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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ***************************************************************************
5 * Copyright (C) 2008-2016, International Business Machines Corporation
6 * and others. All Rights Reserved.
7 ***************************************************************************
8 *   file name:  uspoof.h
9 *   encoding:   UTF-8
10 *   tab size:   8 (not used)
11 *   indentation:4
12 *
13 *   created on: 2008Feb13
14 *   created by: Andy Heninger
15 *
16 *   Unicode Spoof Detection
17 */
18 
19 #ifndef USPOOF_H
20 #define USPOOF_H
21 
22 #include "unicode/utypes.h"
23 #include "unicode/uset.h"
24 #include "unicode/parseerr.h"
25 #include "unicode/localpointer.h"
26 
27 #if !UCONFIG_NO_NORMALIZATION
28 
29 
30 #if U_SHOW_CPLUSPLUS_API
31 #include "unicode/unistr.h"
32 #include "unicode/uniset.h"
33 #endif
34 
35 
36 /**
37  * \file
38  * \brief Unicode Security and Spoofing Detection, C API.
39  *
40  * <p>
41  * This class, based on <a href="http://unicode.org/reports/tr36">Unicode Technical Report #36</a> and
42  * <a href="http://unicode.org/reports/tr39">Unicode Technical Standard #39</a>, has two main functions:
43  *
44  * <ol>
45  * <li>Checking whether two strings are visually <em>confusable</em> with each other, such as "Harvest" and
46  * &quot;&Eta;arvest&quot;, where the second string starts with the Greek capital letter Eta.</li>
47  * <li>Checking whether an individual string is likely to be an attempt at confusing the reader (<em>spoof
48  * detection</em>), such as "paypal" with some Latin characters substituted with Cyrillic look-alikes.</li>
49  * </ol>
50  *
51  * <p>
52  * Although originally designed as a method for flagging suspicious identifier strings such as URLs,
53  * <code>USpoofChecker</code> has a number of other practical use cases, such as preventing attempts to evade bad-word
54  * content filters.
55  *
56  * <p>
57  * The functions of this class are exposed as C API, with a handful of syntactical conveniences for C++.
58  *
59  * <h2>Confusables</h2>
60  *
61  * <p>
62  * The following example shows how to use <code>USpoofChecker</code> to check for confusability between two strings:
63  *
64  * \code{.c}
65  * UErrorCode status = U_ZERO_ERROR;
66  * UChar* str1 = (UChar*) u"Harvest";
67  * UChar* str2 = (UChar*) u"\u0397arvest";  // with U+0397 GREEK CAPITAL LETTER ETA
68  *
69  * USpoofChecker* sc = uspoof_open(&status);
70  * uspoof_setChecks(sc, USPOOF_CONFUSABLE, &status);
71  *
72  * int32_t bitmask = uspoof_areConfusable(sc, str1, -1, str2, -1, &status);
73  * UBool result = bitmask != 0;
74  * // areConfusable: 1 (status: U_ZERO_ERROR)
75  * printf("areConfusable: %d (status: %s)\n", result, u_errorName(status));
76  * uspoof_close(sc);
77  * \endcode
78  *
79  * <p>
80  * The call to {@link uspoof_open} creates a <code>USpoofChecker</code> object; the call to {@link uspoof_setChecks}
81  * enables confusable checking and disables all other checks; the call to {@link uspoof_areConfusable} performs the
82  * confusability test; and the following line extracts the result out of the return value. For best performance,
83  * the instance should be created once (e.g., upon application startup), and the efficient
84  * {@link uspoof_areConfusable} method can be used at runtime.
85  *
86  * <p>
87  * The type {@link LocalUSpoofCheckerPointer} is exposed for C++ programmers.  It will automatically call
88  * {@link uspoof_close} when the object goes out of scope:
89  *
90  * \code{.cpp}
91  * UErrorCode status = U_ZERO_ERROR;
92  * LocalUSpoofCheckerPointer sc(uspoof_open(&status));
93  * uspoof_setChecks(sc.getAlias(), USPOOF_CONFUSABLE, &status);
94  * // ...
95  * \endcode
96  *
97  * UTS 39 defines two strings to be <em>confusable</em> if they map to the same <em>skeleton string</em>. A skeleton can
98  * be thought of as a "hash code". {@link uspoof_getSkeleton} computes the skeleton for a particular string, so
99  * the following snippet is equivalent to the example above:
100  *
101  * \code{.c}
102  * UErrorCode status = U_ZERO_ERROR;
103  * UChar* str1 = (UChar*) u"Harvest";
104  * UChar* str2 = (UChar*) u"\u0397arvest";  // with U+0397 GREEK CAPITAL LETTER ETA
105  *
106  * USpoofChecker* sc = uspoof_open(&status);
107  * uspoof_setChecks(sc, USPOOF_CONFUSABLE, &status);
108  *
109  * // Get skeleton 1
110  * int32_t skel1Len = uspoof_getSkeleton(sc, 0, str1, -1, NULL, 0, &status);
111  * UChar* skel1 = (UChar*) malloc(++skel1Len * sizeof(UChar));
112  * status = U_ZERO_ERROR;
113  * uspoof_getSkeleton(sc, 0, str1, -1, skel1, skel1Len, &status);
114  *
115  * // Get skeleton 2
116  * int32_t skel2Len = uspoof_getSkeleton(sc, 0, str2, -1, NULL, 0, &status);
117  * UChar* skel2 = (UChar*) malloc(++skel2Len * sizeof(UChar));
118  * status = U_ZERO_ERROR;
119  * uspoof_getSkeleton(sc, 0, str2, -1, skel2, skel2Len, &status);
120  *
121  * // Are the skeletons the same?
122  * UBool result = u_strcmp(skel1, skel2) == 0;
123  * // areConfusable: 1 (status: U_ZERO_ERROR)
124  * printf("areConfusable: %d (status: %s)\n", result, u_errorName(status));
125  * uspoof_close(sc);
126  * free(skel1);
127  * free(skel2);
128  * \endcode
129  *
130  * If you need to check if a string is confusable with any string in a dictionary of many strings, rather than calling
131  * {@link uspoof_areConfusable} many times in a loop, {@link uspoof_getSkeleton} can be used instead, as shown below:
132  *
133  * \code{.c}
134  * UErrorCode status = U_ZERO_ERROR;
135  * #define DICTIONARY_LENGTH 2
136  * UChar* dictionary[DICTIONARY_LENGTH] = { (UChar*) u"lorem", (UChar*) u"ipsum" };
137  * UChar* skeletons[DICTIONARY_LENGTH];
138  * UChar* str = (UChar*) u"1orern";
139  *
140  * // Setup:
141  * USpoofChecker* sc = uspoof_open(&status);
142  * uspoof_setChecks(sc, USPOOF_CONFUSABLE, &status);
143  * for (size_t i=0; i<DICTIONARY_LENGTH; i++) {
144  *     UChar* word = dictionary[i];
145  *     int32_t len = uspoof_getSkeleton(sc, 0, word, -1, NULL, 0, &status);
146  *     skeletons[i] = (UChar*) malloc(++len * sizeof(UChar));
147  *     status = U_ZERO_ERROR;
148  *     uspoof_getSkeleton(sc, 0, word, -1, skeletons[i], len, &status);
149  * }
150  *
151  * // Live Check:
152  * {
153  *     int32_t len = uspoof_getSkeleton(sc, 0, str, -1, NULL, 0, &status);
154  *     UChar* skel = (UChar*) malloc(++len * sizeof(UChar));
155  *     status = U_ZERO_ERROR;
156  *     uspoof_getSkeleton(sc, 0, str, -1, skel, len, &status);
157  *     UBool result = FALSE;
158  *     for (size_t i=0; i<DICTIONARY_LENGTH; i++) {
159  *         result = u_strcmp(skel, skeletons[i]) == 0;
160  *         if (result == TRUE) { break; }
161  *     }
162  *     // Has confusable in dictionary: 1 (status: U_ZERO_ERROR)
163  *     printf("Has confusable in dictionary: %d (status: %s)\n", result, u_errorName(status));
164  *     free(skel);
165  * }
166  *
167  * for (size_t i=0; i<DICTIONARY_LENGTH; i++) {
168  *     free(skeletons[i]);
169  * }
170  * uspoof_close(sc);
171  * \endcode
172  *
173  * <b>Note:</b> Since the Unicode confusables mapping table is frequently updated, confusable skeletons are <em>not</em>
174  * guaranteed to be the same between ICU releases. We therefore recommend that you always compute confusable skeletons
175  * at runtime and do not rely on creating a permanent, or difficult to update, database of skeletons.
