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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 
26 #if !UCONFIG_NO_NORMALIZATION
27 
28 
29 #if U_SHOW_CPLUSPLUS_API
30 #include "unicode/localpointer.h"
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_CAPI 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_CAPI 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_CAPI 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_CAPI 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_CAPI 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,
695  * OR together only the bit constants for the desired checks.
696  * For example, to fail strings containing characters outside of
697  * the set specified by {@link uspoof_setAllowedChars} and
698  * also strings that contain digits from mixed numbering systems:
699  *
700  * <pre>
701  * {@code
702  * uspoof_setChecks(USPOOF_CHAR_LIMIT | USPOOF_MIXED_NUMBERS);
703  * }
704  * </pre>
705  *
706  * To disable specific checks and enable all others,
707  * start with ALL_CHECKS and "AND away" the not-desired checks.
708  * For example, if you are not planning to use the {@link uspoof_areConfusable} functionality,
709  * it is good practice to disable the CONFUSABLE check:
710  *
711  * <pre>
712  * {@code
713  * uspoof_setChecks(USPOOF_ALL_CHECKS & ~USPOOF_CONFUSABLE);
714  * }
715  * </pre>
716  *
717  * Note that methods such as {@link uspoof_setAllowedChars}, {@link uspoof_setAllowedLocales}, and
718  * {@link uspoof_setRestrictionLevel} will enable certain checks when called. Those methods will OR the check they
719  * enable onto the existing bitmask specified by this method. For more details, see the documentation of those
720  * methods.
721  *
722  * @param sc       The USpoofChecker
723  * @param checks         The set of checks that this spoof checker will perform.
724  *                 The value is a bit set, obtained by OR-ing together
725  *                 values from enum USpoofChecks.
726  * @param status   The error code, set if this function encounters a problem.
727  * @stable ICU 4.2
728  *
729  */
730 U_CAPI void U_EXPORT2
731 uspoof_setChecks(USpoofChecker *sc, int32_t checks, UErrorCode *status);
732 
733 /**
734  * Get the set of checks that this Spoof Checker has been configured to perform.
735  *
736  * @param sc       The USpoofChecker
737  * @param status   The error code, set if this function encounters a problem.
738  * @return         The set of checks that this spoof checker will perform.
739  *                 The value is a bit set, obtained by OR-ing together
740  *                 values from enum USpoofChecks.
741  * @stable ICU 4.2
742  *
743  */
744 U_CAPI int32_t U_EXPORT2
745 uspoof_getChecks(const USpoofChecker *sc, UErrorCode *status);
746 
747 /**
748  * Set the loosest restriction level allowed for strings. The default if this is not called is
749  * {@link USPOOF_HIGHLY_RESTRICTIVE}. Calling this method enables the {@link USPOOF_RESTRICTION_LEVEL} and
750  * {@link USPOOF_MIXED_NUMBERS} checks, corresponding to Sections 5.1 and 5.2 of UTS 39. To customize which checks are
751  * to be performed by {@link uspoof_check}, see {@link uspoof_setChecks}.
752  *
753  * @param sc       The USpoofChecker
754  * @param restrictionLevel The loosest restriction level allowed.
755  * @see URestrictionLevel
756  * @stable ICU 51
757  */
758 U_CAPI void U_EXPORT2
759 uspoof_setRestrictionLevel(USpoofChecker *sc, URestrictionLevel restrictionLevel);
760 
761 
762 /**
763   * Get the Restriction Level that will be tested if the checks include {@link USPOOF_RESTRICTION_LEVEL}.
764   *
765   * @return The restriction level
766   * @see URestrictionLevel
767   * @stable ICU 51
768   */
769 U_CAPI URestrictionLevel U_EXPORT2
770 uspoof_getRestrictionLevel(const USpoofChecker *sc);
771 
772 /**
773  * Limit characters that are acceptable in identifiers being checked to those
774  * normally used with the languages associated with the specified locales.
775  * Any previously specified list of locales is replaced by the new settings.
776  *
777  * A set of languages is determined from the locale(s), and
778  * from those a set of acceptable Unicode scripts is determined.
779  * Characters from this set of scripts, along with characters from
780  * the "common" and "inherited" Unicode Script categories
781  * will be permitted.
782  *
783  * Supplying an empty string removes all restrictions;
784  * characters from any script will be allowed.
785  *
786  * The {@link USPOOF_CHAR_LIMIT} test is automatically enabled for this
787  * USpoofChecker when calling this function with a non-empty list
788  * of locales.
789  *
790  * The Unicode Set of characters that will be allowed is accessible
791  * via the uspoof_getAllowedChars() function.  uspoof_setAllowedLocales()
792  * will <i>replace</i> any previously applied set of allowed characters.
793  *
794  * Adjustments, such as additions or deletions of certain classes of characters,
795  * can be made to the result of uspoof_setAllowedLocales() by
796  * fetching the resulting set with uspoof_getAllowedChars(),
797  * manipulating it with the Unicode Set API, then resetting the
798  * spoof detectors limits with uspoof_setAllowedChars().
