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1 /*
2  *******************************************************************************
3  *
4  *   Copyright (C) 2003-2012, International Business Machines
5  *   Corporation and others.  All Rights Reserved.
6  *
7  *******************************************************************************
8  *   file name:  uidna.h
9  *   encoding:   US-ASCII
10  *   tab size:   8 (not used)
11  *   indentation:4
12  *
13  *   created on: 2003feb1
14  *   created by: Ram Viswanadha
15  */
16 
17 #ifndef __UIDNA_H__
18 #define __UIDNA_H__
19 
20 #include "unicode/utypes.h"
21 
22 #if !UCONFIG_NO_IDNA
23 
24 #include "unicode/localpointer.h"
25 #include "unicode/parseerr.h"
26 
27 /**
28  * \file
29  * \brief C API: Internationalizing Domain Names in Applications (IDNA)
30  *
31  * IDNA2008 is implemented according to UTS #46, see the IDNA C++ class in idna.h.
32  *
33  * The C API functions which do take a UIDNA * service object pointer
34  * implement UTS #46 and IDNA2008.
35  * The C API functions which do not take a service object pointer
36  * implement IDNA2003.
37  */
38 
39 /*
40  * IDNA option bit set values.
41  */
42 enum {
43     /**
44      * Default options value: None of the other options are set.
45      * For use in static worker and factory methods.
46      * @stable ICU 2.6
47      */
48     UIDNA_DEFAULT=0,
49     /**
50      * Option to allow unassigned code points in domain names and labels.
51      * For use in static worker and factory methods.
52      * <p>This option is ignored by the UTS46 implementation.
53      * (UTS #46 disallows unassigned code points.)
54      * @stable ICU 2.6
55      */
56     UIDNA_ALLOW_UNASSIGNED=1,
57     /**
58      * Option to check whether the input conforms to the STD3 ASCII rules,
59      * for example the restriction of labels to LDH characters
60      * (ASCII Letters, Digits and Hyphen-Minus).
61      * For use in static worker and factory methods.
62      * @stable ICU 2.6
63      */
64     UIDNA_USE_STD3_RULES=2,
65     /**
66      * IDNA option to check for whether the input conforms to the BiDi rules.
67      * For use in static worker and factory methods.
68      * <p>This option is ignored by the IDNA2003 implementation.
69      * (IDNA2003 always performs a BiDi check.)
70      * @stable ICU 4.6
71      */
72     UIDNA_CHECK_BIDI=4,
73     /**
74      * IDNA option to check for whether the input conforms to the CONTEXTJ rules.
75      * For use in static worker and factory methods.
76      * <p>This option is ignored by the IDNA2003 implementation.
77      * (The CONTEXTJ check is new in IDNA2008.)
78      * @stable ICU 4.6
79      */
80     UIDNA_CHECK_CONTEXTJ=8,
81     /**
82      * IDNA option for nontransitional processing in ToASCII().
83      * For use in static worker and factory methods.
84      * <p>By default, ToASCII() uses transitional processing.
85      * <p>This option is ignored by the IDNA2003 implementation.
86      * (This is only relevant for compatibility of newer IDNA implementations with IDNA2003.)
87      * @stable ICU 4.6
88      */
89     UIDNA_NONTRANSITIONAL_TO_ASCII=0x10,
90     /**
91      * IDNA option for nontransitional processing in ToUnicode().
92      * For use in static worker and factory methods.
93      * <p>By default, ToUnicode() uses transitional processing.
94      * <p>This option is ignored by the IDNA2003 implementation.
95      * (This is only relevant for compatibility of newer IDNA implementations with IDNA2003.)
96      * @stable ICU 4.6
97      */
98     UIDNA_NONTRANSITIONAL_TO_UNICODE=0x20,
99 #ifndef U_HIDE_DRAFT_API
100     /**
101      * IDNA option to check for whether the input conforms to the CONTEXTO rules.
102      * For use in static worker and factory methods.
103      * <p>This option is ignored by the IDNA2003 implementation.
104      * (The CONTEXTO check is new in IDNA2008.)
105      * <p>This is for use by registries for IDNA2008 conformance.
106      * UTS #46 does not require the CONTEXTO check.
107      * @draft ICU 49
108      */
109     UIDNA_CHECK_CONTEXTO=0x40
110 #endif  /* U_HIDE_DRAFT_API */
111 };
112 
113 /**
114  * Opaque C service object type for the new IDNA API.