176  *
177  * <h2>Spoof Detection</h2>
178  *
179  * The following snippet shows a minimal example of using <code>USpoofChecker</code> to perform spoof detection on a
180  * string:
181  *
182  * \code{.c}
183  * UErrorCode status = U_ZERO_ERROR;
184  * UChar* str = (UChar*) u"p\u0430ypal";  // with U+0430 CYRILLIC SMALL LETTER A
185  *
186  * // Get the default set of allowable characters:
187  * USet* allowed = uset_openEmpty();
188  * uset_addAll(allowed, uspoof_getRecommendedSet(&status));
189  * uset_addAll(allowed, uspoof_getInclusionSet(&status));
190  *
191  * USpoofChecker* sc = uspoof_open(&status);
192  * uspoof_setAllowedChars(sc, allowed, &status);
193  * uspoof_setRestrictionLevel(sc, USPOOF_MODERATELY_RESTRICTIVE);
194  *
195  * int32_t bitmask = uspoof_check(sc, str, -1, NULL, &status);
196  * UBool result = bitmask != 0;
197  * // fails checks: 1 (status: U_ZERO_ERROR)
198  * printf("fails checks: %d (status: %s)\n", result, u_errorName(status));
199  * uspoof_close(sc);
200  * uset_close(allowed);
201  * \endcode
202  *
203  * As in the case for confusability checking, it is good practice to create one <code>USpoofChecker</code> instance at
204  * startup, and call the cheaper {@link uspoof_check} online. We specify the set of
205  * allowed characters to be those with type RECOMMENDED or INCLUSION, according to the recommendation in UTS 39.
206  *
207  * In addition to {@link uspoof_check}, the function {@link uspoof_checkUTF8} is exposed for UTF8-encoded char* strings,
208  * and {@link uspoof_checkUnicodeString} is exposed for C++ programmers.
209  *
210  * If the {@link USPOOF_AUX_INFO} check is enabled, a limited amount of information on why a string failed the checks
211  * is available in the returned bitmask.  For complete information, use the {@link uspoof_check2} class of functions
212  * with a {@link USpoofCheckResult} parameter:
213  *
214  * \code{.c}
215  * UErrorCode status = U_ZERO_ERROR;
216  * UChar* str = (UChar*) u"p\u0430ypal";  // with U+0430 CYRILLIC SMALL LETTER A
217  *
218  * // Get the default set of allowable characters:
219  * USet* allowed = uset_openEmpty();
220  * uset_addAll(allowed, uspoof_getRecommendedSet(&status));
221  * uset_addAll(allowed, uspoof_getInclusionSet(&status));
222  *
223  * USpoofChecker* sc = uspoof_open(&status);
224  * uspoof_setAllowedChars(sc, allowed, &status);
225  * uspoof_setRestrictionLevel(sc, USPOOF_MODERATELY_RESTRICTIVE);
226  *
227  * USpoofCheckResult* checkResult = uspoof_openCheckResult(&status);
228  * int32_t bitmask = uspoof_check2(sc, str, -1, checkResult, &status);
229  *
230  * int32_t failures1 = bitmask;
231  * int32_t failures2 = uspoof_getCheckResultChecks(checkResult, &status);
232  * assert(failures1 == failures2);
233  * // checks that failed: 0x00000010 (status: U_ZERO_ERROR)
234  * printf("checks that failed: %#010x (status: %s)\n", failures1, u_errorName(status));
235  *
236  * // Cleanup:
237  * uspoof_close(sc);
238  * uset_close(allowed);
239  * uspoof_closeCheckResult(checkResult);
240  * \endcode
241  *
242  * C++ users can take advantage of a few syntactical conveniences.  The following snippet is functionally
243  * equivalent to the one above:
244  *
245  * \code{.cpp}
246  * UErrorCode status = U_ZERO_ERROR;
247  * UnicodeString str((UChar*) u"p\u0430ypal");  // with U+0430 CYRILLIC SMALL LETTER A
248  *
249  * // Get the default set of allowable characters:
250  * UnicodeSet allowed;
251  * allowed.addAll(*uspoof_getRecommendedUnicodeSet(&status));
252  * allowed.addAll(*uspoof_getInclusionUnicodeSet(&status));
253  *
254  * LocalUSpoofCheckerPointer sc(uspoof_open(&status));
255  * uspoof_setAllowedChars(sc.getAlias(), allowed.toUSet(), &status);
256  * uspoof_setRestrictionLevel(sc.getAlias(), USPOOF_MODERATELY_RESTRICTIVE);
257  *
258  * LocalUSpoofCheckResultPointer checkResult(uspoof_openCheckResult(&status));
259  * int32_t bitmask = uspoof_check2UnicodeString(sc.getAlias(), str, checkResult.getAlias(), &status);
260  *
261  * int32_t failures1 = bitmask;
262  * int32_t failures2 = uspoof_getCheckResultChecks(checkResult.getAlias(), &status);
263  * assert(failures1 == failures2);
264  * // checks that failed: 0x00000010 (status: U_ZERO_ERROR)
265  * printf("checks that failed: %#010x (status: %s)\n", failures1, u_errorName(status));
266  *
267  * // Explicit cleanup not necessary.
268  * \endcode
269  *
270  * The return value is a bitmask of the checks that failed. In this case, there was one check that failed:
271  * {@link USPOOF_RESTRICTION_LEVEL}, corresponding to the fifth bit (16). The possible checks are:
272  *
273  * <ul>
274  * <li><code>RESTRICTION_LEVEL</code>: flags strings that violate the
275  * <a href="http://unicode.org/reports/tr39/#Restriction_Level_Detection">Restriction Level</a> test as specified in UTS
276  * 39; in most cases, this means flagging strings that contain characters from multiple different scripts.</li>
277  * <li><code>INVISIBLE</code>: flags strings that contain invisible characters, such as zero-width spaces, or character
278  * sequences that are likely not to display, such as multiple occurrences of the same non-spacing mark.</li>
279  * <li><code>CHAR_LIMIT</code>: flags strings that contain characters outside of a specified set of acceptable
280  * characters. See {@link uspoof_setAllowedChars} and {@link uspoof_setAllowedLocales}.</li>
281  * <li><code>MIXED_NUMBERS</code>: flags strings that contain digits from multiple different numbering systems.</li>
282  * </ul>
283  *
284  * <p>
285  * These checks can be enabled independently of each other. For example, if you were interested in checking for only the
286  * INVISIBLE and MIXED_NUMBERS conditions, you could do:
287  *
288  * \code{.c}
289  * UErrorCode status = U_ZERO_ERROR;
290  * UChar* str = (UChar*) u"8\u09EA";  // 8 mixed with U+09EA BENGALI DIGIT FOUR
291  *
292  * USpoofChecker* sc = uspoof_open(&status);
293  * uspoof_setChecks(sc, USPOOF_INVISIBLE | USPOOF_MIXED_NUMBERS, &status);
294  *
295  * int32_t bitmask = uspoof_check2(sc, str, -1, NULL, &status);
296  * UBool result = bitmask != 0;
297  * // fails checks: 1 (status: U_ZERO_ERROR)
298  * printf("fails checks: %d (status: %s)\n", result, u_errorName(status));
299  * uspoof_close(sc);
300  * \endcode
301  *
302  * Here is an example in C++ showing how to compute the restriction level of a string:
303  *
304  * \code{.cpp}
305  * UErrorCode status = U_ZERO_ERROR;
306  * UnicodeString str((UChar*) u"p\u0430ypal");  // with U+0430 CYRILLIC SMALL LETTER A
307  *
308  * // Get the default set of allowable characters:
309  * UnicodeSet allowed;
310  * allowed.addAll(*uspoof_getRecommendedUnicodeSet(&status));
311  * allowed.addAll(*uspoof_getInclusionUnicodeSet(&status));
312  *
313  * LocalUSpoofCheckerPointer sc(uspoof_open(&status));
314  * uspoof_setAllowedChars(sc.getAlias(), allowed.toUSet(), &status);
315  * uspoof_setRestrictionLevel(sc.getAlias(), USPOOF_MODERATELY_RESTRICTIVE);
316  * uspoof_setChecks(sc.getAlias(), USPOOF_RESTRICTION_LEVEL | USPOOF_AUX_INFO, &status);
317  *
318  * LocalUSpoofCheckResultPointer checkResult(uspoof_openCheckResult(&status));
319  * int32_t bitmask = uspoof_check2UnicodeString(sc.getAlias(), str, checkResult.getAlias(), &status);
320  *
321  * URestrictionLevel restrictionLevel = uspoof_getCheckResultRestrictionLevel(checkResult.getAlias(), &status);
322  * // Since USPOOF_AUX_INFO was enabled, the restriction level is also available in the upper bits of the bitmask:
323  * assert((restrictionLevel & bitmask) == restrictionLevel);
324  * // Restriction level: 0x50000000 (status: U_ZERO_ERROR)
325  * printf("Restriction level: %#010x (status: %s)\n", restrictionLevel, u_errorName(status));
326  * \endcode
327  *
328  * The code '0x50000000' corresponds to the restriction level USPOOF_MINIMALLY_RESTRICTIVE.  Since
329  * USPOOF_MINIMALLY_RESTRICTIVE is weaker than USPOOF_MODERATELY_RESTRICTIVE, the string fails the check.
