CURLOPT_PROXY_CAINFO_BLOB - Man Page

#include <curl/curl.h>

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

This option is for connecting to an HTTPS proxy, not an HTTPS server.

Pass a pointer to a curl_blob structure, which contains information (pointer and size) about a memory block with binary data of PEM encoded content holding one or more certificates to verify the HTTPS proxy with.

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.

If CURLOPT_PROXY_SSL_VERIFYPEER(3) is zero and you avoid verifying the server's certificate, CURLOPT_PROXY_CAINFO_BLOB(3) is not needed.

This option overrides CURLOPT_PROXY_CAINFO(3).

NULL

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

This option works only with the following TLS backends: OpenSSL, Schannel, Secure Transport and rustls

#include <string.h> /* for strlen */

extern char *strpem; /* strpem must point to a PEM string */
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 = strpem;
    blob.len = strlen(strpem);
    blob.flags = CURL_BLOB_COPY;
    curl_easy_setopt(curl, CURLOPT_PROXY_CAINFO_BLOB, &blob);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

Added in curl 7.77.0

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

CURLOPT_CAINFO(3), CURLOPT_CAINFO_BLOB(3), CURLOPT_CAPATH(3), CURLOPT_PROXY_CAINFO(3), CURLOPT_PROXY_CAPATH(3), CURLOPT_PROXY_SSL_VERIFYHOST(3), CURLOPT_PROXY_SSL_VERIFYPEER(3), CURLOPT_SSL_VERIFYHOST(3), CURLOPT_SSL_VERIFYPEER(3)

curl_easy_setopt(3), CURLOPT_PROXY_CAINFO(3), libcurl-symbols(3).