draft-ietf-idn-amc-ace-m-00.txt

bind-3.2.

        <de>        = U+3067         (hiragana)
        <suru>      = U+3059 U+308B  (hiragana)
        <byou><mae> = U+79D2 U+524D  (kanji)

        UTF-8:  Maji???Koi??????5??????
        UTF-16: ??????????????????????????
        AMC-M:  bsm-Maji-r-Koi-b2m-5-z37cxuwp
        BRACE:  ji8-Maji-g-Koi-qe7x-5-wx7p6ma
        DUDE:   Mdhqpj067G06bvpj059obg035n9d2l24d
        RACE:   3aag2adbabvaa2jqm4agwadpabutawjqrmadk6oskjgq
        LACE:   74ag2adbabvaa2jqm4agwadpabutawjqrmadk6oskjgq

    (F) <pafii>de<runba>  (Japanese song title)

        <pafii> = U+30D1 U+30D5 U+30A3 U+30FC  (katakana)
        <runba> = U+30EB U+30F3 U+30D0         (katakana)

        UTF-16: ??????????????
        BRACE:  3iu8pazt-de-pygi
        AMC-M:  bs3jp4d9n-de-8m9di
        RACE:   gdi5li7475sp6zpl6pia
        DUDE:   j0d1lq3vcg064lj0ebv3t0
        UTF-8:  ????????????de?????????
        LACE:   aqyndvnd7qbaazdfamyox46q

    (G) <sono><supiido><de>  (Japanese song title)

        <sono>    = U+305D U+306E                (hiragana)
        <supiido> = U+30B9 U+30D4 U+30FC U+30C9  (katakana)
        <de>      = U+3067                       (hiragana)

        RACE:   gbow5oou7tewo
        UTF-16: ??????????????
        BRACE:  bidprdmp9wt7mi
        LACE:   a4yf23vz2t6mszy
        AMC-M:  bsmfyq5j7e9n6jr
        DUDE:   j05dmer9t4vcs9m7
        UTF-8:  ?????????????????????

    The next several examples are all translations of the sentence "Why
    can't they just speak in <language>?" (courtesy of Michael Kaplan's
    "provincial" page [PROVINCIAL]).  Word breaks and punctuation have
    been removed, as is often done in domain names.

    (H) Arabic (Egyptian):
        U+0644 U+064A U+0647 U+0645 U+0627 U+0628 U+062A U+0643 U+0644
        U+0645 U+0648 U+0634 U+0639 U+0631 U+0628 U+064A U+061F

        DUDE:   m44qnli7oqk3kloj4phi8kahf
        BRACE:  28akcjwcmp3ciwb4t3ngd4nbaz
        AMC-M:  agiekhfuhuiukdefivevjvbuiktr
        RACE:   azceur2fe4ucuq2eivediojrfbfb6
        LACE:   cedeisshiutsqksdircuqnbzgeueuhy
        UTF-16: ??????????????????????????????????
        UTF-8:  ??????????????????????????????????

    (I) Chinese (simplified):
        U+4ED6 U+4EEC U+4E3A U+4EC0 U+4E48 U+4E0D U+8BF4 U+4E2D U+6587

        UTF-16: ??????????????????
        BRACE:  kgcqqsgp26i5h4zn7req5i
        AMC-M:  uqj7g8nvk6awispn9wupdnh
        DUDE:   ked6ucjas0k8gdobf4ke2dm587
        UTF-8:  ???????????????????????????
        LACE:   azhnn3b2ybea2aml6qau4libmwdq
        RACE:   3bhnmtxmjy5e5qcojbha3c7ujywwlby

    (J) Czech: Pro<ccaron>prost<ecaron>nemluv<iacute><ccaron>esky

        <ccaron> = U+010D
        <ecaron> = U+011B
        <iacute> = U+00ED

        UTF-8:  Pro??prost??nemluv????esky
        AMC-M:  g26-Pro-p-prost-9m-nemluv-6pp-esky
        BRACE:  i32-Pro-u-prost-8y-nemluv-29f3n-esky
        DUDE:   N0imfh0dg70imfn3kh1bg6eltsn5mudh0dg65n3mbn9
        UTF-16: ????????????????????????????????????????????
        LACE:   amaha4tpaeaq2biaobzg643uaearwbyanzsw23dvo3wqcainaqagk43\
                lpe
        RACE:   ah7xb73s75xq373q75zp6377op7xig77n37wl73n75wp65p7o3762dp\
                7mx7xh73l754q

