CURLOPT_SSH_PUBLIC_KEYFILE (3) - Linux Manuals
CURLOPT_SSH_PUBLIC_KEYFILE: set public key file for SSH auth
NAME
CURLOPT_SSH_PUBLIC_KEYFILE - set public key file for SSH authSYNOPSIS
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_PUBLIC_KEYFILE, char *filename);
DESCRIPTION
Pass a char * pointing to a filename for your public key. If not used, libcurl defaults to $HOME/.ssh/id_dsa.pub if the HOME environment variable is set, and just "id_dsa.pub" in the current directory if HOME is not set.If an empty string is passed, libcurl will pass no public key to libssh2 which then tries to compute it from the private key, this is known to work when libssh2 1.4.0+ is linked against OpenSSL.