///

## パスワードのハッシュ化 { #password-hashing }

「ハッシュ化」とは、あるコンテンツ（ここではパスワード）を、規則性のないバイト列（単なる文字列）に変換することです。

特徴として、全く同じ内容（全く同じパスワード）を渡すと、全く同じ規則性のないバイト列に変換されます。

しかし、規則性のないバイト列から元のパスワードに戻すことはできません。

### パスワードのハッシュ化を使う理由 { #why-use-password-hashing }

データベースが盗まれても、ユーザーの平文のパスワードは盗まれず、ハッシュ値だけが盗まれます。

Guava is a set of core Java libraries from Google that includes new collection
types (such as multimap and multiset), immutable collections, a graph library,
and utilities for concurrency, I/O, hashing, primitives, strings, and more! It
is widely used on most Java projects within Google, and widely used by many
other companies as well.



Guava comes in two flavors:

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.CollectPreconditions.checkNonnegative;
import static com.google.common.collect.Hashing.smearedHash;
import static com.google.common.collect.NullnessCasts.uncheckedCastNullableTToT;
import static com.google.common.collect.NullnessCasts.unsafeNull;

import com.google.common.annotations.GwtCompatible;

import org.opensearch.search.SearchHit;
import org.opensearch.search.SearchHits;
import org.opensearch.search.sort.SortBuilder;

import com.google.common.hash.HashFunction;
import com.google.common.hash.Hashing;

import jakarta.annotation.Resource;

/**
 * Abstract base class for crawler services that interact with OpenSearch.
 *
 * @author shinsuke
 *
 */
public abstract class AbstractCrawlerService {

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.hash;

import static com.google.common.hash.Hashing.crc32c;
import static java.nio.charset.StandardCharsets.UTF_8;

import java.util.Arrays;
import java.util.Random;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**

Si no lo sabes, aprenderás qué es un "hash de contraseña" en los [capítulos de seguridad](security/simple-oauth2.md#password-hashing).

///

## Múltiples modelos { #multiple-models }

Aquí tienes una idea general de cómo podrían ser los modelos con sus campos de contraseña y los lugares donde se utilizan:

Никогда не храните пароли пользователей в чистом виде. Всегда храните "безопасный хэш", который вы затем сможете проверить.

Если вам это не знакомо, вы можете узнать про "хэш пароля" в [главах о безопасности](security/simple-oauth2.md#password-hashing).

///

## Множественные модели { #multiple-models }

Ниже изложена основная идея того, как могут выглядеть эти модели с полями для паролей, а также описаны места, где они используются:

Nunca armazene senhas em texto simples dos usuários. Sempre armazene uma "hash segura" que você pode verificar depois.

Se não souber, você aprenderá o que é uma "senha hash" nos [capítulos de segurança](security/simple-oauth2.md#password-hashing).

///

## Múltiplos modelos { #multiple-models }

Aqui está uma ideia geral de como os modelos poderiam parecer com seus campos de senha e os lugares onde são usados:

   * can hold setSize elements with the desired load factor. Always returns at least setSize + 2.
   */
  // TODO(cpovirk): Move to Hashing or something, since it's used elsewhere in the Android version.
  static int chooseTableSize(int setSize) {
    setSize = max(setSize, 2);
    // Correct the size for open addressing to match desired load factor.

/// danger

Never store user's plaintext passwords. Always store a "secure hash" that you can then verify.

If you don't know, you will learn what a "password hash" is in the [security chapters](security/simple-oauth2.md#password-hashing).

///

## Multiple models { #multiple-models }

Here's a general idea of how the models could look like with their password fields and the places where they are used: