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1  // Copyright (C) 2016 and later: Unicode, Inc. and others.
2  // License & terms of use: http://www.unicode.org/copyright.html
3  /*
4  ***************************************************************************
5  * Copyright (C) 2008-2013, International Business Machines Corporation
6  * and others. All Rights Reserved.
7  ***************************************************************************
8  *
9  *  uspoof_impl.h
10  *
11  *    Implemenation header for spoof detection
12  *
13  */
14  
15  #ifndef USPOOFIM_H
16  #define USPOOFIM_H
17  
18  #include "uassert.h"
19  #include "unicode/utypes.h"
20  #include "unicode/uspoof.h"
21  #include "unicode/uscript.h"
22  #include "unicode/udata.h"
23  
24  #include "utrie2.h"
25  
26  #if !UCONFIG_NO_NORMALIZATION
27  
28  #ifdef __cplusplus
29  
30  U_NAMESPACE_BEGIN
31  
32  // The maximium length (in UTF-16 UChars) of the skeleton replacement string resulting from
33  //   a single input code point.  This is function of the unicode.org data.
34  #define USPOOF_MAX_SKELETON_EXPANSION 20
35  
36  // The default stack buffer size for copies or conversions or normalizations
37  // of input strings being checked.  (Used in multiple places.)
38  #define USPOOF_STACK_BUFFER_SIZE 100
39  
40  // Magic number for sanity checking spoof data.
41  #define USPOOF_MAGIC 0x3845fdef
42  
43  // Magic number for sanity checking spoof checkers.
44  #define USPOOF_CHECK_MAGIC 0x2734ecde
45  
46  class ScriptSet;
47  class SpoofData;
48  struct SpoofDataHeader;
49  class ConfusableDataUtils;
50  
51  /**
52    *  Class SpoofImpl corresponds directly to the plain C API opaque type
53    *  USpoofChecker.  One can be cast to the other.
54    */
55  class SpoofImpl : public UObject  {
56  public:
57      SpoofImpl(SpoofData *data, UErrorCode& status);
58      SpoofImpl(UErrorCode& status);
59      SpoofImpl();
60      void construct(UErrorCode& status);
61      virtual ~SpoofImpl();
62  
63      /** Copy constructor, used by the user level uspoof_clone() function.
64       */
65      SpoofImpl(const SpoofImpl &src, UErrorCode &status);
66  
67      USpoofChecker *asUSpoofChecker();
68      static SpoofImpl *validateThis(USpoofChecker *sc, UErrorCode &status);
69      static const SpoofImpl *validateThis(const USpoofChecker *sc, UErrorCode &status);
70  
71      /** Set and Get AllowedLocales, implementations of the corresponding API */
72      void setAllowedLocales(const char *localesList, UErrorCode &status);
73      const char * getAllowedLocales(UErrorCode &status);
74  
75      // Add (union) to the UnicodeSet all of the characters for the scripts used for
76      // the specified locale.  Part of the implementation of setAllowedLocales.
77      void addScriptChars(const char *locale, UnicodeSet *allowedChars, UErrorCode &status);
78  
79      // Functions implementing the features of UTS 39 section 5.
80      static void getAugmentedScriptSet(UChar32 codePoint, ScriptSet& result, UErrorCode& status);
81      void getResolvedScriptSet(const UnicodeString& input, ScriptSet& result, UErrorCode& status) const;
82      void getResolvedScriptSetWithout(const UnicodeString& input, UScriptCode script, ScriptSet& result, UErrorCode& status) const;
83      void getNumerics(const UnicodeString& input, UnicodeSet& result, UErrorCode& status) const;
84      URestrictionLevel getRestrictionLevel(const UnicodeString& input, UErrorCode& status) const;
85  
86      /** parse a hex number.  Untility used by the builders.   */
87      static UChar32 ScanHex(const UChar *s, int32_t start, int32_t limit, UErrorCode &status);
88  
89      static UClassID U_EXPORT2 getStaticClassID(void);
90      virtual UClassID getDynamicClassID(void) const;
91  
92      //
93      // Data Members
94      //
95  
96      int32_t           fMagic;             // Internal sanity check.
97      int32_t           fChecks;            // Bit vector of checks to perform.
98  
99      SpoofData        *fSpoofData;
100  
101      const UnicodeSet *fAllowedCharsSet;   // The UnicodeSet of allowed characters.
102                                            //   for this Spoof Checker.  Defaults to all chars.
103  
104      const char       *fAllowedLocales;    // The list of allowed locales.
105      URestrictionLevel fRestrictionLevel;  // The maximum restriction level for an acceptable identifier.
106  };
107  
108  /**
109   *  Class CheckResult corresponds directly to the plain C API opaque type
110   *  USpoofCheckResult.  One can be cast to the other.
