quickjs-tart

quickjs-based runtime for wallet-core logic
Log | Files | Refs | README | LICENSE

CURLOPT_SSH_HOSTKEYFUNCTION.md (2371B)

      1 ---
      2 c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      3 SPDX-License-Identifier: curl
      4 Title: CURLOPT_SSH_HOSTKEYFUNCTION
      5 Section: 3
      6 Source: libcurl
      7 See-also:
      8   - CURLOPT_SSH_HOSTKEYDATA (3)
      9   - CURLOPT_SSH_KNOWNHOSTS (3)
     10 Protocol:
     11   - SFTP
     12   - SCP
     13 Added-in: 7.84.0
     14 ---
     15 
     16 # NAME
     17 
     18 CURLOPT_SSH_HOSTKEYFUNCTION - callback to check host key
     19 
     20 # SYNOPSIS
     21 
     22 ~~~c
     23 #include <curl/curl.h>
     24 
     25 int keycallback(void *clientp,
     26                 int keytype,
     27                 const char *key,
     28                 size_t keylen);
     29 
     30 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_HOSTKEYFUNCTION,
     31                           keycallback);
     32 ~~~
     33 
     34 # DESCRIPTION
     35 
     36 Pass a pointer to your callback function, which should match the prototype
     37 shown above. It overrides CURLOPT_SSH_KNOWNHOSTS(3).
     38 
     39 This callback gets called when the verification of the SSH host key is needed.
     40 
     41 **key** is **keylen** bytes long and is the key to check. **keytype**
     42 says what type it is, from the **CURLKHTYPE_*** series in the
     43 **curl_khtype** enum.
     44 
     45 **clientp** is a custom pointer set with CURLOPT_SSH_HOSTKEYDATA(3).
     46 
     47 The callback MUST return one of the following return codes to tell libcurl how
     48 to act:
     49 
     50 ## CURLKHMATCH_OK
     51 
     52 The host key is accepted, the connection should continue.
     53 
     54 ## CURLKHMATCH_MISMATCH
     55 
     56 the host key is rejected, the connection is canceled.
     57 
     58 # DEFAULT
     59 
     60 NULL
     61 
     62 # %PROTOCOLS%
     63 
     64 # EXAMPLE
     65 
     66 ~~~c
     67 struct mine {
     68   void *custom;
     69 };
     70 
     71 int hostkeycb(void *clientp,    /* passed with CURLOPT_SSH_HOSTKEYDATA */
     72               int keytype,      /* CURLKHTYPE */
     73               const char *key,  /* host key to check */
     74               size_t keylen)    /* length of the key */
     75 {
     76   /* 'clientp' points to the callback_data struct */
     77   /* investigate the situation and return the correct value */
     78   return CURLKHMATCH_OK;
     79 }
     80 int main(void)
     81 {
     82   struct mine callback_data;
     83   CURL *curl = curl_easy_init();
     84   if(curl) {
     85     curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/thisfile.txt");
     86     curl_easy_setopt(curl, CURLOPT_SSH_HOSTKEYFUNCTION, hostkeycb);
     87     curl_easy_setopt(curl, CURLOPT_SSH_HOSTKEYDATA, &callback_data);
     88 
     89     curl_easy_perform(curl);
     90   }
     91 }
     92 ~~~
     93 
     94 # NOTES
     95 
     96 Work only with the libssh2 backend.
     97 
     98 # %AVAILABILITY%
     99 
    100 # RETURN VALUE
    101 
    102 curl_easy_setopt(3) returns a CURLcode indicating success or error.
    103 
    104 CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
    105 libcurl-errors(3).