330  *
331  * <b>Note:</b> The Restriction Level is the most powerful of the checks. The full logic is documented in
332  * <a href="http://unicode.org/reports/tr39/#Restriction_Level_Detection">UTS 39</a>, but the basic idea is that strings
333  * are restricted to contain characters from only a single script, <em>except</em> that most scripts are allowed to have
334  * Latin characters interspersed. Although the default restriction level is <code>HIGHLY_RESTRICTIVE</code>, it is
335  * recommended that users set their restriction level to <code>MODERATELY_RESTRICTIVE</code>, which allows Latin mixed
336  * with all other scripts except Cyrillic, Greek, and Cherokee, with which it is often confusable. For more details on
337  * the levels, see UTS 39 or {@link URestrictionLevel}. The Restriction Level test is aware of the set of
338  * allowed characters set in {@link uspoof_setAllowedChars}. Note that characters which have script code
339  * COMMON or INHERITED, such as numbers and punctuation, are ignored when computing whether a string has multiple
340  * scripts.
341  *
342  * <h2>Additional Information</h2>
343  *
344  * A <code>USpoofChecker</code> instance may be used repeatedly to perform checks on any number of identifiers.
345  *
346  * <b>Thread Safety:</b> The test functions for checking a single identifier, or for testing whether
347  * two identifiers are possible confusable, are thread safe. They may called concurrently, from multiple threads,
348  * using the same USpoofChecker instance.
349  *
350  * More generally, the standard ICU thread safety rules apply: functions that take a const USpoofChecker parameter are
351  * thread safe. Those that take a non-const USpoofChecker are not thread safe..
352  *
353  * @stable ICU 4.6
354  */
355 
356 U_CDECL_BEGIN
357 
358 struct USpoofChecker;
359 /**
360  * @stable ICU 4.2
361  */
362 typedef struct USpoofChecker USpoofChecker; /**< typedef for C of USpoofChecker */
363 
364 struct USpoofCheckResult;
365 /**
366  * @see uspoof_openCheckResult
367  * @stable ICU 58
368  */
369 typedef struct USpoofCheckResult USpoofCheckResult;
370 
371 /**
372  * Enum for the kinds of checks that USpoofChecker can perform.
373  * These enum values are used both to select the set of checks that
374  * will be performed, and to report results from the check function.
375  *
376  * @stable ICU 4.2
377  */
378 typedef enum USpoofChecks {
379     /**
380      * When performing the two-string {@link uspoof_areConfusable} test, this flag in the return value indicates
381      * that the two strings are visually confusable and that they are from the same script, according to UTS 39 section
382      * 4.
383      *
384      * @see uspoof_areConfusable
385      * @stable ICU 4.2
386      */
387     USPOOF_SINGLE_SCRIPT_CONFUSABLE =   1,
388 
389     /**
390      * When performing the two-string {@link uspoof_areConfusable} test, this flag in the return value indicates
391      * that the two strings are visually confusable and that they are <b>not</b> from the same script, according to UTS
392      * 39 section 4.
393      *
394      * @see uspoof_areConfusable
395      * @stable ICU 4.2
396      */
397     USPOOF_MIXED_SCRIPT_CONFUSABLE  =   2,
398 
399     /**
400      * When performing the two-string {@link uspoof_areConfusable} test, this flag in the return value indicates
401      * that the two strings are visually confusable and that they are not from the same script but both of them are
402      * single-script strings, according to UTS 39 section 4.
403      *
404      * @see uspoof_areConfusable
405      * @stable ICU 4.2
406      */
407     USPOOF_WHOLE_SCRIPT_CONFUSABLE  =   4,
408 
409     /**
410      * Enable this flag in {@link uspoof_setChecks} to turn on all types of confusables.  You may set
411      * the checks to some subset of SINGLE_SCRIPT_CONFUSABLE, MIXED_SCRIPT_CONFUSABLE, or WHOLE_SCRIPT_CONFUSABLE to
412      * make {@link uspoof_areConfusable} return only those types of confusables.
413      *
414      * @see uspoof_areConfusable
415      * @see uspoof_getSkeleton
416      * @stable ICU 58
417      */
418     USPOOF_CONFUSABLE               =   USPOOF_SINGLE_SCRIPT_CONFUSABLE | USPOOF_MIXED_SCRIPT_CONFUSABLE | USPOOF_WHOLE_SCRIPT_CONFUSABLE,
419 
420 #ifndef U_HIDE_DEPRECATED_API
421     /**
422       * This flag is deprecated and no longer affects the behavior of SpoofChecker.
423       *
424       * @deprecated ICU 58  Any case confusable mappings were removed from UTS 39; the corresponding ICU API was deprecated.
425       */
426     USPOOF_ANY_CASE                 =   8,
427 #endif  /* U_HIDE_DEPRECATED_API */
428 
429     /**
430       * Check that an identifier is no looser than the specified RestrictionLevel.
431       * The default if {@link uspoof_setRestrictionLevel} is not called is HIGHLY_RESTRICTIVE.
432       *
433       * If USPOOF_AUX_INFO is enabled the actual restriction level of the
434       * identifier being tested will also be returned by uspoof_check().
435       *
436       * @see URestrictionLevel
437       * @see uspoof_setRestrictionLevel
438       * @see USPOOF_AUX_INFO
439       *
440       * @stable ICU 51
441       */
442     USPOOF_RESTRICTION_LEVEL        = 16,
443 
444 #ifndef U_HIDE_DEPRECATED_API
445     /** Check that an identifier contains only characters from a
446       * single script (plus chars from the common and inherited scripts.)
447       * Applies to checks of a single identifier check only.
448       * @deprecated ICU 51  Use RESTRICTION_LEVEL instead.
449       */
450     USPOOF_SINGLE_SCRIPT            =  USPOOF_RESTRICTION_LEVEL,
451 #endif  /* U_HIDE_DEPRECATED_API */
452 
453     /** Check an identifier for the presence of invisible characters,
454       * such as zero-width spaces, or character sequences that are
455       * likely not to display, such as multiple occurrences of the same
456       * non-spacing mark.  This check does not test the input string as a whole
457       * for conformance to any particular syntax for identifiers.
458       */
459     USPOOF_INVISIBLE                =  32,
460 
461     /** Check that an identifier contains only characters from a specified set
462       * of acceptable characters.  See {@link uspoof_setAllowedChars} and
463       * {@link uspoof_setAllowedLocales}.  Note that a string that fails this check
464       * will also fail the {@link USPOOF_RESTRICTION_LEVEL} check.
465       */
466     USPOOF_CHAR_LIMIT               =  64,
467 
468     /**
469      * Check that an identifier does not mix numbers from different numbering systems.
470      * For more information, see UTS 39 section 5.3.
471      *
472      * @stable ICU 51
473      */
474     USPOOF_MIXED_NUMBERS            = 128,
475 
476     /**
477      * Check that an identifier does not have a combining character following a character in which that
478      * combining character would be hidden; for example 'i' followed by a U+0307 combining dot.
479      *
480      * More specifically, the following characters are forbidden from preceding a U+0307:
481      * <ul>
482      * <li>Those with the Soft_Dotted Unicode property (which includes 'i' and 'j')</li>
483      * <li>Latin lowercase letter 'l'</li>
484      * <li>Dotless 'i' and 'j' ('ı' and 'ȷ', U+0131 and U+0237)</li>
485      * <li>Any character whose confusable prototype ends with such a character
486      * (Soft_Dotted, 'l', 'ı', or 'ȷ')</li>
487      * </ul>
488      * In addition, combining characters are allowed between the above characters and U+0307 except those
489      * with combining class 0 or combining class "Above" (230, same class as U+0307).
490      *
491      * This list and the number of combing characters considered by this check may grow over time.
492      *
493      * @stable ICU 62
494      */
495     USPOOF_HIDDEN_OVERLAY            = 256,
496 
497    /**
498      * Enable all spoof checks.
499      *
500      * @stable ICU 4.6
501      */
502     USPOOF_ALL_CHECKS               = 0xFFFF,
503 
504     /**
505       * Enable the return of auxillary (non-error) information in the
506       * upper bits of the check results value.
507       *
508       * If this "check" is not enabled, the results of {@link uspoof_check} will be
509       * zero when an identifier passes all of the enabled checks.
510       *
511       * If this "check" is enabled, (uspoof_check() & {@link USPOOF_ALL_CHECKS}) will
512       * be zero when an identifier passes all checks.
513       *
514       * @stable ICU 51
515       */
516     USPOOF_AUX_INFO                  = 0x40000000
517 
518     } USpoofChecks;
519 
520 
521     /**
522      * Constants from UAX #39 for use in {@link uspoof_setRestrictionLevel}, and
523      * for returned identifier restriction levels in check results.
524      *
525      * @stable ICU 51
526      *
527      * @see uspoof_setRestrictionLevel
528      * @see uspoof_check
529      */
530     typedef enum URestrictionLevel {
531         /**
532          * All characters in the string are in the identifier profile and all characters in the string are in the
533          * ASCII range.
