iOS AES Cryptography note

hex string of salt and iv(initial vector) have to be converted into bytes, of which the length will be half of the original string.
- (NSData *)dataFromHexString {
const char *chars = [self UTF8String];
int i = 0, len = self.length;

         NSMutableData *data = [NSMutableData dataWithCapacity:len / 2];
         char byteChars[3] = {'\0','\0','\0'};
         unsigned long wholeByte;

         while (i < len) {
             byteChars[0] = chars[i++];
             byteChars[1] = chars[i++];
             wholeByte = strtoul(byteChars, NULL, 16);
             [data appendBytes:&wholeByte length:1];
         }

         return data;
     }

Details about CommonCrypto

IV has to be 16 bytes.

On iOS, you should be using the CCCrypt*() functions for AES.