799  *
800  * @param sc           The USpoofChecker
801  * @param localesList  A list list of locales, from which the language
802  *                     and associated script are extracted.  The locales
803  *                     are comma-separated if there is more than one.
804  *                     White space may not appear within an individual locale,
805  *                     but is ignored otherwise.
806  *                     The locales are syntactically like those from the
807  *                     HTTP Accept-Language header.
808  *                     If the localesList is empty, no restrictions will be placed on
809  *                     the allowed characters.
810  *
811  * @param status       The error code, set if this function encounters a problem.
812  * @stable ICU 4.2
813  */
814 U_CAPI void U_EXPORT2
815 uspoof_setAllowedLocales(USpoofChecker *sc, const char *localesList, UErrorCode *status);
816 
817 /**
818  * Get a list of locales for the scripts that are acceptable in strings
819  *  to be checked.  If no limitations on scripts have been specified,
820  *  an empty string will be returned.
821  *
822  *  uspoof_setAllowedChars() will reset the list of allowed to be empty.
823  *
824  *  The format of the returned list is the same as that supplied to
825  *  uspoof_setAllowedLocales(), but returned list may not be identical
826  *  to the originally specified string; the string may be reformatted,
827  *  and information other than languages from
828  *  the originally specified locales may be omitted.
829  *
830  * @param sc           The USpoofChecker
831  * @param status       The error code, set if this function encounters a problem.
832  * @return             A string containing a list of  locales corresponding
833  *                     to the acceptable scripts, formatted like an
834  *                     HTTP Accept Language value.
835  *
836  * @stable ICU 4.2
837  */
838 U_CAPI const char * U_EXPORT2
839 uspoof_getAllowedLocales(USpoofChecker *sc, UErrorCode *status);
840 
841 
842 /**
843  * Limit the acceptable characters to those specified by a Unicode Set.
844  *   Any previously specified character limit is
845  *   is replaced by the new settings.  This includes limits on
846  *   characters that were set with the uspoof_setAllowedLocales() function.
847  *
848  * The USPOOF_CHAR_LIMIT test is automatically enabled for this
849  * USpoofChecker by this function.
850  *
851  * @param sc       The USpoofChecker
852  * @param chars    A Unicode Set containing the list of
853  *                 characters that are permitted.  Ownership of the set
854  *                 remains with the caller.  The incoming set is cloned by
855  *                 this function, so there are no restrictions on modifying
856  *                 or deleting the USet after calling this function.
857  * @param status   The error code, set if this function encounters a problem.
858  * @stable ICU 4.2
859  */
860 U_CAPI void U_EXPORT2
861 uspoof_setAllowedChars(USpoofChecker *sc, const USet *chars, UErrorCode *status);
862 
863 
864 /**
865  * Get a USet for the characters permitted in an identifier.
866  * This corresponds to the limits imposed by the Set Allowed Characters
867  * functions. Limitations imposed by other checks will not be
868  * reflected in the set returned by this function.
869  *
870  * The returned set will be frozen, meaning that it cannot be modified
871  * by the caller.
872  *
873  * Ownership of the returned set remains with the Spoof Detector.  The
874  * returned set will become invalid if the spoof detector is closed,
875  * or if a new set of allowed characters is specified.
876  *
877  *
878  * @param sc       The USpoofChecker
879  * @param status   The error code, set if this function encounters a problem.
880  * @return         A USet containing the characters that are permitted by
881  *                 the USPOOF_CHAR_LIMIT test.
882  * @stable ICU 4.2
883  */
884 U_CAPI const USet * U_EXPORT2
885 uspoof_getAllowedChars(const USpoofChecker *sc, UErrorCode *status);
886 
887 
888 /**
889  * Check the specified string for possible security issues.
890  * The text to be checked will typically be an identifier of some sort.
891  * The set of checks to be performed is specified with uspoof_setChecks().
892  *
893  * \note
894  *   Consider using the newer API, {@link uspoof_check2}, instead.
895  *   The newer API exposes additional information from the check procedure
896  *   and is otherwise identical to this method.
897  *
898  * @param sc      The USpoofChecker
899  * @param id      The identifier to be checked for possible security issues,
900  *                in UTF-16 format.
901  * @param length  the length of the string to be checked, expressed in
902  *                16 bit UTF-16 code units, or -1 if the string is
903  *                zero terminated.
904  * @param position  Deprecated in ICU 51.  Always returns zero.
905  *                Originally, an out parameter for the index of the first
906  *                string position that failed a check.
907  *                This parameter may be NULL.
908  * @param status  The error code, set if an error occurred while attempting to
909  *                perform the check.
910  *                Spoofing or security issues detected with the input string are
911  *                not reported here, but through the function's return value.
912  * @return        An integer value with bits set for any potential security
913  *                or spoofing issues detected.  The bits are defined by
914  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
915  *                will be zero if the input string passes all of the
916  *                enabled checks.
