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/*
***************************************************************************
* Copyright (C) 2008-2011, International Business Machines Corporation
* and others. All Rights Reserved.
***************************************************************************
*
* Unicode Spoof Detection
*/
package com.ibm.icu.text;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.LineNumberReader;
import java.io.Reader;
import java.text.ParseException;
import java.util.Collections;
import java.util.Comparator;
import java.util.Hashtable;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.Vector;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.ibm.icu.impl.Trie2;
import com.ibm.icu.impl.Trie2Writable;
import com.ibm.icu.lang.UCharacter;
import com.ibm.icu.lang.UCharacterCategory;
import com.ibm.icu.lang.UProperty;
import com.ibm.icu.lang.UScript;
import com.ibm.icu.util.ULocale;
/**
*
* <b>Unicode Security and Spoofing Detection.</b>
*
* <p>This class is intended to check strings, typically
* identifiers of some type, such as URLs, for the presence of
* characters that are likely to be visually confusing -
* for cases where the displayed form of an identifier may
* not be what it appears to be.
*
* <p>Unicode Technical Report #36,
* <a href="http://unicode.org/reports/tr36">http://unicode.org/reports/tr36</a> and
* Unicode Technical Standard #39,
* <a href="http://unicode.org/reports/tr39">http://unicode.org/reports/tr39</a>
* "Unicode security considerations", give more background on
* security and spoofing issues with Unicode identifiers.
* The tests and checks provided by this module implement the recommendations
* from these Unicode documents.
*
* <p>The tests available on identifiers fall into two general categories:
* <ul>
* <li> Single identifier tests. Check whether an identifier is
* potentially confusable with any other string, or is suspicious
* for other reasons. </li>
* <li> Two identifier tests. Check whether two specific identifiers are confusable.
* This does not consider whether either of strings is potentially
* confusable with any string other than the exact one specified. </li>
* </ul>
*
* <p>The steps to perform confusability testing are
* <ul>
* <li> Create a <code>SpoofChecker.Builder</code> </li>
* <li> Configure the Builder for the desired set of tests. The tests that will
* be performed are specified by a set of SpoofCheck flags. </li>
* <li> Build a <code>SpoofChecker</code> from the Builder. </li>
* <li> Perform the checks using the pre-configured <code>SpoofChecker</code>. The results indicate
* which (if any) of the selected tests have identified possible problems with the identifier.
* Results are reported as a set of SpoofCheck flags; this mirrors the form in which
* the set of tests to perform was originally specified to the SpoofChecker. </li>
* </ul>
*
* <p>A <code>SpoofChecker</code> instance may be used repeatedly to perform checks on any number
* of identifiers.
*
* <p>Thread Safety: The methods on SpoofChecker objects are thread safe.
* The test functions for checking a single identifier, or for testing
* whether two identifiers are potentially confusable, may called concurrently
* from multiple threads using the same SpoofChecker instance.
*
*
* <p>Descriptions of the available checks.
*
* <p>When testing whether pairs of identifiers are confusable, with <code>areConfusable()</code>
* the relevant tests are
*
* <ul>
* <li> <code>SINGLE_SCRIPT_CONFUSABLE</code>: All of the characters from the two identifiers are
* from a single script, and the two identifiers are visually confusable.</li>
* <li> <code>MIXED_SCRIPT_CONFUSABLE</code>: At least one of the identifiers contains characters
* from more than one script, and the two identifiers are visually confusable.</li>
* <li> <code>WHOLE_SCRIPT_CONFUSABLE</code>: Each of the two identifiers is of a single script, but
* the the two identifiers are from different scripts, and they are visually confusable.</li>
* </ul>
*
* <p>The safest approach is to enable all three of these checks as a group.
*
* <p><code>ANY_CASE</code> is a modifier for the above tests. If the identifiers being checked can
* be of mixed case and are used in a case-sensitive manner, this option should be specified.
*
* <p>If the identifiers being checked are used in a case-insensitive manner, and if they are
* displayed to users in lower-case form only, the <code>ANY_CASE</code> option should not be
* specified. Confusabality issues involving upper case letters will not be reported.
*
* <p>When performing tests on a single identifier, with the check() family of functions,
* the relevant tests are:
*
* <ul>
* <li><code>MIXED_SCRIPT_CONFUSABLE</code>: the identifier contains characters from multiple
* scripts, and there exists an identifier of a single script that is visually confusable.</li>
* <li><code>WHOLE_SCRIPT_CONFUSABLE</code>: the identifier consists of characters from a single
* script, and there exists a visually confusable identifier.
* The visually confusable identifier also consists of characters from a single script.
* but not the same script as the identifier being checked.</li>
* <li><code>ANY_CASE</code>: modifies the mixed script and whole script confusables tests. If
* specified, the checks will find confusable characters of any case.
* If this flag is not set, the test is performed assuming case folded identifiers.</li>
* <li><code>SINGLE_SCRIPT</code>: check that the identifier contains only characters from a
* single script. (Characters from the <em>common</em> and <em>inherited</em> scripts are ignored.)
* This is not a test for confusable identifiers</li>
* <li><code>INVISIBLE</code>: check an identifier for the presence of invisible characters,
* such as zero-width spaces, or character sequences that are
* likely not to display, such as multiple occurrences of the same
* non-spacing mark. This check does not test the input string as a whole
* for conformance to any particular syntax for identifiers.</li>
* <li><code>CHAR_LIMIT</code>: check that an identifier contains only characters from a specified set
* of acceptable characters. See <code>Builder.setAllowedChars()</code> and
* <code>Builder.setAllowedLocales()</code>.</li>
* </ul>
*
* <p>Note on Scripts:
* <blockquote>Characters from the Unicode Scripts "Common" and "Inherited" are ignored when considering
* the script of an identifier. Common characters include digits and symbols that
* are normally used with text from many different scripts. </blockquote>
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public class SpoofChecker {
/**
* Constants for the kinds of checks that USpoofChecker can perform. These values are used both to select the set of
* checks that will be performed, and to report results from the check function.
*
*/
/**
* Single script confusable test. When testing whether two identifiers are confusable, report that they are if both
* are from the same script and they are visually confusable. Note: this test is not applicable to a check of a
* single identifier.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int SINGLE_SCRIPT_CONFUSABLE = 1;
/**
* Mixed script confusable test.
*
* When checking a single identifier, report a problem if the identifier contains multiple scripts, and is also
* confusable with some other identifier in a single script.
*
* When testing whether two identifiers are confusable, report that they are if the two IDs are visually confusable,
* and and at least one contains characters from more than one script.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int MIXED_SCRIPT_CONFUSABLE = 2;
/**
* Whole script confusable test.
*
* When checking a single identifier, report a problem if The identifier is of a single script, and there exists a
* confusable identifier in another script.
*
* When testing whether two Identifiers are confusable, report that they are if each is of a single script, the
* scripts of the two identifiers are different, and the identifiers are visually confusable.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int WHOLE_SCRIPT_CONFUSABLE = 4;
/**
* Any Case Modifier for confusable identifier tests.
*
* When specified, consider all characters, of any case, when looking for confusables. If ANY_CASE is not specified,
* identifiers being checked are assumed to have been case folded, and upper case conusable characters will not be
* checked.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int ANY_CASE = 8;
/**
* Check that an identifer contains only characters from a single script (plus chars from the common and inherited
* scripts.) Applies to checks of a single identifier check only.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int SINGLE_SCRIPT = 16;
/**
* Check an identifier for the presence of invisible characters, such as zero-width spaces, or character sequences
* that are likely not to display, such as multiple occurrences of the same non-spacing mark. This check does not
* test the input string as a whole for conformance to any particular syntax for identifiers.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int INVISIBLE = 32;
/**
* Check that an identifier contains only characters from a specified set of acceptable characters. See
* Builder.setAllowedChars() and Builder.setAllowedLocales().
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int CHAR_LIMIT = 64;
/**
* Enable all spoof checks.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static final int ALL_CHECKS = 0x7f;
// Magic number for sanity checking spoof binary resource data.
static final int MAGIC = 0x3845fdef;
/**
* private constructor: a SpoofChecker has to be built by the builder
*/
private SpoofChecker() {
}
/**
* SpoofChecker Builder. To create a SpoofChecker, first instantiate a SpoofChecker.Builder, set the desired
* checking options on the builder, then call the build() function to create a SpoofChecker instance.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static class Builder {
int fMagic; // Internal sanity check.
int fChecks; // Bit vector of checks to perform.
SpoofData fSpoofData;
UnicodeSet fAllowedCharsSet; // The UnicodeSet of allowed characters.
// for this Spoof Checker. Defaults to all chars.
Set<ULocale> fAllowedLocales; // The list of allowed locales.
/**
* Constructor: Create a default Unicode Spoof Checker Builder, configured to perform all checks except for
* LOCALE_LIMIT and CHAR_LIMIT. Note that additional checks may be added in the future, resulting in the changes
* to the default checking behavior.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public Builder() {
fMagic = MAGIC;
fChecks = ALL_CHECKS;
fSpoofData = null;
fAllowedCharsSet = new UnicodeSet(0, 0x10ffff);
fAllowedLocales = new LinkedHashSet<ULocale>();
}
/**
* Constructor: Create a Spoof Checker Builder, and set the configuration from an existing SpoofChecker.
*
* @param src
* The existing checker.
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public Builder(SpoofChecker src) {
fMagic = src.fMagic;
fChecks = src.fChecks;
fSpoofData = null;
fAllowedCharsSet = src.fAllowedCharsSet.cloneAsThawed();
fAllowedLocales = new LinkedHashSet<ULocale>();
fAllowedLocales.addAll(src.fAllowedLocales);
}
/**
* Create a SpoofChecker with current configuration.
