(Objective-C) PBES1 Password-Based Encryption (PBE)

Demonstrates how to implement password-based encryption according to the PKCS #5 v2.0: Password-Based Cryptography Standard (published by RSA Laboratories). This example uses PBES1, which ise based on the PBKDF1 function and an underlying block cipher such as RC2, DES, etc.

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#import <CkoCrypt2.h>
#import <NSString.h>

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

CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];

// Set properties for PBES1 encryption:

crypt.CryptAlgorithm = @"pbes1";
crypt.PbesPassword = @"mySecretPassword";

// Set the underlying PBE algorithm (and key length):
// For PBES1, the underlying algorithm must be either
// 56-bit DES or 64-bit RC2 
// (this is according to the PKCS#5 specifications at
// http://www.rsa.com/rsalabs/node.asp?id=2127   )
crypt.PbesAlgorithm = @"rc2";
crypt.KeyLength = [NSNumber numberWithInt:64];

// The salt for PBKDF1 is always 8 bytes:
[crypt SetEncodedSalt: @"0102030405060708" encoding: @"hex"];

// A higher iteration count makes the algorithm more
// computationally expensive and therefore exhaustive
// searches (for breaking the encryption) is more difficult:
crypt.IterationCount = [NSNumber numberWithInt:1024];

// A hash algorithm needs to be set for PBES1:
crypt.HashAlgorithm = @"sha1";

// Indicate that the encrypted bytes should be returned
// as a hex string:
crypt.EncodingMode = @"hex";

NSString *plainText = @"To be encrypted.";

NSString *encryptedText = [crypt EncryptStringENC: plainText];

NSLog(@"%@",encryptedText);

// Now decrypt:
NSString *decryptedText = [crypt DecryptStringENC: encryptedText];

NSLog(@"%@",decryptedText);