917  * @see uspoof_check2
918  * @stable ICU 4.2
919  */
920 U_CAPI int32_t U_EXPORT2
921 uspoof_check(const USpoofChecker *sc,
922                          const UChar *id, int32_t length,
923                          int32_t *position,
924                          UErrorCode *status);
925 
926 
927 /**
928  * Check the specified string for possible security issues.
929  * The text to be checked will typically be an identifier of some sort.
930  * The set of checks to be performed is specified with uspoof_setChecks().
931  *
932  * \note
933  *   Consider using the newer API, {@link uspoof_check2UTF8}, instead.
934  *   The newer API exposes additional information from the check procedure
935  *   and is otherwise identical to this method.
936  *
937  * @param sc      The USpoofChecker
938  * @param id      A identifier to be checked for possible security issues, in UTF8 format.
939  * @param length  the length of the string to be checked, or -1 if the string is
940  *                zero terminated.
941  * @param position  Deprecated in ICU 51.  Always returns zero.
942  *                Originally, an out parameter for the index of the first
943  *                string position that failed a check.
944  *                This parameter may be NULL.
945  * @param status  The error code, set if an error occurred while attempting to
946  *                perform the check.
947  *                Spoofing or security issues detected with the input string are
948  *                not reported here, but through the function's return value.
949  *                If the input contains invalid UTF-8 sequences,
950  *                a status of U_INVALID_CHAR_FOUND will be returned.
951  * @return        An integer value with bits set for any potential security
952  *                or spoofing issues detected.  The bits are defined by
953  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
954  *                will be zero if the input string passes all of the
955  *                enabled checks.
956  * @see uspoof_check2UTF8
957  * @stable ICU 4.2
958  */
959 U_CAPI int32_t U_EXPORT2
960 uspoof_checkUTF8(const USpoofChecker *sc,
961                  const char *id, int32_t length,
962                  int32_t *position,
963                  UErrorCode *status);
964 
965 
966 /**
967  * Check the specified string for possible security issues.
968  * The text to be checked will typically be an identifier of some sort.
969  * The set of checks to be performed is specified with uspoof_setChecks().
970  *
971  * @param sc      The USpoofChecker
972  * @param id      The identifier to be checked for possible security issues,
973  *                in UTF-16 format.
974  * @param length  the length of the string to be checked, or -1 if the string is
975  *                zero terminated.
976  * @param checkResult  An instance of USpoofCheckResult to be filled with
977  *                details about the identifier.  Can be NULL.
978  * @param status  The error code, set if an error occurred while attempting to
979  *                perform the check.
980  *                Spoofing or security issues detected with the input string are
981  *                not reported here, but through the function's return value.
982  * @return        An integer value with bits set for any potential security
983  *                or spoofing issues detected.  The bits are defined by
984  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
985  *                will be zero if the input string passes all of the
986  *                enabled checks.  Any information in this bitmask will be
987  *                consistent with the information saved in the optional
988  *                checkResult parameter.
989  * @see uspoof_openCheckResult
990  * @see uspoof_check2UTF8
991  * @see uspoof_check2UnicodeString
992  * @stable ICU 58
993  */
994 U_CAPI int32_t U_EXPORT2
995 uspoof_check2(const USpoofChecker *sc,
996     const UChar* id, int32_t length,
997     USpoofCheckResult* checkResult,
998     UErrorCode *status);
999 
1000 /**
1001  * Check the specified string for possible security issues.
1002  * The text to be checked will typically be an identifier of some sort.
1003  * The set of checks to be performed is specified with uspoof_setChecks().
1004  *
1005  * This version of {@link uspoof_check} accepts a USpoofCheckResult, which
1006  * returns additional information about the identifier.  For more
1007  * information, see {@link uspoof_openCheckResult}.
1008  *
1009  * @param sc      The USpoofChecker
1010  * @param id      A identifier to be checked for possible security issues, in UTF8 format.
1011  * @param length  the length of the string to be checked, or -1 if the string is
1012  *                zero terminated.
1013  * @param checkResult  An instance of USpoofCheckResult to be filled with
1014  *                details about the identifier.  Can be NULL.
1015  * @param status  The error code, set if an error occurred while attempting to
1016  *                perform the check.
1017  *                Spoofing or security issues detected with the input string are
1018  *                not reported here, but through the function's return value.
1019  * @return        An integer value with bits set for any potential security
1020  *                or spoofing issues detected.  The bits are defined by
1021  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1022  *                will be zero if the input string passes all of the
1023  *                enabled checks.  Any information in this bitmask will be
1024  *                consistent with the information saved in the optional
1025  *                checkResult parameter.
