(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.

Note: This example requires Chilkat v11.0.0 or greater.

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

BOOL success = NO;

// 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.
CkoPrivateKey *privKey = [[CkoPrivateKey alloc] init];
success = [rsa GenKey: [NSNumber numberWithInt: 2048] privKey: privKey];
if (success == NO) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

// Get the public part of the key.
CkoPublicKey *pubKey = [[CkoPublicKey alloc] init];
[privKey ToPublicKey: pubKey];

// 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);

// Get the private key as Base64 DER:
// 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);