534          *
535          * @stable ICU 51
536          */
537         USPOOF_ASCII = 0x10000000,
538         /**
539          * The string classifies as ASCII-Only, or all characters in the string are in the identifier profile and
540          * the string is single-script, according to the definition in UTS 39 section 5.1.
541          *
542          * @stable ICU 53
543          */
544         USPOOF_SINGLE_SCRIPT_RESTRICTIVE = 0x20000000,
545         /**
546          * The string classifies as Single Script, or all characters in the string are in the identifier profile and
547          * the string is covered by any of the following sets of scripts, according to the definition in UTS 39
548          * section 5.1:
549          * <ul>
550          *   <li>Latin + Han + Bopomofo (or equivalently: Latn + Hanb)</li>
551          *   <li>Latin + Han + Hiragana + Katakana (or equivalently: Latn + Jpan)</li>
552          *   <li>Latin + Han + Hangul (or equivalently: Latn +Kore)</li>
553          * </ul>
554          * This is the default restriction in ICU.
555          *
556          * @stable ICU 51
557          */
558         USPOOF_HIGHLY_RESTRICTIVE = 0x30000000,
559         /**
560          * The string classifies as Highly Restrictive, or all characters in the string are in the identifier profile
561          * and the string is covered by Latin and any one other Recommended or Aspirational script, except Cyrillic,
562          * Greek, and Cherokee.
563          *
564          * @stable ICU 51
565          */
566         USPOOF_MODERATELY_RESTRICTIVE = 0x40000000,
567         /**
568          * All characters in the string are in the identifier profile.  Allow arbitrary mixtures of scripts.
569          *
570          * @stable ICU 51
571          */
572         USPOOF_MINIMALLY_RESTRICTIVE = 0x50000000,
573         /**
574          * Any valid identifiers, including characters outside of the Identifier Profile.
575          *
576          * @stable ICU 51
577          */
578         USPOOF_UNRESTRICTIVE = 0x60000000,
579         /**
580          * Mask for selecting the Restriction Level bits from the return value of {@link uspoof_check}.
581          *
582          * @stable ICU 53
583          */
584         USPOOF_RESTRICTION_LEVEL_MASK = 0x7F000000,
585 #ifndef U_HIDE_INTERNAL_API
586         /**
587          * An undefined restriction level.
588          * @internal
589          */
590         USPOOF_UNDEFINED_RESTRICTIVE = -1
591 #endif  /* U_HIDE_INTERNAL_API */
592     } URestrictionLevel;
593 
594 /**
595  *  Create a Unicode Spoof Checker, configured to perform all
596  *  checks except for USPOOF_LOCALE_LIMIT and USPOOF_CHAR_LIMIT.
597  *  Note that additional checks may be added in the future,
598  *  resulting in the changes to the default checking behavior.
599  *
600  *  @param status  The error code, set if this function encounters a problem.
601  *  @return        the newly created Spoof Checker
602  *  @stable ICU 4.2
603  */
604 U_STABLE USpoofChecker * U_EXPORT2
605 uspoof_open(UErrorCode *status);
606 
607 
608 /**
609  * Open a Spoof checker from its serialized form, stored in 32-bit-aligned memory.
610  * Inverse of uspoof_serialize().
611  * The memory containing the serialized data must remain valid and unchanged
612  * as long as the spoof checker, or any cloned copies of the spoof checker,
613  * are in use.  Ownership of the memory remains with the caller.
614  * The spoof checker (and any clones) must be closed prior to deleting the
615  * serialized data.
616  *
617  * @param data a pointer to 32-bit-aligned memory containing the serialized form of spoof data
618  * @param length the number of bytes available at data;
619  *               can be more than necessary
620  * @param pActualLength receives the actual number of bytes at data taken up by the data;
621  *                      can be NULL
622  * @param pErrorCode ICU error code
623  * @return the spoof checker.
624  *
625  * @see uspoof_open
626  * @see uspoof_serialize
627  * @stable ICU 4.2
628  */
629 U_STABLE USpoofChecker * U_EXPORT2
630 uspoof_openFromSerialized(const void *data, int32_t length, int32_t *pActualLength,
631                           UErrorCode *pErrorCode);
632 
633 /**
634   * Open a Spoof Checker from the source form of the spoof data.
635   * The input corresponds to the Unicode data file confusables.txt
636   * as described in Unicode UAX #39.  The syntax of the source data
637   * is as described in UAX #39 for this file, and the content of
638   * this file is acceptable input.
639   *
640   * The character encoding of the (char *) input text is UTF-8.
641   *
642   * @param confusables a pointer to the confusable characters definitions,
643   *                    as found in file confusables.txt from unicode.org.
644   * @param confusablesLen The length of the confusables text, or -1 if the
645   *                    input string is zero terminated.
646   * @param confusablesWholeScript
647   *                    Deprecated in ICU 58.  No longer used.
648   * @param confusablesWholeScriptLen
649   *                    Deprecated in ICU 58.  No longer used.
650   * @param errType     In the event of an error in the input, indicates
651   *                    which of the input files contains the error.
652   *                    The value is one of USPOOF_SINGLE_SCRIPT_CONFUSABLE or
653   *                    USPOOF_WHOLE_SCRIPT_CONFUSABLE, or
654   *                    zero if no errors are found.
655   * @param pe          In the event of an error in the input, receives the position
656   *                    in the input text (line, offset) of the error.
657   * @param status      an in/out ICU UErrorCode.  Among the possible errors is
658   *                    U_PARSE_ERROR, which is used to report syntax errors
659   *                    in the input.
660   * @return            A spoof checker that uses the rules from the input files.
661   * @stable ICU 4.2
662   */
663 U_STABLE USpoofChecker * U_EXPORT2
664 uspoof_openFromSource(const char *confusables,  int32_t confusablesLen,
665                       const char *confusablesWholeScript, int32_t confusablesWholeScriptLen,
666                       int32_t *errType, UParseError *pe, UErrorCode *status);
667 
668 
669 /**
670   * Close a Spoof Checker, freeing any memory that was being held by
671   *   its implementation.
672   * @stable ICU 4.2
673   */
674 U_STABLE void U_EXPORT2
675 uspoof_close(USpoofChecker *sc);
676 
677 /**
678  * Clone a Spoof Checker.  The clone will be set to perform the same checks
679  *   as the original source.
680  *
681  * @param sc       The source USpoofChecker
682  * @param status   The error code, set if this function encounters a problem.
683  * @return
684  * @stable ICU 4.2
685  */
686 U_STABLE USpoofChecker * U_EXPORT2
687 uspoof_clone(const USpoofChecker *sc, UErrorCode *status);
688 
689 
690 /**
691  * Specify the bitmask of checks that will be performed by {@link uspoof_check}. Calling this method
692  * overwrites any checks that may have already been enabled. By default, all checks are enabled.
693  *
694  * To enable specific checks and disable all others, the "whitelisted" checks should be ORed together. For
695  * example, to fail strings containing characters outside of the set specified by {@link uspoof_setAllowedChars} and
696  * also strings that contain digits from mixed numbering systems:
697  *
698  * <pre>
699  * {@code
700  * uspoof_setChecks(USPOOF_CHAR_LIMIT | USPOOF_MIXED_NUMBERS);
701  * }
702  * </pre>
703  *
704  * To disable specific checks and enable all others, the "blacklisted" checks should be ANDed away from
705  * ALL_CHECKS. For example, if you are not planning to use the {@link uspoof_areConfusable} functionality,
706  * it is good practice to disable the CONFUSABLE check:
707  *
708  * <pre>
709  * {@code
710  * uspoof_setChecks(USPOOF_ALL_CHECKS & ~USPOOF_CONFUSABLE);
711  * }
712  * </pre>
713  *
714  * Note that methods such as {@link uspoof_setAllowedChars}, {@link uspoof_setAllowedLocales}, and
715  * {@link uspoof_setRestrictionLevel} will enable certain checks when called. Those methods will OR the check they
716  * enable onto the existing bitmask specified by this method. For more details, see the documentation of those
717  * methods.
718  *
719  * @param sc       The USpoofChecker
720  * @param checks         The set of checks that this spoof checker will perform.
721  *                 The value is a bit set, obtained by OR-ing together
722  *                 values from enum USpoofChecks.
723  * @param status   The error code, set if this function encounters a problem.
724  * @stable ICU 4.2
725  *
726  */
727 U_STABLE void U_EXPORT2
728 uspoof_setChecks(USpoofChecker *sc, int32_t checks, UErrorCode *status);
729 
730 /**
731  * Get the set of checks that this Spoof Checker has been configured to perform.
732  *
733  * @param sc       The USpoofChecker
734  * @param status   The error code, set if this function encounters a problem.
735  * @return         The set of checks that this spoof checker will perform.
736  *                 The value is a bit set, obtained by OR-ing together
737  *                 values from enum USpoofChecks.
