(Objective-C) Generate an RSA Key and Get as Base64 DER

Demonstrates how to generate a 2048-bit RSA key and return the public and private parts as unencrypted Base64 encoded DER.

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#import <CkoRsa.h>
#import <CkoPublicKey.h>
#import <NSString.h>
#import <CkoPrivateKey.h>

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

CkoRsa *rsa = [[CkoRsa alloc] init];

// Generate a 2048-bit key.  Chilkat RSA supports
BOOL success = [rsa GenerateKey: [NSNumber numberWithInt: 2048]];
if (success != YES) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

// Get the public part of the key.
CkoPublicKey *pubKey = [rsa ExportPublicKeyObj];

// There are two possible formats for representing the RSA public key 
// in ASN.1 (DER).  The possible formats are PKCS1 and PKCS8.
// We can get either by setting bChoosePkcs1 to YES or NO.
BOOL bChoosePkcs1 = YES;
NSString *pubKeyBase64Der = [pubKey GetEncoded: bChoosePkcs1 encoding: @"base64"];
NSLog(@"%@",@"Public Key Base64 DER:");
NSLog(@"%@",pubKeyBase64Der);

// Now get the private key as Base64 DER:
// Get the private part of the key.
// (Note: A public key is actually just a subset of the private key.  
//  If you have the private key, you also have the public key.
//  Thus Chilkat provides a method to get the public key from the private key.)
CkoPrivateKey *privKey = [rsa ExportPrivateKeyObj];

// Again, we can get PKCS1 or PKCS8, but with different methods:
NSString *privKeyPkcs1 = [privKey GetPkcs1ENC: @"base64"];
NSLog(@"%@",@"Private Key PKCS1 Base64 DER:");
NSLog(@"%@",privKeyPkcs1);

NSString *privKeyPkcs8 = [privKey GetPkcs8ENC: @"base64"];
NSLog(@"%@",@"Private Key PKCS8 Base64 DER:");
NSLog(@"%@",privKeyPkcs8);