1026  * @see uspoof_openCheckResult
1027  * @see uspoof_check2
1028  * @see uspoof_check2UnicodeString
1029  * @stable ICU 58
1030  */
1031 U_CAPI int32_t U_EXPORT2
1032 uspoof_check2UTF8(const USpoofChecker *sc,
1033     const char *id, int32_t length,
1034     USpoofCheckResult* checkResult,
1035     UErrorCode *status);
1036 
1037 /**
1038  * Create a USpoofCheckResult, used by the {@link uspoof_check2} class of functions to return
1039  * information about the identifier.  Information includes:
1040  * <ul>
1041  *   <li>A bitmask of the checks that failed</li>
1042  *   <li>The identifier's restriction level (UTS 39 section 5.2)</li>
1043  *   <li>The set of numerics in the string (UTS 39 section 5.3)</li>
1044  * </ul>
1045  * The data held in a USpoofCheckResult is cleared whenever it is passed into a new call
1046  * of {@link uspoof_check2}.
1047  *
1048  * @param status  The error code, set if this function encounters a problem.
1049  * @return        the newly created USpoofCheckResult
1050  * @see uspoof_check2
1051  * @see uspoof_check2UTF8
1052  * @see uspoof_check2UnicodeString
1053  * @stable ICU 58
1054  */
1055 U_CAPI USpoofCheckResult* U_EXPORT2
1056 uspoof_openCheckResult(UErrorCode *status);
1057 
1058 /**
1059  * Close a USpoofCheckResult, freeing any memory that was being held by
1060  *   its implementation.
1061  *
1062  * @param checkResult  The instance of USpoofCheckResult to close
1063  * @stable ICU 58
1064  */
1065 U_CAPI void U_EXPORT2
1066 uspoof_closeCheckResult(USpoofCheckResult *checkResult);
1067 
1068 /**
1069  * Indicates which of the spoof check(s) have failed. The value is a bitwise OR of the constants for the tests
1070  * in question: USPOOF_RESTRICTION_LEVEL, USPOOF_CHAR_LIMIT, and so on.
1071  *
1072  * @param checkResult  The instance of USpoofCheckResult created by {@link uspoof_openCheckResult}
1073  * @param status       The error code, set if an error occurred.
1074  * @return        An integer value with bits set for any potential security
1075  *                or spoofing issues detected.  The bits are defined by
1076  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1077  *                will be zero if the input string passes all of the
1078  *                enabled checks.
1079  * @see uspoof_setChecks
1080  * @stable ICU 58
1081  */
1082 U_CAPI int32_t U_EXPORT2
1083 uspoof_getCheckResultChecks(const USpoofCheckResult *checkResult, UErrorCode *status);
1084 
1085 /**
1086  * Gets the restriction level that the text meets, if the USPOOF_RESTRICTION_LEVEL check
1087  * was enabled; otherwise, undefined.
1088  *
1089  * @param checkResult  The instance of USpoofCheckResult created by {@link uspoof_openCheckResult}
1090  * @param status       The error code, set if an error occurred.
1091  * @return             The restriction level contained in the USpoofCheckResult
1092  * @see uspoof_setRestrictionLevel
1093  * @stable ICU 58
1094  */
1095 U_CAPI URestrictionLevel U_EXPORT2
1096 uspoof_getCheckResultRestrictionLevel(const USpoofCheckResult *checkResult, UErrorCode *status);
1097 
1098 /**
1099  * Gets the set of numerics found in the string, if the USPOOF_MIXED_NUMBERS check was enabled;
1100  * otherwise, undefined.  The set will contain the zero digit from each decimal number system found
1101  * in the input string.  Ownership of the returned USet remains with the USpoofCheckResult.
1102  * The USet will be free'd when {@link uspoof_closeCheckResult} is called.
1103  *
1104  * @param checkResult  The instance of USpoofCheckResult created by {@link uspoof_openCheckResult}
1105  * @return             The set of numerics contained in the USpoofCheckResult
1106  * @param status       The error code, set if an error occurred.
1107  * @stable ICU 58
1108  */
1109 U_CAPI const USet* U_EXPORT2
1110 uspoof_getCheckResultNumerics(const USpoofCheckResult *checkResult, UErrorCode *status);
1111 
1112 
1113 /**
1114  * Check the whether two specified strings are visually confusable.
1115  *
1116  * If the strings are confusable, the return value will be nonzero, as long as
1117  * {@link USPOOF_CONFUSABLE} was enabled in uspoof_setChecks().
1118  *
1119  * The bits in the return value correspond to flags for each of the classes of
1120  * confusables applicable to the two input strings.  According to UTS 39
1121  * section 4, the possible flags are:
1122  *
1123  * <ul>
1124  *   <li>{@link USPOOF_SINGLE_SCRIPT_CONFUSABLE}</li>
1125  *   <li>{@link USPOOF_MIXED_SCRIPT_CONFUSABLE}</li>
1126  *   <li>{@link USPOOF_WHOLE_SCRIPT_CONFUSABLE}</li>
1127  * </ul>
1128  *
1129  * If one or more of the above flags were not listed in uspoof_setChecks(), this
1130  * function will never report that class of confusable.  The check
1131  * {@link USPOOF_CONFUSABLE} enables all three flags.
