CURLOPT_ISSUERCERT(3)

1CURLOPT_ISSUERCERT(3)      curl_easy_setopt options      CURLOPT_ISSUERCERT(3)
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NAME

6       CURLOPT_ISSUERCERT - issuer SSL certificate filename
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ISSUERCERT, char *file);
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DESCRIPTION

14       Pass  a  char  * to a null-terminated string naming a file holding a CA
15       certificate in PEM format. If the option is set,  an  additional  check
16       against  the  peer certificate is performed to verify the issuer is in‐
17       deed the one associated with the certificate provided  by  the  option.
18       This  additional  check is useful in multi-level PKI where one needs to
19       enforce that the peer certificate is from  a  specific  branch  of  the
20       tree.
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22       This  option  makes  sense  only when used in combination with the CUR‐
23       LOPT_SSL_VERIFYPEER(3) option. Otherwise, the result of  the  check  is
24       not considered as failure.
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26       A  specific error code (CURLE_SSL_ISSUER_ERROR) is defined with the op‐
27       tion, which is returned if the setup of the SSL/TLS session has  failed
28       due to a mismatch with the issuer of peer certificate (CURLOPT_SSL_VER‐
29       IFYPEER(3) has to be set too for the check to fail). (Added in 7.19.0)
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31       The application does not have to keep the string around  after  setting
32       this option.
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DEFAULT

35       NULL
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PROTOCOLS

38       All TLS-based protocols
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EXAMPLE

41       CURL *curl = curl_easy_init();
42       if(curl) {
43         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
44         curl_easy_setopt(curl, CURLOPT_ISSUERCERT, "/etc/certs/cacert.pem");
45         ret = curl_easy_perform(curl);
46         curl_easy_cleanup(curl);
47       }
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AVAILABILITY

50       If built TLS enabled
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RETURN VALUE

53       Returns  CURLE_OK  if  the option is supported, CURLE_UNKNOWN_OPTION if
54       not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
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