*
* @return SpoofChecker
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public SpoofChecker build() {
if (fSpoofData == null) { // read binary file
try {
fSpoofData = SpoofData.getDefault();
} catch (java.io.IOException e) {
return null;
}
}
if (!SpoofData.validateDataVersion(fSpoofData.fRawData)) {
return null;
}
SpoofChecker result = new SpoofChecker();
result.fMagic = this.fMagic;
result.fChecks = this.fChecks;
result.fSpoofData = this.fSpoofData;
result.fAllowedCharsSet = (UnicodeSet) (this.fAllowedCharsSet.clone());
result.fAllowedCharsSet.freeze();
result.fAllowedLocales = this.fAllowedLocales;
return result;
}
/**
* Specify the source form of the spoof data Spoof Checker. The Three inputs correspond to the Unicode data
* files confusables.txt and confusablesWholeScript.txt as described in Unicode UAX 39. The syntax of the source
* data is as described in UAX 39 for these files, and the content of these files is acceptable input.
*
* @param confusables
* the Reader of confusable characters definitions, as found in file confusables.txt from
* unicode.org.
* @param confusablesWholeScript
* the Reader of whole script confusables definitions, as found in the file
* xonfusablesWholeScript.txt from unicode.org.
* @throws ParseException
* To report syntax errors in the input.
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public Builder setData(Reader confusables, Reader confusablesWholeScript) throws ParseException,
java.io.IOException {
// Set up a shell of a spoof detector, with empty data.
fSpoofData = new SpoofData();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
DataOutputStream os = new DataOutputStream(bos);
// Compile the binary data from the source (text) format.
ConfusabledataBuilder.buildConfusableData(fSpoofData, confusables);
WSConfusableDataBuilder.buildWSConfusableData(fSpoofData, os, confusablesWholeScript);
return this;
}
/**
* Specify the set of checks that will be performed by the check functions of this Spoof Checker.
*
* @param checks
* The set of checks that this spoof checker will perform. The value is an 'or' of the desired
* checks.
* @return self
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public Builder setChecks(int checks) {
// Verify that the requested checks are all ones (bits) that
// are acceptable, known values.
if (0 != (checks & ~SpoofChecker.ALL_CHECKS)) {
throw new IllegalArgumentException("Bad Spoof Checks value.");
}
this.fChecks = (checks & SpoofChecker.ALL_CHECKS);
return this;
}
/**
* Limit characters that are acceptable in identifiers being checked to those normally used with the languages
* associated with the specified locales. Any previously specified list of locales is replaced by the new
* settings.
*
* A set of languages is determined from the locale(s), and from those a set of acceptable Unicode scripts is
* determined. Characters from this set of scripts, along with characters from the "common" and "inherited"
* Unicode Script categories will be permitted.
*
* Supplying an empty string removes all restrictions; characters from any script will be allowed.
*
* The CHAR_LIMIT test is automatically enabled for this SpoofChecker when calling this function with a
* non-empty list of locales.
*
* The Unicode Set of characters that will be allowed is accessible via the getAllowedChars() function.
* setAllowedLocales() will <i>replace</i> any previously applied set of allowed characters.
*
* Adjustments, such as additions or deletions of certain classes of characters, can be made to the result of
* setAllowedLocales() by fetching the resulting set with getAllowedChars(), manipulating it with the Unicode
* Set API, then resetting the spoof detectors limits with setAllowedChars()
*
* @param locales
* A Set of ULocales, from which the language and associated script are extracted. If the locales Set
* is null, no restrictions will be placed on the allowed characters.
*
* @return self
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public Builder setAllowedLocales(Set<ULocale> locales) {
fAllowedCharsSet.clear();
for (ULocale locale : locales) {
// Add the script chars for this locale to the accumulating set
// of allowed chars.
addScriptChars(locale, fAllowedCharsSet);
}
// If our caller provided an empty list of locales, we disable the
// allowed characters checking
fAllowedLocales = new LinkedHashSet<ULocale>();
if (locales.size() == 0) {
fAllowedCharsSet.add(0, 0x10ffff);
fChecks &= ~CHAR_LIMIT;
return this;
}
// Add all common and inherited characters to the set of allowed
// chars.
UnicodeSet tempSet = new UnicodeSet();
tempSet.applyIntPropertyValue(UProperty.SCRIPT, UScript.COMMON);
fAllowedCharsSet.addAll(tempSet);
tempSet.applyIntPropertyValue(UProperty.SCRIPT, UScript.INHERITED);
fAllowedCharsSet.addAll(tempSet);
// Store the updated spoof checker state.
fAllowedLocales.addAll(locales);
fChecks |= CHAR_LIMIT;
return this;
}
// Add (union) to the UnicodeSet all of the characters for the scripts
// used for the specified locale. Part of the implementation of
// setAllowedLocales.
private void addScriptChars(ULocale locale, UnicodeSet allowedChars) {
int scripts[] = UScript.getCode(locale);
UnicodeSet tmpSet = new UnicodeSet();
int i;
for (i = 0; i < scripts.length; i++) {
tmpSet.applyIntPropertyValue(UProperty.SCRIPT, scripts[i]);
allowedChars.addAll(tmpSet);
}
}
/**
* Limit the acceptable characters to those specified by a Unicode Set. Any previously specified character limit
* is is replaced by the new settings. This includes limits on characters that were set with the
* setAllowedLocales() function.
*
* The CHAR_LIMIT test is automatically enabled for this SpoofChecker by this function.
*
* @param chars
* A Unicode Set containing the list of characters that are permitted. The incoming set is cloned by
* this function, so there are no restrictions on modifying or deleting the UnicodeSet after calling
* this function. Note that this clears the allowedLocales set.
* @return self
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public Builder setAllowedChars(UnicodeSet chars) {
fAllowedCharsSet = chars.cloneAsThawed();
fAllowedLocales = new LinkedHashSet<ULocale>();
fChecks |= CHAR_LIMIT;
return this;
}
// 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.
//
//
/*
* Internal functions for compililing Whole Script confusable source data into its binary (runtime) form. The
* binary data format is described in uspoof_impl.h
*/
private static class WSConfusableDataBuilder {
// Regular expression for parsing a line from the Unicode file
// confusablesWholeScript.txt
// Example Lines:
// 006F ; Latn; Deva; A # (o) LATIN SMALL LETTER O
// 0048..0049 ; Latn; Grek; A # [2] (H..I) LATIN CAPITAL LETTER H..LATIN
// CAPITAL LETTER I
// | | | |
// | | | |---- Which table, Any Case or Lower Case (A or L)
// | | |----------Target script. We need this.
// | |----------------Src script. Should match the script of the source
// | code points. Beyond checking that, we don't keep it.
// |--------------------------------Source code points or range.
//
// The expression will match _all_ lines, including erroneous lines.
// The result of the parse is returned via the contents of the (match)
// groups.
static String parseExp =
"(?m)" + // Multi-line mode
"^([ \\t]*(?:#.*?)?)$" + // A blank or comment line. Matches Group
// 1.
"|^(?:" + // OR
"\\s*([0-9A-F]{4,})(?:..([0-9A-F]{4,}))?\\s*;" + // Code point
// range. Groups
// 2 and 3.
"\\s*([A-Za-z]+)\\s*;" + // The source script. Group 4.
"\\s*([A-Za-z]+)\\s*;" + // The target script. Group 5.
"\\s*(?:(A)|(L))" + // The table A or L. Group 6 or 7
"[ \\t]*(?:#.*?)?" + // Trailing commment
")$|" + // OR
"^(.*?)$"; // An error line. Group 8.
// Any line not matching the preceding
// parts of the expression.will match
// this, and thus be flagged as an error
// Extract a regular expression match group into a char * string.
// The group must contain only invariant characters.
// Used for script names
//
static void readWholeFileToString(Reader reader, StringBuffer buffer) throws java.io.IOException {
// Convert the user input data from UTF-8 to char (UTF-16)
LineNumberReader lnr = new LineNumberReader(reader);
do {
String line = lnr.readLine();
if (line == null) {
break;
}
buffer.append(line);
buffer.append('\n');
} while (true);
}
// Build the Whole Script Confusable data
//
static void buildWSConfusableData(SpoofData fSpoofData, DataOutputStream os, Reader confusablesWS)
throws ParseException, java.io.IOException {
Pattern parseRegexp = null;
StringBuffer input = new StringBuffer();
int lineNum = 0;
Vector<BuilderScriptSet> scriptSets = null;
int rtScriptSetsCount = 2;
Trie2Writable anyCaseTrie = new Trie2Writable(0, 0);
Trie2Writable lowerCaseTrie = new Trie2Writable(0, 0);
// The scriptSets vector provides a mapping from TRIE values to the set
// of scripts.
//
// Reserved TRIE values:
// 0: Code point has no whole script confusables.
// 1: Code point is of script Common or Inherited.
// These code points do not participate in whole script confusable
// detection.
// (This is logically equivalent to saying that they contain confusables
// in all scripts)
//
// Because Trie values are indexes into the ScriptSets vector, pre-fill
// vector positions 0 and 1 to avoid conflicts with the reserved values.
scriptSets = new Vector<BuilderScriptSet>();
scriptSets.addElement(null);
scriptSets.addElement(null);
readWholeFileToString(confusablesWS, input);
parseRegexp = Pattern.compile(parseExp);
// Zap any Byte Order Mark at the start of input. Changing it to a space
// is benign
// given the syntax of the input.
if (input.charAt(0) == 0xfeff) {
input.setCharAt(0, (char) 0x20);
}
// Parse the input, one line per iteration of this loop.