1132  *
1133  *
1134  * @param sc      The USpoofChecker
1135  * @param id1     The first of the two identifiers to be compared for
1136  *                confusability.  The strings are in UTF-16 format.
1137  * @param length1 the length of the first identifer, expressed in
1138  *                16 bit UTF-16 code units, or -1 if the string is
1139  *                nul terminated.
1140  * @param id2     The second of the two identifiers to be compared for
1141  *                confusability.  The identifiers are in UTF-16 format.
1142  * @param length2 The length of the second identifiers, expressed in
1143  *                16 bit UTF-16 code units, or -1 if the string is
1144  *                nul terminated.
1145  * @param status  The error code, set if an error occurred while attempting to
1146  *                perform the check.
1147  *                Confusability of the identifiers is not reported here,
1148  *                but through this function's return value.
1149  * @return        An integer value with bit(s) set corresponding to
1150  *                the type of confusability found, as defined by
1151  *                enum USpoofChecks.  Zero is returned if the identifiers
1152  *                are not confusable.
1153  *
1154  * @stable ICU 4.2
1155  */
1156 U_CAPI int32_t U_EXPORT2
1157 uspoof_areConfusable(const USpoofChecker *sc,
1158                      const UChar *id1, int32_t length1,
1159                      const UChar *id2, int32_t length2,
1160                      UErrorCode *status);
1161 
1162 
1163 
1164 /**
1165  * A version of {@link uspoof_areConfusable} accepting strings in UTF-8 format.
1166  *
1167  * @param sc      The USpoofChecker
1168  * @param id1     The first of the two identifiers to be compared for
1169  *                confusability.  The strings are in UTF-8 format.
1170  * @param length1 the length of the first identifiers, in bytes, or -1
1171  *                if the string is nul terminated.
1172  * @param id2     The second of the two identifiers to be compared for
1173  *                confusability.  The strings are in UTF-8 format.
1174  * @param length2 The length of the second string in bytes, or -1
1175  *                if the string is nul terminated.
1176  * @param status  The error code, set if an error occurred while attempting to
1177  *                perform the check.
1178  *                Confusability of the strings is not reported here,
1179  *                but through this function's return value.
1180  * @return        An integer value with bit(s) set corresponding to
1181  *                the type of confusability found, as defined by
1182  *                enum USpoofChecks.  Zero is returned if the strings
1183  *                are not confusable.
1184  *
1185  * @stable ICU 4.2
1186  *
1187  * @see uspoof_areConfusable
1188  */
1189 U_CAPI int32_t U_EXPORT2
1190 uspoof_areConfusableUTF8(const USpoofChecker *sc,
1191                          const char *id1, int32_t length1,
1192                          const char *id2, int32_t length2,
1193                          UErrorCode *status);
1194 
1195 
1196 
1197 
1198 /**
1199  *  Get the "skeleton" for an identifier.
1200  *  Skeletons are a transformation of the input identifier;
1201  * Two identifiers are confusable if their skeletons are identical.
1202  *  See Unicode UAX #39 for additional information.
1203  *
1204  *  Using skeletons directly makes it possible to quickly check
1205  *  whether an identifier is confusable with any of some large
1206  *  set of existing identifiers, by creating an efficiently
1207  *  searchable collection of the skeletons.
1208  *
1209  * @param sc      The USpoofChecker
1210  * @param type    Deprecated in ICU 58.  You may pass any number.
1211  *                Originally, controlled which of the Unicode confusable data
1212  *                tables to use.
1213  * @param id      The input identifier whose skeleton will be computed.
1214  * @param length  The length of the input identifier, expressed in 16 bit
1215  *                UTF-16 code units, or -1 if the string is zero terminated.
1216  * @param dest    The output buffer, to receive the skeleton string.
1217  * @param destCapacity  The length of the output buffer, in 16 bit units.
1218  *                The destCapacity may be zero, in which case the function will
1219  *                return the actual length of the skeleton.
1220  * @param status  The error code, set if an error occurred while attempting to
1221  *                perform the check.
1222  * @return        The length of the skeleton string.  The returned length
1223  *                is always that of the complete skeleton, even when the
1224  *                supplied buffer is too small (or of zero length)
1225  *
1226  * @stable ICU 4.2
1227  * @see uspoof_areConfusable
1228  */
1229 U_CAPI int32_t U_EXPORT2
1230 uspoof_getSkeleton(const USpoofChecker *sc,
1231                    uint32_t type,
1232                    const UChar *id,  int32_t length,
1233                    UChar *dest, int32_t destCapacity,
1234                    UErrorCode *status);
1235 
1236 /**
1237  *  Get the "skeleton" for an identifier.
1238  *  Skeletons are a transformation of the input identifier;
1239  *  Two identifiers are confusable if their skeletons are identical.
1240  *  See Unicode UAX #39 for additional information.
