rfc3492.txt

bind 9.3结合mysql数据库

   ToUnicode performs a higher level re-encoding and comparison, and a
   mismatch has the same consequence as if the Punycode decoder had
   failed.

7. Punycode examples

7.1 Sample strings

   In the Punycode encodings below, the ACE prefix is not shown.
   Backslashes show where line breaks have been inserted in strings too
   long for one line.

   The first 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.

   (A) 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
       Punycode: egbpdaj6bu4bxfgehfvwxn

   (B) Chinese (simplified):
       u+4ED6 u+4EEC u+4E3A u+4EC0 u+4E48 u+4E0D u+8BF4 u+4E2D u+6587
       Punycode: ihqwcrb4cv8a8dqg056pqjye

   (C) Chinese (traditional):
       u+4ED6 u+5011 u+7232 u+4EC0 u+9EBD u+4E0D u+8AAA u+4E2D u+6587
       Punycode: ihqwctvzc91f659drss3x8bo0yb

   (D) Czech: Pro<ccaron>prost<ecaron>nemluv<iacute><ccaron>esky
       U+0050 u+0072 u+006F u+010D u+0070 u+0072 u+006F u+0073 u+0074
       u+011B u+006E u+0065 u+006D u+006C u+0075 u+0076 u+00ED u+010D
       u+0065 u+0073 u+006B u+0079
       Punycode: Proprostnemluvesky-uyb24dma41a






Costello                    Standards Track                    [Page 14]

RFC 3492                     IDNA Punycode                    March 2003


   (E) 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
       Punycode: 4dbcagdahymbxekheh6e0a7fei0b

   (F) Hindi (Devanagari):
       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
       Punycode: i1baa7eci9glrd9b2ae1bj0hfcgg6iyaf8o0a1dig0cd

   (G) Japanese (kanji and hiragana):
       u+306A u+305C u+307F u+3093 u+306A u+65E5 u+672C u+8A9E u+3092
       u+8A71 u+3057 u+3066 u+304F u+308C u+306A u+3044 u+306E u+304B
       Punycode: n8jok5ay5dzabd5bym9f0cm5685rrjetr6pdxa

   (H) Korean (Hangul syllables):
       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
       Punycode: 989aomsvi5e83db1d2a355cv1e0vak1dwrv93d5xbh15a0dt30a5j\
                 psd879ccm6fea98c

   (I) Russian (Cyrillic):
       U+043F 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
       Punycode: b1abfaaepdrnnbgefbaDotcwatmq2g4l

   (J) Spanish: Porqu<eacute>nopuedensimplementehablarenEspa<ntilde>ol
       U+0050 u+006F u+0072 u+0071 u+0075 u+00E9 u+006E u+006F u+0070
       u+0075 u+0065 u+0064 u+0065 u+006E u+0073 u+0069 u+006D u+0070
       u+006C u+0065 u+006D u+0065 u+006E u+0074 u+0065 u+0068 u+0061
       u+0062 u+006C u+0061 u+0072 u+0065 u+006E U+0045 u+0073 u+0070
       u+0061 u+00F1 u+006F u+006C
       Punycode: PorqunopuedensimplementehablarenEspaol-fmd56a

   (K) Vietnamese:
       T<adotbelow>isaoh<odotbelow>kh<ocirc>ngth<ecirchookabove>ch\
       <ihookabove>n<oacute>iti<ecircacute>ngVi<ecircdotbelow>t
       U+0054 u+1EA1 u+0069 u+0073 u+0061 u+006F u+0068 u+1ECD u+006B
       u+0068 u+00F4 u+006E u+0067 u+0074 u+0068 u+1EC3 u+0063 u+0068
       u+1EC9 u+006E u+00F3 u+0069 u+0074 u+0069 u+1EBF u+006E u+0067
       U+0056 u+0069 u+1EC7 u+0074
       Punycode: TisaohkhngthchnitingVit-kjcr8268qyxafd2f1b9g



Costello                    Standards Track                    [Page 15]

RFC 3492                     IDNA Punycode                    March 2003


   The next several examples are all names of Japanese music artists,
   song titles, and TV programs, just because the author happens to have
   them handy (but Japanese is useful for providing examples of single-
   row text, two-row text, ideographic text, and various mixtures
   thereof).

