*   <li>The performance of using the associated {@code Builder} class can be assumed to be no
 *       worse, and possibly better, than creating a mutable collection and copying it.
 *   <li>Implementations generally do not cache hash codes. If your element or key type has a slow
 *       {@code hashCode} implementation, it should cache it itself.
 * </ul>
 *
 * <h4>Example usage</h4>
 *
 * {@snippet :
 * class Foo {

                                && Objects.equals(this.children, that.children());
            }

            @Override
            public int hashCode() {
                return Objects.hash(name, value, attributes, children);
            }

            @Override
            public String toString() {
                try {
                    StringWriter writer = new StringWriter();

# OAuth2 实现密码哈希与 Bearer  JWT 令牌验证

至此，我们已经编写了所有安全流，本章学习如何使用 <abbr title="JSON Web Tokens">JWT</abbr> 令牌（Token）和安全密码哈希（Hash）实现真正的安全机制。

本章的示例代码真正实现了在应用的数据库中保存哈希密码等功能。

接下来，我们紧接上一章，继续完善安全机制。

## JWT 简介

JWT 即**JSON 网络令牌**（JSON Web Tokens）。

JWT 是一种将 JSON 对象编码为没有空格，且难以理解的长字符串的标准。JWT 的内容如下所示：

```

		}

		h := xxhash.New()
		for _, s := range setArgs {
			for _, d := range s {
				h.WriteString(d)
			}
		}

		layout.pools = append(layout.pools, poolDisksLayout{
			cmdline: fmt.Sprintf("hash:%x", h.Sum(nil)),
			layout:  setArgs,
		})
	}
	return layout, err
}

// mergeDisksLayoutFromArgs supports with and without ellipses transparently.

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"context"
	"encoding/binary"
	"errors"
	"fmt"
	"hash/crc32"
	"math/rand"
	"net/http"
	"reflect"
	"strings"
	"sync"
	"time"

	"github.com/dchest/siphash"
	"github.com/google/uuid"
	"github.com/minio/madmin-go/v3"
	"github.com/minio/minio-go/v7/pkg/set"

Para o OAuth2, eles são apenas strings.

///

## Visão global { #global-view }

Primeiro, vamos olhar rapidamente as partes que mudam dos exemplos do **Tutorial - Guia de Usuário** para [OAuth2 com Senha (e hash), Bearer com tokens JWT](../../tutorial/security/oauth2-jwt.md){.internal-link target=_blank}. Agora utilizando escopos OAuth2:

{* ../../docs_src/security/tutorial005_an_py310.py hl[5,9,13,47,65,106,108:116,122:126,130:136,141,157] *}

  }

  /**
   * Sets the minimum total size for the internal hash tables. For example, if the initial capacity
   * is {@code 60}, and the concurrency level is {@code 8}, then eight segments are created, each
   * having a hash table of size eight. Providing a large enough estimate at construction time

            && Objects.equals(getValue(), other.getValue());
      }
      return false;
    }

    @Override
    public int hashCode() {
      return Objects.hash(getRowKey(), getColumnKey(), getValue());
    }

    @Override
    public String toString() {
      return "(" + getRowKey() + "," + getColumnKey() + ")=" + getValue();
    }
  }

  /**

	tlsInfo := madmin.TLSInfo{
		TLSEnabled: globalIsTLS,
		Certs:      []madmin.TLSCert{},
	}

	if globalIsTLS {
		for _, c := range globalPublicCerts {
			check := xxh3.Hash(c.RawIssuer)
			check ^= xxh3.Hash(c.RawSubjectPublicKeyInfo)
			// We XOR, so order doesn't matter.
			for _, v := range c.DNSNames {
				check ^= xxh3.HashString(v)
			}
			for _, v := range c.EmailAddresses {

pkg hash/crc64, const ISO ideal-int
pkg hash/crc64, const Size ideal-int
pkg hash/crc64, func Checksum([]uint8, *Table) uint64
pkg hash/crc64, func MakeTable(uint64) *Table
pkg hash/crc64, func New(*Table) hash.Hash64
pkg hash/crc64, func Update(uint64, *Table, []uint8) uint64
pkg hash/crc64, type Table [256]uint64
pkg hash/fnv, func New32() hash.Hash32
pkg hash/fnv, func New32a() hash.Hash32
pkg hash/fnv, func New64() hash.Hash64