I'm writing an application with a dBASE database file in Borland Delphi 7.
Note: I think this question is file-security related and you can forget the dBASE thing (consider it as a TXT file) in this question.
The database must be accessed just by the application. Then it must be encrypted. Unfortunately dBASE doesn't support any password mechanism and i had to encrypt the file by myself (and i also HAVE to use dBASE)
What approach do you suggest to secure the database file?
The simple one is:
Encrypting the database file and placing it near beside the application EXE file.
When the application runs, it should decrypt the file (with a hard-coded password) and copy the result to a temporary file that has DeleteOnClose and NoSharingPermission flags.
When Closing, application should encrypt the temp dBASE file and replaces the old encrypted file with the new one.
I think this is a fair secure approach. But it have two big problems:
With an undelete tool the user can restore and access to the deleted temp file.
Worse: When application is running, if the system rebooted suddenly the DeleteOnClose flag fails and the temp file remains on hard disk and user can access it.
Is there any solution for, at least, the second part?
Is there any other solution?
You could also try to create a TrueCrypt file-based containter, mount it, and then put the dBase file inside the mounted encrypted volume. TrueCrypt is free (in both senses) and it's accessible via command line parameters from your application (mount before start, unmount before quit).
Depending on what you're doing with the database, you may be able to get away with just decrypting the records you actually need. For example, you could build indexes based on hash codes (rather than real data); this would reduce seeks into the database to a smaller set of data. Each record in the subset would have to be decrypted, but this could be a lot better than decrypting the entire database.
Related
I am writing a Windows VCL desktop using c++ builder. The app uses Firedac and a SQLite database.
I want to protect this SQLite database:
Only my vcl app can connect to it and use it
Other programs and people cannot use the SQLite file
So far I found that the easiest thing that I can do is Encryption, you make it so that anybody without a correct password gets a message like "This file is not a database" if he tries to open it.
Yes we can do this with Embarcadero VCL, doc. using a TFDSQLiteSecurity component and these lines :
FDSQLiteSecurity1->Password = "";/* we are protecting (encrypting) our uncyphered database*/
FDSQLiteSecurity1->ToPassword = 'newpassword';
FDSQLiteSecurity1->ChangePassword();
Unfortunately the VCL Firedac app cannot connect to an encrypted sqlite database so it must decrypt it first.
In order to make things work my program starts and decrypts the database ( removes password) then it connects to the database and use it. When finished I recrypt the database again (when closing app).
THE PROBLEM:
During this time (My program is up and running and the database in uncrypted) can I stop other programs from opening the SQLITE database? Is there a better approach, I am opened for any suggestion
Once it is encrypted by FireDac just set the appropriate properties on the FDConnection. Those would be password to the password and encrypt to the encryption method.
Firedac can open a SQLite database it has encrypted itself so the problem resolves itself by doing that as a better approach. Other programs only see the encrypted version on disk and can't open it without the password.
http://hbase.apache.org/book.html#_server_side_configuration_3
I have checked the URL in which it'll encrypt the data based on the Java java.security.KeyStore. But we need to keep the file .jks which contains master key for all the hbase servers (all master and Region servers have to have this file).
NOTE: Also the password to open the file has been given in hbase-site.xml.
For HDFS alone, there is option to keep the keystore file in the KMS server and not for HBase. Still now we need to keep it in the local store.
I don't need KMS option. I need something to keep the value in common place has to be accessed instaed of having same file in the all servers.
Is there any method/custom class available to get master key from the common storage like DB/redis/Zookeeper?
UPDATE #1
Someone has asked similar question but no solution for that: Encrypt HBase at-rest data in Cloud.
The database can be open()ed using the same encryption key and it works fine. Tried with multiple encrypted databases - all can be opened, but not attached.
This works when encrypted and when not encrypted (bytearray is null):
connection.open(file, "create", false, 1024, bytearray);
This only works when not encrypted:
connection.attach("db" + newnum.toString(), file, new Responder(attachEncryptedSuccess, openEncryptedError), bytearray);
Any help is appreciated.
UPDATE:
Just found a strange pattern here:
It seems that if I create an encrypted database, and then create new databases and attach them, everything works fine.
The created files, after unloading, will only be properly opened using the command that they were initially created with. Therefore, the encrypted database that I created before using open() will only open with open() method. All the encrypted databases that were initially created using attach() will only be able to be opened using attach(). It also doesn't matter which database was open()ed first, aka which one is the main database. It can even be not encrypted.
This is something very strange. Is this a bug? Or am I doing something wrong here?
