---
name: "CURLOPT_PROXY_SSLCERT_BLOB"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_PROXY_SSLCERT_BLOB"
---

# CURLOPT\_PROXY\_SSLCERT\_BLOB(3)

SSL proxy client certificate from memory blob

## NAME

CURLOPT\_PROXY\_SSLCERT\_BLOB - SSL proxy client certificate from memory blob

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLCERT_BLOB,
                          struct curl_blob *blob);
```

## DESCRIPTION

Pass a pointer to a curl\_blob structure, which contains information (pointer and size) about a memory block with binary data of the certificate used to connect to the HTTPS proxy. The format must be "P12" on Secure Transport or Schannel. The format must be "P12" or "PEM" on OpenSSL. The string "P12" or "PEM" must be specified with *[CURLOPT\_PROXY\_SSLCERTTYPE(3)](/CURLOPT_PROXY_SSLCERTTYPE/3.md)*.

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\_SSLCERT(3)](/CURLOPT_PROXY_SSLCERT/3.md)* which instead expects a filename as input.

## DEFAULT

NULL

## PROTOCOLS

Used with HTTPS proxy

## EXAMPLE

```
extern char *certificateData; /* point to data */
extern size_t filesize; /* size of the data */
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    struct curl_blob blob;
    blob.data = certificateData;
    blob.len = filesize;
    blob.flags = CURL_BLOB_COPY;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    curl_easy_setopt(curl, CURLOPT_PROXY, "https://proxy");
    curl_easy_setopt(curl, CURLOPT_PROXY_SSLKEY, "key.pem");
    curl_easy_setopt(curl, CURLOPT_PROXY_KEYPASSWD, "s3cret");
    curl_easy_setopt(curl, CURLOPT_PROXY_SSLCERT_BLOB, &blob);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added in 7.71.0. This option is supported by the OpenSSL, Secure Transport and Schannel backends.

## RETURN VALUE

Returns CURLE\_OK if TLS enabled, CURLE\_UNKNOWN\_OPTION if not, or CURLE\_OUT\_OF\_MEMORY if there was insufficient heap space.

## SEE ALSO

[**CURLOPT\_PROXY\_SSLCERT**(3)](/CURLOPT_PROXY_SSLCERT/3.md), [**CURLOPT\_PROXY\_SSLCERTTYPE**(3)](/CURLOPT_PROXY_SSLCERTTYPE/3.md), [**CURLOPT\_PROXY\_SSLKEY**(3)](/CURLOPT_PROXY_SSLKEY/3.md), [**CURLOPT\_SSLCERT\_BLOB**(3)](/CURLOPT_SSLCERT_BLOB/3.md)