Method equals

java/org/apache/tomcat/util/security/ConstantTime.java:47–78

Implements String equality which always compares all characters in the string, without stopping early if any characters do not match. Note: This implementation was adapted from MessageDigest#isEqual which we assume is as optimizer-defeating as possible. @param s1 The firs

(final String s1, final String s2, final boolean ignoreCase)

     * @return <code>true</code> if the strings are equal to each other, <code>false</code> otherwise.
     */
    public static boolean equals(final String s1, final String s2, final boolean ignoreCase) {
        if (s1 == s2) {
            return true;
        }
        if (s1 == null || s2 == null) {
            return false;
        }

        final int len1 = s1.length();
        final int len2 = s2.length();

        if (len2 == 0) {
            return len1 == 0;
        }

        int result = 0;
        result |= len1 - len2;

        // time-constant comparison
        for (int i = 0; i < len1; i++) {
            // If i >= len2, index2 is 0; otherwise, i.
            final int index2 = ((i - len2) >>> 31) * i;
            char c1 = s1.charAt(i);
            char c2 = s2.charAt(index2);
            if (ignoreCase) {
                c1 = Character.toLowerCase(c1);
                c2 = Character.toLowerCase(c2);
            }
            result |= c1 ^ c2;
        }
        return result == 0;
    }


    /**