Home | History | Annotate | Download | only in unicode
      1 /*
      2 ***************************************************************************
      3 * Copyright (C) 2008-2010, International Business Machines Corporation
      4 * and others. All Rights Reserved.
      5 ***************************************************************************
      6 *   file name:  uspoof.h
      7 *   encoding:   US-ASCII
      8 *   tab size:   8 (not used)
      9 *   indentation:4
     10 *
     11 *   created on: 2008Feb13
     12 *   created by: Andy Heninger
     13 *
     14 *   Unicode Spoof Detection
     15 */
     16 
     17 #ifndef USPOOF_H
     18 #define USPOOF_H
     19 
     20 #include "unicode/utypes.h"
     21 #include "unicode/uset.h"
     22 #include "unicode/parseerr.h"
     23 #include "unicode/localpointer.h"
     24 
     25 #if !UCONFIG_NO_NORMALIZATION
     26 
     27 
     28 #if U_SHOW_CPLUSPLUS_API
     29 #include "unicode/unistr.h"
     30 #include "unicode/uniset.h"
     31 
     32 U_NAMESPACE_USE
     33 #endif
     34 
     35 
     36 /**
     37  * \file
     38  * \brief Unicode Security and Spoofing Detection, C API.
     39  *
     40  * These functions are intended to check strings, typically
     41  * identifiers of some type, such as URLs, for the presence of
     42  * characters that are likely to be visually confusing -
     43  * for cases where the displayed form of an identifier may
     44  * not be what it appears to be.
     45  *
     46  * Unicode Technical Report #36, http://unicode.org/reports/tr36, and
     47  * Unicode Technical Standard #39, http://unicode.org/reports/tr39
     48  * "Unicode security considerations", give more background on
     49  * security an spoofing issues with Unicode identifiers.
     50  * The tests and checks provided by this module implement the recommendations
     51  * from those Unicode documents.
     52  *
     53  * The tests available on identifiers fall into two general categories:
     54  *   -#  Single identifier tests.  Check whether an identifier is
     55  *       potentially confusable with any other string, or is suspicious
     56  *       for other reasons.
     57  *   -#  Two identifier tests.  Check whether two specific identifiers are confusable.
     58  *       This does not consider whether either of strings is potentially
     59  *       confusable with any string other than the exact one specified.
     60  *
     61  * The steps to perform confusability testing are
     62  *   -#  Open a USpoofChecker.
     63  *   -#  Configure the USPoofChecker for the desired set of tests.  The tests that will
     64  *       be performed are specified by a set of USpoofChecks flags.
     65  *   -#  Perform the checks using the pre-configured USpoofChecker.  The results indicate
     66  *       which (if any) of the selected tests have identified possible problems with the identifier.
     67  *       Results are reported as a set of USpoofChecks flags;  this mirrors the form in which
     68  *       the set of tests to perform was originally specified to the USpoofChecker.
     69  *
     70  * A USpoofChecker may be used repeatedly to perform checks on any number of identifiers.
     71  *
     72  * Thread Safety: The test functions for checking a single identifier, or for testing
     73  * whether two identifiers are possible confusable, are thread safe.
     74  * They may called concurrently, from multiple threads, using the same USpoofChecker instance.
     75  *
     76  * More generally, the standard ICU thread safety rules apply:  functions that take a
     77  * const USpoofChecker parameter are thread safe.  Those that take a non-const
     78  * USpoofChecier are not thread safe.
     79  *
     80  *
     81  * Descriptions of the available checks.
     82  *
     83  * When testing whether pairs of identifiers are confusable, with the uspoof_areConfusable()
     84  * family of functions, the relevant tests are
     85  *
     86  *   -# USPOOF_SINGLE_SCRIPT_CONFUSABLE:  All of the characters from the two identifiers are
     87  *      from a single script, and the two identifiers are visually confusable.
     88  *   -# USPOOF_MIXED_SCRIPT_CONFUSABLE:  At least one of the identifiers contains characters
     89  *      from more than one script, and the two identifiers are visually confusable.
     90  *   -# USPOOF_WHOLE_SCRIPT_CONFUSABLE: Each of the two identifiers is of a single script, but
     91  *      the two identifiers are from different scripts, and they are visually confusable.
     92  *
     93  * The safest approach is to enable all three of these checks as a group.
     94  *
     95  * USPOOF_ANY_CASE is a modifier for the above tests.  If the identifiers being checked can
     96  * be of mixed case and are used in a case-sensitive manner, this option should be specified.
     97  *
     98  * If the identifiers being checked are used in a case-insensitive manner, and if they are
     99  * displayed to users in lower-case form only, the USPOOF_ANY_CASE option should not be
    100  * specified.  Confusabality issues involving upper case letters will not be reported.
    101  *
    102  * When performing tests on a single identifier, with the uspoof_check() family of functions,
    103  * the relevant tests are:
    104  *
    105  *    -# USPOOF_MIXED_SCRIPT_CONFUSABLE: the identifier contains characters from multiple
    106  *       scripts, and there exists an identifier of a single script that is visually confusable.
