(Objective-C) HMAC Hex String

Demonstrates how to compute an HMAC using a hexidecimal key and data.

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#import <CkoCrypt2.h>
#import <NSString.h>
#import <CkoBinData.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 the MAC algorithm to HMAC
crypt.MacAlgorithm = @"hmac";

// Our HMAC key will be the bytes represented in the following hex string.
// In other words, the HMAC key is composed of the bytes 0x41, 0xC2, 0x1C, ...
// (It is not composed of the us-ascii string '4', '1', 'C', ...)
NSString *keyHex = @"41C21CB9D7A02FC5D4FADB9E4755B9DE";
BOOL success = [crypt SetMacKeyEncoded: keyHex encoding: @"hex"];

// Our desire is to HMAC the bytes represented in the following string:
NSString *dataHex = @"C22078065B01460001000000010062043BF5B18228C8E02D17BCFE4E00561FA6DEC216EA97195CEB579942E275C21932258E3CD391E507FF4E7FD4C787A8447DA111C54A9C1795E7FF4C0BAA2EDA";

// We'll need to decode the hex to binary:
CkoBinData *bd = [[CkoBinData alloc] init];
[bd AppendEncoded: dataHex encoding: @"hex"];

// Do the HMAC-SHA256 hash and return as a hex string:
crypt.EncodingMode = @"hex";
crypt.HashAlgorithm = @"sha-256";
NSString *macHex = [crypt MacBdENC: bd];
NSLog(@"%@",macHex);