111   */
112  class CheckResult : public UObject {
113  public:
114      CheckResult();
115      virtual ~CheckResult();
116  
117      USpoofCheckResult *asUSpoofCheckResult();
118      static CheckResult *validateThis(USpoofCheckResult *ptr, UErrorCode &status);
119      static const CheckResult *validateThis(const USpoofCheckResult *ptr, UErrorCode &status);
120  
121      void clear();
122  
123      // Used to convert this CheckResult to the older int32_t return value API
124      int32_t toCombinedBitmask(int32_t expectedChecks);
125  
126      // Data Members
127      int32_t fMagic;                        // Internal sanity check.
128      int32_t fChecks;                       // Bit vector of checks that were failed.
129      UnicodeSet fNumerics;                  // Set of numerics found in the string.
130      URestrictionLevel fRestrictionLevel;   // The restriction level of the string.
131  };
132  
133  
134  //
135  //  Confusable Mappings Data Structures, version 2.0
136  //
137  //    For the confusable data, we are essentially implementing a map,
138  //       key:    a code point
139  //       value:  a string.  Most commonly one char in length, but can be more.
140  //
141  //    The keys are stored as a sorted array of 32 bit ints.
142  //             bits 0-23    a code point value
143  //             bits 24-31   length of value string, in UChars (between 1 and 256 UChars).
144  //        The key table is sorted in ascending code point order.  (not on the
145  //        32 bit int value, the flag bits do not participate in the sorting.)
146  //
147  //        Lookup is done by means of a binary search in the key table.
148  //
149  //    The corresponding values are kept in a parallel array of 16 bit ints.
150  //        If the value string is of length 1, it is literally in the value array.
151  //        For longer strings, the value array contains an index into the strings table.
152  //
153  //    String Table:
154  //       The strings table contains all of the value strings (those of length two or greater)
155  //       concatentated together into one long UChar (UTF-16) array.
156  //
157  //       There is no nul character or other mark between adjacent strings.
158  //
159  //----------------------------------------------------------------------------
160  //
161  //  Changes from format version 1 to format version 2:
162  //      1) Removal of the whole-script confusable data tables.
163  //      2) Removal of the SL/SA/ML/MA and multi-table flags in the key bitmask.
164  //      3) Expansion of string length value in the key bitmask from 2 bits to 8 bits.
165  //      4) Removal of the string lengths table since 8 bits is sufficient for the
166  //         lengths of all entries in confusables.txt.
167  
168  
169  
170  // Internal functions for manipulating confusable data table keys
171  #define USPOOF_CONFUSABLE_DATA_FORMAT_VERSION 2  // version for ICU 58
172  class ConfusableDataUtils {
173  public:
keyToCodePoint(int32_t key)174      inline static UChar32 keyToCodePoint(int32_t key) {
175          return key & 0x00ffffff;
176      }
keyToLength(int32_t key)177      inline static int32_t keyToLength(int32_t key) {
178          return ((key & 0xff000000) >> 24) + 1;
179      }
codePointAndLengthToKey(UChar32 codePoint,int32_t length)180      inline static int32_t codePointAndLengthToKey(UChar32 codePoint, int32_t length) {
181          U_ASSERT((codePoint & 0x00ffffff) == codePoint);
182          U_ASSERT(length <= 256);
183          return codePoint | ((length - 1) << 24);
184      }
185  };
186  
187  
188  //-------------------------------------------------------------------------------------
189  //
190  //  SpoofData
191  //
192  //    A small class that wraps the raw (usually memory mapped) spoof data.
193  //    Serves two primary functions:
194  //      1.  Convenience.  Contains real pointers to the data, to avoid dealing with
195  //          the offsets in the raw data.
196  //      2.  Reference counting.  When a spoof checker is cloned, the raw data is shared
197  //          and must be retained until all checkers using the data are closed.
198  //    Nothing in this struct includes state that is specific to any particular
199  //    USpoofDetector object.
200  //
201  //---------------------------------------------------------------------------------------
202  class SpoofData: public UMemory {
203    public:
204      static SpoofData* getDefault(UErrorCode &status);   // Get standard ICU spoof data.
205      static void releaseDefault();   // Cleanup reference to default spoof data.
206  
207      SpoofData(UErrorCode &status);   // Create new spoof data wrapper.
208                                       // Only used when building new data from rules.
209  
210      // Constructor for use when creating from prebuilt default data.
211      //   A UDataMemory is what the ICU internal data loading functions provide.
212      //   The udm is adopted by the SpoofData.
213      SpoofData(UDataMemory *udm, UErrorCode &status);
214  
215      // Constructor for use when creating from serialized data.
216      //
217      SpoofData(const void *serializedData, int32_t length, UErrorCode &status);
218  
219      //  Check raw Spoof Data Version compatibility.
220      //  Return TRUE it looks good.