Matcher matcher = parseRegexp.matcher(input);
while (matcher.find()) {
lineNum++;
if (matcher.start(1) >= 0) {
// this was a blank or comment line.
continue;
}
if (matcher.start(8) >= 0) {
// input file syntax error.
throw new ParseException("ConfusablesWholeScript, line " + lineNum + ": Unrecognized input: "
+ matcher.group(), matcher.start());
}
// Pick up the start and optional range end code points from the
// parsed line.
int startCodePoint = Integer.parseInt(matcher.group(2), 16);
if (startCodePoint > 0x10ffff) {
throw new ParseException("ConfusablesWholeScript, line " + lineNum
+ ": out of range code point: " + matcher.group(2), matcher.start(2));
}
int endCodePoint = startCodePoint;
if (matcher.start(3) >= 0) {
endCodePoint = Integer.parseInt(matcher.group(3), 16);
}
if (endCodePoint > 0x10ffff) {
throw new ParseException("ConfusablesWholeScript, line " + lineNum
+ ": out of range code point: " + matcher.group(3), matcher.start(3));
}
// Extract the two script names from the source line.
String srcScriptName = matcher.group(4);
String targScriptName = matcher.group(5);
int srcScript = UCharacter.getPropertyValueEnum(UProperty.SCRIPT, srcScriptName);
int targScript = UCharacter.getPropertyValueEnum(UProperty.SCRIPT, targScriptName);
if (srcScript == UScript.INVALID_CODE) {
throw new ParseException("ConfusablesWholeScript, line " + lineNum
+ ": Invalid script code t: " + matcher.group(4), matcher.start(4));
}
if (targScript == UScript.INVALID_CODE) {
throw new ParseException("ConfusablesWholeScript, line " + lineNum
+ ": Invalid script code t: " + matcher.group(5), matcher.start(5));
}
// select the table - (A) any case or (L) lower case only
Trie2Writable table = anyCaseTrie;
if (matcher.start(7) >= 0) {
table = lowerCaseTrie;
}
// Build the set of scripts containing confusable characters for
// the code point(s) specified in this input line.
// Sanity check that the script of the source code point is the same
// as the source script indicated in the input file. Failure of this
// check is an error in the input file.
//
// Include the source script in the set (needed for Mixed Script
// Confusable detection).
//
int cp;
for (cp = startCodePoint; cp <= endCodePoint; cp++) {
int setIndex = table.get(cp);
BuilderScriptSet bsset = null;
if (setIndex > 0) {
assert (setIndex < scriptSets.size());
bsset = scriptSets.elementAt(setIndex);
} else {
bsset = new BuilderScriptSet();
bsset.codePoint = cp;
bsset.trie = table;
bsset.sset = new ScriptSet();
setIndex = scriptSets.size();
bsset.index = setIndex;
bsset.rindex = 0;
scriptSets.addElement(bsset);
table.set(cp, setIndex);
}
bsset.sset.Union(targScript);
bsset.sset.Union(srcScript);
int cpScript = UScript.getScript(cp);
if (cpScript != srcScript) {
// status = U_INVALID_FORMAT_ERROR;
throw new ParseException("ConfusablesWholeScript, line " + lineNum
+ ": Mismatch between source script and code point " + Integer.toString(cp, 16),
matcher.start(5));
}
}
}
// Eliminate duplicate script sets. At this point we have a separate
// script set for every code point that had data in the input file.
//
// We eliminate underlying ScriptSet objects, not the BuildScriptSets
// that wrap them
//
// printf("Number of scriptSets: %d\n", scriptSets.size());
{
int duplicateCount = 0;
rtScriptSetsCount = 2;
for (int outeri = 2; outeri < scriptSets.size(); outeri++) {
BuilderScriptSet outerSet = scriptSets.elementAt(outeri);
if (outerSet.index != outeri) {
// This set was already identified as a duplicate.
// It will not be allocated a position in the runtime array
// of ScriptSets.
continue;
}
outerSet.rindex = rtScriptSetsCount++;
for (int inneri = outeri + 1; inneri < scriptSets.size(); inneri++) {
BuilderScriptSet innerSet = scriptSets.elementAt(inneri);
if (outerSet.sset.equals(innerSet.sset) && outerSet.sset != innerSet.sset) {
innerSet.sset = outerSet.sset;
innerSet.index = outeri;
innerSet.rindex = outerSet.rindex;
duplicateCount++;
}
// But this doesn't get all. We need to fix the TRIE.
}
}
// printf("Number of distinct script sets: %d\n",
// rtScriptSetsCount);
}
// Update the Trie values to be reflect the run time script indexes
// (after duplicate merging).
// (Trie Values 0 and 1 are reserved, and the corresponding slots in
// scriptSets
// are unused, which is why the loop index starts at 2.)
{
for (int i = 2; i < scriptSets.size(); i++) {
BuilderScriptSet bSet = scriptSets.elementAt(i);
if (bSet.rindex != i) {
bSet.trie.set(bSet.codePoint, bSet.rindex);
}
}
}
// For code points with script==Common or script==Inherited,
// Set the reserved value of 1 into both Tries. These characters do not
// participate
// in Whole Script Confusable detection; this reserved value is the
// means
// by which they are detected.
{
UnicodeSet ignoreSet = new UnicodeSet();
ignoreSet.applyIntPropertyValue(UProperty.SCRIPT, UScript.COMMON);
UnicodeSet inheritedSet = new UnicodeSet();
inheritedSet.applyIntPropertyValue(UProperty.SCRIPT, UScript.INHERITED);
ignoreSet.addAll(inheritedSet);
for (int rn = 0; rn < ignoreSet.getRangeCount(); rn++) {
int rangeStart = ignoreSet.getRangeStart(rn);
int rangeEnd = ignoreSet.getRangeEnd(rn);
anyCaseTrie.setRange(rangeStart, rangeEnd, 1, true);
lowerCaseTrie.setRange(rangeStart, rangeEnd, 1, true);
}
}
// Serialize the data to the Spoof Detector
{
anyCaseTrie.toTrie2_16().serialize(os);
lowerCaseTrie.toTrie2_16().serialize(os);
fSpoofData.fRawData.fScriptSetsLength = rtScriptSetsCount;
int rindex = 2;
for (int i = 2; i < scriptSets.size(); i++) {
BuilderScriptSet bSet = scriptSets.elementAt(i);
if (bSet.rindex < rindex) {
// We have already copied this script set to the serialized
// data.
continue;
}
assert (rindex == bSet.rindex);
bSet.sset.output(os);
rindex++;
}
}
}
// class BuilderScriptSet. Represents the set of scripts (Script Codes)
// containing characters that are confusable with one specific
// code point.
private static class BuilderScriptSet {
int codePoint; // The source code point.
Trie2Writable trie; // Any-case or Lower-case Trie.
// These Trie tables are the final result of the
// build. This flag indicates which of the two
// this set of data is for.
ScriptSet sset; // The set of scripts itself.
// Vectors of all B
int index; // Index of this set in the Build Time vector
// of script sets.
int rindex; // Index of this set in the final (runtime)
// array of sets.
// its underlying sset.
BuilderScriptSet() {
codePoint = -1;
trie = null;
sset = null;
index = 0;
rindex = 0;
}
}
}
/*
* *****************************************************************************
* Internal classes for compililing confusable data into its binary (runtime) form.
* *****************************************************************************
*/
// ---------------------------------------------------------------------
//
// buildConfusableData Compile the source confusable data, as defined by
// the Unicode data file confusables.txt, into the binary
// structures used by the confusable detector.
//
// The binary structures are described in uspoof_impl.h
//
// 1. parse the data, building 4 hash tables, one each for the SL, SA, ML and MA
// tables. Each maps from a int to a String.
//
// 2. Sort all of the strings encountered by length, since they will need to
// be stored in that order in the final string table.
//
// 3. Build a list of keys (UChar32s) from the four mapping tables. Sort the
// list because that will be the ordering of our runtime table.
//
// 4. Generate the run time string table. This is generated before the key & value
// tables because we need the string indexes when building those tables.
//
// 5. Build the run-time key and value tables. These are parallel tables, and
// are built at the same time
// class ConfusabledataBuilder
// An instance of this class exists while the confusable data is being built
// from source.
// It encapsulates the intermediate data structures that are used for building.
// It exports one static function, to do a confusable data build.
private static class ConfusabledataBuilder {
private SpoofData fSpoofData;
private ByteArrayOutputStream bos;
private DataOutputStream os;
private Hashtable<Integer, SPUString> fSLTable;
private Hashtable<Integer, SPUString> fSATable;
private Hashtable<Integer, SPUString> fMLTable;
private Hashtable<Integer, SPUString> fMATable;
private UnicodeSet fKeySet; // A set of all keys (UChar32s) that go into the
// four mapping tables.
// The binary data is first assembled into the following four collections,
// then output to the DataOutputStream os.
private StringBuffer fStringTable;
private Vector<Integer> fKeyVec;
private Vector<Integer> fValueVec;
private Vector<Integer> fStringLengthsTable;
private SPUStringPool stringPool;
private Pattern fParseLine;
private Pattern fParseHexNum;
private int fLineNum;
ConfusabledataBuilder(SpoofData spData, ByteArrayOutputStream bos) {
this.bos = bos;
this.os = new DataOutputStream(bos);
fSpoofData = spData;
fSLTable = new Hashtable<Integer, SPUString>();
fSATable = new Hashtable<Integer, SPUString>();
fMLTable = new Hashtable<Integer, SPUString>();
fMATable = new Hashtable<Integer, SPUString>();
fKeySet = new UnicodeSet();
fKeyVec = new Vector<Integer>();
fValueVec = new Vector<Integer>();
stringPool = new SPUStringPool();
}
void build(Reader confusables) throws ParseException, java.io.IOException {
StringBuffer fInput = new StringBuffer();
WSConfusableDataBuilder.readWholeFileToString(confusables, fInput);
// Regular Expression to parse a line from Confusables.txt. The
// expression will match
// any line. What was matched is determined by examining which capture
// groups have a match.
