1 /* 2 *************************************************************************** 3 * Copyright (C) 2008-2011, International Business Machines Corporation 4 * and others. All Rights Reserved. 5 *************************************************************************** 6 * 7 * uspoof_impl.h 8 * 9 * Implemenation header for spoof detection 10 * 11 */ 12 13 #ifndef USPOOFIM_H 14 #define USPOOFIM_H 15 16 #include "unicode/utypes.h" 17 #include "unicode/uspoof.h" 18 #include "utrie2.h" 19 #include "unicode/uscript.h" 20 #include "unicode/udata.h" 21 22 23 #if !UCONFIG_NO_NORMALIZATION 24 25 #ifdef XP_CPLUSPLUS 26 27 U_NAMESPACE_BEGIN 28 29 // The maximium length (in UTF-16 UChars) of the skeleton replacement string resulting from 30 // a single input code point. This is function of the unicode.org data. 31 #define USPOOF_MAX_SKELETON_EXPANSION 20 32 33 // The default stack buffer size for copies or conversions or normalizations 34 // of input strings being checked. (Used in multiple places.) 35 #define USPOOF_STACK_BUFFER_SIZE 100 36 37 // Magic number for sanity checking spoof data. 38 #define USPOOF_MAGIC 0x3845fdef 39 40 class SpoofData; 41 struct SpoofDataHeader; 42 struct SpoofStringLengthsElement; 43 class ScriptSet; 44 45 /** 46 * Class SpoofImpl corresponds directly to the plain C API opaque type 47 * USpoofChecker. One can be cast to the other. 48 */ 49 class SpoofImpl : public UObject { 50 public: 51 SpoofImpl(SpoofData *data, UErrorCode &status); 52 SpoofImpl(); 53 virtual ~SpoofImpl(); 54 55 /** Copy constructor, used by the user level uspoof_clone() function. 56 */ 57 SpoofImpl(const SpoofImpl &src, UErrorCode &status); 58 59 static SpoofImpl *validateThis(USpoofChecker *sc, UErrorCode &status); 60 static const SpoofImpl *validateThis(const USpoofChecker *sc, UErrorCode &status); 61 62 /** Get the confusable skeleton transform for a single code point. 63 * The result is a string with a length between 1 and 18. 64 * @param tableMask bit flag specifying which confusable table to use. 65 * One of USPOOF_SL_TABLE_FLAG, USPOOF_MA_TABLE_FLAG, etc. 66 * @return The length in UTF-16 code units of the substition string. 67 */ 68 int32_t confusableLookup(UChar32 inChar, int32_t tableMask, UChar *destBuf) const; 69 70 /** Set and Get AllowedLocales, implementations of the corresponding API */ 71 void setAllowedLocales(const char *localesList, UErrorCode &status); 72 const char * getAllowedLocales(UErrorCode &status); 73 74 // Add (union) to the UnicodeSet all of the characters for the scripts used for 75 // the specified locale. Part of the implementation of setAllowedLocales. 76 void addScriptChars(const char *locale, UnicodeSet *allowedChars, UErrorCode &status); 77 78 79 /** parse a hex number. Untility used by the builders. */ 80 static UChar32 ScanHex(const UChar *s, int32_t start, int32_t limit, UErrorCode &status); 81 82 // Implementation for Whole Script tests. 83 // Return the test bit flag to be ORed into the eventual user return value 84 // if a Spoof opportunity is detected. 85 void wholeScriptCheck( 86 const UChar *text, int32_t length, ScriptSet *result, UErrorCode &status) const; 87 88 /** Scan a string to determine how many scripts it includes. 89 * Ignore characters with script=Common and scirpt=Inherited. 90 * @param text The UChar text to be scanned 91 * @param length The length of the input text, -1 for nul termintated. 92 * @param pos An out parameter, set to the first input postion at which 93 * a second script was encountered, ignoring Common and Inherited. 94 * @param status For errors. 95 * @return the number of (non-common,inherited) scripts encountered, 96 * clipped to a max of two. 97 */ 98 int32_t scriptScan(const UChar *text, int32_t length, int32_t &pos, UErrorCode &status) const; 99 100 static UClassID U_EXPORT2 getStaticClassID(void); 101 virtual UClassID getDynamicClassID(void) const; 102 103 // 104 // Data Members 105 // 106 107 int32_t fMagic; // Internal sanity check. 