115  * @stable ICU 4.6
116  */
117 struct UIDNA;
118 typedef struct UIDNA UIDNA;  /**< C typedef for struct UIDNA. @stable ICU 4.6 */
119 
120 /**
121  * Returns a UIDNA instance which implements UTS #46.
122  * Returns an unmodifiable instance, owned by the caller.
123  * Cache it for multiple operations, and uidna_close() it when done.
124  * The instance is thread-safe, that is, it can be used concurrently.
125  *
126  * For details about the UTS #46 implementation see the IDNA C++ class in idna.h.
127  *
128  * @param options Bit set to modify the processing and error checking.
129  *                See option bit set values in uidna.h.
130  * @param pErrorCode Standard ICU error code. Its input value must
131  *                  pass the U_SUCCESS() test, or else the function returns
132  *                  immediately. Check for U_FAILURE() on output or use with
133  *                  function chaining. (See User Guide for details.)
134  * @return the UTS #46 UIDNA instance, if successful
135  * @stable ICU 4.6
136  */
137 U_STABLE UIDNA * U_EXPORT2
138 uidna_openUTS46(uint32_t options, UErrorCode *pErrorCode);
139 
140 /**
141  * Closes a UIDNA instance.
142  * @param idna UIDNA instance to be closed
143  * @stable ICU 4.6
144  */
145 U_STABLE void U_EXPORT2
146 uidna_close(UIDNA *idna);
147 
148 #if U_SHOW_CPLUSPLUS_API
149 
150 U_NAMESPACE_BEGIN
151 
152 /**
153  * \class LocalUIDNAPointer
154  * "Smart pointer" class, closes a UIDNA via uidna_close().
155  * For most methods see the LocalPointerBase base class.
156  *
157  * @see LocalPointerBase
158  * @see LocalPointer
159  * @stable ICU 4.6
160  */
161 U_DEFINE_LOCAL_OPEN_POINTER(LocalUIDNAPointer, UIDNA, uidna_close);
162 
163 U_NAMESPACE_END
164 
165 #endif
166 
167 /**
168  * Output container for IDNA processing errors.
169  * Initialize with UIDNA_INFO_INITIALIZER:
170  * \code
171  * UIDNAInfo info = UIDNA_INFO_INITIALIZER;
172  * int32_t length = uidna_nameToASCII(..., &info, &errorCode);
173  * if(U_SUCCESS(errorCode) && info.errors!=0) { ... }
174  * \endcode
175  * @stable ICU 4.6
176  */
177 typedef struct UIDNAInfo {
178     /** sizeof(UIDNAInfo) @stable ICU 4.6 */
179     int16_t size;
180     /**
181      * Set to TRUE if transitional and nontransitional processing produce different results.
182      * For details see C++ IDNAInfo::isTransitionalDifferent().
183      * @stable ICU 4.6
184      */
185     UBool isTransitionalDifferent;
186     UBool reservedB3;  /**< Reserved field, do not use. @internal */
187     /**
188      * Bit set indicating IDNA processing errors. 0 if no errors.
189      * See UIDNA_ERROR_... constants.
190      * @stable ICU 4.6
191      */
192     uint32_t errors;
193     int32_t reservedI2;  /**< Reserved field, do not use. @internal */
194     int32_t reservedI3;  /**< Reserved field, do not use. @internal */
195 } UIDNAInfo;
196 
197 /**
198  * Static initializer for a UIDNAInfo struct.
199  * @stable ICU 4.6
200  */
201 #define UIDNA_INFO_INITIALIZER { \
202     (int16_t)sizeof(UIDNAInfo), \
203     FALSE, FALSE, \
204     0, 0, 0 }
205 
206 /**
207  * Converts a single domain name label into its ASCII form for DNS lookup.
208  * If any processing step fails, then pInfo->errors will be non-zero and
209  * the result might not be an ASCII string.
210  * The label might be modified according to the types of errors.
211  * Labels with severe errors will be left in (or turned into) their Unicode form.
212  *
213  * The UErrorCode indicates an error only in exceptional cases,
214  * such as a U_MEMORY_ALLOCATION_ERROR.
215  *
216  * @param idna UIDNA instance
217  * @param label Input domain name label
218  * @param length Label length, or -1 if NUL-terminated
219  * @param dest Destination string buffer
220  * @param capacity Destination buffer capacity
221  * @param pInfo Output container of IDNA processing details.