// Capture Group 1: the source char
// Capture Group 2: the replacement chars
// Capture Group 3-6 the table type, SL, SA, ML, or MA
// Capture Group 7: A blank or comment only line.
// Capture Group 8: A syntactically invalid line. Anything that didn't
// match before.
// Example Line from the confusables.txt source file:
// "1D702 ; 006E 0329 ; SL # MATHEMATICAL ITALIC SMALL ETA ... "
fParseLine = Pattern.compile("(?m)^[ \\t]*([0-9A-Fa-f]+)[ \\t]+;" + // Match
// the
// source
// char
"[ \\t]*([0-9A-Fa-f]+" + // Match the replacement char(s)
"(?:[ \\t]+[0-9A-Fa-f]+)*)[ \\t]*;" + // (continued)
"\\s*(?:(SL)|(SA)|(ML)|(MA))" + // Match the table type
"[ \\t]*(?:#.*?)?$" + // Match any trailing #comment
"|^([ \\t]*(?:#.*?)?)$" + // OR match empty lines or lines with
// only a #comment
"|^(.*?)$"); // OR match any line, which catches illegal lines.
// Regular expression for parsing a hex number out of a space-separated
// list of them.
// Capture group 1 gets the number, with spaces removed.
fParseHexNum = Pattern.compile("\\s*([0-9A-F]+)");
// Zap any Byte Order Mark at the start of input. Changing it to a space
// is benign
// given the syntax of the input.
if (fInput.charAt(0) == 0xfeff) {
fInput.setCharAt(0, (char) 0x20);
}
// Parse the input, one line per iteration of this loop.
Matcher matcher = fParseLine.matcher(fInput);
while (matcher.find()) {
fLineNum++;
if (matcher.start(7) >= 0) {
// this was a blank or comment line.
continue;
}
if (matcher.start(8) >= 0) {
// input file syntax error.
// status = U_PARSE_ERROR;
throw new ParseException("Confusables, line " + fLineNum + ": Unrecognized Line: "
+ matcher.group(8), matcher.start(8));
}
// We have a good input line. Extract the key character and mapping
// string, and
// put them into the appropriate mapping table.
int keyChar = Integer.parseInt(matcher.group(1), 16);
if (keyChar > 0x10ffff) {
throw new ParseException("Confusables, line " + fLineNum + ": Bad code point: "
+ matcher.group(1), matcher.start(1));
}
Matcher m = fParseHexNum.matcher(matcher.group(2));
StringBuffer mapString = new StringBuffer();
while (m.find()) {
int c = Integer.parseInt(m.group(1), 16);
if (keyChar > 0x10ffff) {
throw new ParseException("Confusables, line " + fLineNum + ": Bad code point: "
+ Integer.toString(c, 16), matcher.start(2));
}
mapString.append(c);
}
assert (mapString.length() >= 1);
// Put the map (value) string into the string pool
// This a little like a Java intern() - any duplicates will be
// eliminated.
SPUString smapString = stringPool.addString(mapString.toString());
// Add the char . string mapping to the appropriate table.
Hashtable<Integer, SPUString> table = matcher.start(3) >= 0 ? fSLTable
: matcher.start(4) >= 0 ? fSATable : matcher.start(5) >= 0 ? fMLTable
: matcher.start(6) >= 0 ? fMATable : null;
assert (table != null);
table.put(keyChar, smapString);
fKeySet.add(keyChar);
}
// Input data is now all parsed and collected.
// Now create the run-time binary form of the data.
//
// This is done in two steps. First the data is assembled into vectors
// and strings,
// for ease of construction, then the contents of these collections are
// dumped
// into the actual raw-bytes data storage.
// Build up the string array, and record the index of each string
// therein
// in the (build time only) string pool.
// Strings of length one are not entered into the strings array.
// At the same time, build up the string lengths table, which records
// the
// position in the string table of the first string of each length >= 4.
// (Strings in the table are sorted by length)
stringPool.sort();
fStringTable = new StringBuffer();
fStringLengthsTable = new Vector<Integer>();
int previousStringLength = 0;
int previousStringIndex = 0;
int poolSize = stringPool.size();
int i;
for (i = 0; i < poolSize; i++) {
SPUString s = stringPool.getByIndex(i);
int strLen = s.fStr.length();
int strIndex = fStringTable.length();
assert (strLen >= previousStringLength);
if (strLen == 1) {
// strings of length one do not get an entry in the string
// table.
// Keep the single string character itself here, which is the
// same
// convention that is used in the final run-time string table
// index.
s.fStrTableIndex = s.fStr.charAt(0);
} else {
if ((strLen > previousStringLength) && (previousStringLength >= 4)) {
fStringLengthsTable.addElement(previousStringIndex);
fStringLengthsTable.addElement(previousStringLength);
}
s.fStrTableIndex = strIndex;
fStringTable.append(s.fStr);
}
previousStringLength = strLen;
previousStringIndex = strIndex;
}
// Make the final entry to the string lengths table.
// (it holds an entry for the _last_ string of each length, so adding
// the
// final one doesn't happen in the main loop because no longer string
// was encountered.)
if (previousStringLength >= 4) {
fStringLengthsTable.addElement(previousStringIndex);
fStringLengthsTable.addElement(previousStringLength);
}
// Construct the compile-time Key and Value tables
//
// For each key code point, check which mapping tables it applies to,
// and create the final data for the key & value structures.
//
// The four logical mapping tables are conflated into one combined
// table.
// If multiple logical tables have the same mapping for some key, they
// share a single entry in the combined table.
// If more than one mapping exists for the same key code point, multiple
// entries will be created in the table
for (int range = 0; range < fKeySet.getRangeCount(); range++) {
// It is an oddity of the UnicodeSet API that simply enumerating the
// contained
// code points requires a nested loop.
for (int keyChar = fKeySet.getRangeStart(range); keyChar <= fKeySet.getRangeEnd(range); keyChar++) {
addKeyEntry(keyChar, fSLTable, SpoofChecker.SL_TABLE_FLAG);
addKeyEntry(keyChar, fSATable, SpoofChecker.SA_TABLE_FLAG);
addKeyEntry(keyChar, fMLTable, SpoofChecker.ML_TABLE_FLAG);
addKeyEntry(keyChar, fMATable, SpoofChecker.MA_TABLE_FLAG);
}
}
// Put the assembled data into the flat runtime array
outputData();
// All of the intermediate allocated data belongs to the
// ConfusabledataBuilder object (this), and is deleted by Java GC.
}
// Add an entry to the key and value tables being built
// input: data from SLTable, MATable, etc.
// outut: entry added to fKeyVec and fValueVec
// addKeyEntry Construction of the confusable Key and Mapping Values tables.
// This is an intermediate point in the building process.
// We already have the mappings in the hash tables fSLTable, etc.
// This function builds corresponding run-time style table entries into
// fKeyVec and fValueVec
void addKeyEntry(int keyChar, // The key character
Hashtable<Integer, SPUString> table, // The table, one of SATable,
// MATable, etc.
int tableFlag) { // One of SA_TABLE_FLAG, etc.
SPUString targetMapping = table.get(keyChar);
if (targetMapping == null) {
// No mapping for this key character.
// (This function is called for all four tables for each key char
// that
// is seen anywhere, so this no entry cases are very much expected.)
return;
}
// Check whether there is already an entry with the correct mapping.
// If so, simply set the flag in the keyTable saying that the existing
// entry
// applies to the table that we're doing now.
boolean keyHasMultipleValues = false;
int i;
for (i = fKeyVec.size() - 1; i >= 0; i--) {
int key = fKeyVec.elementAt(i);
if ((key & 0x0ffffff) != keyChar) {
// We have now checked all existing key entries for this key
// char (if any)
// without finding one with the same mapping.
break;
}
String mapping = getMapping(i);
if (mapping.equals(targetMapping.fStr)) {
// The run time entry we are currently testing has the correct
// mapping.
// Set the flag in it indicating that it applies to the new
// table also.
key |= tableFlag;
fKeyVec.setElementAt(key, i);
return;
}
keyHasMultipleValues = true;
}
// Need to add a new entry to the binary data being built for this
// mapping.
// Includes adding entries to both the key table and the parallel values
// table.
int newKey = keyChar | tableFlag;
if (keyHasMultipleValues) {
newKey |= SpoofChecker.KEY_MULTIPLE_VALUES;
}
int adjustedMappingLength = targetMapping.fStr.length() - 1;
if (adjustedMappingLength > 3) {
adjustedMappingLength = 3;
}
newKey |= adjustedMappingLength << SpoofChecker.KEY_LENGTH_SHIFT;
int newData = targetMapping.fStrTableIndex;
fKeyVec.addElement(newKey);
fValueVec.addElement(newData);
// If the preceding key entry is for the same key character (but with a
// different mapping)
// set the multiple-values flag on it.
if (keyHasMultipleValues) {
int previousKeyIndex = fKeyVec.size() - 2;
int previousKey = fKeyVec.elementAt(previousKeyIndex);
previousKey |= SpoofChecker.KEY_MULTIPLE_VALUES;
fKeyVec.setElementAt(previousKey, previousKeyIndex);
}
}
// From an index into fKeyVec & fValueVec
// get a String with the corresponding mapping.
