Unicode C

SSH HSM Public Key Authentication

Demonstrates SSH public-key authentication using a private key stored on an HSM — a USB token or smart card — accessed through PKCS#11. A session is opened with the vendor's driver, the key handles are located, and an SshKey object is bound to them with UsePkcs11.

Background: The point of an HSM is that the private key is generated on the device and cannot be exported: the signing operation happens on the hardware, so the key material never reaches your application's memory or disk. Even a fully compromised host cannot yield a copy of the key. PKCS#11 is the vendor-neutral interface to such devices, which is why the driver path and the object-finding template are the only vendor-specific parts of this example.

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#include <C_CkPkcs11W.h>
#include <C_CkJsonObjectW.h>
#include <C_CkSshKeyW.h>
#include <C_CkSshW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPkcs11W pkcs11;
    const wchar_t *pin;
    int userType;
    HCkJsonObjectW json;
    unsigned long priv_handle;
    unsigned long pub_handle;
    HCkSshKeyW key;
    const wchar_t *keyType;
    HCkSshW ssh;
    int port;

    success = FALSE;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  Demonstrates SSH public-key authentication using a private key stored on an HSM (a USB token
    //  or smart card) accessed through PKCS#11.
    //  
    //  Note: Chilkat's PKCS#11 implementation runs on Windows, Linux, macOS, and other supported
    //  operating systems.

    pkcs11 = CkPkcs11W_Create();

    //  The PKCS#11 driver supplied by your HSM vendor: a .dll on Windows, a .so on Linux, or a
    //  .dylib on macOS.
    CkPkcs11W_putSharedLibPath(pkcs11,L"C:/Program Files (x86)/Gemalto/IDGo 800 PKCS#11/IDPrimePKCS1164.dll");

    //  The PIN should come from a secure source rather than being hard-coded.
    pin = L"0000";

    //  Normal user = 1
    userType = 1;

    success = CkPkcs11W_QuickSession(pkcs11,userType,pin);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPkcs11W_lastErrorText(pkcs11));
        CkPkcs11W_Dispose(pkcs11);
        return;
    }

    //  Describe the private key object to be located on the HSM.
    json = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(json,L"class",L"private_key");
    CkJsonObjectW_UpdateString(json,L"label",L"MySshKey");

    priv_handle = CkPkcs11W_FindObject(pkcs11,json);
    if (priv_handle == 0) {
        wprintf(L"%s\n",CkPkcs11W_lastErrorText(pkcs11));
        CkPkcs11W_Dispose(pkcs11);
        CkJsonObjectW_Dispose(json);
        return;
    }

    //  Find the corresponding public key by changing the class in the same template.
    CkJsonObjectW_UpdateString(json,L"class",L"public_key");

    pub_handle = CkPkcs11W_FindObject(pkcs11,json);
    if (pub_handle == 0) {
        wprintf(L"%s\n",CkPkcs11W_lastErrorText(pkcs11));
        CkPkcs11W_Dispose(pkcs11);
        CkJsonObjectW_Dispose(json);
        return;
    }

    //  Create an SSH key object that uses the HSM handles.  The key type may be "rsa" or "ec".
    key = CkSshKeyW_Create();
    keyType = L"rsa";
    success = CkSshKeyW_UsePkcs11(key,pkcs11,priv_handle,pub_handle,keyType);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshKeyW_lastErrorText(key));
        CkPkcs11W_Dispose(pkcs11);
        CkJsonObjectW_Dispose(json);
        CkSshKeyW_Dispose(key);
        return;
    }

    ssh = CkSshW_Create();

    port = 22;
    success = CkSshW_Connect(ssh,L"ssh.example.com",port);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh));
        CkPkcs11W_Dispose(pkcs11);
        CkJsonObjectW_Dispose(json);
        CkSshKeyW_Dispose(key);
        CkSshW_Dispose(ssh);
        return;
    }

    //  The corresponding public key must already be installed on the SSH server for the account.
    //  The signing operation happens on the HSM -- the private key never leaves the device.
    success = CkSshW_AuthenticatePk(ssh,L"mySshLogin",key);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh));
        CkPkcs11W_Dispose(pkcs11);
        CkJsonObjectW_Dispose(json);
        CkSshKeyW_Dispose(key);
        CkSshW_Dispose(ssh);
        return;
    }

    wprintf(L"Public-key authentication successful.\n");

    CkSshW_Disconnect(ssh);

    CkPkcs11W_Logout(pkcs11);
    CkPkcs11W_CloseSession(pkcs11);


    CkPkcs11W_Dispose(pkcs11);
    CkJsonObjectW_Dispose(json);
    CkSshKeyW_Dispose(key);
    CkSshW_Dispose(ssh);

    }