222  * @param pErrorCode Standard ICU error code. Its input value must
223  *                  pass the U_SUCCESS() test, or else the function returns
224  *                  immediately. Check for U_FAILURE() on output or use with
225  *                  function chaining. (See User Guide for details.)
226  * @return destination string length
227  * @stable ICU 4.6
228  */
229 U_STABLE int32_t U_EXPORT2
230 uidna_labelToASCII(const UIDNA *idna,
231                    const UChar *label, int32_t length,
232                    UChar *dest, int32_t capacity,
233                    UIDNAInfo *pInfo, UErrorCode *pErrorCode);
234 
235 /**
236  * Converts a single domain name label into its Unicode form for human-readable display.
237  * If any processing step fails, then pInfo->errors will be non-zero.
238  * The label might be modified according to the types of errors.
239  *
240  * The UErrorCode indicates an error only in exceptional cases,
241  * such as a U_MEMORY_ALLOCATION_ERROR.
242  *
243  * @param idna UIDNA instance
244  * @param label Input domain name label
245  * @param length Label length, or -1 if NUL-terminated
246  * @param dest Destination string buffer
247  * @param capacity Destination buffer capacity
248  * @param pInfo Output container of IDNA processing details.
249  * @param pErrorCode Standard ICU error code. Its input value must
250  *                  pass the U_SUCCESS() test, or else the function returns
251  *                  immediately. Check for U_FAILURE() on output or use with
252  *                  function chaining. (See User Guide for details.)
253  * @return destination string length
254  * @stable ICU 4.6
255  */
256 U_STABLE int32_t U_EXPORT2
257 uidna_labelToUnicode(const UIDNA *idna,
258                      const UChar *label, int32_t length,
259                      UChar *dest, int32_t capacity,
260                      UIDNAInfo *pInfo, UErrorCode *pErrorCode);
261 
262 /**
263  * Converts a whole domain name into its ASCII form for DNS lookup.
264  * If any processing step fails, then pInfo->errors will be non-zero and
265  * the result might not be an ASCII string.
266  * The domain name might be modified according to the types of errors.
267  * Labels with severe errors will be left in (or turned into) their Unicode form.
268  *
269  * The UErrorCode indicates an error only in exceptional cases,
270  * such as a U_MEMORY_ALLOCATION_ERROR.
271  *
272  * @param idna UIDNA instance
273  * @param name Input domain name
274  * @param length Domain name length, or -1 if NUL-terminated
275  * @param dest Destination string buffer
276  * @param capacity Destination buffer capacity
277  * @param pInfo Output container of IDNA processing details.
278  * @param pErrorCode Standard ICU error code. Its input value must
279  *                  pass the U_SUCCESS() test, or else the function returns
280  *                  immediately. Check for U_FAILURE() on output or use with
281  *                  function chaining. (See User Guide for details.)
282  * @return destination string length
283  * @stable ICU 4.6
284  */
285 U_STABLE int32_t U_EXPORT2
286 uidna_nameToASCII(const UIDNA *idna,
287                   const UChar *name, int32_t length,
288                   UChar *dest, int32_t capacity,
289                   UIDNAInfo *pInfo, UErrorCode *pErrorCode);
290 
291 /**
292  * Converts a whole domain name into its Unicode form for human-readable display.
293  * If any processing step fails, then pInfo->errors will be non-zero.
294  * The domain name might be modified according to the types of errors.
295  *
296  * The UErrorCode indicates an error only in exceptional cases,
297  * such as a U_MEMORY_ALLOCATION_ERROR.
298  *
299  * @param idna UIDNA instance
300  * @param name Input domain name
301  * @param length Domain name length, or -1 if NUL-terminated
302  * @param dest Destination string buffer
303  * @param capacity Destination buffer capacity
304  * @param pInfo Output container of IDNA processing details.
305  * @param pErrorCode Standard ICU error code. Its input value must
306  *                  pass the U_SUCCESS() test, or else the function returns
307  *                  immediately. Check for U_FAILURE() on output or use with
308  *                  function chaining. (See User Guide for details.)
