#### 回應時間幫了攻擊者 { #the-time-to-answer-helps-the-attackers }

此時，透過觀察伺服器回覆「Incorrect username or password」多花了幾個微秒，攻擊者就知道他們有某些地方猜對了，前幾個字母是正確的。

接著他們會再嘗試，知道它更可能接近 `stanleyjobsox` 而不是 `johndoe`。

#### 「專業」的攻擊 { #a-professional-attack }

當然，攻擊者不會手動嘗試這一切，他們會寫程式來做，可能每秒進行上千或上百萬次測試，一次只多猜中一個正確字母。

但這樣做，幾分鐘或幾小時內，他們就能在我們應用程式「協助」下，僅靠回應時間就猜出正確的使用者名稱與密碼。

Examples of unacceptable behavior include:

* The use of sexualized language or imagery, and sexual attention or
  advances of any kind
* Trolling, insulting or derogatory comments, and personal or political attacks
* Public or private harassment
* Publishing others' private information, such as a physical or email
  address, without their explicit permission
* Other conduct which could reasonably be considered inappropriate in a

   documentation may negatively impact others.

 * **Be respectful**: We expect people to work together to resolve conflict, assume good intentions,
   and act with empathy. Do not turn disagreements into personal attacks.

 * **Be collaborative**: Collaboration reduces redundancy and improves the quality of our work. We
   strive for transparency within our open source community, and we work closely with upstream

 */
package jcifs.util;

import java.util.regex.Pattern;

/**
 * Comprehensive input validation utility for SMB protocol implementation.
 * Provides validation methods to prevent buffer overflows, injection attacks,
 * and other security vulnerabilities.
 */
public final class InputValidator {

    private InputValidator() {
        // Utility class
    }

            final byte[] cmp = new byte[SIGNATURE_LENGTH];
            System.arraycopy(mac.doFinal(), 0, cmp, 0, SIGNATURE_LENGTH);

            // Use constant-time comparison to prevent timing attacks
            if (!MessageDigest.isEqual(sig, cmp)) {
                return false; // Signature verification failed
            }
            return true; // Signature verification succeeded
        } finally {

Examples of unacceptable behavior by participants include:

*   The use of sexualized language or imagery and unwelcome sexual attention or
    advances.
*   Trolling, insulting/derogatory comments, and personal or political attacks.
*   Public or private harassment.
*   Publishing others' private information, such as a physical or electronic
    address, without explicit permission.

		header.Set("X-XSS-Protection", "1; mode=block")                                // Prevents against XSS attacks
		header.Set("X-Content-Type-Options", "nosniff")                                // Prevent mime-sniff
		header.Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains") // HSTS mitigates variants of MITM attacks

		// Previously, this value was set right before a response was sent to

     * in the data store plugin directory and extracts component class names.
     *
     * <p>The method uses secure XML parsing features to prevent XXE attacks and
     * other XML-based vulnerabilities. Component class names are extracted from
     * the 'class' attribute of 'component' elements in the XML files.</p>
     *

By default, OkHttp trusts the certificate authorities of the host platform. This strategy maximizes connectivity, but it is subject to certificate authority attacks such as the [2011 DigiNotar attack](https://www.computerworld.com/article/2510951/cybercrime-hacking/hackers-spied-on-300-000-iranians-using-fake-google-certificate.html). It also assumes your HTTPS servers’ certificates are signed by a certificate authority.

import java.util.concurrent.atomic.AtomicLong;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jcifs.smb.SmbException;

/**
 * Rate limiter for authentication attempts to prevent brute force attacks.
 *
 * Features:
 * - Per-account rate limiting
 * - Per-IP rate limiting
 * - Global rate limiting
 * - Exponential backoff for repeated failures
 * - Account lockout after threshold