    107  *    -# USPOOF_WHOLE_SCRIPT_CONFUSABLE: the identifier consists of characters from a single
    108  *       script, and there exists a visually confusable identifier.
    109  *       The visually confusable identifier also consists of characters from a single script.
    110  *       but not the same script as the identifier being checked.
    111  *    -# USPOOF_ANY_CASE: modifies the mixed script and whole script confusables tests.  If
    112  *       specified, the checks will consider confusable characters of any case.  If this flag is not
    113  *       set, the test is performed assuming case folded identifiers.
    114  *    -# USPOOF_SINGLE_SCRIPT: check that the identifier contains only characters from a
    115  *       single script.  (Characters from the 'common' and 'inherited' scripts are ignored.)
    116  *       This is not a test for confusable identifiers
    117  *    -# USPOOF_INVISIBLE: check an identifier for the presence of invisible characters,
    118  *       such as zero-width spaces, or character sequences that are
    119  *       likely not to display, such as multiple occurrences of the same
    120  *       non-spacing mark.  This check does not test the input string as a whole
    121  *       for conformance to any particular syntax for identifiers.
    122  *    -# USPOOF_CHAR_LIMIT: check that an identifier contains only characters from a specified set
    123  *       of acceptable characters.  See uspoof_setAllowedChars() and
    124  *       uspoof_setAllowedLocales().
    125  *
    126  *  Note on Scripts:
    127  *     Characters from the Unicode Scripts "Common" and "Inherited" are ignored when considering
    128  *     the script of an identifier. Common characters include digits and symbols that
    129  *     are normally used with text from more than one script.
    130  *
    131  *  Identifier Skeletons:  A skeleton is a transformation of an identifier, such that
    132  *  all identifiers that are confusable with each other have the same skeleton.
    133  *  Using skeletons, it is possible to build a dictionary data structure for
    134  *  a set of identifiers, and then quickly test whether a new identifier is
    135  *  confusable with an identifier already in the set.  The uspoof_getSkeleton()
    136  *  family of functions will produce the skeleton from an identifier.
    137  *
    138  *  Note that skeletons are not guaranteed to be stable between versions
    139  *  of Unicode or ICU, so an applications should not rely on creating a permanent,
    140  *  or difficult to update, database of skeletons.  Instabilities result from
    141  *  identifying new pairs or sequences of characters that are visually
    142  *  confusable, and thus must be mapped to the same skeleton character(s).
    143  *
    144  */
    145 
    146 struct USpoofChecker;
    147 typedef struct USpoofChecker USpoofChecker; /**< typedef for C of USpoofChecker */
    148 
    149 /**
    150  * Enum for the kinds of checks that USpoofChecker can perform.
    151  * These enum values are used both to select the set of checks that
    152  * will be performed, and to report results from the check function.
    153  *
    154  * @stable ICU 4.2
    155  */
    156 typedef enum USpoofChecks {
    157     /**   Single script confusable test.
    158       *   When testing whether two identifiers are confusable, report that they are if
    159       *   both are from the same script and they are visually confusable.
    160       *   Note: this test is not applicable to a check of a single identifier.
    161       */
    162     USPOOF_SINGLE_SCRIPT_CONFUSABLE =   1,
    163 
    164     /** Mixed script confusable test.
    165      *  When checking a single identifier, report a problem if
    166      *    the identifier contains multiple scripts, and
    167      *    is confusable with some other identifier in a single script
    168      *  When testing whether two identifiers are confusable, report that they are if
    169      *    the two IDs are visually confusable,
    170      *    and at least one contains characters from more than one script.
    171      */
    172     USPOOF_MIXED_SCRIPT_CONFUSABLE  =   2,
    173 
    174     /** Whole script confusable test.
    175      *  When checking a single identifier, report a problem if
    176      *    The identifier is of a single script, and
    177      *    there exists a confusable identifier in another script.
    178      *  When testing whether two identifiers are confusable, report that they are if
    179      *    each is of a single script,
    180      *    the scripts of the two identifiers are different, and
    181      *    the identifiers are visually confusable.
    182      */
    183     USPOOF_WHOLE_SCRIPT_CONFUSABLE  =   4,
    184 
    185     /** Any Case Modifier for confusable identifier tests.
    186         If specified, consider all characters, of any case, when looking for confusables.
    187         If USPOOF_ANY_CASE is not specified, identifiers being checked are assumed to have been
    188         case folded.  Upper case confusable characters will not be checked.
    189         Selects between Lower Case Confusable and
    190         Any Case Confusable.   */
    191     USPOOF_ANY_CASE                 =   8,
    192 
    193     /** Check that an identifier contains only characters from a
    194       * single script (plus chars from the common and inherited scripts.)
    195       * Applies to checks of a single identifier check only.
    196       */
    197     USPOOF_SINGLE_SCRIPT            =  16,
    198 
    199     /** Check an identifier for the presence of invisible characters,
    200       * such as zero-width spaces, or character sequences that are
    201       * likely not to display, such as multiple occurrences of the same
    202       * non-spacing mark.  This check does not test the input string as a whole
    203       * for conformance to any particular syntax for identifiers.
