PowerShell

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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Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$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 = New-Object Chilkat.Pkcs11

#  The PKCS#11 driver supplied by your HSM vendor: a .dll on Windows, a .so on Linux, or a
#  .dylib on macOS.
$pkcs11.SharedLibPath = "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 = "0000"

#  Normal user = 1
$userType = 1

$success = $pkcs11.QuickSession($userType,$pin)
if ($success -eq $false) {
    $($pkcs11.LastErrorText)
    exit
}

#  Describe the private key object to be located on the HSM.
$json = New-Object Chilkat.JsonObject
$json.UpdateString("class","private_key")
$json.UpdateString("label","MySshKey")

$priv_handle = $pkcs11.FindObject($json)
if ($priv_handle -eq 0) {
    $($pkcs11.LastErrorText)
    exit
}

#  Find the corresponding public key by changing the class in the same template.
$json.UpdateString("class","public_key")

$pub_handle = $pkcs11.FindObject($json)
if ($pub_handle -eq 0) {
    $($pkcs11.LastErrorText)
    exit
}

#  Create an SSH key object that uses the HSM handles.  The key type may be "rsa" or "ec".
$key = New-Object Chilkat.SshKey
$keyType = "rsa"
$success = $key.UsePkcs11($pkcs11,$priv_handle,$pub_handle,$keyType)
if ($success -eq $false) {
    $($key.LastErrorText)
    exit
}

$ssh = New-Object Chilkat.Ssh

$port = 22
$success = $ssh.Connect("ssh.example.com",$port)
if ($success -eq $false) {
    $($ssh.LastErrorText)
    exit
}

#  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 = $ssh.AuthenticatePk("mySshLogin",$key)
if ($success -eq $false) {
    $($ssh.LastErrorText)
    exit
}

$("Public-key authentication successful.")

$ssh.Disconnect()

$pkcs11.Logout()
$pkcs11.CloseSession()