(Objective-C) 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.

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoPkcs11.h>
#import <NSString.h>
#import <CkoJsonObject.h>
#import <CkoSshKey.h>
#import <CkoSsh.h>

// 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.

CkoPkcs11 *pkcs11 = [[CkoPkcs11 alloc] init];

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

// Use your HSM's PIN.
NSString *pin = @"0000";

// Normal user = 1
int userType = 1;

// Establish a logged-on user session with the HSM.
BOOL success = [pkcs11 QuickSession: [NSNumber numberWithInt: userType] pin: pin];
if (success == NO) {
    NSLog(@"%@",pkcs11.LastErrorText);
    return;
}

// Provide a template to find a PKCS11 object.
CkoJsonObject *jsonTemplate = [[CkoJsonObject alloc] init];

// Find an RSA private key with the label "MySshKey".
// Here's an example of how the key was originally imported: 
// PKCS11 Import SSH Key
[jsonTemplate UpdateString: @"class" value: @"private_key"];
[jsonTemplate UpdateString: @"key_type" value: @"rsa"];
[jsonTemplate UpdateString: @"label" value: @"MySshKey"];

unsigned long privKeyHandle = [pkcs11 FindObject: jsonTemplate];
if (privKeyHandle == 0) {
    NSLog(@"%@",pkcs11.LastErrorText);
    return;
}

// 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:  
NSLog(@"%@%d",@"private key handle: ",privKeyHandle);

// We'll also need the PKCS11 public key handle
// Modify the template by updating the "class" to "public_key"
[jsonTemplate UpdateString: @"class" value: @"public_key"];

unsigned long pubKeyHandle = [pkcs11 FindObject: jsonTemplate];
if (pubKeyHandle == 0) {
    NSLog(@"%@",pkcs11.LastErrorText);
    return;
}

NSLog(@"%@%d",@"public key handle: ",pubKeyHandle);

// Create an empty SSH key object, and tell it to use the PKCS11 handles.
// We also need to indicate the key type.
CkoSshKey *sshKey = [[CkoSshKey alloc] init];
success = [sshKey UsePkcs11: pkcs11 privKeyHandle: privKeyHandle pubKeyHandle: pubKeyHandle keyType: @"rsa"];
if (success == NO) {
    NSLog(@"%@",sshKey.LastErrorText);
    return;
}

// Create an SSH object and authenticate using the SSH key, which will utilize the existing PKCS11 session.
CkoSsh *ssh = [[CkoSsh alloc] init];

success = [ssh Connect: @"my-ssh-server.com" port: [NSNumber numberWithInt: 22]];
if (success == NO) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

// This is where the PKCS11 private key on the smart card is used.
success = [ssh AuthenticatePk: @"your_ssh_username" privateKey: sshKey];
if (success == NO) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

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

[ssh Disconnect];

[pkcs11 Logout];
[pkcs11 CloseSession];