    204       */
    205     USPOOF_INVISIBLE                =  32,
    206 
    207     /** Check that an identifier contains only characters from a specified set
    208       * of acceptable characters.  See uspoof_setAllowedChars() and
    209       * uspoof_setAllowedLocales().
    210       */
    211     USPOOF_CHAR_LIMIT               =  64,
    212 
    213     USPOOF_ALL_CHECKS               = 0x7f
    214     } USpoofChecks;
    215 
    216 
    217 /**
    218  *  Create a Unicode Spoof Checker, configured to perform all
    219  *  checks except for USPOOF_LOCALE_LIMIT and USPOOF_CHAR_LIMIT.
    220  *  Note that additional checks may be added in the future,
    221  *  resulting in the changes to the default checking behavior.
    222  *
    223  *  @param status  The error code, set if this function encounters a problem.
    224  *  @return        the newly created Spoof Checker
    225  *  @stable ICU 4.2
    226  */
    227 U_STABLE USpoofChecker * U_EXPORT2
    228 uspoof_open(UErrorCode *status);
    229 
    230 
    231 /**
    232  * Open a Spoof checker from its serialized from, stored in 32-bit-aligned memory.
    233  * Inverse of uspoof_serialize().
    234  * The memory containing the serialized data must remain valid and unchanged
    235  * as long as the spoof checker, or any cloned copies of the spoof checker,
    236  * are in use.  Ownership of the memory remains with the caller.
    237  * The spoof checker (and any clones) must be closed prior to deleting the
    238  * serialized data.
    239  *
    240  * @param data a pointer to 32-bit-aligned memory containing the serialized form of spoof data
    241  * @param length the number of bytes available at data;
    242  *               can be more than necessary
    243  * @param pActualLength receives the actual number of bytes at data taken up by the data;
    244  *                      can be NULL
    245  * @param pErrorCode ICU error code
    246  * @return the spoof checker.
    247  *
    248  * @see uspoof_open
    249  * @see uspoof_serialize
    250  * @stable ICU 4.2
    251  */
    252 U_STABLE USpoofChecker * U_EXPORT2
    253 uspoof_openFromSerialized(const void *data, int32_t length, int32_t *pActualLength,
    254                           UErrorCode *pErrorCode);
    255 
    256 /**
    257   * Open a Spoof Checker from the source form of the spoof data.
    258   * The Three inputs correspond to the Unicode data files confusables.txt
    259   * confusablesWholeScript.txt and xidmdifications.txt as described in
    260   * Unicode UAX 39.  The syntax of the source data is as described in UAX 39 for
    261   * these files, and the content of these files is acceptable input.
    262   *
    263   * The character encoding of the (char *) input text is UTF-8.
    264   *
    265   * @param confusables a pointer to the confusable characters definitions,
    266   *                    as found in file confusables.txt from unicode.org.
    267   * @param confusablesLen The length of the confusables text, or -1 if the
    268   *                    input string is zero terminated.
    269   * @param confusablesWholeScript
    270   *                    a pointer to the whole script confusables definitions,
    271   *                    as found in the file confusablesWholeScript.txt from unicode.org.
    272   * @param confusablesWholeScriptLen The length of the whole script confusables text, or
    273   *                    -1 if the input string is zero terminated.
    274   * @param errType     In the event of an error in the input, indicates
    275   *                    which of the input files contains the error.
    276   *                    The value is one of USPOOF_SINGLE_SCRIPT_CONFUSABLE or
    277   *                    USPOOF_WHOLE_SCRIPT_CONFUSABLE, or
    278   *                    zero if no errors are found.
    279   * @param pe          In the event of an error in the input, receives the position
    280   *                    in the input text (line, offset) of the error.
    281   * @param status      an in/out ICU UErrorCode.  Among the possible errors is
    282   *                    U_PARSE_ERROR, which is used to report syntax errors
    283   *                    in the input.
    284   * @return            A spoof checker that uses the rules from the input files.
    285   * @stable ICU 4.2
    286   */
    287 U_STABLE USpoofChecker * U_EXPORT2
    288 uspoof_openFromSource(const char *confusables,  int32_t confusablesLen,
    289                       const char *confusablesWholeScript, int32_t confusablesWholeScriptLen,
    290                       int32_t *errType, UParseError *pe, UErrorCode *status);
    291 
    292 
    293 /**
    294   * Close a Spoof Checker, freeing any memory that was being held by
    295   *   its implementation.
    296   * @stable ICU 4.2
    297   */
    298 U_STABLE void U_EXPORT2
    299 uspoof_close(USpoofChecker *sc);
    300 
    301 #if U_SHOW_CPLUSPLUS_API
    302 
    303 U_NAMESPACE_BEGIN
    304 
    305 /**
    306  * \class LocalUSpoofCheckerPointer
    307  * "Smart pointer" class, closes a USpoofChecker via uspoof_close().
    308  * For most methods see the LocalPointerBase base class.
    309  *
    310  * @see LocalPointerBase
    311  * @see LocalPointer
    312  * @stable ICU 4.4
    313  */
    314 U_DEFINE_LOCAL_OPEN_POINTER(LocalUSpoofCheckerPointer, USpoofChecker, uspoof_close);
    315 
    316 U_NAMESPACE_END
    317 
    318 #endif
    319 
    320 /**
    321  * Clone a Spoof Checker.  The clone will be set to perform the same checks
    322  *   as the original source.
