/*
* KeyCalculator.m
*
* Copyright 2011 Roberto Estrada
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

#import <CommonCrypto/CommonDigest.h>
#import "KeyCalculator.h"


@implementation KeyCalculator

+ (NSString *) md5:(NSString *)str {
const char *cStr = [str UTF8String];
unsigned char result[16];
CC_MD5( cStr, strlen(cStr), result );
return [NSString stringWithFormat:
@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
result[0], result[1], result[2], result[3],
result[4], result[5], result[6], result[7],
result[8], result[9], result[10], result[11],
result[12], result[13], result[14], result[15]
];
}

+(NSString*) calculateKeyWithESSID:(NSString*) essid BSSID:(NSString*) bssid {
NSString *trimmedBSSID = [bssid stringByReplacingOccurrencesOfString:@":" withString:@""];
NSString *formattedESSID = nil;
// Removing name from the ESSID, we only want the numbers
if ([essid rangeOfString:@"JAZZTEL_"].location != NSNotFound) {
formattedESSID = [[essid stringByReplacingOccurrencesOfString:@"JAZZTEL_" withString:@""] uppercaseString];
}else if ([essid rangeOfString:@"WLAN_"].location != NSNotFound) {
formattedESSID = [[essid stringByReplacingOccurrencesOfString:@"WLAN_" withString:@""] uppercaseString];
}
if (formattedESSID == nil) {
return nil;
}
// Key calculation
NSRange rng = {0,8};
NSString *stringToHash = [NSString stringWithFormat:@"%@%@%@%@",@"bcgbghgg",[trimmedBSSID substringWithRange:rng],formattedESSID,trimmedBSSID];
// Hashing
NSRange resultrange = {0,20};
NSString *result = [[[self md5:stringToHash] substringWithRange:resultrange]lowercaseString];
return result;
}



@end