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

import jcifs.smb.SmbException;

/**
 * Validator for SMB server responses to prevent buffer overflow and injection attacks.
 *
 * Features:
 * - Buffer bounds checking
 * - Integer overflow prevention
 * - Size validation
 * - Protocol compliance checking
 * - Malformed response detection
 */
public class ServerResponseValidator {

The *Secure Channel* splits the object content into chunks of a fixed size of `65536` bytes. The last chunk may be smaller to avoid adding additional overhead and is treated specially to prevent truncation attacks. The nonce value is 96 bits long and generated randomly per object / multi-part part. The *Secure Channel* supports plaintexts up to `65536 * 2^32 = 256 TiB`.

#### Randomness

            throwValidationError(messages -> messages.addErrorsDesignFileIsUnsupportedType("designFileName"), this::asListHtml);
            return null;
        }

        // Validate path to prevent path traversal attacks
        if (expectedBaseDir != null && !isValidUploadPath(uploadFile, expectedBaseDir)) {
            logger.warn("Path traversal attempt detected: fileName={}", fileName);

   * representation to this hash code.
   *
   * <p><b>Security note:</b> this method uses a constant-time (not short-circuiting) implementation
   * to protect against <a href="http://en.wikipedia.org/wiki/Timing_attack">timing attacks</a>.
   */
  @Override
  public final boolean equals(@Nullable Object object) {
    if (object instanceof HashCode) {
      HashCode that = (HashCode) object;

      return true;
    }

    @Override
    public Iterator<Entry<K, V>> iterator() {
      return entrySetIterator();
    }

    // See java.util.Collections.CheckedEntrySet for details on attacks.

    @Override
    public @Nullable Object[] toArray() {
      return standardToArray();
    }

    @Override
    @SuppressWarnings("nullness") // bug in our checker's handling of toArray signatures

This ensures the endpoint takes roughly the same amount of time to respond whether the username is valid or not, preventing **timing attacks** that could be used to enumerate existing usernames.

/// note

{* ../../docs_src/security/tutorial004_an_py310.py hl[8,49,51,58:59,62:63,72:79] *}

當以不存在於資料庫的使用者名稱呼叫 `authenticate_user` 時，我們仍然會拿一個假的雜湊去跑一次 `verify_password`。

這可確保無論使用者名稱是否有效，端點的回應時間都大致相同，避免可用來枚舉既有使用者名稱的「計時攻擊」（timing attacks）。

/// note | 注意

如果你查看新的（假）資料庫 `fake_users_db`，你會看到雜湊後的密碼現在長這樣：`"$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc"`。

///

{* ../../docs_src/security/tutorial004_an_py310.py hl[8,49,51,58:59,62:63,72:79] *}

当使用一个在数据库中不存在的用户名调用 `authenticate_user` 时，我们仍然会针对一个虚拟哈希运行 `verify_password`。

这可以确保无论用户名是否有效，端点的响应时间大致相同，从而防止可用于枚举已存在用户名的“时间攻击”（timing attacks）。

/// note | 注意

如果你查看新的（伪）数据库 `fake_users_db`，现在你会看到哈希后的密码类似这样：`"$argon2id$v=19$m=65536,t=3,p=4$wagCPXjifgvUFBzq4hqe3w$CYaIb8sB+wtD+Vu/P4uod1+Qof8h+1g7bbDlBID48Rc"`。

///

    # Bir hata döndür
    ...
```

Ancak `secrets.compare_digest()` kullanarak, "timing attacks" denilen bir saldırı türüne karşı güvenli olursunuz.

### Timing Attacks { #timing-attacks }

Peki "timing attack" nedir?

Bazı saldırganların kullanıcı adı ve şifreyi tahmin etmeye çalıştığını düşünelim.

    private static final SecurityAuditLogger auditLogger = SecurityAuditLogger.getInstance();

    /**
     * Performs constant-time comparison of two char arrays to prevent timing attacks.
     * This method always compares the full length of both arrays, regardless of when
     * differences are found, making the execution time independent of the position
     * of differing characters.
     *