108 int32_t fChecks; // Bit vector of checks to perform. 109 110 SpoofData *fSpoofData; 111 112 const UnicodeSet *fAllowedCharsSet; // The UnicodeSet of allowed characters. 113 // for this Spoof Checker. Defaults to all chars. 114 115 const char *fAllowedLocales; // The list of allowed locales. 116 }; 117 118 119 120 // 121 // Confusable Mappings Data Structures 122 // 123 // For the confusable data, we are essentially implementing a map, 124 // key: a code point 125 // value: a string. Most commonly one char in length, but can be more. 126 // 127 // The keys are stored as a sorted array of 32 bit ints. 128 // bits 0-23 a code point value 129 // bits 24-31 flags 130 // 24: 1 if entry applies to SL table 131 // 25: 1 if entry applies to SA table 132 // 26: 1 if entry applies to ML table 133 // 27: 1 if entry applies to MA table 134 // 28: 1 if there are multiple entries for this code point. 135 // 29-30: length of value string, in UChars. 136 // values are (1, 2, 3, other) 137 // The key table is sorted in ascending code point order. (not on the 138 // 32 bit int value, the flag bits do not participate in the sorting.) 139 // 140 // Lookup is done by means of a binary search in the key table. 141 // 142 // The corresponding values are kept in a parallel array of 16 bit ints. 143 // If the value string is of length 1, it is literally in the value array. 144 // For longer strings, the value array contains an index into the strings table. 145 // 146 // String Table: 147 // The strings table contains all of the value strings (those of length two or greater) 148 // concatentated together into one long UChar (UTF-16) array. 149 // 150 // The array is arranged by length of the strings - all strings of the same length 151 // are stored together. The sections are ordered by length of the strings - 152 // all two char strings first, followed by all of the three Char strings, etc. 153 // 154 // There is no nul character or other mark between adjacent strings. 155 // 156 // String Lengths table 157 // The length of strings from 1 to 3 is flagged in the key table. 158 // For strings of length 4 or longer, the string length table provides a 159 // mapping between an index into the string table and the corresponding length. 160 // Strings of these lengths are rare, so lookup time is not an issue. 161 // Each entry consists of 162 // uint16_t index of the _last_ string with this length 163 // uint16_t the length 164 // 165 166 // Flag bits in the Key entries 167 #define USPOOF_SL_TABLE_FLAG (1<<24) 168 #define USPOOF_SA_TABLE_FLAG (1<<25) 169 #define USPOOF_ML_TABLE_FLAG (1<<26) 170 #define USPOOF_MA_TABLE_FLAG (1<<27) 171 #define USPOOF_KEY_MULTIPLE_VALUES (1<<28) 172 #define USPOOF_KEY_LENGTH_SHIFT 29 173 #define USPOOF_KEY_LENGTH_FIELD(x) (((x)>>29) & 3) 174 175 176 struct SpoofStringLengthsElement { 177 uint16_t fLastString; // index in string table of last string with this length 178 uint16_t fStrLength; // Length of strings 179 }; 180 181 182 //------------------------------------------------------------------------------- 183 // 184 // ScriptSet - Wrapper class for the Script code bit sets that are part of the 185 // whole script confusable data. 186 // 187 // This class is used both at data build and at run time. 188 // The constructor is only used at build time. 189 // At run time, just point at the prebuilt data and go. 190 // 191 //------------------------------------------------------------------------------- 192 class ScriptSet: public UMemory { 193 public: 194 ScriptSet(); 195 ~ScriptSet(); 196 197 UBool operator == (const ScriptSet &other); 198 ScriptSet & operator = (const ScriptSet &other); 199 200 void Union(const ScriptSet &other); 201 void Union(UScriptCode script); 202 void intersect(const ScriptSet &other); 203 void intersect(UScriptCode script); 204 void setAll(); 205 void resetAll(); 206 int32_t countMembers(); 207 208 private: 209 uint32_t bits[6]; 210 }; 211 212 213 214 215 //------------------------------------------------------------------------------- 216 // 217 // NFDBuffer A little class to handle the NFD normalization that is 218 // needed on incoming identifiers to be checked. 