ConFoo 2025

Spoofchecker クラス

(PHP 5 >= 5.4.0, PHP 7, PHP 8, PECL intl >= 2.0.0)

はじめに

Unicode は非常にたくさんの文字と、 世界中の様々な表記体系を含んでいます。 そのため使い方を誤ると、 文字の類似性を利用して、 プログラムやシステムに対するセキュリティ攻撃が成立する可能性があります。 そのため、このクラスが提供されています。

このクラスのメソッドを使うと、 個別の文字列が、文字の読み手を混乱させようとしている可能性があるかをチェック(spoof detection)できます。 たとえば、キリル文字の 'а' が混じった "pаypаl" のような文字列のようなものをチェックできます。

クラス概要

class Spoofchecker {
/* 定数 */
public const int ANY_CASE;
public const int SINGLE_SCRIPT;
public const int INVISIBLE;
public const int CHAR_LIMIT;
public const int ASCII;
public const int HIGHLY_RESTRICTIVE;
public const int UNRESTRICTIVE;
public const int MIXED_NUMBERS;
public const int HIDDEN_OVERLAY;
/* メソッド */
public __construct()
public areConfusable(string $string1, string $string2, int &$errorCode = null): bool
public isSuspicious(string $string, int &$errorCode = null): bool
public setAllowedLocales(string $locales): void
public setChecks(int $checks): void
public setRestrictionLevel(int $level): void
}

目次

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User Contributed Notes 2 notes

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3
Anonymous
7 years ago
From http://icu-project.org/apiref/icu4j/com/ibm/icu/text/SpoofChecker.html :
SINGLE_SCRIPT_CONFUSABLE: indicates that the two strings are visually confusable and that they are from the same script
MIXED_SCRIPT_CONFUSABLE: indicates that the two strings are visually confusable and that they are NOT from the same script
WHOLE_SCRIPT_CONFUSABLE: indicates that the two strings are visually confusable and that they are NOT from the same script BUT both of them are single-script strings
ANY_CASE: Deprecated.
SINGLE_SCRIPT: Deprecated.
INVISIBLE: 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.
CHAR_LIMIT: Check that an identifier contains only characters from a specified set of acceptable characters.

Explanation of whole script, mixed script and single script confusables in UTS 39 section 4 : http://unicode.org/reports/tr39/#Confusable_Detection

Details from Java SpoofChecker class at http://icu-project.org/apiref/icu4j/com/ibm/icu/text/SpoofChecker.html
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-1
Anonymous
6 years ago
Spoofchecker yields false positives by defaut when Whole-Script Confusables (WSC) and Mixed-Script Confusables (MSC) checks are used.
They have been deprecated since ICU 58:
http://bugs.icu-project.org/trac/ticket/12549#comment:10

Workarounds: upgrade ICU to 58+, or avoid the MSC and WSC checks with Spoofcheckers' setChecks() function.
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