本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。

# Verified Access 信任数据的默认上下文
<a name="trust-data-default-context"></a>

AWS Verified Access 无论您配置了哪个信任提供商，默认情况下，所有 Cedar 评估都包含有关当前请求的一些元素。如果您愿意，可以编写根据数据进行评估的策略。

以下是评估中包含的数据的示例。

**Topics**
+ [HTTP 请求](#default-context-http-request)
+ [TCP 数据流](#default-context-tcp-flow)

## HTTP 请求
<a name="default-context-http-request"></a>

评估策略时，Verified Access 会在`context.http_request`密钥下方包含 Cedar 上下文中有关当前 HTTP 请求的数据。

```
{
    "title": "HTTP Request data included by Verified Access",
    "type": "object",
    "properties": {
        "http_method": {
            "type": "string",
            "description": "The HTTP method",
            "example": "GET"
        },
        "hostname": {
            "type": "string",
            "description": "The host subcomponent of the authority component of the URI",
            "example": "example.com"
        },
        "path": {
            "type": "string",
            "description": "The path component of the URI",
            "example": "app/images"
        },
        "query": {
            "type": "string",
            "description": "The query component of the URI",
            "example": "value1=1&value2=2"
        },
        "x_forwarded_for": {
            "type": "string",
            "description": "The value of the X-Forwarded-For request header",
            "example": "17.7.7.1"
        },
        "port": { 
           "type": "integer",
           "description": "The endpoint port",
           "example": 443
        },
        "user_agent": {
            "type": "string",
            "description": "The value of the User-Agent request header",
            "example": "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0"
        },
        "client_ip": {
            "type": "string",
            "description": "The IP address connecting to the endpoint",
            "example": "15.248.6.6"
        }
    }
}
```

**策略示例**  
以下是使用 HTTP 请求数据的 Cedar 策略示例。

```
forbid(principal, action, resource) when {
   context.http_request.http_method == "POST"
   && !(context.identity.roles.contains("Administrator"))
 };
```

## TCP 数据流
<a name="default-context-tcp-flow"></a>

评估策略时，Verified Access 会在`context.tcp_flow`密钥下方包含有关 Cedar 上下文中当前 TCP 流的数据。

```
{
    "title": "TCP flow data included by Verified Access",
    "type": "object",
    "properties": {
        "destination_ip": {
            "type": "string",
            "description": "The IP address of the target",
            "example": "192.100.1.3"
        },
        "destination_port": {
            "type": "string",
            "description": "The target port",
            "example": 22
        },
        "client_ip": {
            "type": "string",
            "description": "The IP address connecting to the endpoint",
            "example": "172.154.16.9"
        }
    }
}
```