738  * @stable ICU 4.2
739  *
740  */
741 U_STABLE int32_t U_EXPORT2
742 uspoof_getChecks(const USpoofChecker *sc, UErrorCode *status);
743 
744 /**
745  * Set the loosest restriction level allowed for strings. The default if this is not called is
746  * {@link USPOOF_HIGHLY_RESTRICTIVE}. Calling this method enables the {@link USPOOF_RESTRICTION_LEVEL} and
747  * {@link USPOOF_MIXED_NUMBERS} checks, corresponding to Sections 5.1 and 5.2 of UTS 39. To customize which checks are
748  * to be performed by {@link uspoof_check}, see {@link uspoof_setChecks}.
749  *
750  * @param sc       The USpoofChecker
751  * @param restrictionLevel The loosest restriction level allowed.
752  * @see URestrictionLevel
753  * @stable ICU 51
754  */
755 U_STABLE void U_EXPORT2
756 uspoof_setRestrictionLevel(USpoofChecker *sc, URestrictionLevel restrictionLevel);
757 
758 
759 /**
760   * Get the Restriction Level that will be tested if the checks include {@link USPOOF_RESTRICTION_LEVEL}.
761   *
762   * @return The restriction level
763   * @see URestrictionLevel
764   * @stable ICU 51
765   */
766 U_STABLE URestrictionLevel U_EXPORT2
767 uspoof_getRestrictionLevel(const USpoofChecker *sc);
768 
769 /**
770  * Limit characters that are acceptable in identifiers being checked to those
771  * normally used with the languages associated with the specified locales.
772  * Any previously specified list of locales is replaced by the new settings.
773  *
774  * A set of languages is determined from the locale(s), and
775  * from those a set of acceptable Unicode scripts is determined.
776  * Characters from this set of scripts, along with characters from
777  * the "common" and "inherited" Unicode Script categories
778  * will be permitted.
779  *
780  * Supplying an empty string removes all restrictions;
781  * characters from any script will be allowed.
782  *
783  * The {@link USPOOF_CHAR_LIMIT} test is automatically enabled for this
784  * USpoofChecker when calling this function with a non-empty list
785  * of locales.
786  *
787  * The Unicode Set of characters that will be allowed is accessible
788  * via the uspoof_getAllowedChars() function.  uspoof_setAllowedLocales()
789  * will <i>replace</i> any previously applied set of allowed characters.
790  *
791  * Adjustments, such as additions or deletions of certain classes of characters,
792  * can be made to the result of uspoof_setAllowedLocales() by
793  * fetching the resulting set with uspoof_getAllowedChars(),
794  * manipulating it with the Unicode Set API, then resetting the
795  * spoof detectors limits with uspoof_setAllowedChars().
796  *
797  * @param sc           The USpoofChecker
798  * @param localesList  A list list of locales, from which the language
799  *                     and associated script are extracted.  The locales
800  *                     are comma-separated if there is more than one.
801  *                     White space may not appear within an individual locale,
802  *                     but is ignored otherwise.
803  *                     The locales are syntactically like those from the
804  *                     HTTP Accept-Language header.
805  *                     If the localesList is empty, no restrictions will be placed on
806  *                     the allowed characters.
807  *
808  * @param status       The error code, set if this function encounters a problem.
809  * @stable ICU 4.2
810  */
811 U_STABLE void U_EXPORT2
812 uspoof_setAllowedLocales(USpoofChecker *sc, const char *localesList, UErrorCode *status);
813 
814 /**
815  * Get a list of locales for the scripts that are acceptable in strings
816  *  to be checked.  If no limitations on scripts have been specified,
817  *  an empty string will be returned.
818  *
819  *  uspoof_setAllowedChars() will reset the list of allowed to be empty.
820  *
821  *  The format of the returned list is the same as that supplied to
822  *  uspoof_setAllowedLocales(), but returned list may not be identical
823  *  to the originally specified string; the string may be reformatted,
824  *  and information other than languages from
825  *  the originally specified locales may be omitted.
826  *
827  * @param sc           The USpoofChecker
828  * @param status       The error code, set if this function encounters a problem.
829  * @return             A string containing a list of  locales corresponding
830  *                     to the acceptable scripts, formatted like an
831  *                     HTTP Accept Language value.
832  *
833  * @stable ICU 4.2
834  */
835 U_STABLE const char * U_EXPORT2
836 uspoof_getAllowedLocales(USpoofChecker *sc, UErrorCode *status);
837 
838 
839 /**
840  * Limit the acceptable characters to those specified by a Unicode Set.
841  *   Any previously specified character limit is
842  *   is replaced by the new settings.  This includes limits on
843  *   characters that were set with the uspoof_setAllowedLocales() function.
844  *
845  * The USPOOF_CHAR_LIMIT test is automatically enabled for this
846  * USpoofChecker by this function.
847  *
848  * @param sc       The USpoofChecker
849  * @param chars    A Unicode Set containing the list of
850  *                 characters that are permitted.  Ownership of the set
851  *                 remains with the caller.  The incoming set is cloned by
852  *                 this function, so there are no restrictions on modifying
853  *                 or deleting the USet after calling this function.
854  * @param status   The error code, set if this function encounters a problem.
855  * @stable ICU 4.2
856  */
857 U_STABLE void U_EXPORT2
858 uspoof_setAllowedChars(USpoofChecker *sc, const USet *chars, UErrorCode *status);
859 
860 
861 /**
862  * Get a USet for the characters permitted in an identifier.
863  * This corresponds to the limits imposed by the Set Allowed Characters
864  * functions. Limitations imposed by other checks will not be
865  * reflected in the set returned by this function.
866  *
867  * The returned set will be frozen, meaning that it cannot be modified
868  * by the caller.
869  *
870  * Ownership of the returned set remains with the Spoof Detector.  The
871  * returned set will become invalid if the spoof detector is closed,
872  * or if a new set of allowed characters is specified.
873  *
874  *
875  * @param sc       The USpoofChecker
876  * @param status   The error code, set if this function encounters a problem.
877  * @return         A USet containing the characters that are permitted by
878  *                 the USPOOF_CHAR_LIMIT test.
879  * @stable ICU 4.2
880  */
881 U_STABLE const USet * U_EXPORT2
882 uspoof_getAllowedChars(const USpoofChecker *sc, UErrorCode *status);
883 
884 
885 /**
886  * Check the specified string for possible security issues.
887  * The text to be checked will typically be an identifier of some sort.
888  * The set of checks to be performed is specified with uspoof_setChecks().
889  *
890  * \note
891  *   Consider using the newer API, {@link uspoof_check2}, instead.
892  *   The newer API exposes additional information from the check procedure
893  *   and is otherwise identical to this method.
894  *
895  * @param sc      The USpoofChecker
896  * @param id      The identifier to be checked for possible security issues,
897  *                in UTF-16 format.
898  * @param length  the length of the string to be checked, expressed in
899  *                16 bit UTF-16 code units, or -1 if the string is
900  *                zero terminated.
901  * @param position  Deprecated in ICU 51.  Always returns zero.
902  *                Originally, an out parameter for the index of the first
903  *                string position that failed a check.
904  *                This parameter may be NULL.
905  * @param status  The error code, set if an error occurred while attempting to
906  *                perform the check.
907  *                Spoofing or security issues detected with the input string are
908  *                not reported here, but through the function's return value.
909  * @return        An integer value with bits set for any potential security
910  *                or spoofing issues detected.  The bits are defined by
911  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
912  *                will be zero if the input string passes all of the
913  *                enabled checks.
914  * @see uspoof_check2
915  * @stable ICU 4.2
916  */
917 U_STABLE int32_t U_EXPORT2
918 uspoof_check(const USpoofChecker *sc,
919                          const UChar *id, int32_t length,
920                          int32_t *position,
921                          UErrorCode *status);
922 
923 
924 /**
925  * Check the specified string for possible security issues.
926  * The text to be checked will typically be an identifier of some sort.
927  * The set of checks to be performed is specified with uspoof_setChecks().
928  *
929  * \note
930  *   Consider using the newer API, {@link uspoof_check2UTF8}, instead.
931  *   The newer API exposes additional information from the check procedure
932  *   and is otherwise identical to this method.
933  *
934  * @param sc      The USpoofChecker
935  * @param id      A identifier to be checked for possible security issues, in UTF8 format.
936  * @param length  the length of the string to be checked, or -1 if the string is
937  *                zero terminated.
938  * @param position  Deprecated in ICU 51.  Always returns zero.
939  *                Originally, an out parameter for the index of the first
940  *                string position that failed a check.
941  *                This parameter may be NULL.
942  * @param status  The error code, set if an error occurred while attempting to
943  *                perform the check.
944  *                Spoofing or security issues detected with the input string are
945  *                not reported here, but through the function's return value.
946  *                If the input contains invalid UTF-8 sequences,
947  *                a status of U_INVALID_CHAR_FOUND will be returned.
948  * @return        An integer value with bits set for any potential security
949  *                or spoofing issues detected.  The bits are defined by
950  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
951  *                will be zero if the input string passes all of the
952  *                enabled checks.