    (K) Hebrew:
        U+05DC U+05DE U+05D4 U+05D4 U+05DD U+05E4 U+05E9 U+05D5 U+05D8
        U+05DC U+05D0 U+05DE U+05D3 U+05D1 U+05E8 U+05D9 U+05DD U+05E2
        U+05D1 U+05E8 U+05D9 U+05EA

        AMC-M:  af4nqeep8e8jfinaqdb8ijp8cb8ij8k
        DUDE:   ldcukktu4pt5osgujhu8t9tu2t1u8t9ua
        BRACE:  27vkyp7bgwmbpfjgc4ynx5nd8xsp5nd9c
        RACE:   axon5vgu3xsotvoy3tin5u6r5dm53ywr5dm6u
        LACE:   cyc5zxwu2to6j2ov3donbxwt2huntxpc2hunt2q
        UTF-8:  ????????????????????????????????????????????
        UTF-16: ????????????????????????????????????????????

    (L) Hindi:
        U+092F U+0939 U+0932 U+094B U+0917 U+0939 U+093F U+0928 U+094D
        U+0926 U+0940 U+0915 U+094D U+092F U+094B U+0902 U+0928 U+0939
        U+0940 U+0902 U+092C U+094B U+0932 U+0938 U+0915 U+0924 U+0947
        U+0939 U+0948 U+0902  (Devanagari)

        BRACE:  2b7xtenqdr7zc6uma2pmcz7ibage237kdemicnk9gei32
        RACE:   bextsmslc44t6kcnezabktjpjmbcqokaaiwewmrycuseookiai
        LACE:   dyes6ojsjmltspzijuteafknf5fqekbziabcyszshaksirzzjaba
        AMC-M:  ajhurbvcwmthbhuiwpugitfwpurwmscuibiscunwmvcatfuerbwisc
        DUDE:   p2fj9ikbh7j9vi8kdi6k0h5kdifkbg2i8j9k0g2ickbj2oh5i4k7j9k\
                8g2
        UTF-16: ???????????????????????????????????????????????????????\
                ?????
        UTF-8:  ???????????????????????????????????????????????????????\
                ???????????????????????????????????

    (M) Korean:
        U+C138 U+ACC4 U+C758 U+BAA8 U+B4E0 U+C0AC U+B78C U+B4E4 U+C774
        U+D55C U+AD6D U+C5B4 U+B97C U+C774 U+D574 U+D55C U+B2E4 U+BA74
        U+C5BC U+B9C8 U+B098 U+C88B U+C744 U+AE4C  (Hangul syllables)

        UTF-16: ????????????????????????????????????????????????
        UTF-8:  ???????????????????????????????????????????????????????\
                ?????????????????
        AMC-M:  yhxcj2w6exiaxi68acfn92n68ezehk6xypdpwam6zehmwhk648eavwd\
                p6aqi23ieemweywn
        BRACE:  y394qebjusrcndbs82pkvstf96sxufcr7ffr4vbgdwsxufcx8pdktgb\
                gmnsqydmk7im56arju6pt82
        LACE:   77atrlgey5mlvkfu4dakzn4mwtsmo5gvlsww3rnuxf6mo5gvotkvzmx\
                exj2mlpfzzcyjrsely5ck4ta
        RACE:   3datrlgey5mlvkfu4dakzn4mwtsmo5gvlsww3rnuxf6mo5gvotkvzmx\
                exj2mlpfzzcyjrsely5ck4ta
        DUDE:   s138qcc4s758raa8ke0s0acr78cke4s774t55cqd6ds5b4r97cs774t\
                574lcr2e4q74s5bcr9c8g98s88bn44qe4c

    (N) Russian:
        U+041F U+043E U+0447 U+0435 U+043C U+0443 U+0436 U+0435 U+043E
        U+043D U+0438 U+043D U+0435 U+0433 U+043E U+0432 U+043E U+0440
        U+044F U+0442 U+043F U+043E U+0440 U+0443 U+0441 U+0441 U+043A
        U+0438  (Cyrillic)

        DUDE:   K3fuk7j5sk3j6lutotljuiuk0vijfuk0jhhjao
        AMC-M:  aehHgrvfemvgvfgfafvfvdgvcgiwrkhgimjjca
        BRACE:  269xyjvcyafqfdwyr3xfd8z8byi6z39xyi692s7ug2
        RACE:   aq7t4rzvhrbtmnj6hu4d2njthyzd4qcpii7t4qcdifatuoa
        LACE:   dqcd6pshgu6egnrvhy6tqpjvgm7depsaj5bd6psainaucory
        UTF-16: ???????????????????????????????????????????????????????\
                ???
        UTF-8:  ???????????????????????????????????????????????????????
                ???

