Windows path problems using libssh C++ wrapper - c++

Question

I am having problems with Windows file path separators using the libssh c++ wrapper libsshpp.
Suppose I have following code:
#define SSH_NO_CPP_EXCEPTIONS
#include "libssh/libsshpp.hpp"
#include <iostream>
#pragma comment(lib, "ssh")
int main()
{
ssh::Session session;
int sessionMsg = -1;
std::string host = "myhost.com";
std::string user = "username";
std::string idfile = "%s\\.ssh\\id_ed25519";
std::string hostkeys = "ssh-ed25519";
std::string keyExchange = "curve25519-sha256";
session.setOption(SSH_OPTIONS_HOST, host.c_str());
session.setOption(SSH_OPTIONS_USER, user.c_str());
session.setOption(SSH_OPTIONS_STRICTHOSTKEYCHECK, (long)0);
session.setOption(SSH_OPTIONS_HOSTKEYS, hostkeys.c_str());
session.setOption(SSH_OPTIONS_KEY_EXCHANGE, keyExchange.c_str());
session.setOption(SSH_OPTIONS_ADD_IDENTITY, idfile.c_str());
std::cout << "Trying to connect to " << host << " with user " << user << "...\n";
session.connect();
if (session.isServerKnown() != SSH_SERVER_KNOWN_OK) {
std::cout << "Server unknown.\n";
if (session.writeKnownhost() != SSH_OK) {
std::cout << "Unable to write to known_hosts file.\n";
}
else {
session.connect();
}
}
sessionMsg = session.userauthPublickeyAuto();
std::string err = session.getError();
if (sessionMsg != SSH_AUTH_SUCCESS) {
if (!err.empty()) {
std::cout << err;
}
std::cout << "Auth failed.";
}
else {
std::cout << err.empty() ? session.getIssueBanner() : err;
}
}
In the beginning I had set the idfile value to just id_ed25519 but then libssh complained: Failed to read private key: C:\Users\MyUser/.ssh/id_ed25519 (notice the switching slashes). After changing it to %s\\.ssh\\id_ed25519 it seemed to have had a positive impact on the connection routine, however now I keep falling into the (session.writeKnownhost() != SSH_OK) code part.
Now, I am wondering if this might be due to the same "switching slashes" problem which came up for the private key file path because apparently libssh wants to access C:\Users\MyUser\.ssh\known_hosts but quite possibly the path is set as something like C:\Users\MyUser/.ssh/known_hosts.
My question is: is there a possibility to change the path seperators to windows-style somehow in the session or is there something else I am overseeing or doing wrong here?

Answer 1

I was able to solve the problem adding the SSH_OPTIONS_SSH_DIR option and changing the private key and known_hosts paths (now relative to the ssh directory path):
// note here: %s will be replaced by libssh with the home directory path
std::string sshDir = "%s//.ssh";
std::string idFile = "id_ed25519";
std::string knownHosts = "known_hosts";
// ...
session.setOption(SSH_OPTIONS_USER, user.c_str());
session.setOption(SSH_OPTIONS_SSH_DIR, sshDir.c_str()); // <-- added
// ...