953  * @see uspoof_check2UTF8
954  * @stable ICU 4.2
955  */
956 U_STABLE int32_t U_EXPORT2
957 uspoof_checkUTF8(const USpoofChecker *sc,
958                  const char *id, int32_t length,
959                  int32_t *position,
960                  UErrorCode *status);
961 
962 
963 /**
964  * Check the specified string for possible security issues.
965  * The text to be checked will typically be an identifier of some sort.
966  * The set of checks to be performed is specified with uspoof_setChecks().
967  *
968  * @param sc      The USpoofChecker
969  * @param id      The identifier to be checked for possible security issues,
970  *                in UTF-16 format.
971  * @param length  the length of the string to be checked, or -1 if the string is
972  *                zero terminated.
973  * @param checkResult  An instance of USpoofCheckResult to be filled with
974  *                details about the identifier.  Can be NULL.
975  * @param status  The error code, set if an error occurred while attempting to
976  *                perform the check.
977  *                Spoofing or security issues detected with the input string are
978  *                not reported here, but through the function's return value.
979  * @return        An integer value with bits set for any potential security
980  *                or spoofing issues detected.  The bits are defined by
981  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
982  *                will be zero if the input string passes all of the
983  *                enabled checks.  Any information in this bitmask will be
984  *                consistent with the information saved in the optional
985  *                checkResult parameter.
986  * @see uspoof_openCheckResult
987  * @see uspoof_check2UTF8
988  * @see uspoof_check2UnicodeString
989  * @stable ICU 58
990  */
991 U_STABLE int32_t U_EXPORT2
992 uspoof_check2(const USpoofChecker *sc,
993     const UChar* id, int32_t length,
994     USpoofCheckResult* checkResult,
995     UErrorCode *status);
996 
997 /**
998  * Check the specified string for possible security issues.
999  * The text to be checked will typically be an identifier of some sort.
1000  * The set of checks to be performed is specified with uspoof_setChecks().
1001  *
1002  * This version of {@link uspoof_check} accepts a USpoofCheckResult, which
1003  * returns additional information about the identifier.  For more
1004  * information, see {@link uspoof_openCheckResult}.
1005  *
1006  * @param sc      The USpoofChecker
1007  * @param id      A identifier to be checked for possible security issues, in UTF8 format.
1008  * @param length  the length of the string to be checked, or -1 if the string is
1009  *                zero terminated.
1010  * @param checkResult  An instance of USpoofCheckResult to be filled with
1011  *                details about the identifier.  Can be NULL.
1012  * @param status  The error code, set if an error occurred while attempting to
1013  *                perform the check.
1014  *                Spoofing or security issues detected with the input string are
1015  *                not reported here, but through the function's return value.
1016  * @return        An integer value with bits set for any potential security
1017  *                or spoofing issues detected.  The bits are defined by
1018  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1019  *                will be zero if the input string passes all of the
1020  *                enabled checks.  Any information in this bitmask will be
1021  *                consistent with the information saved in the optional
1022  *                checkResult parameter.
1023  * @see uspoof_openCheckResult
1024  * @see uspoof_check2
1025  * @see uspoof_check2UnicodeString
1026  * @stable ICU 58
1027  */
1028 U_STABLE int32_t U_EXPORT2
1029 uspoof_check2UTF8(const USpoofChecker *sc,
1030     const char *id, int32_t length,
1031     USpoofCheckResult* checkResult,
1032     UErrorCode *status);
1033 
1034 /**
1035  * Create a USpoofCheckResult, used by the {@link uspoof_check2} class of functions to return
1036  * information about the identifier.  Information includes:
1037  * <ul>
1038  *   <li>A bitmask of the checks that failed</li>
1039  *   <li>The identifier's restriction level (UTS 39 section 5.2)</li>
1040  *   <li>The set of numerics in the string (UTS 39 section 5.3)</li>
1041  * </ul>
1042  * The data held in a USpoofCheckResult is cleared whenever it is passed into a new call
1043  * of {@link uspoof_check2}.
1044  *
1045  * @param status  The error code, set if this function encounters a problem.
1046  * @return        the newly created USpoofCheckResult
1047  * @see uspoof_check2
1048  * @see uspoof_check2UTF8
1049  * @see uspoof_check2UnicodeString
1050  * @stable ICU 58
1051  */
1052 U_STABLE USpoofCheckResult* U_EXPORT2
1053 uspoof_openCheckResult(UErrorCode *status);
1054 
1055 /**
1056  * Close a USpoofCheckResult, freeing any memory that was being held by
1057  *   its implementation.
1058  *
1059  * @param checkResult  The instance of USpoofCheckResult to close
1060  * @stable ICU 58
1061  */
1062 U_STABLE void U_EXPORT2
1063 uspoof_closeCheckResult(USpoofCheckResult *checkResult);
1064 
1065 /**
1066  * Indicates which of the spoof check(s) have failed. The value is a bitwise OR of the constants for the tests
1067  * in question: USPOOF_RESTRICTION_LEVEL, USPOOF_CHAR_LIMIT, and so on.
1068  *
1069  * @param checkResult  The instance of USpoofCheckResult created by {@link uspoof_openCheckResult}
1070  * @param status       The error code, set if an error occurred.
1071  * @return        An integer value with bits set for any potential security
1072  *                or spoofing issues detected.  The bits are defined by
1073  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1074  *                will be zero if the input string passes all of the
1075  *                enabled checks.
1076  * @see uspoof_setChecks
1077  * @stable ICU 58
1078  */
1079 U_STABLE int32_t U_EXPORT2
1080 uspoof_getCheckResultChecks(const USpoofCheckResult *checkResult, UErrorCode *status);
1081 
1082 /**
1083  * Gets the restriction level that the text meets, if the USPOOF_RESTRICTION_LEVEL check
1084  * was enabled; otherwise, undefined.
1085  *
1086  * @param checkResult  The instance of USpoofCheckResult created by {@link uspoof_openCheckResult}
1087  * @param status       The error code, set if an error occurred.
1088  * @return             The restriction level contained in the USpoofCheckResult
1089  * @see uspoof_setRestrictionLevel
1090  * @stable ICU 58
1091  */
1092 U_STABLE URestrictionLevel U_EXPORT2
1093 uspoof_getCheckResultRestrictionLevel(const USpoofCheckResult *checkResult, UErrorCode *status);
1094 
1095 /**
1096  * Gets the set of numerics found in the string, if the USPOOF_MIXED_NUMBERS check was enabled;
1097  * otherwise, undefined.  The set will contain the zero digit from each decimal number system found
1098  * in the input string.  Ownership of the returned USet remains with the USpoofCheckResult.
1099  * The USet will be free'd when {@link uspoof_closeCheckResult} is called.
1100  *
1101  * @param checkResult  The instance of USpoofCheckResult created by {@link uspoof_openCheckResult}
1102  * @return             The set of numerics contained in the USpoofCheckResult
1103  * @param status       The error code, set if an error occurred.
1104  * @stable ICU 58
1105  */
1106 U_STABLE const USet* U_EXPORT2
1107 uspoof_getCheckResultNumerics(const USpoofCheckResult *checkResult, UErrorCode *status);
1108 
1109 
1110 /**
1111  * Check the whether two specified strings are visually confusable.
1112  *
1113  * If the strings are confusable, the return value will be nonzero, as long as
1114  * {@link USPOOF_CONFUSABLE} was enabled in uspoof_setChecks().
1115  *
1116  * The bits in the return value correspond to flags for each of the classes of
1117  * confusables applicable to the two input strings.  According to UTS 39
1118  * section 4, the possible flags are:
1119  *
1120  * <ul>
1121  *   <li>{@link USPOOF_SINGLE_SCRIPT_CONFUSABLE}</li>
1122  *   <li>{@link USPOOF_MIXED_SCRIPT_CONFUSABLE}</li>
1123  *   <li>{@link USPOOF_WHOLE_SCRIPT_CONFUSABLE}</li>
1124  * </ul>
1125  *
1126  * If one or more of the above flags were not listed in uspoof_setChecks(), this
1127  * function will never report that class of confusable.  The check
1128  * {@link USPOOF_CONFUSABLE} enables all three flags.
1129  *
1130  *
1131  * @param sc      The USpoofChecker
1132  * @param id1     The first of the two identifiers to be compared for
1133  *                confusability.  The strings are in UTF-16 format.
1134  * @param length1 the length of the first identifer, expressed in
1135  *                16 bit UTF-16 code units, or -1 if the string is
1136  *                nul terminated.
1137  * @param id2     The second of the two identifiers to be compared for
1138  *                confusability.  The identifiers are in UTF-16 format.
1139  * @param length2 The length of the second identifiers, expressed in
1140  *                16 bit UTF-16 code units, or -1 if the string is
1141  *                nul terminated.
1142  * @param status  The error code, set if an error occurred while attempting to
1143  *                perform the check.
1144  *                Confusability of the identifiers is not reported here,
1145  *                but through this function's return value.
1146  * @return        An integer value with bit(s) set corresponding to
1147  *                the type of confusability found, as defined by
1148  *                enum USpoofChecks.  Zero is returned if the identifiers
1149  *                are not confusable.
