PureBasic

SSH Authenticate using Smart Card Private Key

See more SSH Examples

Demonstrates how to use a private key stored on an HSM (smartcard or token) for SSH public-key authentication. (Public-key authentication means the client, which is your application, uses the private key, while the corresponding public key is installed on the server under your SSH account.)

Note: This example requires Chilkat v9.5.0.96 or later.

PureBasic

IncludeFile "CkPkcs11.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkSsh.pb"
IncludeFile "CkSshKey.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ; Note: Chilkat's PKCS11 implementation runs on Windows, Linux, Mac OS X, and other supported operating systems.

    pkcs11.i = CkPkcs11::ckCreate()
    If pkcs11.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Use the PKCS11 driver (.dll, .so, .dylib) for your particular HSM.
    ; For example:
    CkPkcs11::setCkSharedLibPath(pkcs11, "C:/Program Files (x86)/Gemalto/IDGo 800 PKCS#11/IDPrimePKCS11.dll")

    ; Use your HSM's PIN.
    pin.s = "0000"

    ; Normal user = 1
    userType.i = 1

    ; Establish a logged-on user session with the HSM.
    success = CkPkcs11::ckQuickSession(pkcs11,userType,pin)
    If success = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        ProcedureReturn
    EndIf

    ; Provide a template to find a PKCS11 object.
    jsonTemplate.i = CkJsonObject::ckCreate()
    If jsonTemplate.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Find an RSA private key with the label "MySshKey".
    ; Here's an example of how the key was originally imported: 
    ; PKCS11 Import SSH Key
    CkJsonObject::ckUpdateString(jsonTemplate,"class","private_key")
    CkJsonObject::ckUpdateString(jsonTemplate,"key_type","rsa")
    CkJsonObject::ckUpdateString(jsonTemplate,"label","MySshKey")

    privKeyHandle.i = CkPkcs11::ckFindObject(pkcs11,jsonTemplate)
    If privKeyHandle = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        CkJsonObject::ckDispose(jsonTemplate)
        ProcedureReturn
    EndIf

    ; The private key handle is only valid during the PKCS11 session.
    ; If you wish to use the private key in another PKCS11 session,
    ; you'll first need to find it.  See:  
    Debug "private key handle: " + Str(privKeyHandle)

    ; We'll also need the PKCS11 public key handle
    ; Modify the template by updating the "class" to "public_key"
    CkJsonObject::ckUpdateString(jsonTemplate,"class","public_key")

    pubKeyHandle.i = CkPkcs11::ckFindObject(pkcs11,jsonTemplate)
    If pubKeyHandle = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        CkJsonObject::ckDispose(jsonTemplate)
        ProcedureReturn
    EndIf

    Debug "public key handle: " + Str(pubKeyHandle)

    ; Create an empty SSH key object, and tell it to use the PKCS11 handles.
    ; We also need to indicate the key type.
    sshKey.i = CkSshKey::ckCreate()
    If sshKey.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkSshKey::ckUsePkcs11(sshKey,pkcs11,privKeyHandle,pubKeyHandle,"rsa")
    If success = 0
        Debug CkSshKey::ckLastErrorText(sshKey)
        CkPkcs11::ckDispose(pkcs11)
        CkJsonObject::ckDispose(jsonTemplate)
        CkSshKey::ckDispose(sshKey)
        ProcedureReturn
    EndIf

    ; Create an SSH object and authenticate using the SSH key, which will utilize the existing PKCS11 session.
    ssh.i = CkSsh::ckCreate()
    If ssh.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkSsh::ckConnect(ssh,"my-ssh-server.com",22)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkPkcs11::ckDispose(pkcs11)
        CkJsonObject::ckDispose(jsonTemplate)
        CkSshKey::ckDispose(sshKey)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; This is where the PKCS11 private key on the smart card is used.
    success = CkSsh::ckAuthenticatePk(ssh,"your_ssh_username",sshKey)
    If success = 0
        Debug CkSsh::ckLastErrorText(ssh)
        CkPkcs11::ckDispose(pkcs11)
        CkJsonObject::ckDispose(jsonTemplate)
        CkSshKey::ckDispose(sshKey)
        CkSsh::ckDispose(ssh)
        ProcedureReturn
    EndIf

    ; Do whatever it is your app needs to do using the authenticated SSH session....
    ; ...
    ; ...

    CkSsh::ckDisconnect(ssh)

    CkPkcs11::ckLogout(pkcs11)
    CkPkcs11::ckCloseSession(pkcs11)


    CkPkcs11::ckDispose(pkcs11)
    CkJsonObject::ckDispose(jsonTemplate)
    CkSshKey::ckDispose(sshKey)
    CkSsh::ckDispose(ssh)


    ProcedureReturn
EndProcedure