1241  *
1242  *  Using skeletons directly makes it possible to quickly check
1243  *  whether an identifier is confusable with any of some large
1244  *  set of existing identifiers, by creating an efficiently
1245  *  searchable collection of the skeletons.
1246  *
1247  * @param sc      The USpoofChecker
1248  * @param type    Deprecated in ICU 58.  You may pass any number.
1249  *                Originally, controlled which of the Unicode confusable data
1250  *                tables to use.
1251  * @param id      The UTF-8 format identifier whose skeleton will be computed.
1252  * @param length  The length of the input string, in bytes,
1253  *                or -1 if the string is zero terminated.
1254  * @param dest    The output buffer, to receive the skeleton string.
1255  * @param destCapacity  The length of the output buffer, in bytes.
1256  *                The destCapacity may be zero, in which case the function will
1257  *                return the actual length of the skeleton.
1258  * @param status  The error code, set if an error occurred while attempting to
1259  *                perform the check.  Possible Errors include U_INVALID_CHAR_FOUND
1260  *                   for invalid UTF-8 sequences, and
1261  *                   U_BUFFER_OVERFLOW_ERROR if the destination buffer is too small
1262  *                   to hold the complete skeleton.
1263  * @return        The length of the skeleton string, in bytes.  The returned length
1264  *                is always that of the complete skeleton, even when the
1265  *                supplied buffer is too small (or of zero length)
1266  *
1267  * @stable ICU 4.2
1268  */
1269 U_CAPI int32_t U_EXPORT2
1270 uspoof_getSkeletonUTF8(const USpoofChecker *sc,
1271                        uint32_t type,
1272                        const char *id,  int32_t length,
1273                        char *dest, int32_t destCapacity,
1274                        UErrorCode *status);
1275 
1276 /**
1277   * Get the set of Candidate Characters for Inclusion in Identifiers, as defined
1278   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1279   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1280   *
1281   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1282   * be deleted by the caller.
1283   *
1284   * @param status The error code, set if a problem occurs while creating the set.
1285   *
1286   * @stable ICU 51
1287   */
1288 U_CAPI const USet * U_EXPORT2
1289 uspoof_getInclusionSet(UErrorCode *status);
1290 
1291 /**
1292   * Get the set of characters from Recommended Scripts for Inclusion in Identifiers, as defined
1293   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1294   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1295   *
1296   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1297   * be deleted by the caller.
1298   *
1299   * @param status The error code, set if a problem occurs while creating the set.
1300   *
1301   * @stable ICU 51
1302   */
1303 U_CAPI const USet * U_EXPORT2
1304 uspoof_getRecommendedSet(UErrorCode *status);
1305 
1306 /**
1307  * Serialize the data for a spoof detector into a chunk of memory.
1308  * The flattened spoof detection tables can later be used to efficiently
1309  * instantiate a new Spoof Detector.
1310  *
1311  * The serialized spoof checker includes only the data compiled from the
1312  * Unicode data tables by uspoof_openFromSource(); it does not include
1313  * include any other state or configuration that may have been set.
1314  *
1315  * @param sc   the Spoof Detector whose data is to be serialized.
1316  * @param data a pointer to 32-bit-aligned memory to be filled with the data,
1317  *             can be NULL if capacity==0
1318  * @param capacity the number of bytes available at data,
1319  *                 or 0 for preflighting
1320  * @param status an in/out ICU UErrorCode; possible errors include:
1321  * - U_BUFFER_OVERFLOW_ERROR if the data storage block is too small for serialization
1322  * - U_ILLEGAL_ARGUMENT_ERROR  the data or capacity parameters are bad
1323  * @return the number of bytes written or needed for the spoof data
1324  *
1325  * @see utrie2_openFromSerialized()
1326  * @stable ICU 4.2
1327  */
1328 U_CAPI int32_t U_EXPORT2
1329 uspoof_serialize(USpoofChecker *sc,
1330                  void *data, int32_t capacity,
1331                  UErrorCode *status);
1332 
1333 U_CDECL_END
1334 
1335 #if U_SHOW_CPLUSPLUS_API
1336 
1337 U_NAMESPACE_BEGIN
1338 
1339 /**
1340  * \class LocalUSpoofCheckerPointer
1341  * "Smart pointer" class, closes a USpoofChecker via uspoof_close().
1342  * For most methods see the LocalPointerBase base class.
1343  *
1344  * @see LocalPointerBase
1345  * @see LocalPointer
1346  * @stable ICU 4.4
1347  */
1348 /**
1349  * \cond
1350  * Note: Doxygen is giving a bogus warning on this U_DEFINE_LOCAL_OPEN_POINTER.
1351  *       For now, suppress with a Doxygen cond
1352  */
1353 U_DEFINE_LOCAL_OPEN_POINTER(LocalUSpoofCheckerPointer, USpoofChecker, uspoof_close);
1354 /** \endcond */
1355 
1356 /**
1357  * \class LocalUSpoofCheckResultPointer
1358  * "Smart pointer" class, closes a USpoofCheckResult via `uspoof_closeCheckResult()`.