219 // Takes care of buffer handling and normalization 220 // 221 // Instances of this class are intended to be stack-allocated. 222 // 223 // TODO: how to map position offsets back to user values? 224 // 225 //-------------------------------------------------------------------------------- 226 class NFDBuffer: public UMemory { 227 public: 228 NFDBuffer(const UChar *text, int32_t length, UErrorCode &status); 229 ~NFDBuffer(); 230 const UChar *getBuffer(); 231 int32_t getLength(); 232 233 private: 234 const UChar *fOriginalText; 235 UChar *fNormalizedText; 236 int32_t fNormalizedTextLength; 237 UChar fSmallBuf[USPOOF_STACK_BUFFER_SIZE]; 238 }; 239 240 241 242 243 244 //------------------------------------------------------------------------------------- 245 // 246 // SpoofData 247 // 248 // A small class that wraps the raw (usually memory mapped) spoof data. 249 // Serves two primary functions: 250 // 1. Convenience. Contains real pointers to the data, to avoid dealing with 251 // the offsets in the raw data. 252 // 2. Reference counting. When a spoof checker is cloned, the raw data is shared 253 // and must be retained until all checkers using the data are closed. 254 // Nothing in this struct includes state that is specific to any particular 255 // USpoofDetector object. 256 // 257 //--------------------------------------------------------------------------------------- 258 class SpoofData: public UMemory { 259 public: 260 static SpoofData *getDefault(UErrorCode &status); // Load standard ICU spoof data. 261 SpoofData(UErrorCode &status); // Create new spoof data wrapper. 262 // Only used when building new data from rules. 263 264 // Constructor for use when creating from prebuilt default data. 265 // A UDataMemory is what the ICU internal data loading functions provide. 266 // The udm is adopted by the SpoofData. 267 SpoofData(UDataMemory *udm, UErrorCode &status); 268 269 // Constructor for use when creating from serialized data. 270 // 271 SpoofData(const void *serializedData, int32_t length, UErrorCode &status); 272 273 // Check raw Spoof Data Version compatibility. 274 // Return TRUE it looks good. 275 static UBool validateDataVersion(const SpoofDataHeader *rawData, UErrorCode &status); 276 ~SpoofData(); // Destructor not normally used. 277 // Use removeReference() instead. 278 // Reference Counting functions. 279 // Clone of a user-level spoof detector increments the ref count on the data. 280 // Close of a user-level spoof detector decrements the ref count. 281 // If the data is owned by us, it will be deleted when count goes to zero. 282 SpoofData *addReference(); 283 void removeReference(); 284 285 // Reserve space in the raw data. For use by builder when putting together a 286 // new set of data. Init the new storage to zero, to prevent inconsistent 287 // results if it is not all otherwise set by the requester. 288 // Return: 289 // pointer to the new space that was added by this function. 290 void *reserveSpace(int32_t numBytes, UErrorCode &status); 291 292 // initialize the pointers from this object to the raw data. 293 void initPtrs(UErrorCode &status); 294 295 // Reset all fields to an initial state. 296 // Called from the top of all constructors. 