---
name: "CURLOPT_PROXY_SSLKEY_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_SSLKEY_BLOB"
---

# CURLOPT\_PROXY\_SSLKEY\_BLOB(3)

private key for proxy cert from memory blob

## NAME

CURLOPT\_PROXY\_SSLKEY\_BLOB - private key for proxy cert from memory blob

## SYNOPSIS

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

## DESCRIPTION

Pass a pointer to a curl\_blob structure that contains information (pointer and size) about the private key for connecting to the HTTPS proxy. Compatible with OpenSSL. The format (like "PEM") must be specified with *[CURLOPT\_PROXY\_SSLKEYTYPE(3)](/CURLOPT_PROXY_SSLKEYTYPE/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.

## DEFAULT

NULL

## PROTOCOLS

All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

## EXAMPLE

```
extern char *certificateData; /* point to data */
extern size_t filesize; /* size of data */
extern char *privateKeyData; /* point to data */
extern size_t privateKeySize; /* size */
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/");
    curl_easy_setopt(curl, CURLOPT_PROXY, "https://proxy");
    blob.data = certificateData;
    blob.len = filesize;
    blob.flags = CURL_BLOB_COPY;
    curl_easy_setopt(curl, CURLOPT_PROXY_SSLCERT_BLOB, &blob);
    curl_easy_setopt(curl, CURLOPT_PROXY_SSLCERTTYPE, "PEM");
    blob.data = privateKeyData;
    blob.len = privateKeySize;
    curl_easy_setopt(curl, CURLOPT_PROXY_SSLKEY_BLOB, &blob);
    curl_easy_setopt(curl, CURLOPT_PROXY_KEYPASSWD, "s3cret");
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added in 7.71.0. This option is supported by the OpenSSL 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\_SSLKEY**(3)](/CURLOPT_SSLKEY/3.md), [**CURLOPT\_SSLKEYTYPE**(3)](/CURLOPT_SSLKEYTYPE/3.md), [**CURLOPT\_SSLKEY\_BLOB**(3)](/CURLOPT_SSLKEY_BLOB/3.md)