CURLOPT_PROXY_CAINFO_BLOB(3)

💅 CURLOPT_PROXY_CAINFO_BLOB(3) 💅

okay bestie, welcome to the Library Functions Manual page for CURLOPT_PROXY_CAINFO_BLOB(3) — this is the proxy CA blob situation, and it's giving very "trust this HTTPS proxy" energy 🫶

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🎀 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 🌸

okay so first thing: this option is for connecting to an HTTPS proxy, not an HTTPS server. Periodt 💅

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).

🦋 DEFAULT 🦋

NULL — yep, that's the default, bestie 🫶

🌈 PROTOCOLS 🌈

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

This option works only with the following TLS backends: OpenSSL, Rustls and Schannel

🍓 EXAMPLE 🍓

#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 result;
    struct curl_blob blob;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    /* using an HTTPS proxy */
    curl_easy_setopt(curl, CURLOPT_PROXY, "https://proxy.example:443");
    blob.data = strpem;
    blob.len = strlen(strpem);
    blob.flags = CURL_BLOB_COPY;
    curl_easy_setopt(curl, CURLOPT_PROXY_CAINFO_BLOB, &blob);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

⭐ AVAILABILITY ⭐

Added in curl 7.77.0

👑 RETURN VALUE 👑

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

🧚 SEE ALSO 🧚

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)

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okay that's the whole vibe, bestie — signing off with <pink>libcurl</pink> energy and a <pink>2026-10-12</pink> timestamp, mwah 💋