如何将一个64位字符串NSString反译回32bytes的NS

如何将一个64位字符串NSString反译回32bytes的NSData

NSString*newToken =@"fbf4082f57128dd1ed78986c6945dcf91519794b48c461af07a8e951180490de";
    
    NSMutableData*apnsTokenMutableData = [[NSMutableData alloc]init];
    
    unsigned charwhole_byte;
    
    char byte_chars[3] = {'\0','\0','\0'};
    
    int i;
    
    for(i=0; i < [newToken length]/2; i++) {
        
        byte_chars[0] = [newToken characterAtIndex:i*2];
        
        byte_chars[1] = [newToken characterAtIndex:i*2+1];
        
//        whole_byte =strtol(byte_chars,NULL,16);
     
        charwhole_byte= strtol(byte_chars, NULL, 16);
        [apnsTokenMutableData appendBytes:&charwhole_byte length:1];
       
    }
    
    NSData*apnsTokenData = [NSData dataWithData:apnsTokenMutableData];
    
    NSLog(@"反译后=%@",apnsTokenData);