String getMapping(int index) {
int key = fKeyVec.elementAt(index);
int value = fValueVec.elementAt(index);
int length = SpoofChecker.getKeyLength(key);
int lastIndexWithLen;
switch (length) {
case 0:
char[] cs = { (char) value };
return new String(cs);
case 1:
case 2:
return fStringTable.substring(value, value + length + 1); // Note: +1 as optimization
case 3:
length = 0;
int i;
for (i = 0; i < fStringLengthsTable.size(); i += 2) {
lastIndexWithLen = fStringLengthsTable.elementAt(i);
if (value <= lastIndexWithLen) {
length = fStringLengthsTable.elementAt(i + 1);
break;
}
}
assert (length >= 3);
return fStringTable.substring(value, value + length);
default:
assert (false);
}
return new String();
}
// Populate the final binary output data array with the compiled data.
// The confusable data has been compiled and stored in intermediate
// collections and strings. Copy it from there to the final flat
// binary array.
void outputData() throws java.io.IOException {
SpoofDataHeader rawData = fSpoofData.fRawData;
// The Key Table
// While copying the keys to the runtime array,
// also sanity check that they are sorted.
int numKeys = fKeyVec.size();
int i;
int previousKey = 0;
rawData.output(os);
rawData.fCFUKeys = os.size();
assert (rawData.fCFUKeys == 128);
rawData.fCFUKeysSize = numKeys;
for (i = 0; i < numKeys; i++) {
int key = fKeyVec.elementAt(i);
assert ((key & 0x00ffffff) >= (previousKey & 0x00ffffff));
assert ((key & 0xff000000) != 0);
os.writeInt(key);
previousKey = key;
}
// The Value Table, parallels the key table
int numValues = fValueVec.size();
assert (numKeys == numValues);
rawData.fCFUStringIndex = os.size();
rawData.fCFUStringIndexSize = numValues;
for (i = 0; i < numValues; i++) {
int value = fValueVec.elementAt(i);
assert (value < 0xffff);
os.writeShort((short) value);
}
// The Strings Table.
int stringsLength = fStringTable.length();
// Reserve an extra space so the string will be nul-terminated. This is
// only a convenience, for when debugging; it is not needed otherwise.
String strings = fStringTable.toString();
rawData.fCFUStringTable = os.size();
rawData.fCFUStringTableLen = stringsLength;
for (i = 0; i < stringsLength; i++) {
os.writeChar(strings.charAt(i));
}
// The String Lengths Table
// While copying into the runtime array do some sanity checks on the
// values
// Each complete entry contains two fields, an index and an offset.
// Lengths should increase with each entry.
// Offsets should be less than the size of the string table.
int lengthTableLength = fStringLengthsTable.size();
int previousLength = 0;
// Note: StringLengthsSize in the raw data is the number of complete
// entries,
// each consisting of a pair of 16 bit values, hence the divide by 2.
rawData.fCFUStringLengthsSize = lengthTableLength / 2;
rawData.fCFUStringLengths = os.size();
for (i = 0; i < lengthTableLength; i += 2) {
int offset = fStringLengthsTable.elementAt(i);
int length = fStringLengthsTable.elementAt(i + 1);
assert (offset < stringsLength);
assert (length < 40);
assert (length > previousLength);
os.writeShort((short) offset);
os.writeShort((short) length);
previousLength = length;
}
os.flush();
DataInputStream is = new DataInputStream(new ByteArrayInputStream(bos.toByteArray()));
is.mark(Integer.MAX_VALUE);
fSpoofData.initPtrs(is);
}
public static void buildConfusableData(SpoofData spData, Reader confusables) throws java.io.IOException,
ParseException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ConfusabledataBuilder builder = new ConfusabledataBuilder(spData, bos);
builder.build(confusables);
}
/*
* *****************************************************************************
* Internal classes for compiling confusable data into its binary (runtime) form.
* *****************************************************************************
*/
// SPUString
// Holds a string that is the result of one of the mappings defined
// by the confusable mapping data (confusables.txt from Unicode.org)
// Instances of SPUString exist during the compilation process only.
private static class SPUString {
String fStr; // The actual string.
int fStrTableIndex; // Index into the final runtime data for this string.
// (or, for length 1, the single string char itself,
// there being no string table entry for it.)
SPUString(String s) {
fStr = s;
fStrTableIndex = 0;
}
}
// Comparison function for ordering strings in the string pool.
// Compare by length first, then, within a group of the same length,
// by code point order.
// Conforms to the type signature for a USortComparator in uvector.h
private static class SPUStringComparator implements Comparator<SPUString> {
public int compare(SPUString sL, SPUString sR) {
int lenL = sL.fStr.length();
int lenR = sR.fStr.length();
if (lenL < lenR) {
return -1;
} else if (lenL > lenR) {
return 1;
} else {
return sL.fStr.compareTo(sR.fStr);
}
}
}
// String Pool A utility class for holding the strings that are the result of
// the spoof mappings. These strings will utimately end up in the
// run-time String Table.
// This is sort of like a sorted set of strings, except that ICU's anemic
// built-in collections don't support those, so it is implemented with a
// combination of a uhash and a Vector.
private static class SPUStringPool {
public SPUStringPool() {
fVec = new Vector<SPUString>();
fHash = new Hashtable<String, SPUString>();
}
public int size() {
return fVec.size();
}
// Get the n-th string in the collection.
public SPUString getByIndex(int index) {
SPUString retString = fVec.elementAt(index);
return retString;
}
// Add a string. Return the string from the table.
// If the input parameter string is already in the table, delete the
// input parameter and return the existing string.
public SPUString addString(String src) {
SPUString hashedString = fHash.get(src);
if (hashedString == null) {
hashedString = new SPUString(src);
fHash.put(src, hashedString);
fVec.addElement(hashedString);
}
return hashedString;
}
// Sort the contents; affects the ordering of getByIndex().
public void sort() {
Collections.sort(fVec, new SPUStringComparator());
}
private Vector<SPUString> fVec; // Elements are SPUString *
private Hashtable<String, SPUString> fHash; // Key: Value:
}
}
}
/**
* Get the set of checks that this Spoof Checker has been configured to perform.
*
* @return The set of checks that this spoof checker will perform.
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public int getChecks() {
return fChecks;
}
/**
* Get a list of locales for the scripts that are acceptable in strings to be checked. If no limitations on scripts
* have been specified, an empty set will be returned.
*
* setAllowedChars() will reset the list of allowed locales to be empty.
*
* The returned set may not be identical to the originally specified set that is supplied to setAllowedLocales();
* the information other than languages from the originally specified locales may be omitted.
*
* @return A set of locales corresponding to the acceptable scripts.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public Set<ULocale> getAllowedLocales() {
return fAllowedLocales;
}
/**
* Get a UnicodeSet for the characters permitted in an identifier. This corresponds to the limits imposed by the Set
* Allowed Characters functions. Limitations imposed by other checks will not be reflected in the set returned by
* this function.
*
* The returned set will be frozen, meaning that it cannot be modified by the caller.
*
* @return A UnicodeSet containing the characters that are permitted by the CHAR_LIMIT test.
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public UnicodeSet getAllowedChars() {
return fAllowedCharsSet;
}
/**
* A struct-like class to hold the results of a Spoof Check operation.
* Tells which check(s) have failed
* and the position within the string where the failure was found.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public static class CheckResult {
/**
* Indicate which of the spoof check(s) has failed. The value is a bitwise OR
* of the constants for the tests in question, SINGLE_SCRIPT_CONFUSABLE,
* MIXED_SCRIPT_CONFUSABLE, WHOLE_SCRIPT_CONFUSABLE, and so on.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public int checks;
/**
* The index of the first string position that failed a check.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public int position;
/**
* Default constructor
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public CheckResult() {
checks = 0;
position = 0;
}
}
/**
* Check the specified string for possible security issues. The text to be checked will typically be an identifier
* of some sort. The set of checks to be performed was specified when building the SpoofChecker.
*
* @param text
* A String to be checked for possible security issues.
* @param checkResult
* Output parameter, indicates which specific tests failed.
* May be null if the information is not wanted.
* @return True there any issue is found with the input string.
* @draft ICU 4.8
* @provisional This API might change or be removed in a future release.
*/
public boolean failsChecks(String text, CheckResult checkResult) {
int length = text.length();
int result = 0;
int failPos = Integer.MAX_VALUE;
// A count of the number of non-Common or inherited scripts.
// Needed for both the SINGLE_SCRIPT and the
// WHOLE/MIXED_SCIRPT_CONFUSABLE tests.
