It can be used by third party applications and systems.

And it can also be used by yourself, to debug, check and test the same application.

## The `password` flow { #the-password-flow }

Now let's go back a bit and understand what is all that.

The `password` "flow" is one of the ways ("flows") defined in OAuth2, to handle security and authentication.

def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        verify_password(password, DUMMY_HASH)
        return False

        this.parameters = value;
    }

    public String getPassword() {
        checkSpecifiedProperty("password");
        return convertEmptyToNull(password);
    }

    public void setPassword(String value) {
        registerModifiedProperty("password");
        this.password = value;
    }

    public Integer getPort() {
        checkSpecifiedProperty("port");
        return port;
    }

    if not user_dict:
        raise HTTPException(status_code=400, detail="Incorrect username or password")
    user = UserInDB(**user_dict)
    hashed_password = fake_hash_password(form_data.password)
    if not hashed_password == user.hashed_password:
        raise HTTPException(status_code=400, detail="Incorrect username or password")

    return {"access_token": user.username, "token_type": "bearer"}


@app.get("/users/me")

                // encrypted
                try {
                    this.password = pwAuth.getAnsiHash(this.ctx, this.server.encryptionKey);
                } catch (final GeneralSecurityException e) {
                    throw new RuntimeCIFSException("Failed to encrypt password", e);
                }
                this.passwordLength = this.password.length;
            } else if (this.ctx.getConfig().isDisablePlainTextPasswords()) {

          keystorePassword 'keystore-password'
        }
      }
      project.tasks.withType(Test).configureEach { Test task ->
        dependsOn 'fipsResources'
        task.systemProperty('javax.net.ssl.trustStorePassword', 'password')
        task.systemProperty('javax.net.ssl.keyStorePassword', 'password')
        task.systemProperty('javax.net.ssl.trustStoreType', 'BCFKS')

 */

/**
 * Provides the API for the Maven Password Encryption tool ({@code mvnenc}).
 *
 * <p>This package contains interfaces and classes for the password encryption tool,
 * which helps secure sensitive information in Maven settings and configuration files.</p>
 *
 * <p>Key features include:</p>
 * <ul>
 *   <li>Password encryption and decryption</li>
 *   <li>Master password management</li>

import okhttp3.internal.platform.Platform
import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.HeldCertificate
import org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

object TlsUtil {
  val password = "password".toCharArray()

  private val localhost: HandshakeCertificates by lazy {
    // Generate a self-signed cert for the server to serve and the client to trust.
    val heldCertificate =
      HeldCertificate

def get_password_hash(password):
    return password_hash.hash(password)


def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        verify_password(password, DUMMY_HASH)
        return False

///

点击它，会弹出一个授权表单，可输入 `username` 和 `password`（以及其它可选字段）：

<img src="/img/tutorial/security/image02.png">

/// note | 注意

目前无论在表单中输入什么都不会生效，我们稍后就会实现它。

///

这当然不是面向最终用户的前端，但它是一个很棒的自动化工具，可交互式地为整个 API 提供文档。

前端团队（也可能就是你自己）可以使用它。

第三方应用和系统也可以使用它。

你也可以用它来调试、检查和测试同一个应用。

## `password` 流 { #the-password-flow }

现在回过头来理解这些内容。

`password` “流”（flow）是 OAuth2 定义的处理安全与身份验证的一种方式。