在此页

• 句法
• Default policy
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

这是 实验性技术
检查 浏览器兼容性表格 要小心谨慎在生产中使用这之前。

The HTTP Feature-Policy header encrypted-media directive controls whether the current document is allowed to use the 加密媒体扩展 API (EME). When this policy is enabled, the Promise returned by Navigator.requestMediaKeySystemAccess() will reject with a DOMException .

句法

Feature-Policy: encrypted-media <allowlist>;
					

<allowlist>

An allowlist is a list of origins that takes one or more of the following values, separated by spaces:

• * : The feature will be allowed in this document, and all nested browsing contexts (iframes) regardless of their origin.
• 'self' : The feature will be allowed in this document, and in all nested browsing contexts (iframes) in the same origin.
• 'src' : (In an iframe allow attribute only) The feature will be allowed in this iframe, as long as the document loaded into it comes from the same origin as the URL in the iframe's src 属性。 'src' origin is used in the iframe allow attribute only, and is the default allowlist 值。
• 'none' : The feature is disabled in top-level and nested browsing contexts.
• <origin(s)>: The feature is allowed for specific origins (for example, https://example.com). Origins should be separated by a space.

The values * (enable for all origins) or 'none' (disable for all origins) may only be used alone, while 'self' and 'src' may be used with one or more origins.

Features are each defined to have a default allowlist, which is one of:

• * : The feature is allowed by default in top-level browsing contexts and all nested browsing contexts (iframes).
• 'self' : The feature is allowed by default in top-level browsing contexts and in nested browsing contexts (iframes) in the same origin. The feature is not allowed in cross-origin documents in nested browsing contexts.
• 'none' : The feature is disabled in top-level and nested browsing contexts.

Default policy

The allow list is 'self' .

规范

规范	状态	注释
Permissions Policy	编者草案	初始定义。
加密媒体扩展 The definition of 'Feature Policy integration' in that specification.	推荐

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
encrypted-media Experimental	Chrome 完整支持 60	Edge 完整支持 79	Firefox 完整支持 74 完整支持 74 完整支持 65 Disabled Disabled ). To change preferences in Firefox, visit	IE 不支持 No	Opera 完整支持 48	Safari 不支持 No	WebView Android 完整支持 60	Chrome Android 完整支持 60	Firefox Android 完整支持 65 Disabled 完整支持 65 Disabled Disabled ). To change preferences in Firefox, visit	Opera Android 完整支持 45	Safari iOS 不支持 No	Samsung Internet Android 完整支持 8.0

图例

完整支持

完整支持

不支持

不支持

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

用户必须明确启用此特征。

用户必须明确启用此特征。

另请参阅

• Feature-Policy header
• Feature Policy
• Using Feature Policy

元数据

• 最后修改： Aug 9, 2020

相关话题

1. HTTP
2. Guides:
3. Resources and URIs

   1. Identifying resources on the Web
   2. Data URIs
   3. Introduction to MIME Types
   4. Complete list of MIME Types
   5. Choosing between www and non-www URLs
4. HTTP guide

   1. Basics of HTTP
   2. HTTP 概述
   3. Evolution of HTTP
   4. HTTP Messages
   5. A typical HTTP session
   6. Connection management in HTTP/1.x
   7. Protocol upgrade mechanism
5. HTTP 安全性

   1. Content Security Policy (CSP)
   2. HTTP Public Key Pinning (HPKP)
   3. HTTP Strict Transport Security (HSTS)
   4. Cookie security
   5. X-Content-Type-Options
   6. X-Frame-Options
   7. X-XSS-Protection
   8. Mozilla web security guidelines
   9. Mozilla Observatory
6. HTTP access control (CORS)
7. HTTP authentication
8. HTTP caching
9. HTTP compression
10. HTTP conditional requests
11. HTTP content negotiation
12. HTTP cookies
13. HTTP range requests
14. HTTP redirects
15. HTTP specifications
16. Feature policy
17. 参考：
18. HTTP 头

