CURLOPT_PROXY_SSLCERT_BLOB(3) Library Functions Manual
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 Schannel. The format must be "P12" or "PEM" on OpenSSL. The
string "P12" or "PEM" must be specified with
CURLOPT_PROXY_SSLCERTTYPE(3).
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) which instead
expects a filename as input.
DEFAULT
NULL
PROTOCOLS
This functionality affects all TLS based protocols: HTTPS, FTPS,
IMAPS, POP3S, SMTPS etc. only
This option works only with the following TLS backends: OpenSSL and
Schannel
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 result;
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.example");
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);
result = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}
AVAILABILITY
Added in curl 7.71.0
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_PROXY_SSLCERT(3), CURLOPT_PROXY_SSLCERTTYPE(3),
CURLOPT_PROXY_SSLKEY(3), CURLOPT_SSLCERT_BLOB(3)
libcurl 2026-07-05 CURLOPT_PROXY_SSLCERT_BLOB(3)
curl 8.21.0 - Generated Mon Jul 6 08:16:50 CDT 2026