One gotcha that I ran into awhile ago, and it sounds like it might be impacting you. If you are creating both db's from AIR then this should work fine, however if you have created one with any external tool - generally most tools will default the PRAGMA ENCODING = UTF8. AIR, being Adobe, does things a little different than just straight up telling you that they create theirs UTF16-LE.
According to sqlite rules, differing encoding types cannot be attached one way or the other. One way to verify is to use sqliteman or some other sqlite editor to verify the pragma settings.
For me, I ended up having to start from a seeded db (empty databases -just the header- were over written by AIR) that was to be initialized from a template database. If I allowed AIR to create my starting db, it was set to UTF16 to which I could not attach a UTF8 template.
I am completely new to SQLite and I intend to use it in a M2M / client-server environment where a database is generated on the server, sent to the client as a file and used on the client for data lookup.
The question is: can I replace the whole database file while the client is using it at the same time?
The question may sound silly but the client is a Linux thin client and to replace the database file a temporary file would be renamed to the final file name. In Linux, a program which has still open the older version of the file will still access the older data since the old file is preserved by the OS until all file handles have been closed. Only new open()s will access the new version of the file.
So, in short:
client randomly accesses the SQLite database
a new version of the database is received from the server and written to a temporary file
the temporary file is renamed to the SQLite database file
I know it is a very specific question, but maybe someone can tell me if this would be a problem for SQLite or if there are similar methods to replace a database while the client is running. I do not want to send a bunch of SQL statements from the server to the client to update the database.
No, you cannot just replace an open SQLite3 DB file. SQLite will keep using the same file descriptor (or handle in Windows-speak), unless you close and re-open your database. More specifically:
Deleting and replacing an open file is either useless (Linux) or impossible (Windows). SQLite will never get to see the contents of the new file at all.
Overwriting an SQLite3 DB file is a recipe for data corruption. From the SQLite3 documentation:
Likewise, if a rogue process opens a
database file or journal and writes
malformed data into the middle of it,
then the database will become corrupt.
Arbitrarily overwriting the contents of the DB file can cause a whole pile of issues:
If you are very lucky it will just cause DB errors, forcing you to reopen the database anyway.
Depending on how you use the data, your application might just crash and burn.
Your application may try to apply an existing journal on the new file. Sounds painful? It is!
If you are really unlucky, the user will just get back invalid results from any queries.
The best way to deal with this would be a proper client-server implementation where the client DB file is updated from data coming from the server. In the long run that would allow for far more flexibility, while also reducing the bandwidth requirements by sending updates, rather than the whole file.
If that is not possible, you should update the client DB file in three discrete steps:
Send a message to the client application to close the DB. This allows the application to commit any changes, remove any journal files and clean-up its internal state.
Replace/Overwrite the file.
Send a message to the client application to re-open the DB. You would have to setup all prepared statements again, though.
If you do not want to close the DB file for some reason, then you should have your application - or even a separate process - update the original DB file using the new file as input. The SQLite3 backup API might be of interest to you in that case.
Is there an easy/straightforward way to extend the file upload class to encrypt files that are being uploaded? Not just encrypting the filename, but rather the data in the file itself.
I'm using mcrypt for db encryption, and would prefer to use the same for file encryption.
Looking through the Upload.php library, I don't see an obvious place where the uploaded file is read which is where I assume I'd shim in the encryption.
Any help/advice would be appreciated.
edit:
What I'm thinking is that somewhere in do_upload() (I'm thinking file_temp) the file gets encrypted before being moved (not copied!) into its final destination. However, I don't see anywhere in Upload.php where the code is working with any of the files' data outside of filename, size, type, etc. Does this approach make sense?
Rather than encrypting just the upload, use HTTPS/SSL to encrypt the entire connection between the client and server.
I decided to forgo modifying the upload class. What I did was after the file was uploaded, open the file, encrypt it, and write it out again.
$f=file_get_contents(BASE_PATH.$fileFullPath) or die ('<script>window.parent.transUpdateFail(\'no gfc'.$fileFullPath.'\');</script>');
$encf=$this->encrypt->encode($f,$this->e_key) or die ('<script>window.parent.transUpdateFail(\'no encrypt\');</script>');
$nf=fopen(BASE_PATH.$fileFullPath,"r+") or die ('<script>window.parent.transUpdateFail(\'no open '.$fileFullPath.'\');</script>');
$fw=fwrite($nf,$encf) or die ('<script>window.parent.transUpdateFail(\'no fwrite\');</script>');
fclose($nf);