    1. Accept
    2. Accept-CH
    3. Accept-CH-Lifetime
    4. Accept-Charset
    5. Accept-Encoding
    6. Accept-Language
    7. Accept-Patch
    8. Accept-Ranges
    9. Access-Control-Allow-Credentials
    10. Access-Control-Allow-Headers
    11. Access-Control-Allow-Methods
    12. Access-Control-Allow-Origin
    13. Access-Control-Expose-Headers
    14. Access-Control-Max-Age
    15. Access-Control-Request-Headers
    16. Access-Control-Request-Method
    17. Age
    18. Allow
    19. Alt-Svc
    20. Authorization
    21. Cache-Control
    22. Clear-Site-Data
    23. Connection
    24. Content-Disposition
    25. Content-Encoding
    26. Content-Language
    27. Content-Length
    28. Content-Location
    29. Content-Range
    30. Content-Security-Policy
    31. Content-Security-Policy-Report-Only
    32. Content-Type
    33. Cookie
    34. Cookie2
    35. Cross-Origin-Embedder-Policy
    36. Cross-Origin-Opener-Policy
    37. Cross-Origin-Resource-Policy
    38. DNT
    39. DPR
    40. Date
    41. Device-Memory
    42. Digest
    43. ETag
    44. Early-Data
    45. Expect
    46. Expect-CT
    47. Expires
    48. Feature-Policy
    49. Forwarded
    50. From
    51. Host
    52. If-Match
    53. If-Modified-Since
    54. If-None-Match
    55. If-Range
    56. If-Unmodified-Since
    57. 索引
    58. Keep-Alive
    59. Large-Allocation
    60. Last-Modified
    61. Link
    62. Location
    63. NEL
    64. Origin
    65. Pragma
    66. Proxy-Authenticate
    67. Proxy-Authorization
    68. Public-Key-Pins
    69. Public-Key-Pins-Report-Only
    70. Range
    71. Referer
    72. Referrer-Policy
    73. Retry-After
    74. Save-Data
    75. Sec-Fetch-Dest
    76. Sec-Fetch-Mode
    77. Sec-Fetch-Site
    78. Sec-Fetch-User
    79. Sec-WebSocket-Accept
    80. Server
    81. Server-Timing
    82. Set-Cookie
    83. Set-Cookie2
    84. SourceMap
    85. Strict-Transport-Security
    86. TE
    87. Timing-Allow-Origin
    88. Tk
    89. Trailer
    90. Transfer-Encoding
    91. Upgrade-Insecure-Requests
    92. User-Agent
    93. Vary
    94. Via
    95. WWW-Authenticate
    96. Want-Digest
    97. 警告
    98. X-Content-Type-Options
    99. X-DNS-Prefetch-Control
    100. X-Forwarded-For
    101. X-Forwarded-Host
    102. X-Forwarded-Proto
    103. X-Frame-Options
    104. X-XSS-Protection
19. HTTP 请求方法

    1. CONNECT
    2. DELETE
    3. GET
    4. HEAD
    5. OPTIONS
    6. PATCH
    7. POST
    8. PUT
    9. TRACE
20. HTTP 响应状态码

    1. 100 Continue
    2. 101 Switching Protocols
    3. 103 Early Hints
    4. 200 OK
    5. 201 Created
    6. 202 Accepted
    7. 203 Non-Authoritative Information
    8. 204 No Content
    9. 205 Reset Content
    10. 206 Partial Content
    11. 300 Multiple Choices
    12. 301 Moved Permanently
    13. 302 Found
    14. 303 See Other
    15. 304 Not Modified
    16. 307 Temporary Redirect
    17. 308 Permanent Redirect
    18. 400 Bad Request
    19. 401 Unauthorized
    20. 402 Payment Required
    21. 403 Forbidden
    22. 404 Not Found
    23. 405 Method Not Allowed
    24. 406 Not Acceptable
    25. 407 Proxy Authentication Required
    26. 408 Request Timeout
    27. 409 Conflict
    28. 410 Gone
    29. 411 Length Required
    30. 412 Precondition Failed
    31. 413 Payload Too Large
    32. 414 URI Too Long
    33. 415 Unsupported Media Type
    34. 416 Range Not Satisfiable
    35. 417 Expectation Failed
    36. 418 I'm a teapot
    37. 422 Unprocessable Entity
    38. 425 Too Early
    39. 426 Upgrade Required
    40. 428 Precondition Required
    41. 429 Too Many Requests
    42. 431 Request Header Fields Too Large
    43. 451 Unavailable For Legal Reasons
    44. 500 Internal Server Error
    45. 501 Not Implemented
    46. 502 Bad Gateway
    47. 503 Service Unavailable
    48. 504 Gateway Timeout
    49. 505 HTTP Version Not Supported
    50. 506 Variant Also Negotiates
    51. 507 Insufficient Storage
    52. 508 Loop Detected
    53. 510 Not Extended
    54. 511 Network Authentication Required
21. CSP directives