309  * @return destination string length
310  * @stable ICU 4.6
311  */
312 U_STABLE int32_t U_EXPORT2
313 uidna_nameToUnicode(const UIDNA *idna,
314                     const UChar *name, int32_t length,
315                     UChar *dest, int32_t capacity,
316                     UIDNAInfo *pInfo, UErrorCode *pErrorCode);
317 
318 /* UTF-8 versions of the processing methods --------------------------------- */
319 
320 /**
321  * Converts a single domain name label into its ASCII form for DNS lookup.
322  * UTF-8 version of uidna_labelToASCII(), same behavior.
323  *
324  * @param idna UIDNA instance
325  * @param label Input domain name label
326  * @param length Label length, or -1 if NUL-terminated
327  * @param dest Destination string buffer
328  * @param capacity Destination buffer capacity
329  * @param pInfo Output container of IDNA processing details.
330  * @param pErrorCode Standard ICU error code. Its input value must
331  *                  pass the U_SUCCESS() test, or else the function returns
332  *                  immediately. Check for U_FAILURE() on output or use with
333  *                  function chaining. (See User Guide for details.)
334  * @return destination string length
335  * @stable ICU 4.6
336  */
337 U_STABLE int32_t U_EXPORT2
338 uidna_labelToASCII_UTF8(const UIDNA *idna,
339                         const char *label, int32_t length,
340                         char *dest, int32_t capacity,
341                         UIDNAInfo *pInfo, UErrorCode *pErrorCode);
342 
343 /**
344  * Converts a single domain name label into its Unicode form for human-readable display.
345  * UTF-8 version of uidna_labelToUnicode(), same behavior.
346  *
347  * @param idna UIDNA instance
348  * @param label Input domain name label
349  * @param length Label length, or -1 if NUL-terminated
350  * @param dest Destination string buffer
351  * @param capacity Destination buffer capacity
352  * @param pInfo Output container of IDNA processing details.
353  * @param pErrorCode Standard ICU error code. Its input value must
354  *                  pass the U_SUCCESS() test, or else the function returns
355  *                  immediately. Check for U_FAILURE() on output or use with
356  *                  function chaining. (See User Guide for details.)
357  * @return destination string length
358  * @stable ICU 4.6
359  */
360 U_STABLE int32_t U_EXPORT2
361 uidna_labelToUnicodeUTF8(const UIDNA *idna,
362                          const char *label, int32_t length,
363                          char *dest, int32_t capacity,
364                          UIDNAInfo *pInfo, UErrorCode *pErrorCode);
365 
366 /**
367  * Converts a whole domain name into its ASCII form for DNS lookup.
368  * UTF-8 version of uidna_nameToASCII(), same behavior.
369  *
370  * @param idna UIDNA instance
371  * @param name Input domain name
372  * @param length Domain name length, or -1 if NUL-terminated
373  * @param dest Destination string buffer
374  * @param capacity Destination buffer capacity
375  * @param pInfo Output container of IDNA processing details.
376  * @param pErrorCode Standard ICU error code. Its input value must
377  *                  pass the U_SUCCESS() test, or else the function returns
378  *                  immediately. Check for U_FAILURE() on output or use with
379  *                  function chaining. (See User Guide for details.)
380  * @return destination string length
381  * @stable ICU 4.6
382  */
383 U_STABLE int32_t U_EXPORT2
384 uidna_nameToASCII_UTF8(const UIDNA *idna,
385                        const char *name, int32_t length,
386                        char *dest, int32_t capacity,
387                        UIDNAInfo *pInfo, UErrorCode *pErrorCode);
388 
389 /**
390  * Converts a whole domain name into its Unicode form for human-readable display.
391  * UTF-8 version of uidna_nameToUnicode(), same behavior.
392  *
393  * @param idna UIDNA instance
394  * @param name Input domain name
395  * @param length Domain name length, or -1 if NUL-terminated
396  * @param dest Destination string buffer
397  * @param capacity Destination buffer capacity
398  * @param pInfo Output container of IDNA processing details.
399  * @param pErrorCode Standard ICU error code. Its input value must
400  *                  pass the U_SUCCESS() test, or else the function returns
401  *                  immediately. Check for U_FAILURE() on output or use with
402  *                  function chaining. (See User Guide for details.)
403  * @return destination string length
404  * @stable ICU 4.6
405  */
406 U_STABLE int32_t U_EXPORT2
407 uidna_nameToUnicodeUTF8(const UIDNA *idna,
408                         const char *name, int32_t length,
409                         char *dest, int32_t capacity,
410                         UIDNAInfo *pInfo, UErrorCode *pErrorCode);
411 
412 /*
413  * IDNA error bit set values.
