ios加密

在做项目得时候很多数据需要加密，一般用户名，密码等，有的习惯用KeyChain,有的用userDefault.也有用文件。
1. DES 加密

NSString *fileName = [LoginSaveName tripleDES];
NSString *path = [NSString stringWithFormat:@"%@%@", LogInRecordLocalFilePath, fileName];

NSString *encodePasswd = [self.passwd tripleDES];
NSString *encodeLoginKey = [self.loginKey tripleDES];
NSString *encodeUserid = [self.userId tripleDES];

NSDictionary *saveDic = [NSDictionary dictionaryWithObjectsAndKeys:
                         encodeUserid, @"userId",
                         encodePasswd, @"passwd",
                         encodeLoginKey, @"loginKey"
                         ];

[saveDic writeToFile:path atomically:YES];

}
2.DES解密
NSString *fileName = [LoginSaveName tripleDES];
NSString *path = [NSString stringWithFormat:@”%@%@”, LogInRecordLocalFilePath, fileName];
if (![[NSFileManager defaultManager] fileExistsAtPath:path])
return;

NSDictionary *readDic = [NSDictionary dictionaryWithContentsOfFile:path];
NSString *decodeUserId = [[readDic objectForKey:@"userId"] decodeTripleDES];
NSString *decodePasswd = [[readDic objectForKey:@"passwd"] decodeTripleDES];
NSString *decodeLoginKey = [[readDic objectForKey:@"loginKey"] decodeTripleDES];

3.AES 加密AES加密