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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