1359  * For most methods see the LocalPointerBase base class.
1360  *
1361  * @see LocalPointerBase
1362  * @see LocalPointer
1363  * @stable ICU 58
1364  */
1365 
1366 /**
1367  * \cond
1368  * Note: Doxygen is giving a bogus warning on this U_DEFINE_LOCAL_OPEN_POINTER.
1369  *       For now, suppress with a Doxygen cond
1370  */
1371 U_DEFINE_LOCAL_OPEN_POINTER(LocalUSpoofCheckResultPointer, USpoofCheckResult, uspoof_closeCheckResult);
1372 /** \endcond */
1373 
1374 U_NAMESPACE_END
1375 
1376 /**
1377  * Limit the acceptable characters to those specified by a Unicode Set.
1378  *   Any previously specified character limit is
1379  *   is replaced by the new settings.    This includes limits on
1380  *   characters that were set with the uspoof_setAllowedLocales() function.
1381  *
1382  * The USPOOF_CHAR_LIMIT test is automatically enabled for this
1383  * USoofChecker by this function.
1384  *
1385  * @param sc       The USpoofChecker
1386  * @param chars    A Unicode Set containing the list of
1387  *                 characters that are permitted.  Ownership of the set
1388  *                 remains with the caller.  The incoming set is cloned by
1389  *                 this function, so there are no restrictions on modifying
1390  *                 or deleting the UnicodeSet after calling this function.
1391  * @param status   The error code, set if this function encounters a problem.
1392  * @stable ICU 4.2
1393  */
1394 U_CAPI void U_EXPORT2
1395 uspoof_setAllowedUnicodeSet(USpoofChecker *sc, const icu::UnicodeSet *chars, UErrorCode *status);
1396 
1397 
1398 /**
1399  * Get a UnicodeSet for the characters permitted in an identifier.
1400  * This corresponds to the limits imposed by the Set Allowed Characters /
1401  * UnicodeSet functions. Limitations imposed by other checks will not be
1402  * reflected in the set returned by this function.
1403  *
1404  * The returned set will be frozen, meaning that it cannot be modified
1405  * by the caller.
1406  *
1407  * Ownership of the returned set remains with the Spoof Detector.  The
1408  * returned set will become invalid if the spoof detector is closed,
1409  * or if a new set of allowed characters is specified.
1410  *
1411  *
1412  * @param sc       The USpoofChecker
1413  * @param status   The error code, set if this function encounters a problem.
1414  * @return         A UnicodeSet containing the characters that are permitted by
1415  *                 the USPOOF_CHAR_LIMIT test.
1416  * @stable ICU 4.2
1417  */
1418 U_CAPI const icu::UnicodeSet * U_EXPORT2
1419 uspoof_getAllowedUnicodeSet(const USpoofChecker *sc, UErrorCode *status);
1420 
1421 /**
1422  * Check the specified string for possible security issues.
1423  * The text to be checked will typically be an identifier of some sort.
1424  * The set of checks to be performed is specified with uspoof_setChecks().
1425  *
1426  * \note
1427  *   Consider using the newer API, {@link uspoof_check2UnicodeString}, instead.
1428  *   The newer API exposes additional information from the check procedure
1429  *   and is otherwise identical to this method.
1430  *
1431  * @param sc      The USpoofChecker
1432  * @param id      A identifier to be checked for possible security issues.
1433  * @param position  Deprecated in ICU 51.  Always returns zero.
1434  *                Originally, an out parameter for the index of the first
1435  *                string position that failed a check.
1436  *                This parameter may be NULL.
1437  * @param status  The error code, set if an error occurred while attempting to
1438  *                perform the check.
1439  *                Spoofing or security issues detected with the input string are
1440  *                not reported here, but through the function's return value.
1441  * @return        An integer value with bits set for any potential security
1442  *                or spoofing issues detected.  The bits are defined by
1443  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1444  *                will be zero if the input string passes all of the
1445  *                enabled checks.
1446  * @see uspoof_check2UnicodeString
1447  * @stable ICU 4.2
1448  */
1449 U_CAPI int32_t U_EXPORT2
1450 uspoof_checkUnicodeString(const USpoofChecker *sc,
1451                           const icu::UnicodeString &id,
1452                           int32_t *position,
1453                           UErrorCode *status);
1454 
1455 /**
1456  * Check the specified string for possible security issues.
1457  * The text to be checked will typically be an identifier of some sort.
1458  * The set of checks to be performed is specified with uspoof_setChecks().
1459  *
1460  * @param sc      The USpoofChecker
1461  * @param id      A identifier to be checked for possible security issues.
1462  * @param checkResult  An instance of USpoofCheckResult to be filled with
1463  *                details about the identifier.  Can be NULL.
1464  * @param status  The error code, set if an error occurred while attempting to
1465  *                perform the check.