1150  *
1151  * @stable ICU 4.2
1152  */
1153 U_STABLE int32_t U_EXPORT2
1154 uspoof_areConfusable(const USpoofChecker *sc,
1155                      const UChar *id1, int32_t length1,
1156                      const UChar *id2, int32_t length2,
1157                      UErrorCode *status);
1158 
1159 
1160 
1161 /**
1162  * A version of {@link uspoof_areConfusable} accepting strings in UTF-8 format.
1163  *
1164  * @param sc      The USpoofChecker
1165  * @param id1     The first of the two identifiers to be compared for
1166  *                confusability.  The strings are in UTF-8 format.
1167  * @param length1 the length of the first identifiers, in bytes, or -1
1168  *                if the string is nul terminated.
1169  * @param id2     The second of the two identifiers to be compared for
1170  *                confusability.  The strings are in UTF-8 format.
1171  * @param length2 The length of the second string in bytes, or -1
1172  *                if the string is nul terminated.
1173  * @param status  The error code, set if an error occurred while attempting to
1174  *                perform the check.
1175  *                Confusability of the strings is not reported here,
1176  *                but through this function's return value.
1177  * @return        An integer value with bit(s) set corresponding to
1178  *                the type of confusability found, as defined by
1179  *                enum USpoofChecks.  Zero is returned if the strings
1180  *                are not confusable.
1181  *
1182  * @stable ICU 4.2
1183  *
1184  * @see uspoof_areConfusable
1185  */
1186 U_STABLE int32_t U_EXPORT2
1187 uspoof_areConfusableUTF8(const USpoofChecker *sc,
1188                          const char *id1, int32_t length1,
1189                          const char *id2, int32_t length2,
1190                          UErrorCode *status);
1191 
1192 
1193 
1194 
1195 /**
1196  *  Get the "skeleton" for an identifier.
1197  *  Skeletons are a transformation of the input identifier;
1198  * Two identifiers are confusable if their skeletons are identical.
1199  *  See Unicode UAX #39 for additional information.
1200  *
1201  *  Using skeletons directly makes it possible to quickly check
1202  *  whether an identifier is confusable with any of some large
1203  *  set of existing identifiers, by creating an efficiently
1204  *  searchable collection of the skeletons.
1205  *
1206  * @param sc      The USpoofChecker
1207  * @param type    Deprecated in ICU 58.  You may pass any number.
1208  *                Originally, controlled which of the Unicode confusable data
1209  *                tables to use.
1210  * @param id      The input identifier whose skeleton will be computed.
1211  * @param length  The length of the input identifier, expressed in 16 bit
1212  *                UTF-16 code units, or -1 if the string is zero terminated.
1213  * @param dest    The output buffer, to receive the skeleton string.
1214  * @param destCapacity  The length of the output buffer, in 16 bit units.
1215  *                The destCapacity may be zero, in which case the function will
1216  *                return the actual length of the skeleton.
1217  * @param status  The error code, set if an error occurred while attempting to
1218  *                perform the check.
1219  * @return        The length of the skeleton string.  The returned length
1220  *                is always that of the complete skeleton, even when the
1221  *                supplied buffer is too small (or of zero length)
1222  *
1223  * @stable ICU 4.2
1224  * @see uspoof_areConfusable
1225  */
1226 U_STABLE int32_t U_EXPORT2
1227 uspoof_getSkeleton(const USpoofChecker *sc,
1228                    uint32_t type,
1229                    const UChar *id,  int32_t length,
1230                    UChar *dest, int32_t destCapacity,
1231                    UErrorCode *status);
1232 
1233 /**
1234  *  Get the "skeleton" for an identifier.
1235  *  Skeletons are a transformation of the input identifier;
1236  *  Two identifiers are confusable if their skeletons are identical.
1237  *  See Unicode UAX #39 for additional information.
1238  *
1239  *  Using skeletons directly makes it possible to quickly check
1240  *  whether an identifier is confusable with any of some large
1241  *  set of existing identifiers, by creating an efficiently
1242  *  searchable collection of the skeletons.
1243  *
1244  * @param sc      The USpoofChecker
1245  * @param type    Deprecated in ICU 58.  You may pass any number.
1246  *                Originally, controlled which of the Unicode confusable data
1247  *                tables to use.
1248  * @param id      The UTF-8 format identifier whose skeleton will be computed.
1249  * @param length  The length of the input string, in bytes,
1250  *                or -1 if the string is zero terminated.
1251  * @param dest    The output buffer, to receive the skeleton string.
1252  * @param destCapacity  The length of the output buffer, in bytes.
1253  *                The destCapacity may be zero, in which case the function will
1254  *                return the actual length of the skeleton.
1255  * @param status  The error code, set if an error occurred while attempting to
1256  *                perform the check.  Possible Errors include U_INVALID_CHAR_FOUND
1257  *                   for invalid UTF-8 sequences, and
1258  *                   U_BUFFER_OVERFLOW_ERROR if the destination buffer is too small
1259  *                   to hold the complete skeleton.
1260  * @return        The length of the skeleton string, in bytes.  The returned length
1261  *                is always that of the complete skeleton, even when the
1262  *                supplied buffer is too small (or of zero length)
1263  *
1264  * @stable ICU 4.2
1265  */
1266 U_STABLE int32_t U_EXPORT2
1267 uspoof_getSkeletonUTF8(const USpoofChecker *sc,
1268                        uint32_t type,
1269                        const char *id,  int32_t length,
1270                        char *dest, int32_t destCapacity,
1271                        UErrorCode *status);
1272 
1273 /**
1274   * Get the set of Candidate Characters for Inclusion in Identifiers, as defined
1275   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1276   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1277   *
1278   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1279   * be deleted by the caller.
1280   *
1281   * @param status The error code, set if a problem occurs while creating the set.
1282   *
1283   * @stable ICU 51
1284   */
1285 U_STABLE const USet * U_EXPORT2
1286 uspoof_getInclusionSet(UErrorCode *status);
1287 
1288 /**
1289   * Get the set of characters from Recommended Scripts for Inclusion in Identifiers, as defined
1290   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1291   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1292   *
1293   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1294   * be deleted by the caller.
1295   *
1296   * @param status The error code, set if a problem occurs while creating the set.
1297   *
1298   * @stable ICU 51
1299   */
1300 U_STABLE const USet * U_EXPORT2
1301 uspoof_getRecommendedSet(UErrorCode *status);
1302 
1303 /**
1304  * Serialize the data for a spoof detector into a chunk of memory.
1305  * The flattened spoof detection tables can later be used to efficiently
1306  * instantiate a new Spoof Detector.
1307  *
1308  * The serialized spoof checker includes only the data compiled from the
1309  * Unicode data tables by uspoof_openFromSource(); it does not include
1310  * include any other state or configuration that may have been set.
1311  *
1312  * @param sc   the Spoof Detector whose data is to be serialized.
1313  * @param data a pointer to 32-bit-aligned memory to be filled with the data,
1314  *             can be NULL if capacity==0
1315  * @param capacity the number of bytes available at data,
1316  *                 or 0 for preflighting
1317  * @param status an in/out ICU UErrorCode; possible errors include:
1318  * - U_BUFFER_OVERFLOW_ERROR if the data storage block is too small for serialization
1319  * - U_ILLEGAL_ARGUMENT_ERROR  the data or capacity parameters are bad
1320  * @return the number of bytes written or needed for the spoof data
1321  *
1322  * @see utrie2_openFromSerialized()
1323  * @stable ICU 4.2
1324  */
1325 U_STABLE int32_t U_EXPORT2
1326 uspoof_serialize(USpoofChecker *sc,
1327                  void *data, int32_t capacity,
1328                  UErrorCode *status);
1329 
1330 U_CDECL_END
1331 
1332 #if U_SHOW_CPLUSPLUS_API
1333 
1334 U_NAMESPACE_BEGIN
1335 
1336 /**
1337  * \class LocalUSpoofCheckerPointer
1338  * "Smart pointer" class, closes a USpoofChecker via uspoof_close().
1339  * For most methods see the LocalPointerBase base class.
1340  *
1341  * @see LocalPointerBase
1342  * @see LocalPointer
1343  * @stable ICU 4.4
1344  */
1345 /**
1346  * \cond
1347  * Note: Doxygen is giving a bogus warning on this U_DEFINE_LOCAL_OPEN_POINTER.
1348  *       For now, suppress with a Doxygen cond
1349  */
1350 U_DEFINE_LOCAL_OPEN_POINTER(LocalUSpoofCheckerPointer, USpoofChecker, uspoof_close);
1351 /** \endcond */
1352 
1353 /**
1354  * \class LocalUSpoofCheckResultPointer
1355  * "Smart pointer" class, closes a USpoofCheckResult via `uspoof_closeCheckResult()`.
1356  * For most methods see the LocalPointerBase base class.
1357  *
1358  * @see LocalPointerBase
1359  * @see LocalPointer
1360  * @stable ICU 58
1361  */
1362 
1363 /**
1364  * \cond
1365  * Note: Doxygen is giving a bogus warning on this U_DEFINE_LOCAL_OPEN_POINTER.
