7; 01D8; Case map
01D9; 01DA; Case map
01DB; 01DC; Case map
01DE; 01DF; Case map
01E0; 01E1; Case map
01E2; 01E3; Case map
01E4; 01E5; Case map
01E6; 01E7; Case map
01E8; 01E9; Case map
01EA; 01EB; Case map
01EC; 01ED; Case map
01EE; 01EF; Case map
01F0; 006A 030C; Case map
01F1; 01F3; Case map
01F2; 01F3; Case map
01F4; 01F5; Case map
01F6; 0195; Case map
01F7; 01BF; Case map
01F8; 01F9; Case map
01FA; 01FB; Case map
01FC; 01FD; Case map
01FE; 01FF; Case map
0200; 0201; Case map
0202; 0203; Case map
0204; 0205; Case map
0206; 0207; Case map
0208; 0209; Case map
020A; 020B; Case map
020C; 020D; Case map
020E; 020F; Case map
0210; 0211; Case map
0212; 0213; Case map
0214; 0215; Case map
0216; 0217; Case map
0218; 0219; Case map
021A; 021B; Case map
021C; 021D; Case map
021E; 021F; Case map
0222; 0223; Case map
0224; 0225; Case map
0226; 0227; Case map
0228; 0229; Case map
022A; 022B; Case map
022C; 022D; Case map
022E; 022F; Case map
0230; 0231; Case map
0232; 0233; Case map
0345; 03B9; Case map
037A; 0020 03B9; Additional folding
0386; 03AC; Case map
0388; 03AD; Case map
0389; 03AE; Case map
038A; 03AF; Case map
038C; 03CC; Case map
038E; 03CD; Case map
038F; 03CE; Case map
0390; 03B9 0308 0301; Case map
0391; 03B1; Case map
0392; 03B2; Case map
0393; 03B3; Case map
0394; 03B4; Case map
0395; 03B5; Case map
0396; 03B6; Case map
0397; 03B7; Case map
0398; 03B8; Case map
0399; 03B9; Case map
039A; 03BA; Case map
039B; 03BB; Case map
039C; 03BC; Case map
039D; 03BD; Case map
039E; 03BE; Case map
039F; 03BF; Case map
03A0; 03C0; Case map
03A1; 03C1; Case map
03A3; 03C2; Case map
03A4; 03C4; Case map
03A5; 03C5; Case map
03A6; 03C6; Case map
03A7; 03C7; Case map
03A8; 03C8; Case map
03A9; 03C9; Case map
03AA; 03CA; Case map
03AB; 03CB; Case map
03B0; 03C5 0308 0301; Case map
03C2; 03C2; Case map
03C3; 03C2; Case map
03D0; 03B2; Case map
03D1; 03B8; Case map
03D2; 03C5; Additional folding
03D3; 03CD; Additional folding
03D4; 03CB; Additional folding
03D5; 03C6; Case map
03D6; 03C0; Case map
03DA; 03DB; Case map
03DC; 03DD; Case map
03DE; 03DF; Case map
03E0; 03E1; Case map
03E2; 03E3; Case map
03E4; 03E5; Case map
03E6; 03E7; Case map
03E8; 03E9; Case map
03EA; 03EB; Case map
03EC; 03ED; Case map
03EE; 03EF; Case map
03F0; 03BA; Case map
03F1; 03C1; Case map
03F2; 03C2; Case map
0400; 0450; Case map
0401; 0451; Case map
0402; 0452; Case map
0403; 0453; Case map
0404; 0454; Case map
0405; 0455; Case map
0406; 0456; Case map
0407; 0457; Case map
0408; 0458; Case map
0409; 0459; Case map
040A; 045A; Case map
040B; 045B; Case map
040C; 045C; Case map
040D; 045D; Case map
040E; 045E; Case map
040F; 045F; Case map
0410; 0430; Case map
0411; 0431; Case map
0412; 0432; Case map
0413; 0433; Case map
0414; 0434; Case map
0415; 0435; Case map
0416; 0436; Case map
0417; 0437; Case map
0418; 0438; Case map
0419; 0439; Case map
041A; 043A; Case map
041B; 043B; Case map
041C; 043C; Case map
041D; 043D; Case map
041E; 043E; Case map
041F; 043F; Case map
0420; 0440; Case map
0421; 0441; Case map
0422; 0442; Case map