/*
***************************************************************************
* Copyright (C) 2008-2010, International Business Machines Corporation
* and others. All Rights Reserved.
***************************************************************************
*
* uspoof_impl.h
*
* Implemenation header for spoof detection
*
*/
#ifndef USPOOFIM_H
#define USPOOFIM_H
#include "unicode/utypes.h"
#include "unicode/uspoof.h"
#include "utrie2.h"
#include "unicode/uscript.h"
#include "unicode/udata.h"
#if !UCONFIG_NO_NORMALIZATION
#ifdef XP_CPLUSPLUS
U_NAMESPACE_BEGIN
// The maximium length (in UTF-16 UChars) of the skeleton replacement string resulting from
// a single input code point. This is function of the unicode.org data.
#define USPOOF_MAX_SKELETON_EXPANSION 20
// The default stack buffer size for copies or conversions or normalizations
// of input strings being checked. (Used in multiple places.)
#define USPOOF_STACK_BUFFER_SIZE 100
// Magic number for sanity checking spoof data.
#define USPOOF_MAGIC 0x3845fdef
class SpoofData;
struct SpoofDataHeader;
struct SpoofStringLengthsElement;
class ScriptSet;
/**
* Class SpoofImpl corresponds directly to the plain C API opaque type
* USpoofChecker. One can be cast to the other.
*/
class SpoofImpl : public UObject {
public:
SpoofImpl(SpoofData *data, UErrorCode &status);
SpoofImpl();
virtual ~SpoofImpl();
/** Copy constructor, used by the user level uspoof_clone() function.
*/
SpoofImpl(const SpoofImpl &src, UErrorCode &status);
static SpoofImpl *validateThis(USpoofChecker *sc, UErrorCode &status);
static const SpoofImpl *validateThis(const USpoofChecker *sc, UErrorCode &status);
/** Get the confusable skeleton transform for a single code point.
* The result is a string with a length between 1 and 18.
* @param tableMask bit flag specifying which confusable table to use.
* One of USPOOF_SL_TABLE_FLAG, USPOOF_MA_TABLE_FLAG, etc.
* @return The length in UTF-16 code units of the substition string.
*/
int32_t confusableLookup(UChar32 inChar, int32_t tableMask, UChar *destBuf) const;
/** Set and Get AllowedLocales, implementations of the corresponding API */
void setAllowedLocales(const char *localesList, UErrorCode &status);
const char * getAllowedLocales(UErrorCode &status);
// Add (union) to the UnicodeSet all of the characters for the scripts used for
// the specified locale. Part of the implementation of setAllowedLocales.
void addScriptChars(const char *locale, UnicodeSet *allowedChars, UErrorCode &status);
/** parse a hex number. Untility used by the builders. */
static UChar32 ScanHex(const UChar *s, int32_t start, int32_t limit, UErrorCode &status);
// Implementation for Whole Script tests.
// Return the test bit flag to be ORed into the eventual user return value
// if a Spoof opportunity is detected.
void wholeScriptCheck(
const UChar *text, int32_t length, ScriptSet *result, UErrorCode &status) const;
/** Scan a string to determine how many scripts it includes.
* Ignore characters with script=Common and scirpt=Inherited.
* @param text The UChar text to be scanned
* @param length The length of the input text, -1 for nul termintated.
* @param pos An out parameter, set to the first input postion at which
* a second script was encountered, ignoring Common and Inherited.
* @param status For errors.
* @return the number of (non-common,inherited) scripts encountered,
* clipped to a max of two.
*/
int32_t scriptScan(const UChar *text, int32_t length, int32_t &pos, UErrorCode &status) const;
// WholeScript and MixedScript check implementation.
//
ScriptSet *WholeScriptCheck(const UChar *text, int32_t length, UErrorCode &status) const;
static UClassID U_EXPORT2 getStaticClassID(void);
virtual UClassID getDynamicClassID(void) const;
//
// Data Members
//
int32_t fMagic; // Internal sanity check.
int32_t fChecks; // Bit vector of checks to perform.
SpoofData *fSpoofData;
int32_t fCheckMask; // Spoof table selector. f(Check Type)
const UnicodeSet *fAllowedCharsSet; // The UnicodeSet of allowed characters.
// for this Spoof Checker. Defaults to all chars.
const char *fAllowedLocales; // The list of allowed locales.
};
//
// Confusable Mappings Data Structures
//
// For the confusable data, we are essentially implementing a map,
// key: a code point
// value: a string. Most commonly one char in length, but can be more.
//
// The keys are stored as a sorted array of 32 bit ints.
