curl / libcurl / API / curl_easy_setopt / CURLOPT_PROXY_CAINFO_BLOB

CURLOPT_PROXY_CAINFO_BLOB explained

Name

CURLOPT_PROXY_CAINFO_BLOB - proxy Certificate Authority (CA) bundle in PEM format

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_CAINFO_BLOB,
                          struct curl_blob *stblob);

Description

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

This option overrides CURLOPT_PROXY_CAINFO.

Default

NULL

Protocols

Used with HTTPS proxy

Example

char *strpem; /* strpem must point to a PEM string */
CURL *curl = curl_easy_init();
if(curl) {
  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);
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}

Availability

Added in 7.77.0.

This option is supported by the rustls (since 7.82.0), OpenSSL, Secure Transport and Schannel 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.