// Share the computation when possible. scriptCount == -1 means that we
// haven't done it yet.
int scriptCount = -1;
if (0 != ((this.fChecks) & SINGLE_SCRIPT)) {
scriptCount = this.scriptScan(text, checkResult);
// no need to set failPos, it will be set to checkResult.position inside this.scriptScan
// printf("scriptCount (clipped to 2) = %d\n", scriptCount);
if (scriptCount >= 2) {
// Note: scriptCount == 2 covers all cases of the number of
// scripts >= 2
result |= SINGLE_SCRIPT;
}
}
if (0 != (this.fChecks & CHAR_LIMIT)) {
int i;
int c;
for (i = 0; i < length;) {
// U16_NEXT(text, i, length, c);
c = Character.codePointAt(text, i);
i = Character.offsetByCodePoints(text, i, 1);
if (!this.fAllowedCharsSet.contains(c)) {
result |= CHAR_LIMIT;
if (i < failPos) {
failPos = i;
}
break;
}
}
}
if (0 != (this.fChecks & (WHOLE_SCRIPT_CONFUSABLE | MIXED_SCRIPT_CONFUSABLE | INVISIBLE))) {
// These are the checks that need to be done on NFD input
String nfdText = Normalizer.normalize(text, Normalizer.NFD, 0);
if (0 != (this.fChecks & INVISIBLE)) {
// scan for more than one occurence of the same non-spacing mark
// in a sequence of non-spacing marks.
int i;
int c;
int firstNonspacingMark = 0;
boolean haveMultipleMarks = false;
UnicodeSet marksSeenSoFar = new UnicodeSet(); // Set of combining marks in a
// single combining sequence.
for (i = 0; i < length;) {
// U16_NEXT(nfdText, i, nfdLength, c);
c = Character.codePointAt(nfdText, i);
i = Character.offsetByCodePoints(nfdText, i, 1);
if (Character.getType(c) != UCharacterCategory.NON_SPACING_MARK) {
firstNonspacingMark = 0;
if (haveMultipleMarks) {
marksSeenSoFar.clear();
haveMultipleMarks = false;
}
continue;
}
if (firstNonspacingMark == 0) {
firstNonspacingMark = c;
continue;
}
if (!haveMultipleMarks) {
marksSeenSoFar.add(firstNonspacingMark);
haveMultipleMarks = true;
}
if (marksSeenSoFar.contains(c)) {
// report the error, and stop scanning.
// No need to find more than the first failure.
result |= INVISIBLE;
failPos = i;
break;
}
marksSeenSoFar.add(c);
}
}
if (0 != (this.fChecks & (WHOLE_SCRIPT_CONFUSABLE | MIXED_SCRIPT_CONFUSABLE))) {
// The basic test is the same for both whole and mixed script
// confusables.
// Compute the set of scripts that every input character has a
// confusable in.
// For this computation an input character is always considered
// to be
// confusable with itself in its own script.
// If the number of such scripts is two or more, and the input
// consisted of
// characters all from a single script, we have a whole script
// confusable.
// (The two scripts will be the original script and the one that
// is confusable)
// If the number of such scripts >= one, and the original input
// contained characters from
// more than one script, we have a mixed script confusable. (We
// can transform
// some of the characters, and end up with a visually similar
// string all in
// one script.)
if (scriptCount == -1) {
scriptCount = this.scriptScan(text, null);
}
ScriptSet scripts = new ScriptSet();
this.wholeScriptCheck(nfdText, scripts);
int confusableScriptCount = scripts.countMembers();
// printf("confusableScriptCount = %d\n",
// confusableScriptCount);
if ((0 != (this.fChecks & WHOLE_SCRIPT_CONFUSABLE)) && confusableScriptCount >= 2 && scriptCount == 1) {
result |= WHOLE_SCRIPT_CONFUSABLE;
}
if ((0 != (this.fChecks & MIXED_SCRIPT_CONFUSABLE)) && confusableScriptCount >= 1 && scriptCount > 1) {
result |= MIXED_SCRIPT_CONFUSABLE;
}
}
}
if (checkResult != null) {
checkResult.checks = result;
if (failPos != Integer.MAX_VALUE) {
checkResult.position = failPos;
}
}
return (0 != result);
}
/**
* Check the specified string for possible security issues. The text to be checked will typically be an identifier
* of some sort. The set of checks to be performed was specified when building the SpoofChecker.
*
* @param text
* A String to be checked for possible security issues.
* @return True there any issue is found with the input string.
* @draft ICU 4.8
* @provisional This API might change or be removed in a future release.
*/
public boolean failsChecks(String text) {
return failsChecks(text, null);
}
/**
* Check the whether two specified strings are visually confusable. The types of confusability to be tested - single
* script, mixed script, or whole script - are determined by the check options set for the SpoofChecker.
*
* The tests to be performed are controlled by the flags SINGLE_SCRIPT_CONFUSABLE MIXED_SCRIPT_CONFUSABLE
* WHOLE_SCRIPT_CONFUSABLE At least one of these tests must be selected.
*
* ANY_CASE is a modifier for the tests. Select it if the identifiers may be of mixed case. If identifiers are case
* folded for comparison and display to the user, do not select the ANY_CASE option.
*
*
* @param s1
* The first of the two strings to be compared for confusability.
* @param s2
* The second of the two strings to be compared for confusability.
* @return Non-zero if s1 and s1 are confusable. If not 0, the value will indicate the type(s) of confusability
* found, as defined by spoof check test constants.
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public int areConfusable(String s1, String s2) {
//
// See section 4 of UAX 39 for the algorithm for checking whether two
// strings are confusable,
// and for definitions of the types (single, whole, mixed-script) of
// confusables.
// We only care about a few of the check flags. Ignore the others.
// If no tests relavant to this function have been specified, signal an
// error.
// TODO: is this really the right thing to do? It's probably an error on
// the caller's part, but logically we would just return 0 (no error).
if ((this.fChecks & (SINGLE_SCRIPT_CONFUSABLE | MIXED_SCRIPT_CONFUSABLE | WHOLE_SCRIPT_CONFUSABLE)) == 0) {
throw new IllegalArgumentException("No confusable checks are enabled.");
}
int flagsForSkeleton = this.fChecks & ANY_CASE;
String s1Skeleton;
String s2Skeleton;
int result = 0;
int s1ScriptCount = this.scriptScan(s1, null);
int s2ScriptCount = this.scriptScan(s2, null);
if (0 != (this.fChecks & SINGLE_SCRIPT_CONFUSABLE)) {
// Do the Single Script compare.
if (s1ScriptCount <= 1 && s2ScriptCount <= 1) {
flagsForSkeleton |= SINGLE_SCRIPT_CONFUSABLE;
s1Skeleton = getSkeleton(flagsForSkeleton, s1);
s2Skeleton = getSkeleton(flagsForSkeleton, s2);
if (s1Skeleton.length() == s2Skeleton.length() && s1Skeleton.equals(s2Skeleton)) {
result |= SINGLE_SCRIPT_CONFUSABLE;
}
}
}
if (0 != (result & SINGLE_SCRIPT_CONFUSABLE)) {
// If the two inputs are single script confusable they cannot also
// be
// mixed or whole script confusable, according to the UAX39
// definitions.
// So we can skip those tests.
return result;
}
// Optimization for whole script confusables test: two identifiers are
// whole script confusable if
// each is of a single script and they are mixed script confusable.
boolean possiblyWholeScriptConfusables = s1ScriptCount <= 1 && s2ScriptCount <= 1
&& (0 != (this.fChecks & WHOLE_SCRIPT_CONFUSABLE));
// Mixed Script Check
if ((0 != (this.fChecks & MIXED_SCRIPT_CONFUSABLE)) || possiblyWholeScriptConfusables) {
// For getSkeleton(), resetting the SINGLE_SCRIPT_CONFUSABLE flag
// will get us
// the mixed script table skeleton, which is what we want.
// The Any Case / Lower Case bit in the skelton flags was set at the
// top of the function.
flagsForSkeleton &= ~SINGLE_SCRIPT_CONFUSABLE;
s1Skeleton = getSkeleton(flagsForSkeleton, s1);
s2Skeleton = getSkeleton(flagsForSkeleton, s2);
if (s1Skeleton.length() == s2Skeleton.length() && s1Skeleton.equals(s2Skeleton)) {
result |= MIXED_SCRIPT_CONFUSABLE;
if (possiblyWholeScriptConfusables) {
result |= WHOLE_SCRIPT_CONFUSABLE;
}
}
}
return result;
}
/**
* Get the "skeleton" for an identifier string. Skeletons are a transformation of the input string; Two strings are
* confusable if their skeletons are identical. See Unicode UAX 39 for additional information.
*
* Using skeletons directly makes it possible to quickly check whether an identifier is confusable with any of some
* large set of existing identifiers, by creating an efficiently searchable collection of the skeletons.
*
* @param type
* The type of skeleton, corresponding to which of the Unicode confusable data tables to use. The default
* is Mixed-Script, Lowercase. Allowed options are SINGLE_SCRIPT_CONFUSABLE and ANY_CASE_CONFUSABLE. The
* two flags may be ORed.
* @param s
* The input string whose skeleton will be genereated.
* @return The output skeleton string.
*
* @draft ICU 4.6
* @provisional This API might change or be removed in a future release.
*/
public String getSkeleton(int type, String s) {
// TODO: this function could be sped up a bit
// Skip the input normalization when not needed, work from callers data.
// It probably won't need normalization.
if ((type & ~(SINGLE_SCRIPT_CONFUSABLE | ANY_CASE)) != 0) {
// *status = U_ILLEGAL_ARGUMENT_ERROR;
return null;
}
int tableMask = 0;
switch (type) {
case 0:
tableMask = ML_TABLE_FLAG;
break;
case SINGLE_SCRIPT_CONFUSABLE:
tableMask = SL_TABLE_FLAG;
break;
case ANY_CASE:
tableMask = MA_TABLE_FLAG;
break;
case SINGLE_SCRIPT_CONFUSABLE | ANY_CASE:
tableMask = SA_TABLE_FLAG;
break;
default:
// *status = U_ILLEGAL_ARGUMENT_ERROR;
return null;
}
// NFD transform of the user supplied input
String nfdInput = Normalizer.normalize(s, Normalizer.NFD, 0);
int normalizedLen = nfdInput.length();
// Apply the skeleton mapping to the NFD normalized input string
// Accumulate the skeleton, possibly unnormalized, in a String.
int inputIndex = 0;
StringBuilder skelStr = new StringBuilder();
while (inputIndex < normalizedLen) {
int c;
c = Character.codePointAt(nfdInput, inputIndex);
inputIndex = Character.offsetByCodePoints(nfdInput, inputIndex, 1);
this.confusableLookup(c, tableMask, skelStr);
}
String result = skelStr.toString();
String normedResult;
// Check the skeleton for NFD, normalize it if needed.
