NAME

       CURLOPT_PROXY_ISSUERCERT_BLOB - proxy issuer SSL certificate from memory blob

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_ISSUERCERT_BLOB,
                                 struct curl_blob *blob);

DESCRIPTION

       Pass  a pointer to a curl_blob struct, 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 of the
       HTTPS proxy 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_PROXY_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_PROXY_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_PROXY_ISSUERCERT(3)  which  instead  expects  a
       filename as input.

DEFAULT

       NULL

PROTOCOLS

       This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

       This option works only with the following TLS backends: OpenSSL

EXAMPLE

       extern char *certificateData; /* point to the data */
       size_t filesize; /* size of the data */

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode res;
           struct curl_blob blob;
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
           /* using an HTTPS proxy */
           curl_easy_setopt(curl, CURLOPT_PROXY, "https://localhost:443");
           blob.data = certificateData;
           blob.len = filesize;
           blob.flags = CURL_BLOB_COPY;
           curl_easy_setopt(curl, CURLOPT_PROXY_ISSUERCERT_BLOB, &blob);
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY

       Added in curl 7.71.0

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_BLOB(3),                               CURLOPT_PROXY_SSL_VERIFYHOST(3),
       CURLOPT_PROXY_SSL_VERIFYPEER(3), CURLOPT_SSL_VERIFYHOST(3), CURLOPT_SSL_VERIFYPEER(3)