   (L) 3<nen>B<gumi><kinpachi><sensei>
       u+0033 u+5E74 U+0042 u+7D44 u+91D1 u+516B u+5148 u+751F
       Punycode: 3B-ww4c5e180e575a65lsy2b

   (M) <amuro><namie>-with-SUPER-MONKEYS
       u+5B89 u+5BA4 u+5948 u+7F8E u+6075 u+002D u+0077 u+0069 u+0074
       u+0068 u+002D U+0053 U+0055 U+0050 U+0045 U+0052 u+002D U+004D
       U+004F U+004E U+004B U+0045 U+0059 U+0053
       Punycode: -with-SUPER-MONKEYS-pc58ag80a8qai00g7n9n

   (N) Hello-Another-Way-<sorezore><no><basho>
       U+0048 u+0065 u+006C u+006C u+006F u+002D U+0041 u+006E u+006F
       u+0074 u+0068 u+0065 u+0072 u+002D U+0057 u+0061 u+0079 u+002D
       u+305D u+308C u+305E u+308C u+306E u+5834 u+6240
       Punycode: Hello-Another-Way--fc4qua05auwb3674vfr0b

   (O) <hitotsu><yane><no><shita>2
       u+3072 u+3068 u+3064 u+5C4B u+6839 u+306E u+4E0B u+0032
       Punycode: 2-u9tlzr9756bt3uc0v

   (P) Maji<de>Koi<suru>5<byou><mae>
       U+004D u+0061 u+006A u+0069 u+3067 U+004B u+006F u+0069 u+3059
       u+308B u+0035 u+79D2 u+524D
       Punycode: MajiKoi5-783gue6qz075azm5e

   (Q) <pafii>de<runba>
       u+30D1 u+30D5 u+30A3 u+30FC u+0064 u+0065 u+30EB u+30F3 u+30D0
       Punycode: de-jg4avhby1noc0d

   (R) <sono><supiido><de>
       u+305D u+306E u+30B9 u+30D4 u+30FC u+30C9 u+3067
       Punycode: d9juau41awczczp

   The last example is an ASCII string that breaks the existing rules
   for host name labels.  (It is not a realistic example for IDNA,
   because IDNA never encodes pure ASCII labels.)

   (S) -> $1.00 <-
       u+002D u+003E u+0020 u+0024 u+0031 u+002E u+0030 u+0030 u+0020
       u+003C u+002D
       Punycode: -> $1.00 <--




Costello                    Standards Track                    [Page 16]

RFC 3492                     IDNA Punycode                    March 2003


7.2 Decoding traces

   In the following traces, the evolving state of the decoder is shown
   as a sequence of hexadecimal values, representing the code points in
   the extended string.  An asterisk appears just after the most
   recently inserted code point, indicating both n (the value preceeding
   the asterisk) and i (the position of the value just after the
   asterisk).  Other numerical values are decimal.

   Decoding trace of example B from section 7.1:

   n is 128, i is 0, bias is 72
   input is "ihqwcrb4cv8a8dqg056pqjye"
   there is no delimiter, so extended string starts empty
   delta "ihq" decodes to 19853
   bias becomes 21
   4E0D *
   delta "wc" decodes to 64
   bias becomes 20
   4E0D 4E2D *
   delta "rb" decodes to 37
   bias becomes 13
   4E3A * 4E0D 4E2D
   delta "4c" decodes to 56
   bias becomes 17
   4E3A 4E48 * 4E0D 4E2D
   delta "v8a" decodes to 599
   bias becomes 32
   4E3A 4EC0 * 4E48 4E0D 4E2D
   delta "8d" decodes to 130
   bias becomes 23
   4ED6 * 4E3A 4EC0 4E48 4E0D 4E2D
   delta "qg" decodes to 154
   bias becomes 25
   4ED6 4EEC * 4E3A 4EC0 4E48 4E0D 4E2D
   delta "056p" decodes to 46301
   bias becomes 84
   4ED6 4EEC 4E3A 4EC0 4E48 4E0D 4E2D 6587 *
   delta "qjye" decodes to 88531
   bias becomes 90
   4ED6 4EEC 4E3A 4EC0 4E48 4E0D 8BF4 * 4E2D 6587