    323  *
    324  * @param sc       The source USpoofChecker
    325  * @param status   The error code, set if this function encounters a problem.
    326  * @return
    327  * @stable ICU 4.2
    328  */
    329 U_STABLE USpoofChecker * U_EXPORT2
    330 uspoof_clone(const USpoofChecker *sc, UErrorCode *status);
    331 
    332 
    333 /**
    334  * Specify the set of checks that will be performed by the check
    335  * functions of this Spoof Checker.
    336  *
    337  * @param sc       The USpoofChecker
    338  * @param checks         The set of checks that this spoof checker will perform.
    339  *                 The value is a bit set, obtained by OR-ing together
    340  *                 values from enum USpoofChecks.
    341  * @param status   The error code, set if this function encounters a problem.
    342  * @stable ICU 4.2
    343  *
    344  */
    345 U_STABLE void U_EXPORT2
    346 uspoof_setChecks(USpoofChecker *sc, int32_t checks, UErrorCode *status);
    347 
    348 /**
    349  * Get the set of checks that this Spoof Checker has been configured to perform.
    350  *
    351  * @param sc       The USpoofChecker
    352  * @param status   The error code, set if this function encounters a problem.
    353  * @return         The set of checks that this spoof checker will perform.
    354  *                 The value is a bit set, obtained by OR-ing together
    355  *                 values from enum USpoofChecks.
    356  * @stable ICU 4.2
    357  *
    358  */
    359 U_STABLE int32_t U_EXPORT2
    360 uspoof_getChecks(const USpoofChecker *sc, UErrorCode *status);
    361 
    362 /**
    363  * Limit characters that are acceptable in identifiers being checked to those
    364  * normally used with the languages associated with the specified locales.
    365  * Any previously specified list of locales is replaced by the new settings.
    366  *
    367  * A set of languages is determined from the locale(s), and
    368  * from those a set of acceptable Unicode scripts is determined.
    369  * Characters from this set of scripts, along with characters from
    370  * the "common" and "inherited" Unicode Script categories
    371  * will be permitted.
    372  *
    373  * Supplying an empty string removes all restrictions;
    374  * characters from any script will be allowed.
    375  *
    376  * The USPOOF_CHAR_LIMIT test is automatically enabled for this
    377  * USpoofChecker when calling this function with a non-empty list
    378  * of locales.
    379  *
    380  * The Unicode Set of characters that will be allowed is accessible
    381  * via the uspoof_getAllowedChars() function.  uspoof_setAllowedLocales()
    382  * will <i>replace</i> any previously applied set of allowed characters.
    383  *
    384  * Adjustments, such as additions or deletions of certain classes of characters,
    385  * can be made to the result of uspoof_setAllowedLocales() by
    386  * fetching the resulting set with uspoof_getAllowedChars(),
    387  * manipulating it with the Unicode Set API, then resetting the
    388  * spoof detectors limits with uspoof_setAllowedChars()
    389  *
    390  * @param sc           The USpoofChecker
    391  * @param localesList  A list list of locales, from which the language
    392  *                     and associated script are extracted.  The locales
    393  *                     are comma-separated if there is more than one.
    394  *                     White space may not appear within an individual locale,
    395  *                     but is ignored otherwise.
    396  *                     The locales are syntactically like those from the
    397  *                     HTTP Accept-Language header.
    398  *                     If the localesList is empty, no restrictions will be placed on
    399  *                     the allowed characters.
    400  *
    401  * @param status       The error code, set if this function encounters a problem.
    402  * @stable ICU 4.2
    403  */
    404 U_STABLE void U_EXPORT2
    405 uspoof_setAllowedLocales(USpoofChecker *sc, const char *localesList, UErrorCode *status);
    406 
    407 /**
    408  * Get a list of locales for the scripts that are acceptable in strings
    409  *  to be checked.  If no limitations on scripts have been specified,
    410  *  an empty string will be returned.
    411  *
    412  *  uspoof_setAllowedChars() will reset the list of allowed to be empty.
    413  *
    414  *  The format of the returned list is the same as that supplied to
    415  *  uspoof_setAllowedLocales(), but returned list may not be identical
    416  *  to the originally specified string; the string may be reformatted,
    417  *  and information other than languages from
    418  *  the originally specified locales may be omitted.
    419  *
    420  * @param sc           The USpoofChecker
    421  * @param status       The error code, set if this function encounters a problem.
    422  * @return             A string containing a list of  locales corresponding
    423  *                     to the acceptable scripts, formatted like an
    424  *                     HTTP Accept Language value.
    425  *
    426  * @stable ICU 4.2
    427  */
    428 U_STABLE const char * U_EXPORT2
    429 uspoof_getAllowedLocales(USpoofChecker *sc, UErrorCode *status);
    430 
    431 
    432 /**
    433  * Limit the acceptable characters to those specified by a Unicode Set.
    434  *   Any previously specified character limit is
    435  *   is replaced by the new settings.  This includes limits on
    436  *   characters that were set with the uspoof_setAllowedLocales() function.