// bits 0-23 a code point value
// bits 24-31 flags
// 24: 1 if entry applies to SL table
// 25: 1 if entry applies to SA table
// 26: 1 if entry applies to ML table
// 27: 1 if entry applies to MA table
// 28: 1 if there are multiple entries for this code point.
// 29-30: length of value string, in UChars.
// values are (1, 2, 3, other)
// The key table is sorted in ascending code point order. (not on the
// 32 bit int value, the flag bits do not participate in the sorting.)
//
// Lookup is done by means of a binary search in the key table.
//
// The corresponding values are kept in a parallel array of 16 bit ints.
// If the value string is of length 1, it is literally in the value array.
// For longer strings, the value array contains an index into the strings table.
//
// String Table:
// The strings table contains all of the value strings (those of length two or greater)
// concatentated together into one long UChar (UTF-16) array.
//
// The array is arranged by length of the strings - all strings of the same length
// are stored together. The sections are ordered by length of the strings -
// all two char strings first, followed by all of the three Char strings, etc.
//
// There is no nul character or other mark between adjacent strings.
//
// String Lengths table
// The length of strings from 1 to 3 is flagged in the key table.
// For strings of length 4 or longer, the string length table provides a
// mapping between an index into the string table and the corresponding length.
// Strings of these lengths are rare, so lookup time is not an issue.
// Each entry consists of
// uint16_t index of the _last_ string with this length
// uint16_t the length
//
// Flag bits in the Key entries
#define USPOOF_SL_TABLE_FLAG (1<<24)
#define USPOOF_SA_TABLE_FLAG (1<<25)
#define USPOOF_ML_TABLE_FLAG (1<<26)
#define USPOOF_MA_TABLE_FLAG (1<<27)
#define USPOOF_KEY_MULTIPLE_VALUES (1<<28)
#define USPOOF_KEY_LENGTH_SHIFT 29
#define USPOOF_KEY_LENGTH_FIELD(x) (((x)>>29) & 3)
struct SpoofStringLengthsElement {
uint16_t fLastString; // index in string table of last string with this length
uint16_t fStrLength; // Length of strings
};
//-------------------------------------------------------------------------------
//
// ScriptSet - Wrapper class for the Script code bit sets that are part of the
// whole script confusable data.
//
// This class is used both at data build and at run time.
// The constructor is only used at build time.
// At run time, just point at the prebuilt data and go.
//
//-------------------------------------------------------------------------------
class ScriptSet: public UMemory {
public:
ScriptSet();
~ScriptSet();
UBool operator == (const ScriptSet &other);
ScriptSet & operator = (const ScriptSet &other);
void Union(const ScriptSet &other);
void Union(UScriptCode script);
void intersect(const ScriptSet &other);
void intersect(UScriptCode script);
void setAll();
void resetAll();
int32_t countMembers();
private:
uint32_t bits[6];
};
//-------------------------------------------------------------------------------
//
// NFKDBuffer A little class to handle the NFKD normalization that is
// needed on incoming identifiers to be checked.
// Takes care of buffer handling and normalization
//
// Instances of this class are intended to be stack-allocated.
//
// TODO: how to map position offsets back to user values?
//
//--------------------------------------------------------------------------------
class NFKDBuffer: public UMemory {
public:
NFKDBuffer(const UChar *text, int32_t length, UErrorCode &status);
~NFKDBuffer();
const UChar *getBuffer();
int32_t getLength();
private:
const UChar *fOriginalText;
UChar *fNormalizedText;
int32_t fNormalizedTextLength;
UChar fSmallBuf[USPOOF_STACK_BUFFER_SIZE];
};
//-------------------------------------------------------------------------------------
//
// SpoofData
//
// A small class that wraps the raw (usually memory mapped) spoof data.
// Serves two primary functions:
// 1. Convenience. Contains real pointers to the data, to avoid dealing with
// the offsets in the raw data.
// 2. Reference counting. When a spoof checker is cloned, the raw data is shared
// and must be retained until all checkers using the data are closed.
// Nothing in this struct includes state that is specific to any particular
// USpoofDetector object.
//
//---------------------------------------------------------------------------------------
class SpoofData: public UMemory {
public:
static SpoofData *getDefault(UErrorCode &status); // Load standard ICU spoof data.
SpoofData(UErrorCode &status); // Create new spoof data wrapper.
// Only used when building new data from rules.
// Constructor for use when creating from prebuilt default data.
// A UDataMemory is what the ICU internal data loading functions provide.
// The udm is adopted by the SpoofData.
SpoofData(UDataMemory *udm, UErrorCode &status);
// Constructor for use when creating from serialized data.
