4.3. 资源所有者密码凭据许可(4.3. Resource Owner Password Credentials Grant)

4.3. 资源所有者密码凭据许可

资源所有者密码凭据许可类型适合于资源所有者与客户端具有信任关系的情况，如设备操作系统或高级特权应用。当启用这种许可类型时授权服务器应该特别关照且只有当其他流程都不可用时才可以。

这种许可类型适合于能够获得资源所有者凭据（用户名和密码，通常使用交互的形式）的客户端。通过转换已存储的凭据至访问令牌，它也用于迁移现存的使用如HTTP基本或摘要身份验证的直接身份验证方案的客户端至OAuth。

 +----------+
 | Resource |
 |  Owner   |
 |          |
 +----------+
      v
      |    Resource Owner
     (A) Password Credentials
      |
      v
 +---------+                                  +---------------+
 |         |>--(B)---- Resource Owner ------->|               |
 |         |         Password Credentials     | Authorization |
 | Client  |                                  |     Server    |
 |         |<--(C)---- Access Token ---------<|               |
 |         |    (w/ Optional Refresh Token)   |               |
 +---------+                                  +---------------+

图5：资源所有者密码凭据流程

图5中的所示流程包含以下步骤：

• （A）资源所有者提供给客户端它的用户名和密码。

• （B）通过包含从资源所有者处接收到的凭据，客户端从授权服务器的令牌端点请求访问令牌。当发起请求时，客户端与授权服务器进行身份验证。

• （C）授权服务器对客户端进行身份验证，验证资源所有者的凭证，如果有效，颁发访问令牌。

4.3. Resource Owner Password Credentials Grant

   The resource owner password credentials grant type is suitable in
   cases where the resource owner has a trust relationship with the
   client, such as the device operating system or a highly privileged



Hardt                        Standards Track                   [Page 37]

 
RFC 6749                        OAuth 2.0                   October 2012


   application.  The authorization server should take special care when
   enabling this grant type and only allow it when other flows are not
   viable.

   This grant type is suitable for clients capable of obtaining the
   resource owner's credentials (username and password, typically using
   an interactive form).  It is also used to migrate existing clients
   using direct authentication schemes such as HTTP Basic or Digest
   authentication to OAuth by converting the stored credentials to an
   access token.

     +----------+
     | Resource |
     |  Owner   |
     |          |
     +----------+
          v
          |    Resource Owner
         (A) Password Credentials
          |
          v
     +---------+                                  +---------------+
     |         |>--(B)---- Resource Owner ------->|               |
     |         |         Password Credentials     | Authorization |
     | Client  |                                  |     Server    |
     |         |<--(C)---- Access Token ---------<|               |
     |         |    (w/ Optional Refresh Token)   |               |
     +---------+                                  +---------------+

            Figure 5: Resource Owner Password Credentials Flow

   The flow illustrated in Figure 5 includes the following steps:

   (A)  The resource owner provides the client with its username and
        password.

   (B)  The client requests an access token from the authorization
        server's token endpoint by including the credentials received
        from the resource owner.  When making the request, the client
        authenticates with the authorization server.

   (C)  The authorization server authenticates the client and validates
        the resource owner credentials, and if valid, issues an access
        token.