    437  *
    438  * The USPOOF_CHAR_LIMIT test is automatically enabled for this
    439  * USpoofChecker by this function.
    440  *
    441  * @param sc       The USpoofChecker
    442  * @param chars    A Unicode Set containing the list of
    443  *                 characters that are permitted.  Ownership of the set
    444  *                 remains with the caller.  The incoming set is cloned by
    445  *                 this function, so there are no restrictions on modifying
    446  *                 or deleting the USet after calling this function.
    447  * @param status   The error code, set if this function encounters a problem.
    448  * @stable ICU 4.2
    449  */
    450 U_STABLE void U_EXPORT2
    451 uspoof_setAllowedChars(USpoofChecker *sc, const USet *chars, UErrorCode *status);
    452 
    453 
    454 /**
    455  * Get a USet for the characters permitted in an identifier.
    456  * This corresponds to the limits imposed by the Set Allowed Characters
    457  * functions. Limitations imposed by other checks will not be
    458  * reflected in the set returned by this function.
    459  *
    460  * The returned set will be frozen, meaning that it cannot be modified
    461  * by the caller.
    462  *
    463  * Ownership of the returned set remains with the Spoof Detector.  The
    464  * returned set will become invalid if the spoof detector is closed,
    465  * or if a new set of allowed characters is specified.
    466  *
    467  *
    468  * @param sc       The USpoofChecker
    469  * @param status   The error code, set if this function encounters a problem.
    470  * @return         A USet containing the characters that are permitted by
    471  *                 the USPOOF_CHAR_LIMIT test.
    472  * @stable ICU 4.2
    473  */
    474 U_STABLE const USet * U_EXPORT2
    475 uspoof_getAllowedChars(const USpoofChecker *sc, UErrorCode *status);
    476 
    477 
    478 #if U_SHOW_CPLUSPLUS_API
    479 /**
    480  * Limit the acceptable characters to those specified by a Unicode Set.
    481  *   Any previously specified character limit is
    482  *   is replaced by the new settings.    This includes limits on
    483  *   characters that were set with the uspoof_setAllowedLocales() function.
    484  *
    485  * The USPOOF_CHAR_LIMIT test is automatically enabled for this
    486  * USoofChecker by this function.
    487  *
    488  * @param sc       The USpoofChecker
    489  * @param chars    A Unicode Set containing the list of
    490  *                 characters that are permitted.  Ownership of the set
    491  *                 remains with the caller.  The incoming set is cloned by
    492  *                 this function, so there are no restrictions on modifying
    493  *                 or deleting the USet after calling this function.
    494  * @param status   The error code, set if this function encounters a problem.
    495  * @stable ICU 4.2
    496  */
    497 U_STABLE void U_EXPORT2
    498 uspoof_setAllowedUnicodeSet(USpoofChecker *sc, const UnicodeSet *chars, UErrorCode *status);
    499 
    500 
    501 /**
    502  * Get a UnicodeSet for the characters permitted in an identifier.
    503  * This corresponds to the limits imposed by the Set Allowed Characters /
    504  * UnicodeSet functions. Limitations imposed by other checks will not be
    505  * reflected in the set returned by this function.
    506  *
    507  * The returned set will be frozen, meaning that it cannot be modified
    508  * by the caller.
    509  *
    510  * Ownership of the returned set remains with the Spoof Detector.  The
    511  * returned set will become invalid if the spoof detector is closed,
    512  * or if a new set of allowed characters is specified.
    513  *
    514  *
    515  * @param sc       The USpoofChecker
    516  * @param status   The error code, set if this function encounters a problem.
    517  * @return         A UnicodeSet containing the characters that are permitted by
    518  *                 the USPOOF_CHAR_LIMIT test.
    519  * @stable ICU 4.2
    520  */
    521 U_STABLE const UnicodeSet * U_EXPORT2
    522 uspoof_getAllowedUnicodeSet(const USpoofChecker *sc, UErrorCode *status);
    523 #endif
    524 
    525 
    526 /**
    527  * Check the specified string for possible security issues.
    528  * The text to be checked will typically be an identifier of some sort.
    529  * The set of checks to be performed is specified with uspoof_setChecks().
    530  *
    531  * @param sc      The USpoofChecker
    532  * @param text    The string to be checked for possible security issues,
    533  *                in UTF-16 format.
    534  * @param length  the length of the string to be checked, expressed in
    535  *                16 bit UTF-16 code units, or -1 if the string is
    536  *                zero terminated.
    537  * @param position      An out parameter that receives the index of the
    538  *                first string position that fails the allowed character
    539  *                limitation checks.
    540  *                This parameter may be null if the position information
    541  *                is not needed.
    542  *                If the string passes the requested checks the
    543  *                parameter value will not be set.
    544  * @param status  The error code, set if an error occurred while attempting to
    545  *                perform the check.
    546  *                Spoofing or security issues detected with the input string are
    547  *                not reported here, but through the function's return value.
    548  * @return        An integer value with bits set for any potential security
    549  *                or spoofing issues detected.  The bits are defined by
    550  *                enum USpoofChecks.  Zero is returned if no issues
    551  *                are found with the input string.
