Objective-C

Generate a Random 256-bit AES Key and RSA Encrypt

See more RSA Examples

Generates a random 256-bit AES key and encrypts using an RSA public key. Only the owner of the RSA private key will be able to decrypt the AES key. Objective-C

#import <CkoPublicKey.h>
#import <CkoRsa.h>
#import <CkoBinData.h>
#import <CkoPrng.h>

BOOL success = NO;

//  The RSA public key is used for encryption, and the private key for decryption.

//  The public key's role is to make encryption accessible to anyone while ensuring that
//  only the private key holder can decrypt the messages.
//  The public key is designed to be widely distributed so anyone can use it to encrypt messages
//  intended for the owner of the private key.

//  Load our 2048-bit RSA public key.
CkoPublicKey *pubKey = [[CkoPublicKey alloc] init];
//  In all Chilkat methods expecting a path, you pass either absolute or relative paths.
success = [pubKey LoadFromFile: @"rsaKeys/Test2048Rsa.pem"];
if (success == NO) {
    NSLog(@"%@",pubKey.LastErrorText);
    return;
}

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

//  Tell RSA to use the public key.
[rsa UsePublicKey: pubKey];

//  Generate a random 256-bit AES key (32 bytes)
CkoBinData *bdAesKey = [[CkoBinData alloc] init];
CkoPrng *prng = [[CkoPrng alloc] init];
[prng GenRandomBd: [NSNumber numberWithInt: 32] bd: bdAesKey];

//  RSA encrypt.
[rsa EncryptBd: bdAesKey usePrivateKey: NO];

//  Save the RSA encrypted AES key to a file.
success = [bdAesKey WriteFile: @"rsaEncrypted/myAes.key"];