    (O) Spanish: Porqu<eacute>nopuedensimplementehablarenEspa<ntilde>ol

        <eacute> = U+00E9
        <ntilde> = U+00F1

        UTF-8:  Porqu??nopuedensimplementehablarenEspa??ol
        AMC-M:  aa7-Porqu-b-nopuedensimplementehablarenEspa-j-ol
        BRACE:  22x-Porqu-9-nopuedensimplementehablarenEspa-j-ol
        DUDE:   N0mfn2hlu9mevn0lm5klun3m9tn0mcltlun4m5ohishn2m5uLn3gm1v\
                1mfs
        RACE:   abyg64troxuw433qovswizloonuw24dmmvwwk3tumvugcytmmfzgk3t\
                fonygd4lpnq
        LACE:   faaha33sof26s3tpob2wkzdfnzzws3lqnrsw2zloorswqylcnrqxezl\
                omvzxayprn5wa
        UTF-16: ???????????????????????????????????????????????????????\
                ?????????????????????????

    (P) Taiwanese:
        U+4ED6 U+5011 U+7232 U+4EC0 U+9EBD U+4E0D U+8AAA U+4E2D U+6587

        UTF-16: ??????????????????
        UTF-8:  ???????????????????????????
        AMC-M:  uqj7g2tbgtu6a385pspnxkupdnh
        BRACE:  kgcqui49gatc2wyrn8y7cndgte9
        RACE:   3bhnmuaroize5qe6xvha3cvkjywwlby
        LACE:   75hnmuaroize5qe6xvha3cvkjywwlby
        DUDE:   ked6l011n232kec0pebdke0doaaake2dm587

    (Q) Vietnamese:
        Ta<dotbelow>isaoho<dotbelow>kh<ocirc>ngth<ecirc><hookabove>chi\
        <hookabove>no<acute>iti<ecirc><acute>ngVi<ecirc><dotbelow>t

        <dotbelow>  = U+0323
        <ocirc>     = U+00F4
        <ecirc>     = U+00EA
        <hookabove> = U+0309
        <acute>     = U+0301

        UTF-8:  Ta??isaoho??kh??ngth????chi??no??iti????ngVi????t
        AMC-M:  ada-Ta-ud-isaoho-ud-kh-s9e-ngth-s8kj-chi-j-no-b-iti-s8k\
                b-ngVi-s8kud-t
        BRACE:  i54-Ta-8-isaoho-ay-kh-29n-ngth-s2xa6i-chi-k-no-2g-iti-2\
                9c29-ngVi-25p48-t
        UTF-16: ???????????????????????????????????????????????????????\
                ?????????????????????
        DUDE:   N4m1j23g69n3m1vovj23g6bov4menn4m8uaj09g63opj09g6evj01g6\
                9n4m9uaj01g6enN6m9uaj23g74
        LACE:   aiahiyibamrqmadjonqw62dpaebsgcaannupi3thoruouaidbebqay3\
                ineaqgcicabxg6aidaecaa2lunhvacaybauag4z3wnhvacazdaeahi
        RACE:   ap7xj73bep7wt73t75q76377nd7w6i77np7wr77u75xp6z77ot7wr77\
                kbh7wh73i75uqt73o75xqd73j752p62p75ia763x7m77xn73j77vch7\
                3u

    The last example is an ASCII string that breaks not only the
    existing rules for host name labels but also the rules proposed in
    [NAMEPREP02] for internationalized domain names.

    (R) -> $1.00 <-

        UTF-8:  -> $1.00 <-
        DUDE:   -jei0kj1iej0gi0jc-
        RACE:   aawt4ibegexdambahqwq
        LACE:   bmac2praeqys4mbqea6c2
        UTF-16: ??????????????????????
        AMC-M:  aae--vqae-1-q-00-avn--
        BRACE:  229--t2b4-1-w-00-i9i--

Security considerations

    Users expect each domain name in DNS to be controlled by a single
    authority.  If a Unicode string intended for use as a domain label
    could map to multiple ACE labels, then an internationalized domain
    name could map to multiple ACE domain names, each controlled by
    a different authority, some of which could be spoofs that hijack
    service requests intended for another.  Therefore AMC-ACE-M is
    designed so that each Unicode string has a unique encoding.