    552  * @stable ICU 4.2
    553  */
    554 U_STABLE int32_t U_EXPORT2
    555 uspoof_check(const USpoofChecker *sc,
    556                          const UChar *text, int32_t length,
    557                          int32_t *position,
    558                          UErrorCode *status);
    559 
    560 
    561 /**
    562  * Check the specified string for possible security issues.
    563  * The text to be checked will typically be an identifier of some sort.
    564  * The set of checks to be performed is specified with uspoof_setChecks().
    565  *
    566  * @param sc      The USpoofChecker
    567  * @param text    A UTF-8 string to be checked for possible security issues.
    568  * @param length  the length of the string to be checked, or -1 if the string is
    569  *                zero terminated.
    570  * @param position      An out parameter that receives the index of the
    571  *                first string position that fails the allowed character
    572  *                limitation checks.
    573  *                This parameter may be null if the position information
    574  *                is not needed.
    575  *                If the string passes the requested checks the
    576  *                parameter value will not be set.
    577  * @param status  The error code, set if an error occurred while attempting to
    578  *                perform the check.
    579  *                Spoofing or security issues detected with the input string are
    580  *                not reported here, but through the function's return value.
    581  *                If the input contains invalid UTF-8 sequences,
    582  *                a status of U_INVALID_CHAR_FOUND will be returned.
    583  * @return        An integer value with bits set for any potential security
    584  *                or spoofing issues detected.  The bits are defined by
    585  *                enum USpoofChecks.  Zero is returned if no issues
    586  *                are found with the input string.
    587  * @stable ICU 4.2
    588  */
    589 U_STABLE int32_t U_EXPORT2
    590 uspoof_checkUTF8(const USpoofChecker *sc,
    591                  const char *text, int32_t length,
    592                  int32_t *position,
    593                  UErrorCode *status);
    594 
    595 
    596 #if U_SHOW_CPLUSPLUS_API
    597 /**
    598  * Check the specified string for possible security issues.
    599  * The text to be checked will typically be an identifier of some sort.
    600  * The set of checks to be performed is specified with uspoof_setChecks().
    601  *
    602  * @param sc      The USpoofChecker
    603  * @param text    A UnicodeString to be checked for possible security issues.
    604  * @position      An out parameter that receives the index of the
    605  *                first string position that fails the allowed character
    606  *                limitation checks.
    607  *                This parameter may be null if the position information
    608  *                is not needed.
    609  *                If the string passes the requested checks the
    610  *                parameter value will not be set.
    611  * @param status  The error code, set if an error occurred while attempting to
    612  *                perform the check.
    613  *                Spoofing or security issues detected with the input string are
    614  *                not reported here, but through the function's return value.
    615 
    616  * @return        An integer value with bits set for any potential security
    617  *                or spoofing issues detected.  The bits are defined by
    618  *                enum USpoofChecks.  Zero is returned if no issues
    619  *                are found with the input string.
    620  * @stable ICU 4.2
    621  */
    622 U_STABLE int32_t U_EXPORT2
    623 uspoof_checkUnicodeString(const USpoofChecker *sc,
    624                           const U_NAMESPACE_QUALIFIER UnicodeString &text,
    625                           int32_t *position,
    626                           UErrorCode *status);
    627 
    628 #endif
    629 
    630 
    631 /**
    632  * Check the whether two specified strings are visually confusable.
    633  * The types of confusability to be tested - single script, mixed script,
    634  * or whole script - are determined by the check options set for the
    635  * USpoofChecker.
    636  *
    637  * The tests to be performed are controlled by the flags
    638  *   USPOOF_SINGLE_SCRIPT_CONFUSABLE
    639  *   USPOOF_MIXED_SCRIPT_CONFUSABLE
    640  *   USPOOF_WHOLE_SCRIPT_CONFUSABLE
    641  * At least one of these tests must be selected.
    642  *
    643  * USPOOF_ANY_CASE is a modifier for the tests.  Select it if the identifiers
    644  *   may be of mixed case.
    645  * If identifiers are case folded for comparison and
    646  * display to the user, do not select the USPOOF_ANY_CASE option.
    647  *
    648  *
    649  * @param sc      The USpoofChecker
    650  * @param s1      The first of the two strings to be compared for
    651  *                confusability.  The strings are in UTF-16 format.
    652  * @param length1 the length of the first string, expressed in
    653  *                16 bit UTF-16 code units, or -1 if the string is
    654  *                zero terminated.
    655  * @param s2      The second of the two strings to be compared for
    656  *                confusability.  The strings are in UTF-16 format.
    657  * @param length2 The length of the second string, expressed in
    658  *                16 bit UTF-16 code units, or -1 if the string is
    659  *                zero terminated.
    660  * @param status  The error code, set if an error occurred while attempting to
    661  *                perform the check.
    662  *                Confusability of the strings is not reported here,
    663  *                but through this function's return value.
    664  * @return        An integer value with bit(s) set corresponding to
    665  *                the type of confusability found, as defined by
    666  *                enum USpoofChecks.  Zero is returned if the strings
    667  *                are not confusable.