221      UBool validateDataVersion(UErrorCode &status) const;
222  
223      ~SpoofData();                    // Destructor not normally used.
224                                       // Use removeReference() instead.
225      // Reference Counting functions.
226      //    Clone of a user-level spoof detector increments the ref count on the data.
227      //    Close of a user-level spoof detector decrements the ref count.
228      //    If the data is owned by us, it will be deleted when count goes to zero.
229      SpoofData *addReference();
230      void removeReference();
231  
232      // Reset all fields to an initial state.
233      // Called from the top of all constructors.
234      void reset();
235  
236      // Copy this instance's raw data buffer to the specified address.
237      int32_t serialize(void *buf, int32_t capacity, UErrorCode &status) const;
238  
239      // Get the total number of bytes of data backed by this SpoofData.
240      // Not to be confused with length, which returns the number of confusable entries.
241      int32_t size() const;
242  
243      // Get the confusable skeleton transform for a single code point.
244      // The result is a string with a length between 1 and 18 as of Unicode 9.
245      // This is the main public endpoint for this class.
246      // @return   The length in UTF-16 code units of the substition string.
247      int32_t confusableLookup(UChar32 inChar, UnicodeString &dest) const;
248  
249      // Get the number of confusable entries in this SpoofData.
250      int32_t length() const;
251  
252      // Get the code point (key) at the specified index.
253      UChar32 codePointAt(int32_t index) const;
254  
255      // Get the confusable skeleton (value) at the specified index.
256      // Append it to the specified UnicodeString&.
257      // @return   The length in UTF-16 code units of the skeleton string.
258      int32_t appendValueTo(int32_t index, UnicodeString& dest) const;
259  
260    private:
261      // Reserve space in the raw data.  For use by builder when putting together a
262      //   new set of data.  Init the new storage to zero, to prevent inconsistent
263      //   results if it is not all otherwise set by the requester.
264      //  Return:
265      //    pointer to the new space that was added by this function.
266      void *reserveSpace(int32_t numBytes, UErrorCode &status);
267  
268      // initialize the pointers from this object to the raw data.
269      void initPtrs(UErrorCode &status);
270  
271      SpoofDataHeader             *fRawData;          // Ptr to the raw memory-mapped data
272      UBool                       fDataOwned;         // True if the raw data is owned, and needs
273                                                      //  to be deleted when refcount goes to zero.
274      UDataMemory                 *fUDM;              // If not NULL, our data came from a
275                                                      //   UDataMemory, which we must close when
276                                                      //   we are done.
277  
278      uint32_t                    fMemLimit;          // Limit of available raw data space
279      u_atomic_int32_t            fRefCount;
280  
281      // Confusable data
282      int32_t                     *fCFUKeys;
283      uint16_t                    *fCFUValues;
284      UChar                       *fCFUStrings;
285  
286      friend class ConfusabledataBuilder;
287  };
288  
289  //---------------------------------------------------------------------------------------
290  //
291  //  Raw Binary Data Formats, as loaded from the ICU data file,
292  //    or as built by the builder.
293  //
294  //---------------------------------------------------------------------------------------
295  struct SpoofDataHeader {
296      int32_t       fMagic;                // (0x3845fdef)
297      uint8_t       fFormatVersion[4];     // Data Format. Same as the value in struct UDataInfo
298                                           //   if there is one associated with this data.
299      int32_t       fLength;               // Total lenght in bytes of this spoof data,
300                                           //   including all sections, not just the header.
301  
302      // The following four sections refer to data representing the confusable data
303      //   from the Unicode.org data from "confusables.txt"
304  
305      int32_t       fCFUKeys;               // byte offset to Keys table (from SpoofDataHeader *)
306      int32_t       fCFUKeysSize;           // number of entries in keys table  (32 bits each)
307  
308      // TODO: change name to fCFUValues, for consistency.
309      int32_t       fCFUStringIndex;        // byte offset to String Indexes table
310      int32_t       fCFUStringIndexSize;    // number of entries in String Indexes table (16 bits each)
311                                            //     (number of entries must be same as in Keys table
312  
313      int32_t       fCFUStringTable;        // byte offset of String table
314      int32_t       fCFUStringTableLen;     // length of string table (in 16 bit UChars)
315  
316      // The following sections are for data from xidmodifications.txt
317  
318      int32_t       unused[15];              // Padding, Room for Expansion
319  };
320  
321  
322  
323  U_NAMESPACE_END
324  #endif /* __cplusplus */
325  
326  /**
327    * Endianness swap function for binary spoof data.
328    * @internal
329    */
330  U_CAPI int32_t U_EXPORT2
331  uspoof_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData,
332              UErrorCode *status);
333  
334  
335  #endif
336  
337  #endif  /* USPOOFIM_H */
338  
339