Costello                    Standards Track                    [Page 17]

RFC 3492                     IDNA Punycode                    March 2003


   Decoding trace of example L from section 7.1:

   n is 128, i is 0, bias is 72
   input is "3B-ww4c5e180e575a65lsy2b"
   literal portion is "3B-", so extended string starts as:
   0033 0042
   delta "ww4c" decodes to 62042
   bias becomes 27
   0033 0042 5148 *
   delta "5e" decodes to 139
   bias becomes 24
   0033 0042 516B * 5148
   delta "180e" decodes to 16683
   bias becomes 67
   0033 5E74 * 0042 516B 5148
   delta "575a" decodes to 34821
   bias becomes 82
   0033 5E74 0042 516B 5148 751F *
   delta "65l" decodes to 14592
   bias becomes 67
   0033 5E74 0042 7D44 * 516B 5148 751F
   delta "sy2b" decodes to 42088
   bias becomes 84
   0033 5E74 0042 7D44 91D1 * 516B 5148 751F



























Costello                    Standards Track                    [Page 18]

RFC 3492                     IDNA Punycode                    March 2003


7.3 Encoding traces

   In the following traces, code point values are hexadecimal, while
   other numerical values are decimal.

   Encoding trace of example B from section 7.1:

   bias is 72
   input is:
   4ED6 4EEC 4E3A 4EC0 4E48 4E0D 8BF4 4E2D 6587
   there are no basic code points, so no literal portion
   next code point to insert is 4E0D
   needed delta is 19853, encodes as "ihq"
   bias becomes 21
   next code point to insert is 4E2D
   needed delta is 64, encodes as "wc"
   bias becomes 20
   next code point to insert is 4E3A
   needed delta is 37, encodes as "rb"
   bias becomes 13
   next code point to insert is 4E48
   needed delta is 56, encodes as "4c"
   bias becomes 17
   next code point to insert is 4EC0
   needed delta is 599, encodes as "v8a"
   bias becomes 32
   next code point to insert is 4ED6
   needed delta is 130, encodes as "8d"
   bias becomes 23
   next code point to insert is 4EEC
   needed delta is 154, encodes as "qg"
   bias becomes 25
   next code point to insert is 6587
   needed delta is 46301, encodes as "056p"
   bias becomes 84
   next code point to insert is 8BF4
   needed delta is 88531, encodes as "qjye"
   bias becomes 90
   output is "ihqwcrb4cv8a8dqg056pqjye"












Costello                    Standards Track                    [Page 19]

RFC 3492                     IDNA Punycode                    March 2003


   Encoding trace of example L from section 7.1:

   bias is 72
   input is:
   0033 5E74 0042 7D44 91D1 516B 5148 751F
   basic code points (0033, 0042) are copied to literal portion: "3B-"
   next code point to insert is 5148
   needed delta is 62042, encodes as "ww4c"
   bias becomes 27
   next code point to insert is 516B
   needed delta is 139, encodes as "5e"
   bias becomes 24
   next code point to insert is 5E74
   needed delta is 16683, encodes as "180e"
   bias becomes 67
   next code point to insert is 751F
   needed delta is 34821, encodes as "575a"
   bias becomes 82
   next code point to insert is 7D44
   needed delta is 14592, encodes as "65l"
   bias becomes 67
   next code point to insert is 91D1
   needed delta is 42088, encodes as "sy2b"
   bias becomes 84
   output is "3B-ww4c5e180e575a65lsy2b"

8. 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 ASCII domain names, each controlled by a
   different authority, some of which could be spoofs that hijack
   service requests intended for another.  Therefore Punycode 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, and this work is leveraged for domain names by
   Nameprep [NAMEPREP].