1366  *       For now, suppress with a Doxygen cond
1367  */
1368 U_DEFINE_LOCAL_OPEN_POINTER(LocalUSpoofCheckResultPointer, USpoofCheckResult, uspoof_closeCheckResult);
1369 /** \endcond */
1370 
1371 U_NAMESPACE_END
1372 
1373 /**
1374  * Limit the acceptable characters to those specified by a Unicode Set.
1375  *   Any previously specified character limit is
1376  *   is replaced by the new settings.    This includes limits on
1377  *   characters that were set with the uspoof_setAllowedLocales() function.
1378  *
1379  * The USPOOF_CHAR_LIMIT test is automatically enabled for this
1380  * USoofChecker by this function.
1381  *
1382  * @param sc       The USpoofChecker
1383  * @param chars    A Unicode Set containing the list of
1384  *                 characters that are permitted.  Ownership of the set
1385  *                 remains with the caller.  The incoming set is cloned by
1386  *                 this function, so there are no restrictions on modifying
1387  *                 or deleting the UnicodeSet after calling this function.
1388  * @param status   The error code, set if this function encounters a problem.
1389  * @stable ICU 4.2
1390  */
1391 U_STABLE void U_EXPORT2
1392 uspoof_setAllowedUnicodeSet(USpoofChecker *sc, const icu::UnicodeSet *chars, UErrorCode *status);
1393 
1394 
1395 /**
1396  * Get a UnicodeSet for the characters permitted in an identifier.
1397  * This corresponds to the limits imposed by the Set Allowed Characters /
1398  * UnicodeSet functions. Limitations imposed by other checks will not be
1399  * reflected in the set returned by this function.
1400  *
1401  * The returned set will be frozen, meaning that it cannot be modified
1402  * by the caller.
1403  *
1404  * Ownership of the returned set remains with the Spoof Detector.  The
1405  * returned set will become invalid if the spoof detector is closed,
1406  * or if a new set of allowed characters is specified.
1407  *
1408  *
1409  * @param sc       The USpoofChecker
1410  * @param status   The error code, set if this function encounters a problem.
1411  * @return         A UnicodeSet containing the characters that are permitted by
1412  *                 the USPOOF_CHAR_LIMIT test.
1413  * @stable ICU 4.2
1414  */
1415 U_STABLE const icu::UnicodeSet * U_EXPORT2
1416 uspoof_getAllowedUnicodeSet(const USpoofChecker *sc, UErrorCode *status);
1417 
1418 /**
1419  * Check the specified string for possible security issues.
1420  * The text to be checked will typically be an identifier of some sort.
1421  * The set of checks to be performed is specified with uspoof_setChecks().
1422  *
1423  * \note
1424  *   Consider using the newer API, {@link uspoof_check2UnicodeString}, instead.
1425  *   The newer API exposes additional information from the check procedure
1426  *   and is otherwise identical to this method.
1427  *
1428  * @param sc      The USpoofChecker
1429  * @param id      A identifier to be checked for possible security issues.
1430  * @param position  Deprecated in ICU 51.  Always returns zero.
1431  *                Originally, an out parameter for the index of the first
1432  *                string position that failed a check.
1433  *                This parameter may be NULL.
1434  * @param status  The error code, set if an error occurred while attempting to
1435  *                perform the check.
1436  *                Spoofing or security issues detected with the input string are
1437  *                not reported here, but through the function's return value.
1438  * @return        An integer value with bits set for any potential security
1439  *                or spoofing issues detected.  The bits are defined by
1440  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1441  *                will be zero if the input string passes all of the
1442  *                enabled checks.
1443  * @see uspoof_check2UnicodeString
1444  * @stable ICU 4.2
1445  */
1446 U_STABLE int32_t U_EXPORT2
1447 uspoof_checkUnicodeString(const USpoofChecker *sc,
1448                           const icu::UnicodeString &id,
1449                           int32_t *position,
1450                           UErrorCode *status);
1451 
1452 /**
1453  * Check the specified string for possible security issues.
1454  * The text to be checked will typically be an identifier of some sort.
1455  * The set of checks to be performed is specified with uspoof_setChecks().
1456  *
1457  * @param sc      The USpoofChecker
1458  * @param id      A identifier to be checked for possible security issues.
1459  * @param checkResult  An instance of USpoofCheckResult to be filled with
1460  *                details about the identifier.  Can be NULL.
1461  * @param status  The error code, set if an error occurred while attempting to
1462  *                perform the check.
1463  *                Spoofing or security issues detected with the input string are
1464  *                not reported here, but through the function's return value.
1465  * @return        An integer value with bits set for any potential security
1466  *                or spoofing issues detected.  The bits are defined by
1467  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1468  *                will be zero if the input string passes all of the
1469  *                enabled checks.  Any information in this bitmask will be
1470  *                consistent with the information saved in the optional
1471  *                checkResult parameter.
1472  * @see uspoof_openCheckResult
1473  * @see uspoof_check2
1474  * @see uspoof_check2UTF8
1475  * @stable ICU 58
1476  */
1477 U_STABLE int32_t U_EXPORT2
1478 uspoof_check2UnicodeString(const USpoofChecker *sc,
1479     const icu::UnicodeString &id,
1480     USpoofCheckResult* checkResult,
1481     UErrorCode *status);
1482 
1483 /**
1484  * A version of {@link uspoof_areConfusable} accepting UnicodeStrings.
1485  *
1486  * @param sc      The USpoofChecker
1487  * @param s1     The first of the two identifiers to be compared for
1488  *                confusability.  The strings are in UTF-8 format.
1489  * @param s2     The second of the two identifiers to be compared for
1490  *                confusability.  The strings are in UTF-8 format.
1491  * @param status  The error code, set if an error occurred while attempting to
1492  *                perform the check.
1493  *                Confusability of the identifiers is not reported here,
1494  *                but through this function's return value.
1495  * @return        An integer value with bit(s) set corresponding to
1496  *                the type of confusability found, as defined by
1497  *                enum USpoofChecks.  Zero is returned if the identifiers
1498  *                are not confusable.
1499  *
1500  * @stable ICU 4.2
1501  *
1502  * @see uspoof_areConfusable
1503  */
1504 U_STABLE int32_t U_EXPORT2
1505 uspoof_areConfusableUnicodeString(const USpoofChecker *sc,
1506                                   const icu::UnicodeString &s1,
1507                                   const icu::UnicodeString &s2,
1508                                   UErrorCode *status);
1509 
1510 /**
1511  *  Get the "skeleton" for an identifier.
1512  *  Skeletons are a transformation of the input identifier;
1513  *  Two identifiers are confusable if their skeletons are identical.
1514  *  See Unicode UAX #39 for additional information.
1515  *
1516  *  Using skeletons directly makes it possible to quickly check
1517  *  whether an identifier is confusable with any of some large
1518  *  set of existing identifiers, by creating an efficiently
1519  *  searchable collection of the skeletons.
1520  *
1521  * @param sc      The USpoofChecker.
1522  * @param type    Deprecated in ICU 58.  You may pass any number.
1523  *                Originally, controlled which of the Unicode confusable data
1524  *                tables to use.
1525  * @param id      The input identifier whose skeleton will be computed.
1526  * @param dest    The output identifier, to receive the skeleton string.
1527  * @param status  The error code, set if an error occurred while attempting to
1528  *                perform the check.
1529  * @return        A reference to the destination (skeleton) string.
1530  *
1531  * @stable ICU 4.2
1532  */
1533 U_I18N_API icu::UnicodeString & U_EXPORT2
1534 uspoof_getSkeletonUnicodeString(const USpoofChecker *sc,
1535                                 uint32_t type,
1536                                 const icu::UnicodeString &id,
1537                                 icu::UnicodeString &dest,
1538                                 UErrorCode *status);
1539 
1540 /**
1541   * Get the set of Candidate Characters for Inclusion in Identifiers, as defined
1542   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1543   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1544   *
1545   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1546   * be deleted by the caller.
1547   *
1548   * @param status The error code, set if a problem occurs while creating the set.
1549   *
1550   * @stable ICU 51
1551   */
1552 U_STABLE const icu::UnicodeSet * U_EXPORT2
1553 uspoof_getInclusionUnicodeSet(UErrorCode *status);
1554 
1555 /**
1556   * Get the set of characters from Recommended Scripts for Inclusion in Identifiers, as defined
1557   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1558   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1559   *
1560   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1561   * be deleted by the caller.
1562   *
1563   * @param status The error code, set if a problem occurs while creating the set.
1564   *
1565   * @stable ICU 51
1566   */
1567 U_STABLE const icu::UnicodeSet * U_EXPORT2
1568 uspoof_getRecommendedUnicodeSet(UErrorCode *status);
1569 
1570 #endif /* U_SHOW_CPLUSPLUS_API */
1571 
1572 #endif /* UCONFIG_NO_NORMALIZATION */
1573 
1574 #endif   /* USPOOF_H */
1575