NAME

       CURLOPT_ISSUERCERT_BLOB - issuer SSL certificate from memory blob

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ISSUERCERT_BLOB,
                                 struct curl_blob *stblob);

DESCRIPTION

       Pass  a  pointer  to  a curl_blob structure, which contains information (pointer and size) about a memory
       block with binary data of a CA certificate in PEM format. If the  option  is  set,  an  additional  check
       against  the  peer  certificate  is  performed to verify the issuer is indeed the one associated with the
       certificate provided by the option. This additional check is useful in multi-level PKI where one needs to
       enforce that the peer certificate is from a specific branch of the tree.

       This  option  should  be  used  in  combination with the CURLOPT_SSL_VERIFYPEER(3) option. Otherwise, the
       result of the check is not considered as failure.

       A specific error code (CURLE_SSL_ISSUER_ERROR) is defined with the option, which is returned if the setup
       of   the   SSL/TLS   session  has  failed  due  to  a  mismatch  with  the  issuer  of  peer  certificate
       (CURLOPT_SSL_VERIFYPEER(3) has to be set too for the check to fail).

       If the blob is initialized with  the  flags  member  of  struct  curl_blob  set  to  CURL_BLOB_COPY,  the
       application does not have to keep the buffer around after setting this.

       This option is an alternative to CURLOPT_ISSUERCERT(3) which instead expects a file name as input.

DEFAULT

       NULL

PROTOCOLS

       All TLS-based protocols

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         struct curl_blob blob;
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
         blob.data = certificateData;
         blob.len = filesize;
         blob.flags = CURL_BLOB_COPY;
         curl_easy_setopt(curl, CURLOPT_ISSUERCERT_BLOB, &blob);
         ret = curl_easy_perform(curl);
         curl_easy_cleanup(curl);
       }

AVAILABILITY

       Added in 7.71.0. This option is supported by the OpenSSL backends.

RETURN VALUE

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

SEE ALSO

       CURLOPT_ISSUERCERT(3), CURLOPT_CRLFILE(3), CURLOPT_SSL_VERIFYPEER(3),