CURLOPT_HSTSREADFUNCTION(3)

1CURLOPT_HSTSREADFUNCTION(3)curl_easy_setopt optionsCURLOPT_HSTSREADFUNCTION(3)
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NAME

6       CURLOPT_HSTSREADFUNCTION - read callback for HSTS hosts
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLSTScode  hstsread(CURL  *easy,  struct  curl_hstsentry  *sts,  void
12       *userp);
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14       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTSREADFUNCTION,  hst‐
15       sread);
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EXPERIMENTAL

18       Warning:  this  feature is early code and is marked as experimental. It
19       can only be enabled by explicitly telling configure with --enable-hsts.
20       You  are advised to not ship this in production before the experimental
21       label is removed.
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DESCRIPTION

24       Pass a pointer to your callback function, as the prototype shows above.
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26       This callback function gets called by libcurl repeatedly when it  popu‐
27       lates the in-memory HSTS cache.
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29       Set  the  userp  argument with the CURLOPT_HSTSREADDATA(3) option or it
30       will be NULL.
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32       When this callback is invoked, the sts pointer points  to  a  populated
33       struct:  Copy the host name to 'name' (no longer than 'namelen' bytes).
34       Make it null-terminated. Set 'includeSubDomains' to TRUE or FALSE.  Set
35       'expire'  to  a date stamp or a zero length string for *forever* (wrong
36       date stamp format might cause the name to not get accepted)
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38       The callback should return CURLSTS_OK if it returns a name and is  pre‐
39       pared  to  be called again (for another host) or CURLSTS_DONE if it has
40       no entry to return. It can also return CURLSTS_FAIL to signal error.
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42       This option doesn't enable HSTS, you need to  use  CURLOPT_HSTS_CTRL(3)
43       to do that.
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DEFAULT

46       NULL - no callback.
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PROTOCOLS

49       This feature is only used for HTTP(S) transfer.
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EXAMPLE

52       {
53         /* set HSTS read callback */
54         curl_easy_setopt(curl, CURLOPT_HSTSREADFUNCTION, hstsread);
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56         /* pass in suitable argument to the callback */
57         curl_easy_setopt(curl, CURLOPT_HSTSREADDATA, &hstspreload[0]);
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59         result = curl_easy_perform(curl);
60       }
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AVAILABILITY

63       Added in 7.74.0
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RETURN VALUE

66       This will return CURLE_OK.
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