414  * When a domain name or label fails a processing step or does not meet the
415  * validity criteria, then one or more of these error bits are set.
416  */
417 enum {
418     /**
419      * A non-final domain name label (or the whole domain name) is empty.
420      * @stable ICU 4.6
421      */
422     UIDNA_ERROR_EMPTY_LABEL=1,
423     /**
424      * A domain name label is longer than 63 bytes.
425      * (See STD13/RFC1034 3.1. Name space specifications and terminology.)
426      * This is only checked in ToASCII operations, and only if the output label is all-ASCII.
427      * @stable ICU 4.6
428      */
429     UIDNA_ERROR_LABEL_TOO_LONG=2,
430     /**
431      * A domain name is longer than 255 bytes in its storage form.
432      * (See STD13/RFC1034 3.1. Name space specifications and terminology.)
433      * This is only checked in ToASCII operations, and only if the output domain name is all-ASCII.
434      * @stable ICU 4.6
435      */
436     UIDNA_ERROR_DOMAIN_NAME_TOO_LONG=4,
437     /**
438      * A label starts with a hyphen-minus ('-').
439      * @stable ICU 4.6
440      */
441     UIDNA_ERROR_LEADING_HYPHEN=8,
442     /**
443      * A label ends with a hyphen-minus ('-').
444      * @stable ICU 4.6
445      */
446     UIDNA_ERROR_TRAILING_HYPHEN=0x10,
447     /**
448      * A label contains hyphen-minus ('-') in the third and fourth positions.
449      * @stable ICU 4.6
450      */
451     UIDNA_ERROR_HYPHEN_3_4=0x20,
452     /**
453      * A label starts with a combining mark.
454      * @stable ICU 4.6
455      */
456     UIDNA_ERROR_LEADING_COMBINING_MARK=0x40,
457     /**
458      * A label or domain name contains disallowed characters.
459      * @stable ICU 4.6
460      */
461     UIDNA_ERROR_DISALLOWED=0x80,
462     /**
463      * A label starts with "xn--" but does not contain valid Punycode.
464      * That is, an xn-- label failed Punycode decoding.
465      * @stable ICU 4.6
466      */
467     UIDNA_ERROR_PUNYCODE=0x100,
468     /**
469      * A label contains a dot=full stop.
470      * This can occur in an input string for a single-label function.
471      * @stable ICU 4.6
472      */
473     UIDNA_ERROR_LABEL_HAS_DOT=0x200,
474     /**
475      * An ACE label does not contain a valid label string.
476      * The label was successfully ACE (Punycode) decoded but the resulting
477      * string had severe validation errors. For example,
478      * it might contain characters that are not allowed in ACE labels,
479      * or it might not be normalized.
480      * @stable ICU 4.6
481      */
482     UIDNA_ERROR_INVALID_ACE_LABEL=0x400,
483     /**
484      * A label does not meet the IDNA BiDi requirements (for right-to-left characters).
485      * @stable ICU 4.6
486      */
487     UIDNA_ERROR_BIDI=0x800,
488     /**
489      * A label does not meet the IDNA CONTEXTJ requirements.
490      * @stable ICU 4.6
491      */
492     UIDNA_ERROR_CONTEXTJ=0x1000,
493 #ifndef U_HIDE_DRAFT_API
494     /**
495      * A label does not meet the IDNA CONTEXTO requirements for punctuation characters.
496      * Some punctuation characters "Would otherwise have been DISALLOWED"
497      * but are allowed in certain contexts. (RFC 5892)
498      * @draft ICU 49
499      */
500     UIDNA_ERROR_CONTEXTO_PUNCTUATION=0x2000,
501     /**
502      * A label does not meet the IDNA CONTEXTO requirements for digits.
503      * Arabic-Indic Digits (U+066x) must not be mixed with Extended Arabic-Indic Digits (U+06Fx).
504      * @draft ICU 49
505      */
506     UIDNA_ERROR_CONTEXTO_DIGITS=0x4000
507 #endif  /* U_HIDE_DRAFT_API */
508 };
509 
510 /* IDNA2003 API ------------------------------------------------------------- */
511 
512 /**
513  * IDNA2003: This function implements the ToASCII operation as defined in the IDNA RFC.
