CURLOPT_SSLKEY_BLOB − private key for client cert from memory blob
curl_easy_setopt(CURL *handle, CURLOPT_SSLKEY_BLOB,
struct curl_blob *blob);
Pass a pointer to a curl_blob structure, which contains information (pointer and size) for a private key. Compatible with OpenSSL. The format (like "PEM") must be specified with CURLOPT_SSLKEYTYPE(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_SSLKEY(3) which instead expects a file name as input.
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
CURL *curl =
struct curl_blob blob;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
blob.data = certificateData;
blob.len = filesize;
blob.flags = CURL_BLOB_COPY;
curl_easy_setopt(curl, CURLOPT_SSLCERT_BLOB, &blob);
curl_easy_setopt(curl, CURLOPT_SSLCERTTYPE, "PEM");
blob.len = privateKeySize;
curl_easy_setopt(curl, CURLOPT_SSLKEY_BLOB, &blob);
curl_easy_setopt(curl, CURLOPT_KEYPASSWD, "s3cret");
curl_easy_setopt(curl, CURLOPT_SSLKEYTYPE, "PEM");
ret = curl_easy_perform(curl);
Added in libcurl 7.71.0. This option is supported by the OpenSSL backends.
Returns CURLE_OK if TLS enabled, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.