//
SpoofData(const void *serializedData, int32_t length, UErrorCode &status);
// Check raw Spoof Data Version compatibility.
// Return TRUE it looks good.
static UBool validateDataVersion(const SpoofDataHeader *rawData, UErrorCode &status);
~SpoofData(); // Destructor not normally used.
// Use removeReference() instead.
// Reference Counting functions.
// Clone of a user-level spoof detector increments the ref count on the data.
// Close of a user-level spoof detector decrements the ref count.
// If the data is owned by us, it will be deleted when count goes to zero.
SpoofData *addReference();
void removeReference();
// Reserve space in the raw data. For use by builder when putting together a
// new set of data. Init the new storage to zero, to prevent inconsistent
// results if it is not all otherwise set by the requester.
// Return:
// pointer to the new space that was added by this function.
void *reserveSpace(int32_t numBytes, UErrorCode &status);
// initialize the pointers from this object to the raw data.
void initPtrs(UErrorCode &status);
// Reset all fields to an initial state.
// Called from the top of all constructors.
void reset();
SpoofDataHeader *fRawData; // Ptr to the raw memory-mapped data
UBool fDataOwned; // True if the raw data is owned, and needs
// to be deleted when refcount goes to zero.
UDataMemory *fUDM; // If not NULL, our data came from a
// UDataMemory, which we must close when
// we're done.
uint32_t fMemLimit; // Limit of available raw data space
int32_t fRefCount;
// Confusable data
int32_t *fCFUKeys;
uint16_t *fCFUValues;
SpoofStringLengthsElement *fCFUStringLengths;
UChar *fCFUStrings;
// Whole Script Confusable Data
UTrie2 *fAnyCaseTrie;
UTrie2 *fLowerCaseTrie;
ScriptSet *fScriptSets;
};
//---------------------------------------------------------------------------------------
//
// Raw Binary Data Formats, as loaded from the ICU data file,
// or as built by the builder.
//
//---------------------------------------------------------------------------------------
struct SpoofDataHeader {
int32_t fMagic; // (0x3845fdef)
uint8_t fFormatVersion[4]; // Data Format. Same as the value in struct UDataInfo
// if there is one associated with this data.
int32_t fLength; // Total lenght in bytes of this spoof data,
// including all sections, not just the header.
// The following four sections refer to data representing the confusable data
// from the Unicode.org data from "confusables.txt"
int32_t fCFUKeys; // byte offset to Keys table (from SpoofDataHeader *)
int32_t fCFUKeysSize; // number of entries in keys table (32 bits each)
// TODO: change name to fCFUValues, for consistency.
int32_t fCFUStringIndex; // byte offset to String Indexes table
int32_t fCFUStringIndexSize; // number of entries in String Indexes table (16 bits each)
// (number of entries must be same as in Keys table
int32_t fCFUStringTable; // byte offset of String table
int32_t fCFUStringTableLen; // length of string table (in 16 bit UChars)
int32_t fCFUStringLengths; // byte offset to String Lengths table
int32_t fCFUStringLengthsSize; // number of entries in lengths table. (2 x 16 bits each)
// The following sections are for data from confusablesWholeScript.txt
int32_t fAnyCaseTrie; // byte offset to the serialized Any Case Trie
int32_t fAnyCaseTrieLength; // Length (bytes) of the serialized Any Case Trie
int32_t fLowerCaseTrie; // byte offset to the serialized Lower Case Trie
int32_t fLowerCaseTrieLength; // Length (bytes) of the serialized Lower Case Trie
int32_t fScriptSets; // byte offset to array of ScriptSets
int32_t fScriptSetsLength; // Number of ScriptSets (24 bytes each)
// The following sections are for data from xidmodifications.txt
int32_t unused[15]; // Padding, Room for Expansion
};
//
// Structure for the Whole Script Confusable Data
// See Unicode UAX-39, Unicode Security Mechanisms, for a description of the
// Whole Script confusable data
//
// The data provides mappings from code points to a set of scripts
// that contain characters that might be confused with the code point.
// There are two mappings, one for lower case only, and one for characters
// of any case.
//
// The actual data consists of a utrie2 to map from a code point to an offset,
// and an array of UScriptSets (essentially bit maps) that is indexed
// by the offsets obtained from the Trie.
//
//
U_NAMESPACE_END
#endif /* XP_CPLUSPLUS */
/**
* Endianness swap function for binary spoof data.
* @internal
*/
U_CAPI int32_t U_EXPORT2
uspoof_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData,
UErrorCode *status);
#endif
#endif /* USPOOFIM_H */