514  * This operation is done on <b>single labels</b> before sending it to something that expects
515  * ASCII names. A label is an individual part of a domain name. Labels are usually
516  * separated by dots; e.g. "www.example.com" is composed of 3 labels "www","example", and "com".
517  *
518  * IDNA2003 API Overview:
519  *
520  * The uidna_ API implements the IDNA protocol as defined in the IDNA RFC
521  * (http://www.ietf.org/rfc/rfc3490.txt).
522  * The RFC defines 2 operations: ToASCII and ToUnicode. Domain name labels
523  * containing non-ASCII code points are processed by the
524  * ToASCII operation before passing it to resolver libraries. Domain names
525  * that are obtained from resolver libraries are processed by the
526  * ToUnicode operation before displaying the domain name to the user.
527  * IDNA requires that implementations process input strings with Nameprep
528  * (http://www.ietf.org/rfc/rfc3491.txt),
529  * which is a profile of Stringprep (http://www.ietf.org/rfc/rfc3454.txt),
530  * and then with Punycode (http://www.ietf.org/rfc/rfc3492.txt).
531  * Implementations of IDNA MUST fully implement Nameprep and Punycode;
532  * neither Nameprep nor Punycode are optional.
533  * The input and output of ToASCII and ToUnicode operations are Unicode
534  * and are designed to be chainable, i.e., applying ToASCII or ToUnicode operations
535  * multiple times to an input string will yield the same result as applying the operation
536  * once.
537  * ToUnicode(ToUnicode(ToUnicode...(ToUnicode(string)))) == ToUnicode(string)
538  * ToASCII(ToASCII(ToASCII...(ToASCII(string))) == ToASCII(string).
539  *
540  * @param src               Input UChar array containing label in Unicode.
541  * @param srcLength         Number of UChars in src, or -1 if NUL-terminated.
542  * @param dest              Output UChar array with ASCII (ACE encoded) label.
543  * @param destCapacity      Size of dest.
544  * @param options           A bit set of options:
545  *
546  *  - UIDNA_DEFAULT             Use default options, i.e., do not process unassigned code points
547  *                              and do not use STD3 ASCII rules
548  *                              If unassigned code points are found the operation fails with
549  *                              U_UNASSIGNED_ERROR error code.
550  *
551  *  - UIDNA_ALLOW_UNASSIGNED    Unassigned values can be converted to ASCII for query operations
552  *                              If this option is set, the unassigned code points are in the input
553  *                              are treated as normal Unicode code points.
554  *
555  *  - UIDNA_USE_STD3_RULES      Use STD3 ASCII rules for host name syntax restrictions
556  *                              If this option is set and the input does not satisfy STD3 rules,
557  *                              the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR
558  *
559  * @param parseError        Pointer to UParseError struct to receive information on position
560  *                          of error if an error is encountered. Can be NULL.
561  * @param status            ICU in/out error code parameter.
562  *                          U_INVALID_CHAR_FOUND if src contains
563  *                          unmatched single surrogates.
564  *                          U_INDEX_OUTOFBOUNDS_ERROR if src contains
565  *                          too many code points.
566  *                          U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough
567  * @return The length of the result string, if successful - or in case of a buffer overflow,
568  *         in which case it will be greater than destCapacity.
569  * @stable ICU 2.6
570  */
571 U_STABLE int32_t U_EXPORT2
572 uidna_toASCII(const UChar* src, int32_t srcLength,
573               UChar* dest, int32_t destCapacity,
574               int32_t options,
575               UParseError* parseError,
576               UErrorCode* status);
577 
578 
579 /**
580  * IDNA2003: This function implements the ToUnicode operation as defined in the IDNA RFC.
581  * This operation is done on <b>single labels</b> before sending it to something that expects
582  * Unicode names. A label is an individual part of a domain name. Labels are usually
583  * separated by dots; for e.g. "www.example.com" is composed of 3 labels "www","example", and "com".
584  *
585  * @param src               Input UChar array containing ASCII (ACE encoded) label.
586  * @param srcLength         Number of UChars in src, or -1 if NUL-terminated.
587  * @param dest Output       Converted UChar array containing Unicode equivalent of label.
588  * @param destCapacity      Size of dest.