// Unnormalized results should be very rare.
if (!Normalizer.isNormalized(result, Normalizer.NFD, 0)) {
normedResult = Normalizer.normalize(result, Normalizer.NFD, 0);
result = normedResult;
}
return result;
}
/*
* Append the confusable skeleton transform for a single code point to a StringBuilder. The string to be appended
* will between 1 and 18 characters.
*
* This is the heart of the confusable skeleton generation implementation.
*
* @param tableMask bit flag specifying which confusable table to use. One of SL_TABLE_FLAG, MA_TABLE_FLAG, etc.
*/
private void confusableLookup(int inChar, int tableMask, StringBuilder dest) {
// Binary search the spoof data key table for the inChar
int low = 0;
int mid = 0;
int limit = fSpoofData.fRawData.fCFUKeysSize;
int midc;
boolean foundChar = false;
// [low, limit), i.e low is inclusive, limit is exclusive
do {
int delta = (limit - low) / 2;
mid = low + delta;
midc = fSpoofData.fCFUKeys[mid] & 0x1fffff;
if (inChar == midc) {
foundChar = true;
break;
} else if (inChar < midc) {
limit = mid; // limit is exclusive
} else {
// we have checked mid is not the char we looking for, the next
// char
// we want to check is (mid + 1)
low = mid + 1; // low is inclusive
}
} while (low < limit);
if (!foundChar) { // Char not found. It maps to itself.
dest.appendCodePoint(inChar);
return;
}
boolean foundKey = false;
int keyFlags = fSpoofData.fCFUKeys[mid] & 0xff000000;
if ((keyFlags & tableMask) == 0) {
// We found the right key char, but the entry doesn't pertain to the
// table we need. See if there is an adjacent key that does
if (0 != (keyFlags & SpoofChecker.KEY_MULTIPLE_VALUES)) {
int altMid;
for (altMid = mid - 1; (fSpoofData.fCFUKeys[altMid] & 0x00ffffff) == inChar; altMid--) {
keyFlags = fSpoofData.fCFUKeys[altMid] & 0xff000000;
if (0 != (keyFlags & tableMask)) {
mid = altMid;
foundKey = true;
break;
}
}
if (!foundKey) {
for (altMid = mid + 1; (fSpoofData.fCFUKeys[altMid] & 0x00ffffff) == inChar; altMid++) {
keyFlags = fSpoofData.fCFUKeys[altMid] & 0xff000000;
if (0 != (keyFlags & tableMask)) {
mid = altMid;
foundKey = true;
break;
}
}
}
}
if (!foundKey) {
// No key entry for this char & table.
// The input char maps to itself.
dest.appendCodePoint(inChar);
return;
}
}
int stringLen = getKeyLength(keyFlags) + 1;
int keyTableIndex = mid;
// Value is either a char (for strings of length 1) or
// an index into the string table (for longer strings)
short value = fSpoofData.fCFUValues[keyTableIndex];
if (stringLen == 1) {
dest.append((char) value);
return;
}
// String length of 4 from the above lookup is used for all strings of
// length >= 4.
// For these, get the real length from the string lengths table,
// which maps string table indexes to lengths.
// All strings of the same length are stored contiguously in the string
// table.
// 'value' from the lookup above is the starting index for the desired
// string.
int ix;
if (stringLen == 4) {
int stringLengthsLimit = fSpoofData.fRawData.fCFUStringLengthsSize;
for (ix = 0; ix < stringLengthsLimit; ix++) {
if (fSpoofData.fCFUStringLengths[ix].fLastString >= value) {
stringLen = fSpoofData.fCFUStringLengths[ix].fStrLength;
break;
}
}
assert (ix < stringLengthsLimit);
}
assert (value + stringLen < fSpoofData.fRawData.fCFUStringTableLen);
dest.append(fSpoofData.fCFUStrings, value, stringLen);
return;
}
// WholeScript and MixedScript check implementation.
// 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.
// Input text is already normalized to NFD
// Return the set of scripts, each of which can represent something that is
// confusable with the input text. The script of the input text
// is included; input consisting of characters from a single script will
// always produce a result consisting of a set containing that script.
void wholeScriptCheck(CharSequence text, ScriptSet result) {
int inputIdx = 0;
int c;
Trie2 table = (0 != (fChecks & ANY_CASE)) ? fSpoofData.fAnyCaseTrie : fSpoofData.fLowerCaseTrie;
result.setAll();
while (inputIdx < text.length()) {
c = Character.codePointAt(text, inputIdx);
inputIdx = Character.offsetByCodePoints(text, inputIdx, 1);
int index = table.get(c);
if (index == 0) {
// No confusables in another script for this char.
// TODO: we should change the data to have sets with just the single script
// bit for the script of this char. Gets rid of this special case.
// Until then, grab the script from the char and intersect it with the set.
int cpScript = UScript.getScript(c);
assert (cpScript > UScript.INHERITED);
result.intersect(cpScript);
} else if (index == 1) {
// Script == Common or Inherited. Nothing to do.
} else {
result.intersect(fSpoofData.fScriptSets[index]);
}
}
}
/**
* Scan a string to determine how many scripts it includes. Ignore characters with script=Common and
* scirpt=Inherited.
*
* @param text
* The char text to be scanned
* @param checkResult
* Optional caller provided fill-in parameter. If not null, on return it will be filled. set to the first
* input postion at which a second script was encountered, ignoring Common and Inherited.
* @return the number of (non-common,inherited) scripts encountered, clipped to a max of two.
* @internal
*/
int scriptScan(CharSequence text, CheckResult checkResult) {
int inputIdx = 0;
int c;
int scriptCount = 0;
int lastScript = UScript.INVALID_CODE;
int sc = UScript.INVALID_CODE;
while ((inputIdx < text.length()) && scriptCount < 2) {
c = Character.codePointAt(text, inputIdx);
inputIdx = Character.offsetByCodePoints(text, inputIdx, 1);
sc = UScript.getScript(c);
if (sc == UScript.COMMON || sc == UScript.INHERITED || sc == UScript.UNKNOWN) {
continue;
}
// Temporary fix: fold Japanese and Korean into Han.
// Names are allowed to mix these scripts.
// A more general solution will follow later for characters that are
// used with multiple scripts.
if (sc == UScript.KATAKANA || sc == UScript.HIRAGANA || sc == UScript.HANGUL) {
sc = UScript.HAN;
}
if (sc != lastScript) {
scriptCount++;
lastScript = sc;
}
}
if (scriptCount == 2 && checkResult != null) {
checkResult.position = inputIdx;
}
return scriptCount;
}
// Data Members
private int fMagic; // Internal sanity check.
private int fChecks; // Bit vector of checks to perform.
private SpoofData fSpoofData;
private Set<ULocale> fAllowedLocales; // The Set of allowed locales.
private UnicodeSet fAllowedCharsSet; // The UnicodeSet of allowed characters.
// for this Spoof Checker. Defaults to all chars.
//
// 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 char (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
// short index of the _last_ string with this length
// short the length
// Flag bits in the Key entries
static final int SL_TABLE_FLAG = (1 << 24);
static final int SA_TABLE_FLAG = (1 << 25);
static final int ML_TABLE_FLAG = (1 << 26);
static final int MA_TABLE_FLAG = (1 << 27);
static final int KEY_MULTIPLE_VALUES = (1 << 28);
static final int KEY_LENGTH_SHIFT = 29;
static final int getKeyLength(int x) {
return (((x) >> 29) & 3);
}
// ---------------------------------------------------------------------------------------
//
// Raw Binary Data Formats, as loaded from the ICU data file,
// or as built by the builder.
//
// ---------------------------------------------------------------------------------------
private static class SpoofDataHeader {
int fMagic; // (0x8345fdef)
byte[] fFormatVersion = new byte[4]; // Data Format. Same as the value in
// class UDataInfo
// if there is one associated with this data.
int 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"
int fCFUKeys; // byte offset to Keys table (from SpoofDataHeader *)
int fCFUKeysSize; // number of entries in keys table (32 bits each)
// TODO: change name to fCFUValues, for consistency.
