#import <CommonCrypto/CommonDigest.h>;
- (NSString*)MD5:(NSString*)str{
const char *cStr = [str UTF8String];
unsigned char result[32];
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]];
}