589  * @param options           A bit set of options:
590  *
591  *  - UIDNA_DEFAULT             Use default options, i.e., do not process unassigned code points
592  *                              and do not use STD3 ASCII rules
593  *                              If unassigned code points are found the operation fails with
594  *                              U_UNASSIGNED_ERROR error code.
595  *
596  *  - UIDNA_ALLOW_UNASSIGNED      Unassigned values can be converted to ASCII for query operations
597  *                              If this option is set, the unassigned code points are in the input
598  *                              are treated as normal Unicode code points. <b> Note: </b> This option is
599  *                              required on toUnicode operation because the RFC mandates
600  *                              verification of decoded ACE input by applying toASCII and comparing
601  *                              its output with source
602  *
603  *  - UIDNA_USE_STD3_RULES      Use STD3 ASCII rules for host name syntax restrictions
604  *                              If this option is set and the input does not satisfy STD3 rules,
605  *                              the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR
606  *
607  * @param parseError        Pointer to UParseError struct to receive information on position
608  *                          of error if an error is encountered. Can be NULL.
609  * @param status            ICU in/out error code parameter.
610  *                          U_INVALID_CHAR_FOUND if src contains
611  *                          unmatched single surrogates.
612  *                          U_INDEX_OUTOFBOUNDS_ERROR if src contains
613  *                          too many code points.
614  *                          U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough
615  * @return The length of the result string, if successful - or in case of a buffer overflow,
616  *         in which case it will be greater than destCapacity.
617  * @stable ICU 2.6
618  */
619 U_STABLE int32_t U_EXPORT2
620 uidna_toUnicode(const UChar* src, int32_t srcLength,
621                 UChar* dest, int32_t destCapacity,
622                 int32_t options,
623                 UParseError* parseError,
624                 UErrorCode* status);
625 
626 
627 /**
628  * IDNA2003: Convenience function that implements the IDNToASCII operation as defined in the IDNA RFC.
629  * This operation is done on complete domain names, e.g: "www.example.com".
630  * It is important to note that this operation can fail. If it fails, then the input
631  * domain name cannot be used as an Internationalized Domain Name and the application
632  * should have methods defined to deal with the failure.
633  *
634  * <b>Note:</b> IDNA RFC specifies that a conformant application should divide a domain name
635  * into separate labels, decide whether to apply allowUnassigned and useSTD3ASCIIRules on each,
636  * and then convert. This function does not offer that level of granularity. The options once
637  * set will apply to all labels in the domain name
638  *
639  * @param src               Input UChar array containing IDN in Unicode.
640  * @param srcLength         Number of UChars in src, or -1 if NUL-terminated.
641  * @param dest              Output UChar array with ASCII (ACE encoded) IDN.
642  * @param destCapacity      Size of dest.
643  * @param options           A bit set of options:
644  *
645  *  - UIDNA_DEFAULT             Use default options, i.e., do not process unassigned code points
646  *                              and do not use STD3 ASCII rules
647  *                              If unassigned code points are found the operation fails with
648  *                              U_UNASSIGNED_CODE_POINT_FOUND error code.
649  *
650  *  - UIDNA_ALLOW_UNASSIGNED    Unassigned values can be converted to ASCII for query operations
651  *                              If this option is set, the unassigned code points are in the input
652  *                              are treated as normal Unicode code points.
653  *
654  *  - UIDNA_USE_STD3_RULES      Use STD3 ASCII rules for host name syntax restrictions
655  *                              If this option is set and the input does not satisfy STD3 rules,
656  *                              the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR
657  *
658  * @param parseError        Pointer to UParseError struct to receive information on position
659  *                          of error if an error is encountered. Can be NULL.
660  * @param status            ICU in/out error code parameter.
661  *                          U_INVALID_CHAR_FOUND if src contains
662  *                          unmatched single surrogates.
663  *                          U_INDEX_OUTOFBOUNDS_ERROR if src contains
664  *                          too many code points.
665  *                          U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough
666  * @return The length of the result string, if successful - or in case of a buffer overflow,
667  *         in which case it will be greater than destCapacity.
668  * @stable ICU 2.6
669  */
670 U_STABLE int32_t U_EXPORT2
671 uidna_IDNToASCII(  const UChar* src, int32_t srcLength,
672                    UChar* dest, int32_t destCapacity,
673                    int32_t options,
674                    UParseError* parseError,
675                    UErrorCode* status);
676 
677 /**
678  * IDNA2003: Convenience function that implements the IDNToUnicode operation as defined in the IDNA RFC.