    1. CSP: base-uri
    2. CSP: block-all-mixed-content
    3. CSP: child-src
    4. CSP: connect-src
    5. CSP: default-src
    6. CSP: font-src
    7. CSP: form-action
    8. CSP: frame-ancestors
    9. CSP: frame-src
    10. CSP: img-src
    11. CSP: manifest-src
    12. CSP: media-src
    13. CSP: navigate-to
    14. CSP: object-src
    15. CSP: plugin-types
    16. CSP: prefetch-src
    17. CSP: referrer
    18. CSP: report-to
    19. CSP: report-uri
    20. CSP: require-sri-for
    21. CSP: sandbox
    22. CSP: script-src
    23. CSP: script-src-attr
    24. CSP: script-src-elem
    25. CSP: style-src
    26. CSP: style-src-attr
    27. CSP: style-src-elem
    28. CSP: trusted-types
    29. CSP: upgrade-insecure-requests
    30. CSP: worker-src
22. CORS errors

    1. Reason: CORS disabled
    2. Reason: CORS header 'Access-Control-Allow-Origin' does not match 'xyz'
    3. Reason: CORS header 'Access-Control-Allow-Origin' missing
    4. Reason: CORS header ‘Origin’ cannot be added
    5. Reason: CORS preflight channel did not succeed
    6. Reason: CORS request did not succeed
    7. Reason: CORS request external redirect not allowed
    8. Reason: CORS request not HTTP
    9. Reason: Credential is not supported if the CORS header ‘Access-Control-Allow-Origin’ is ‘*’
    10. Reason: Did not find method in CORS header ‘Access-Control-Allow-Methods’
    11. Reason: Multiple CORS header 'Access-Control-Allow-Origin' not allowed
    12. Reason: expected ‘true’ in CORS header ‘Access-Control-Allow-Credentials’
    13. Reason: invalid token ‘xyz’ in CORS header ‘Access-Control-Allow-Headers’
    14. Reason: invalid token ‘xyz’ in CORS header ‘Access-Control-Allow-Methods’
    15. Reason: missing token ‘xyz’ in CORS header ‘Access-Control-Allow-Headers’ from CORS preflight channel
23. Feature-Policy directives

    1. Feature-Policy: accelerometer
    2. Feature-Policy: ambient-light-sensor
    3. Feature-Policy: autoplay
    4. Feature-Policy: battery
    5. Feature-Policy: camera
    6. Feature-Policy: display-capture
    7. Feature-Policy: document-domain
    8. Feature-Policy: encrypted-media
    9. Feature-Policy: fullscreen
    10. Feature-Policy: geolocation
    11. Feature-Policy: gyroscope
    12. Feature-Policy: layout-animations
    13. Feature-Policy: legacy-image-formats
    14. Feature-Policy: magnetometer
    15. Feature-Policy: microphone
    16. Feature-Policy: midi
    17. Feature-Policy: oversized-images
    18. Feature-Policy: payment
    19. Feature-Policy: picture-in-picture
    20. Feature-Policy: publickey-credentials-get
    21. Feature-Policy: screen-wake-lock
    22. Feature-Policy: sync-xhr
    23. Feature-Policy: unoptimized-images
    24. Feature-Policy: unsized-media
    25. Feature-Policy: usb
    26. Feature-Policy: vibrate
    27. Feature-Policy: vr
    28. Feature-Policy: wake-lock
    29. Feature-Policy: xr
    30. Feature-Policy: xr-spatial-tracking
    31. web-share