    668  * @stable ICU 4.2
    669  */
    670 U_STABLE int32_t U_EXPORT2
    671 uspoof_areConfusable(const USpoofChecker *sc,
    672                      const UChar *s1, int32_t length1,
    673                      const UChar *s2, int32_t length2,
    674                      UErrorCode *status);
    675 
    676 
    677 
    678 /**
    679  * Check the whether two specified strings are visually confusable.
    680  * The types of confusability to be tested - single script, mixed script,
    681  * or whole script - are determined by the check options set for the
    682  * USpoofChecker.
    683  *
    684  * @param sc      The USpoofChecker
    685  * @param s1      The first of the two strings to be compared for
    686  *                confusability.  The strings are in UTF-8 format.
    687  * @param length1 the length of the first string, in bytes, or -1
    688  *                if the string is zero terminated.
    689  * @param s2      The second of the two strings to be compared for
    690  *                confusability.  The strings are in UTF-18 format.
    691  * @param length2 The length of the second string in bytes, or -1
    692  *                if the string is zero terminated.
    693  * @param status  The error code, set if an error occurred while attempting to
    694  *                perform the check.
    695  *                Confusability of the strings is not reported here,
    696  *                but through this function's return value.
    697  * @return        An integer value with bit(s) set corresponding to
    698  *                the type of confusability found, as defined by
    699  *                enum USpoofChecks.  Zero is returned if the strings
    700  *                are not confusable.
    701  * @stable ICU 4.2
    702  */
    703 U_STABLE int32_t U_EXPORT2
    704 uspoof_areConfusableUTF8(const USpoofChecker *sc,
    705                          const char *s1, int32_t length1,
    706                          const char *s2, int32_t length2,
    707                          UErrorCode *status);
    708 
    709 
    710 
    711 
    712 #if U_SHOW_CPLUSPLUS_API
    713 /**
    714  * Check the whether two specified strings are visually confusable.
    715  * The types of confusability to be tested - single script, mixed script,
    716  * or whole script - are determined by the check options set for the
    717  * USpoofChecker.
    718  *
    719  * @param sc      The USpoofChecker
    720  * @param s1      The first of the two strings to be compared for
    721  *                confusability.  The strings are in UTF-8 format.
    722  * @param s2      The second of the two strings to be compared for
    723  *                confusability.  The strings are in UTF-18 format.
    724  * @param status  The error code, set if an error occurred while attempting to
    725  *                perform the check.
    726  *                Confusability of the strings is not reported here,
    727  *                but through this function's return value.
    728  * @return        An integer value with bit(s) set corresponding to
    729  *                the type of confusability found, as defined by
    730  *                enum USpoofChecks.  Zero is returned if the strings
    731  *                are not confusable.
    732  * @stable ICU 4.2
    733  */
    734 U_STABLE int32_t U_EXPORT2
    735 uspoof_areConfusableUnicodeString(const USpoofChecker *sc,
    736                                   const U_NAMESPACE_QUALIFIER UnicodeString &s1,
    737                                   const U_NAMESPACE_QUALIFIER UnicodeString &s2,
    738                                   UErrorCode *status);
    739 #endif
    740 
    741 
    742 /**
    743   *  Get the "skeleton" for an identifier string.
    744   *  Skeletons are a transformation of the input string;
    745   *  Two strings are confusable if their skeletons are identical.
    746   *  See Unicode UAX 39 for additional information.
    747   *
    748   *  Using skeletons directly makes it possible to quickly check
    749   *  whether an identifier is confusable with any of some large
    750   *  set of existing identifiers, by creating an efficiently
    751   *  searchable collection of the skeletons.
    752   *
    753   * @param sc      The USpoofChecker
    754   * @param type    The type of skeleton, corresponding to which
    755   *                of the Unicode confusable data tables to use.
    756   *                The default is Mixed-Script, Lowercase.
    757   *                Allowed options are USPOOF_SINGLE_SCRIPT_CONFUSABLE and
    758   *                USPOOF_ANY_CASE_CONFUSABLE.  The two flags may be ORed.
    759   * @param s       The input string whose skeleton will be computed.
    760   * @param length  The length of the input string, expressed in 16 bit
    761   *                UTF-16 code units, or -1 if the string is zero terminated.
    762   * @param dest    The output buffer, to receive the skeleton string.
    763   * @param destCapacity  The length of the output buffer, in 16 bit units.
    764   *                The destCapacity may be zero, in which case the function will
    765   *                return the actual length of the skeleton.
    766   * @param status  The error code, set if an error occurred while attempting to
    767   *                perform the check.
    768   * @return        The length of the skeleton string.  The returned length
    769   *                is always that of the complete skeleton, even when the
    770   *                supplied buffer is too small (or of zero length)
    771   *
    772   * @stable ICU 4.2
    773   */
    774 U_STABLE int32_t U_EXPORT2
    775 uspoof_getSkeleton(const USpoofChecker *sc,
    776                    uint32_t type,
    777                    const UChar *s,  int32_t length,
    778                    UChar *dest, int32_t destCapacity,
    779                    UErrorCode *status);
    780 
    781 /**
    782   *  Get the "skeleton" for an identifier string.