int fCFUStringIndex; // byte offset to String Indexes table
int fCFUStringIndexSize; // number of entries in String Indexes table (16 bits each)
// (number of entries must be same as in Keys table
int fCFUStringTable; // byte offset of String table
int fCFUStringTableLen; // length of string table (in 16 bit UChars)
int fCFUStringLengths; // byte offset to String Lengths table
int fCFUStringLengthsSize; // number of entries in lengths table. (2 x 16 bits each)
// The following sections are for data from confusablesWholeScript.txt
int fAnyCaseTrie; // byte offset to the serialized Any Case Trie
int fAnyCaseTrieLength; // Length (bytes) of the serialized Any Case Trie
int fLowerCaseTrie; // byte offset to the serialized Lower Case Trie
int fLowerCaseTrieLength; // Length (bytes) of the serialized Lower Case Trie
int fScriptSets; // byte offset to array of ScriptSets
int fScriptSetsLength; // Number of ScriptSets (24 bytes each)
// The following sections are for data from xidmodifications.txt
int[] unused = new int[15]; // Padding, Room for Expansion
public SpoofDataHeader() {
}
public SpoofDataHeader(DataInputStream dis) throws IOException {
int i;
fMagic = dis.readInt();
for (i = 0; i < fFormatVersion.length; i++) {
fFormatVersion[i] = dis.readByte();
}
fLength = dis.readInt();
fCFUKeys = dis.readInt();
fCFUKeysSize = dis.readInt();
fCFUStringIndex = dis.readInt();
fCFUStringIndexSize = dis.readInt();
fCFUStringTable = dis.readInt();
fCFUStringTableLen = dis.readInt();
fCFUStringLengths = dis.readInt();
fCFUStringLengthsSize = dis.readInt();
fAnyCaseTrie = dis.readInt();
fAnyCaseTrieLength = dis.readInt();
fLowerCaseTrie = dis.readInt();
fLowerCaseTrieLength = dis.readInt();
fScriptSets = dis.readInt();
fScriptSetsLength = dis.readInt();
for (i = 0; i < unused.length; i++) {
unused[i] = dis.readInt();
}
}
public void output(DataOutputStream os) throws java.io.IOException {
int i;
os.writeInt(fMagic);
for (i = 0; i < fFormatVersion.length; i++) {
os.writeByte(fFormatVersion[i]);
}
os.writeInt(fLength);
os.writeInt(fCFUKeys);
os.writeInt(fCFUKeysSize);
os.writeInt(fCFUStringIndex);
os.writeInt(fCFUStringIndexSize);
os.writeInt(fCFUStringTable);
os.writeInt(fCFUStringTableLen);
os.writeInt(fCFUStringLengths);
os.writeInt(fCFUStringLengthsSize);
os.writeInt(fAnyCaseTrie);
os.writeInt(fAnyCaseTrieLength);
os.writeInt(fLowerCaseTrie);
os.writeInt(fLowerCaseTrieLength);
os.writeInt(fScriptSets);
os.writeInt(fScriptSetsLength);
for (i = 0; i < unused.length; i++) {
os.writeInt(unused[i]);
}
}
}
// -------------------------------------------------------------------------------------
// SpoofData
//
// A small class that wraps the raw (was memory mapped in the C world) spoof data.
// Nothing in this class includes state that is specific to any particular
// SpoofDetector object.
// ---------------------------------------------------------------------------------------
private static class SpoofData {
// getDefault() - return a wrapper around the spoof data that is
// baked into the default ICU data.
// Load standard ICU spoof data.
public static SpoofData getDefault() throws java.io.IOException {
// TODO: Cache it. Lazy create, keep until cleanup.
InputStream is = com.ibm.icu.impl.ICUData.getRequiredStream(com.ibm.icu.impl.ICUResourceBundle.ICU_BUNDLE
+ "/confusables.cfu");
SpoofData This = new SpoofData(is);
return This;
}
// SpoofChecker Data constructor for use from data builder.
// Initializes a new, empty data area that will be populated later.
public SpoofData() {
// The spoof header should already be sized to be a multiple of 16
// bytes.
// Just in case it's not, round it up.
fRawData = new SpoofDataHeader();
fRawData.fMagic = SpoofChecker.MAGIC;
fRawData.fFormatVersion[0] = 1;
fRawData.fFormatVersion[1] = 0;
fRawData.fFormatVersion[2] = 0;
fRawData.fFormatVersion[3] = 0;
}
// Constructor for use when creating from prebuilt default data.
// A InputStream is what the ICU internal data loading functions provide.
public SpoofData(InputStream is) throws java.io.IOException {
// Seek past the ICU data header.
// TODO: verify that the header looks good.
DataInputStream dis = new DataInputStream(new BufferedInputStream(is));
dis.skip(0x80);
assert (dis.markSupported());
dis.mark(Integer.MAX_VALUE);
fRawData = new SpoofDataHeader(dis);
initPtrs(dis);
}
// Check raw SpoofChecker Data Version compatibility.
// Return true it looks good.
static boolean validateDataVersion(SpoofDataHeader rawData) {
if (rawData == null || rawData.fMagic != SpoofChecker.MAGIC || rawData.fFormatVersion[0] > 1
|| rawData.fFormatVersion[1] > 0) {
return false;
}
return true;
}
// build SpoofChecker from DataInputStream
// read from binay data input stream
// initialize the pointers from this object to the raw data.
// Initialize the pointers to the various sections of the raw data.
//
// This function is used both during the Trie building process (multiple
// times, as the individual data sections are added), and
// during the opening of a SpoofChecker Checker from prebuilt data.
//
// The pointers for non-existent data sections (identified by an offset of
// 0) are set to null.
void initPtrs(DataInputStream dis) throws java.io.IOException {
int i;
fCFUKeys = null;
fCFUValues = null;
fCFUStringLengths = null;
fCFUStrings = null;
// the binary file from C world is memory-mapped, each section of data
// is align-ed to 16-bytes boundary, to make the code more robust we call
// reset()/skip() which essensially seek() to the correct offset.
dis.reset();
dis.skip(fRawData.fCFUKeys);
if (fRawData.fCFUKeys != 0) {
fCFUKeys = new int[fRawData.fCFUKeysSize];
for (i = 0; i < fRawData.fCFUKeysSize; i++) {
fCFUKeys[i] = dis.readInt();
}
}
dis.reset();
dis.skip(fRawData.fCFUStringIndex);
if (fRawData.fCFUStringIndex != 0) {
fCFUValues = new short[fRawData.fCFUStringIndexSize];
for (i = 0; i < fRawData.fCFUStringIndexSize; i++) {
fCFUValues[i] = dis.readShort();
}
}
dis.reset();
dis.skip(fRawData.fCFUStringTable);
if (fRawData.fCFUStringTable != 0) {
fCFUStrings = new char[fRawData.fCFUStringTableLen];
for (i = 0; i < fRawData.fCFUStringTableLen; i++) {
fCFUStrings[i] = dis.readChar();
}
}
dis.reset();
dis.skip(fRawData.fCFUStringLengths);
if (fRawData.fCFUStringLengths != 0) {
fCFUStringLengths = new SpoofStringLengthsElement[fRawData.fCFUStringLengthsSize];
for (i = 0; i < fRawData.fCFUStringLengthsSize; i++) {
fCFUStringLengths[i] = new SpoofStringLengthsElement();
fCFUStringLengths[i].fLastString = dis.readShort();
fCFUStringLengths[i].fStrLength = dis.readShort();
}
}
dis.reset();
dis.skip(fRawData.fAnyCaseTrie);
if (fAnyCaseTrie == null && fRawData.fAnyCaseTrie != 0) {
fAnyCaseTrie = Trie2.createFromSerialized(dis);
}
dis.reset();
dis.skip(fRawData.fLowerCaseTrie);
if (fLowerCaseTrie == null && fRawData.fLowerCaseTrie != 0) {
fLowerCaseTrie = Trie2.createFromSerialized(dis);
}
dis.reset();
dis.skip(fRawData.fScriptSets);
if (fRawData.fScriptSets != 0) {
fScriptSets = new ScriptSet[fRawData.fScriptSetsLength];
for (i = 0; i < fRawData.fScriptSetsLength; i++) {
fScriptSets[i] = new ScriptSet(dis);
}
}
}
SpoofDataHeader fRawData;
// Confusable data
int[] fCFUKeys;
short[] fCFUValues;
SpoofStringLengthsElement[] fCFUStringLengths;
char[] fCFUStrings;
// Whole Script Confusable Data
Trie2 fAnyCaseTrie;
Trie2 fLowerCaseTrie;
ScriptSet[] fScriptSets;
private static class SpoofStringLengthsElement {
short fLastString; // index in string table of last string with this length
short fStrLength; // Length of strings
}
}
// -------------------------------------------------------------------------------
//
// ScriptSet - Script code bit sets. Used with the whole script confusable data.
// Used both at data build and at run time.
// Could almost be a Java BitSet, except that the input and output would
// be awkward.
//
// -------------------------------------------------------------------------------
private static class ScriptSet {
public ScriptSet() {
}
public ScriptSet(DataInputStream dis) throws java.io.IOException {
for (int j = 0; j < bits.length; j++) {
bits[j] = dis.readInt();
}
}
public void output(DataOutputStream os) throws java.io.IOException {
for (int i = 0; i < bits.length; i++) {
os.writeInt(bits[i]);
}
}
public boolean equals(ScriptSet other) {
for (int i = 0; i < bits.length; i++) {
if (bits[i] != other.bits[i]) {
return false;
}
}
return true;
}
public void Union(int script) {
int index = script / 32;
int bit = 1 << (script & 31);
assert (index < bits.length * 4 * 4);
bits[index] |= bit;
}
@SuppressWarnings("unused")
public void Union(ScriptSet other) {
for (int i = 0; i < bits.length; i++) {
bits[i] |= other.bits[i];
}
}
public void intersect(ScriptSet other) {
for (int i = 0; i < bits.length; i++) {
bits[i] &= other.bits[i];
}
}
public void intersect(int script) {
int index = script / 32;
int bit = 1 << (script & 31);
assert (index < bits.length * 4 * 4);
int i;
for (i = 0; i < index; i++) {
bits[i] = 0;
}
bits[index] &= bit;
for (i = index + 1; i < bits.length; i++) {
bits[i] = 0;
}
}
public void setAll() {
for (int i = 0; i < bits.length; i++) {
bits[i] = 0xffffffff;
}
}
@SuppressWarnings("unused")
public void resetAll() {
for (int i = 0; i < bits.length; i++) {
bits[i] = 0;
}
}
public int countMembers() {
// This bit counter is good for sparse numbers of '1's, which is
// very much the case that we will usually have.
int count = 0;
for (int i = 0; i < bits.length; i++) {
int x = bits[i];
while (x > 0) {
count++;
x &= (x - 1); // and off the least significant one bit.
}
}
return count;
}
private int[] bits = new int[6];
}
}