297 void reset(); 298 299 SpoofDataHeader *fRawData; // Ptr to the raw memory-mapped data 300 UBool fDataOwned; // True if the raw data is owned, and needs 301 // to be deleted when refcount goes to zero. 302 UDataMemory *fUDM; // If not NULL, our data came from a 303 // UDataMemory, which we must close when 304 // we are done. 305 306 uint32_t fMemLimit; // Limit of available raw data space 307 int32_t fRefCount; 308 309 // Confusable data 310 int32_t *fCFUKeys; 311 uint16_t *fCFUValues; 312 SpoofStringLengthsElement *fCFUStringLengths; 313 UChar *fCFUStrings; 314 315 // Whole Script Confusable Data 316 UTrie2 *fAnyCaseTrie; 317 UTrie2 *fLowerCaseTrie; 318 ScriptSet *fScriptSets; 319 }; 320 321 322 //--------------------------------------------------------------------------------------- 323 // 324 // Raw Binary Data Formats, as loaded from the ICU data file, 325 // or as built by the builder. 326 // 327 //--------------------------------------------------------------------------------------- 328 struct SpoofDataHeader { 329 int32_t fMagic; // (0x3845fdef) 330 uint8_t fFormatVersion[4]; // Data Format. Same as the value in struct UDataInfo 331 // if there is one associated with this data. 332 int32_t fLength; // Total lenght in bytes of this spoof data, 333 // including all sections, not just the header. 334 335 // The following four sections refer to data representing the confusable data 336 // from the Unicode.org data from "confusables.txt" 337 338 int32_t fCFUKeys; // byte offset to Keys table (from SpoofDataHeader *) 339 int32_t fCFUKeysSize; // number of entries in keys table (32 bits each) 340 341 // TODO: change name to fCFUValues, for consistency. 342 int32_t fCFUStringIndex; // byte offset to String Indexes table 343 int32_t fCFUStringIndexSize; // number of entries in String Indexes table (16 bits each) 344 // (number of entries must be same as in Keys table 345 346 int32_t fCFUStringTable; // byte offset of String table 347 int32_t fCFUStringTableLen; // length of string table (in 16 bit UChars) 348 349 int32_t fCFUStringLengths; // byte offset to String Lengths table 350 int32_t fCFUStringLengthsSize; // number of entries in lengths table. (2 x 16 bits each) 351 352 353 // The following sections are for data from confusablesWholeScript.txt 354 355 int32_t fAnyCaseTrie; // byte offset to the serialized Any Case Trie 356 int32_t fAnyCaseTrieLength; // Length (bytes) of the serialized Any Case Trie 357 358 int32_t fLowerCaseTrie; // byte offset to the serialized Lower Case Trie 359 int32_t fLowerCaseTrieLength; // Length (bytes) of the serialized Lower Case Trie 360 361 int32_t fScriptSets; // byte offset to array of ScriptSets 362 int32_t fScriptSetsLength; // Number of ScriptSets (24 bytes each) 363 364 365 // The following sections are for data from xidmodifications.txt 366 367 368 int32_t unused[15]; // Padding, Room for Expansion 369 370 }; 371 372 373 374 375 // 376 // Structure for the Whole Script Confusable Data 377 // See Unicode UAX-39, Unicode Security Mechanisms, for a description of the 378 // Whole Script confusable data 379 // 380 // The data provides mappings from code points to a set of scripts 381 // that contain characters that might be confused with the code point. 382 // There are two mappings, one for lower case only, and one for characters 383 // of any case. 384 // 385 // The actual data consists of a utrie2 to map from a code point to an offset, 386 // and an array of UScriptSets (essentially bit maps) that is indexed 387 // by the offsets obtained from the Trie. 388 // 389 // 390 391 392 U_NAMESPACE_END 393 #endif /* XP_CPLUSPLUS */ 394 395 /** 396 * Endianness swap function for binary spoof data. 397 * @internal 398 */ 399 U_CAPI int32_t U_EXPORT2 400 uspoof_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData, 401 UErrorCode *status); 402 403 404 #endif 405 406 #endif /* USPOOFIM_H */ 407 408