    783   *  Skeletons are a transformation of the input string;
    784   *  Two strings are confusable if their skeletons are identical.
    785   *  See Unicode UAX 39 for additional information.
    786   *
    787   *  Using skeletons directly makes it possible to quickly check
    788   *  whether an identifier is confusable with any of some large
    789   *  set of existing identifiers, by creating an efficiently
    790   *  searchable collection of the skeletons.
    791   *
    792   * @param sc      The USpoofChecker
    793   * @param type    The type of skeleton, corresponding to which
    794   *                of the Unicode confusable data tables to use.
    795   *                The default is Mixed-Script, Lowercase.
    796   *                Allowed options are USPOOF_SINGLE_SCRIPT_CONFUSABLE and
    797   *                USPOOF_ANY_CASE.  The two flags may be ORed.
    798   * @param s       The UTF-8 format input string whose skeleton will be computed.
    799   * @param length  The length of the input string, in bytes,
    800   *                or -1 if the string is zero terminated.
    801   * @param dest    The output buffer, to receive the skeleton string.
    802   * @param destCapacity  The length of the output buffer, in bytes.
    803   *                The destCapacity may be zero, in which case the function will
    804   *                return the actual length of the skeleton.
    805   * @param status  The error code, set if an error occurred while attempting to
    806   *                perform the check.  Possible Errors include U_INVALID_CHAR_FOUND
    807   *                   for invalid UTF-8 sequences, and
    808   *                   U_BUFFER_OVERFLOW_ERROR if the destination buffer is too small
    809   *                   to hold the complete skeleton.
    810   * @return        The length of the skeleton string, in bytes.  The returned length
    811   *                is always that of the complete skeleton, even when the
    812   *                supplied buffer is too small (or of zero length)
    813   *
    814   * @stable ICU 4.2
    815   */
    816 U_STABLE int32_t U_EXPORT2
    817 uspoof_getSkeletonUTF8(const USpoofChecker *sc,
    818                        uint32_t type,
    819                        const char *s,  int32_t length,
    820                        char *dest, int32_t destCapacity,
    821                        UErrorCode *status);
    822 
    823 #if U_SHOW_CPLUSPLUS_API
    824 /**
    825   *  Get the "skeleton" for an identifier string.
    826   *  Skeletons are a transformation of the input string;
    827   *  Two strings are confusable if their skeletons are identical.
    828   *  See Unicode UAX 39 for additional information.
    829   *
    830   *  Using skeletons directly makes it possible to quickly check
    831   *  whether an identifier is confusable with any of some large
    832   *  set of existing identifiers, by creating an efficiently
    833   *  searchable collection of the skeletons.
    834   *
    835   * @param sc      The USpoofChecker.
    836   * @param type    The type of skeleton, corresponding to which
    837   *                of the Unicode confusable data tables to use.
    838   *                The default is Mixed-Script, Lowercase.
    839   *                Allowed options are USPOOF_SINGLE_SCRIPT_CONFUSABLE and
    840   *                USPOOF_ANY_CASE_CONFUSABLE.  The two flags may be ORed.
    841   * @param s       The input string whose skeleton will be computed.
    842   * @param dest    The output string, to receive the skeleton string.
    843   * @param destCapacity  The length of the output buffer, in bytes.
    844   *                The destCapacity may be zero, in which case the function will
    845   *                return the actual length of the skeleton.
    846   * @param status  The error code, set if an error occurred while attempting to
    847   *                perform the check.
    848   * @return        A reference to the destination (skeleton) string.
    849   *
    850   * @stable ICU 4.2
    851   */
    852 U_STABLE UnicodeString & U_EXPORT2
    853 uspoof_getSkeletonUnicodeString(const USpoofChecker *sc,
    854                                 uint32_t type,
    855                                 const UnicodeString &s,
    856                                 UnicodeString &dest,
    857                                 UErrorCode *status);
    858 #endif   /* U_SHOW_CPLUSPLUS_API */
    859 
    860 
    861 /**
    862  * Serialize the data for a spoof detector into a chunk of memory.
    863  * The flattened spoof detection tables can later be used to efficiently
    864  * instantiate a new Spoof Detector.
    865  *
    866  * @param sc   the Spoof Detector whose data is to be serialized.
    867  * @param data a pointer to 32-bit-aligned memory to be filled with the data,
    868  *             can be NULL if capacity==0
    869  * @param capacity the number of bytes available at data,
    870  *                 or 0 for preflighting
    871  * @param status an in/out ICU UErrorCode; possible errors include:
    872  * - U_BUFFER_OVERFLOW_ERROR if the data storage block is too small for serialization
    873  * - U_ILLEGAL_ARGUMENT_ERROR  the data or capacity parameters are bad
    874  * @return the number of bytes written or needed for the spoof data
    875  *
    876  * @see utrie2_openFromSerialized()
    877  * @stable ICU 4.2
    878  */
    879 U_STABLE int32_t U_EXPORT2
    880 uspoof_serialize(USpoofChecker *sc,
    881                  void *data, int32_t capacity,
    882                  UErrorCode *status);
    883 
    884 
    885 #endif
    886 
    887 #endif   /* USPOOF_H */
    888