679  * This operation is done on complete domain names, e.g: "www.example.com".
680  *
681  * <b>Note:</b> IDNA RFC specifies that a conformant application should divide a domain name
682  * into separate labels, decide whether to apply allowUnassigned and useSTD3ASCIIRules on each,
683  * and then convert. This function does not offer that level of granularity. The options once
684  * set will apply to all labels in the domain name
685  *
686  * @param src               Input UChar array containing IDN in ASCII (ACE encoded) form.
687  * @param srcLength         Number of UChars in src, or -1 if NUL-terminated.
688  * @param dest Output       UChar array containing Unicode equivalent of source IDN.
689  * @param destCapacity      Size of dest.
690  * @param options           A bit set of options:
691  *
692  *  - UIDNA_DEFAULT             Use default options, i.e., do not process unassigned code points
693  *                              and do not use STD3 ASCII rules
694  *                              If unassigned code points are found the operation fails with
695  *                              U_UNASSIGNED_CODE_POINT_FOUND error code.
696  *
697  *  - UIDNA_ALLOW_UNASSIGNED    Unassigned values can be converted to ASCII for query operations
698  *                              If this option is set, the unassigned code points are in the input
699  *                              are treated as normal Unicode code points.
700  *
701  *  - UIDNA_USE_STD3_RULES      Use STD3 ASCII rules for host name syntax restrictions
702  *                              If this option is set and the input does not satisfy STD3 rules,
703  *                              the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR
704  *
705  * @param parseError        Pointer to UParseError struct to receive information on position
706  *                          of error if an error is encountered. Can be NULL.
707  * @param status            ICU in/out error code parameter.
708  *                          U_INVALID_CHAR_FOUND if src contains
709  *                          unmatched single surrogates.
710  *                          U_INDEX_OUTOFBOUNDS_ERROR if src contains
711  *                          too many code points.
712  *                          U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough
713  * @return The length of the result string, if successful - or in case of a buffer overflow,
714  *         in which case it will be greater than destCapacity.
715  * @stable ICU 2.6
716  */
717 U_STABLE int32_t U_EXPORT2
718 uidna_IDNToUnicode(  const UChar* src, int32_t srcLength,
719                      UChar* dest, int32_t destCapacity,
720                      int32_t options,
721                      UParseError* parseError,
722                      UErrorCode* status);
723 
724 /**
725  * IDNA2003: Compare two IDN strings for equivalence.
726  * This function splits the domain names into labels and compares them.
727  * According to IDN RFC, whenever two labels are compared, they are
728  * considered equal if and only if their ASCII forms (obtained by
729  * applying toASCII) match using an case-insensitive ASCII comparison.
730  * Two domain names are considered a match if and only if all labels
731  * match regardless of whether label separators match.
732  *
733  * @param s1                First source string.
734  * @param length1           Length of first source string, or -1 if NUL-terminated.
735  *
736  * @param s2                Second source string.
737  * @param length2           Length of second source string, or -1 if NUL-terminated.
738  * @param options           A bit set of options:
739  *
740  *  - UIDNA_DEFAULT             Use default options, i.e., do not process unassigned code points
741  *                              and do not use STD3 ASCII rules
742  *                              If unassigned code points are found the operation fails with
743  *                              U_UNASSIGNED_CODE_POINT_FOUND error code.
744  *
745  *  - UIDNA_ALLOW_UNASSIGNED    Unassigned values can be converted to ASCII for query operations
746  *                              If this option is set, the unassigned code points are in the input
747  *                              are treated as normal Unicode code points.
748  *
749  *  - UIDNA_USE_STD3_RULES      Use STD3 ASCII rules for host name syntax restrictions
750  *                              If this option is set and the input does not satisfy STD3 rules,
751  *                              the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR
752  *
753  * @param status            ICU error code in/out parameter.
754  *                          Must fulfill U_SUCCESS before the function call.
755  * @return <0 or 0 or >0 as usual for string comparisons
756  * @stable ICU 2.6
757  */
758 U_STABLE int32_t U_EXPORT2
759 uidna_compare(  const UChar *s1, int32_t length1,
760                 const UChar *s2, int32_t length2,
761                 int32_t options,
762                 UErrorCode* status);
763 
764 #endif /* #if !UCONFIG_NO_IDNA */
765 
766 #endif
767