    However, there can still be multiple Unicode representations of the
    "same" text, for various definitions of "same".  This problem is
    addressed to some extent by the Unicode standard under the topic
    of canonicalization, but some text strings may be misleading or
    ambiguous to humans when used as domain names, such as strings
    containing dots, slashes, at-signs, etc.  These issues are being
    further studied under the topic of "nameprep" [NAMEPREP02].

References

    [ACEID01] Yoshiro Yoneya, Naomasa Maruyama, "Proposal for
    a determining process of ACE identifier", 2000-Dec-19,
    draft-ietf-idn-aceid-01.

    [BRACE00] Adam Costello, "BRACE: Bi-mode Row-based
    ASCII-Compatible Encoding for IDN version 0.1.2", 2000-Sep-19,
    draft-ietf-idn-brace-00.

    [DUDE00] Brian Spolarich, Mark Welter, "DUDE: Differential Unicode
    Domain Encoding", 2000-Nov-21, draft-ietf-idn-dude-00.

    [IDN] Internationalized Domain Names (IETF working group),
    http://www.i-d-n.net/, [e-mail].

    [LACE01] Paul Hoffman, Mark Davis, "LACE: Length-based ASCII
    Compatible Encoding for IDN", 2001-Jan-05, draft-ietf-idn-lace-01.

    [NAMEPREP02] Paul Hoffman, Marc Blanchet, "Preparation
    of Internationalized Host Names", 2001-Jan-17,
    draft-ietf-idn-nameprep-02.

    [PROVINCIAL] Michael Kaplan, "The 'anyone can be provincial!' page",
    http://www.trigeminal.com/samples/provincial.html.

    [RACE03] Paul Hoffman, "RACE: Row-based ASCII Compatible Encoding
    for IDN", 2000-Nov-28, draft-ietf-idn-race-03.

    [RFC952] K. Harrenstien, M. Stahl, E. Feinler, "DOD Internet Host
    Table Specification", 1985-Oct, RFC 952.

    [RFC1034] P. Mockapetris, "Domain Names - Concepts and Facilities",
    1987-Nov, RFC 1034.

    [RFC1123] Internet Engineering Task Force, R. Braden (editor),
    "Requirements for Internet Hosts -- Application and Support",
    1989-Oct, RFC 1123.

    [SACE] Dan Oscarsson, "Simple ASCII Compatible Encoding (SACE)",
    draft-ietf-idn-sace-*.

    [UNICODE] The Unicode Consortium, "The Unicode Standard",
    http://www.unicode.org/unicode/standard/standard.html.

    [UTF5] James Seng, Martin Duerst, Tin Wee Tan, "UTF-5, a
    Transformation Format of Unicode and ISO 10646", draft-jseng-utf5-*.

    [UTF6] Mark Welter, Brian W. Spolarich, "UTF-6 - Yet Another
    ASCII-Compatible Encoding for IDN", draft-ietf-idn-utf6-*.

    [UTFCONV] Mark Davis, "UTF Converter",
    http://www.macchiato.com/unicode/convert.html.

Author

    Adam M. Costello <[e-mail]>
    http://www.cs.berkeley.edu/~amc/


Example implementation


/******************************************/
/* amc-ace-m.c 0.1.0 (2001-Feb-12-Mon)    */
/* Adam M. Costello <[e-mail]> */
/******************************************/

/* This is ANSI C code implementing AMC-ACE-M version 0.1.*. */


/************************************************************/
/* Public interface (would normally go in its own .h file): */

#include <limits.h>

enum amc_ace_status {
  amc_ace_success,
  amc_ace_invalid_input,
  amc_ace_output_too_big
};

enum case_sensitivity { case_sensitive, case_insensitive };

#if UINT_MAX >= 0x10FFFF
typedef unsigned int u_code_point;
#else
typedef unsigned long u_code_point;
#endif

int amc_ace_m_encode(
  unsigned int input_length,
  const u_code_point *input,
  const unsigned char *uppercase_flags,
  unsigned int *output_size,
  unsigned char *output );

    /* amc_ace_m_encode() converts Unicode to AMC-ACE-M.  The input  */
    /* must be represented as an array of Unicode code points        */
    /* (not code units; surrogate pairs are not allowed), and the    */
    /* output will be represented as null-terminated ASCII.  The     */
    /* input_length is the number of code points in the input.  The  */
    /* output_size is an in/out argument: the caller must pass       */
    /* in the maximum number of characters that may be output        */
    /* (including the terminating null), and on successful return    */
    /* it will contain the number of characters actually output      */
    /* (including the terminating null, so it will be one more than  */