Objective-C

Duplicate PHP RSA Encryption

See more RSA Examples

Demonstrates how to duplicate the following PHP function. Objective-C

#import <NSString.h>
#import <CkoBinData.h>
#import <CkoXml.h>
#import <CkoPublicKey.h>
#import <CkoRsa.h>

BOOL success = NO;

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

// Duplicate the following PHP code:
// 
//    public function encryptRSA($plainText,$rsaMOD,$pubKEY){
//         $rsa  = new RSA();
//         $rsa->setEncryptionMode(RSA::ENCRYPTION_PKCS1);
//         $publicKey = [
//             'e' => new BigInteger($pubKEY,16),
//             'n' => new BigInteger($rsaMOD,16)
//         ];
// 		
//         $rsa->loadKey($publicKey);
//         $ciphertext = $rsa->encrypt($plainText);
//         return bin2hex($ciphertext);
//     }
// 
//     $plainText="key=abcdefghijkmnopq&iv=abcdefghijkmnopq&h=12345678&s=12345678"
//     $rsaMOD="F0946D8F05604809E24B8CFFD30349CEA9E5F4D320BFD9E9AA1B088863F02C43E7997D37A3E27B4F8F359F1744DB6B20A437067C0D325A80660D12FF56A57673"
//     $pubKEY="010001"

// We have the RSA modulus in hex
NSString *rsaMOD = @"F0946D8F05604809E24B8CFFD30349CEA9E5F4D320BFD9E9AA1B088863F02C43E7997D37A3E27B4F8F359F1744DB6B20A437067C0D325A80660D12FF56A57673";

// The RSA exponent in hex is "010001", which is 65537 in decimal.  It's typically the exponent that is always used.
NSString *rsaEXP = @"010001";

// Get the RSA modulus and exponent in base64.
CkoBinData *bdMod = [[CkoBinData alloc] init];
CkoBinData *bdExp = [[CkoBinData alloc] init];
success = [bdMod AppendEncoded: rsaMOD encoding: @"hex"];
success = [bdExp AppendEncoded: rsaEXP encoding: @"hex"];

// Build the XML representation of the RSA public key
CkoXml *xml = [[CkoXml alloc] init];
xml.Tag = @"RSAPublicKey";
[xml UpdateChildContent: @"Modulus" value: [bdMod GetEncoded: @"base64"]];
[xml UpdateChildContent: @"Exponent" value: [bdExp GetEncoded: @"base64"]];

// Load the RSA public key into a Chilkat public key object.
CkoPublicKey *pubkey = [[CkoPublicKey alloc] init];
success = [pubkey LoadFromString: [xml GetXml]];

// Setup the RSA object for encryption and do it..
CkoRsa *rsa = [[CkoRsa alloc] init];
rsa.VerboseLogging = YES;
success = [rsa UsePublicKey: pubkey];

// Use PKCSv1.5 padding
rsa.PkcsPadding = YES;

// Encrypt and return the string as hex.
rsa.EncodingMode = @"hex";
NSString *plainText = @"key=abcdefghijkmnopq&iv=abcdefghijkmnopq&h=12345678&s=12345678";
NSString *cipherText = [rsa EncryptStringENC: plainText bUsePrivateKey: NO];
if (rsa.LastMethodSuccess == NO) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

// Note: The PKCSv1_5 padding incorporates random bytes.  Therefore, the RSA encryption will produce different results each time -- all of which are valid 
// and decrypt correctly to the same original text.
NSLog(@"%@",cipherText);