What is HTTP header caching?
The cache control is an HTTP header used to specify browser caching policies on both client requests and server responses. Policies include how a resource is cached, where it is cached, and its maximum age before it expires (ie time to live).
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How does HTTP support caching?
HTTP supports caching so that the browser can store content locally and reuse it when needed. Browser caching is controlled through the use of the Cache-Control, Last-Modified, and Expires response headers.
How do I set the cache control HTTP header?
To use the cache control in HTML, use the meta tag, for example, the value in the content field is defined as one of the four values below. HTTP 1.1. Allowed values = PUBLIC | PRIVATE | NO CACHE | NO STORE.
How are HTTP headers used to prevent caching?
However, the data is still cached locally on disk and thus only provides little security benefit, but prevents an attacker from directly using the browser’s back button to read the data without having to access the cache itself. the file system. For example: Expires: Thu, 01 Jan 1970 00:00:00 GMT The HTTP 1.1 equivalent of the expire header.
Can cacheless pragma be used as request header?
Later, the HTTP/1.1 specification states that the Pragma: no-cache response should be handled as Cache-Control: no-cache, but it is not a reliable replacement due to the fact that it is still a request header. I also still use Pragma: no-cache as an OWASP security recommendation.
Why do browsers cache HTTP redirect headers indefinitely?
The logic is that you are specifying a “permanent” redirect and not giving them any other caching instructions, so they will treat it as if you wanted to cache it indefinitely. Browsers still honor the Cache-Control and Expires headers as with any other response, if specified.
What to expect from a cached request header?
When sending the “If-None-Match” request header with the ETag of a cached resource, the browser expects a 200 OK response with a new resource or an empty 304 Not Modified response, indicating that it should use a resource cached. instead of downloading a new one.