(Objective-C) PBKDF2 - Derive Key from Password

Demonstrates how to derive a symmetric encryption key from a password using PBKDF2.

For more information, see https://www.chilkatsoft.com/key_derivation_pbkdf2.asp

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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];

NSString *pw = @"password";

NSString *pwCharset = @"utf-8";

// Such as sha256, sha512
NSString *hashAlg = @"sha256";

// 16 bytes
NSString *saltHex = @"78578E5A5D63CB0668AB39B21C8637FA";

int iterationCount = 100000;

// Derive a 256-bit key from the password.
int outputBitLen = 256;

// The derived key is returned as a hex or base64 encoded string.
// (Note: The salt argument must be a string that also uses
// the same encoding.)
NSString *enc = @"hex";

NSString *hexKey = [crypt Pbkdf2: pw charset: pwCharset hashAlg: hashAlg salt: saltHex iterationCount: [NSNumber numberWithInt: iterationCount] outputKeyBitLen: [NSNumber numberWithInt: outputBitLen] encoding: enc];

NSLog(@"%@",hexKey);

// Sample output:
// AE96E261E32792D0FD6F0E72F8E872D046F7DB4C1FA7C83892EC73C49F461B70