1466  *                Spoofing or security issues detected with the input string are
1467  *                not reported here, but through the function's return value.
1468  * @return        An integer value with bits set for any potential security
1469  *                or spoofing issues detected.  The bits are defined by
1470  *                enum USpoofChecks.  (returned_value & USPOOF_ALL_CHECKS)
1471  *                will be zero if the input string passes all of the
1472  *                enabled checks.  Any information in this bitmask will be
1473  *                consistent with the information saved in the optional
1474  *                checkResult parameter.
1475  * @see uspoof_openCheckResult
1476  * @see uspoof_check2
1477  * @see uspoof_check2UTF8
1478  * @stable ICU 58
1479  */
1480 U_CAPI int32_t U_EXPORT2
1481 uspoof_check2UnicodeString(const USpoofChecker *sc,
1482     const icu::UnicodeString &id,
1483     USpoofCheckResult* checkResult,
1484     UErrorCode *status);
1485 
1486 /**
1487  * A version of {@link uspoof_areConfusable} accepting UnicodeStrings.
1488  *
1489  * @param sc      The USpoofChecker
1490  * @param s1     The first of the two identifiers to be compared for
1491  *                confusability.  The strings are in UTF-8 format.
1492  * @param s2     The second of the two identifiers to be compared for
1493  *                confusability.  The strings are in UTF-8 format.
1494  * @param status  The error code, set if an error occurred while attempting to
1495  *                perform the check.
1496  *                Confusability of the identifiers is not reported here,
1497  *                but through this function's return value.
1498  * @return        An integer value with bit(s) set corresponding to
1499  *                the type of confusability found, as defined by
1500  *                enum USpoofChecks.  Zero is returned if the identifiers
1501  *                are not confusable.
1502  *
1503  * @stable ICU 4.2
1504  *
1505  * @see uspoof_areConfusable
1506  */
1507 U_CAPI int32_t U_EXPORT2
1508 uspoof_areConfusableUnicodeString(const USpoofChecker *sc,
1509                                   const icu::UnicodeString &s1,
1510                                   const icu::UnicodeString &s2,
1511                                   UErrorCode *status);
1512 
1513 /**
1514  *  Get the "skeleton" for an identifier.
1515  *  Skeletons are a transformation of the input identifier;
1516  *  Two identifiers are confusable if their skeletons are identical.
1517  *  See Unicode UAX #39 for additional information.
1518  *
1519  *  Using skeletons directly makes it possible to quickly check
1520  *  whether an identifier is confusable with any of some large
1521  *  set of existing identifiers, by creating an efficiently
1522  *  searchable collection of the skeletons.
1523  *
1524  * @param sc      The USpoofChecker.
1525  * @param type    Deprecated in ICU 58.  You may pass any number.
1526  *                Originally, controlled which of the Unicode confusable data
1527  *                tables to use.
1528  * @param id      The input identifier whose skeleton will be computed.
1529  * @param dest    The output identifier, to receive the skeleton string.
1530  * @param status  The error code, set if an error occurred while attempting to
1531  *                perform the check.
1532  * @return        A reference to the destination (skeleton) string.
1533  *
1534  * @stable ICU 4.2
1535  */
1536 U_I18N_API icu::UnicodeString & U_EXPORT2
1537 uspoof_getSkeletonUnicodeString(const USpoofChecker *sc,
1538                                 uint32_t type,
1539                                 const icu::UnicodeString &id,
1540                                 icu::UnicodeString &dest,
1541                                 UErrorCode *status);
1542 
1543 /**
1544   * Get the set of Candidate Characters for Inclusion in Identifiers, as defined
1545   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1546   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1547   *
1548   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1549   * be deleted by the caller.
1550   *
1551   * @param status The error code, set if a problem occurs while creating the set.
1552   *
1553   * @stable ICU 51
1554   */
1555 U_CAPI const icu::UnicodeSet * U_EXPORT2
1556 uspoof_getInclusionUnicodeSet(UErrorCode *status);
1557 
1558 /**
1559   * Get the set of characters from Recommended Scripts for Inclusion in Identifiers, as defined
1560   * in http://unicode.org/Public/security/latest/xidmodifications.txt
1561   * and documented in http://www.unicode.org/reports/tr39/, Unicode Security Mechanisms.
1562   *
1563   * The returned set is frozen. Ownership of the set remains with the ICU library; it must not
1564   * be deleted by the caller.
1565   *
1566   * @param status The error code, set if a problem occurs while creating the set.
1567   *
1568   * @stable ICU 51
1569   */
1570 U_CAPI const icu::UnicodeSet * U_EXPORT2
1571 uspoof_getRecommendedUnicodeSet(UErrorCode *status);
1572 
1573 #endif /* U_SHOW_CPLUSPLUS_API */
1574 
1575 #endif /* UCONFIG_NO_NORMALIZATION */
1576 
1577 #endif   /* USPOOF_H */
1578