CURLOPT_CAINFO(3)

1CURLOPT_CAINFO(3)          curl_easy_setopt options          CURLOPT_CAINFO(3)
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NAME

6       CURLOPT_CAINFO - path to Certificate Authority (CA) bundle
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SYNOPSIS

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

14       Pass  a char * to a zero terminated string naming a file holding one or
15       more certificates to verify the peer with.
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17       If CURLOPT_SSL_VERIFYPEER(3)  is  zero  and  you  avoid  verifying  the
18       server's  certificate,  CURLOPT_CAINFO(3)  need  not  even  indicate an
19       accessible file.
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21       This option is by default set to the system path where libcurl's cacert
22       bundle is assumed to be stored, as established at build time.
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24       If  curl is built against the NSS SSL library, the NSS PEM PKCS#11 mod‐
25       ule (libnsspem.so) needs to be available for this option to work  prop‐
26       erly.   Starting  with  curl-7.55.0, if both CURLOPT_CAINFO(3) and CUR‐
27       LOPT_CAPATH(3) are unset, NSS-linked  libcurl  tries  to  load  libnss‐
28       ckbi.so,  which  contains a more comprehensive set of trust information
29       than supported by nss-pem, because libnssckbi.so also includes informa‐
30       tion about distrusted certificates.
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32       (iOS  and  macOS  only) If curl is built against Secure Transport, then
33       this option is supported for  backward  compatibility  with  other  SSL
34       engines,  but it should not be set. If the option is not set, then curl
35       will use the certificates in the system and user Keychain to verify the
36       peer, which is the preferred method of verifying the peer's certificate
37       chain.
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39       (Schannel/WinSSL only) This option is supported for WinSSL in Windows 7
40       or later with libcurl 7.60 or later. This option is supported for back‐
41       ward compatibility with other SSL engines; instead it is recommended to
42       use Windows' store of root certificates (the default for WinSSL).
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44       The  application  does not have to keep the string around after setting
45       this option.
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DEFAULT

48       Built-in system specific
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PROTOCOLS

51       All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
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EXAMPLE

54       CURL *curl = curl_easy_init();
55       if(curl) {
56         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
57         curl_easy_setopt(curl, CURLOPT_CAINFO, "/etc/certs/cabundle.pem");
58         ret = curl_easy_perform(curl);
59         curl_easy_cleanup(curl);
60       }
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AVAILABILITY

63       For SSL engines that don't support certificate files the CURLOPT_CAINFO
64       option is ignored. Refer to https://curl.haxx.se/docs/ssl-compared.html
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RETURN VALUE

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