BTREE - C# Api, Can't encrypt database

Question

Hi. I've a problem using berkeley api for C#. I'm trying to create an encrypted db.
That's an example of code I'm trying using:
BTreeDatabase btreeDB;
DatabaseEntry key ;
DatabaseEntry data;
public void dummy()
dbo.dbs = dbs;
String dbFileName = "Messaggi.db";
BTreeDatabaseConfig cfg = new BTreeDatabaseConfig();
DatabaseEnvironmentConfig dbCfg = new DatabaseEnvironmentConfig();
if (File.Exists(dbFileName))
MessageBox.Show("Elimino il database");
File.Delete(dbFileName);
try
cfg.Creation = CreatePolicy.ALWAYS;
cfg.Encrypted = true;//?? it's needed?
cfg.SetEncryption("123456789", EncryptionAlgorithm.DEFAULT);
btreeDB = BTreeDatabase.Open(dbFileName, cfg);
catch (BerkeleyDB.DatabaseException dbex)
Debug.WriteLine(dbex.StackTrace);
return;
but it throw that's exception:
Eccezione first-chance di tipo 'BerkeleyDB.DatabaseException' in libdb_dotnet53.dll
+'ExportMessages.vshost.exe' (Gestito (v4.0.30319)): caricato 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\mscorlib.resources\v4.0_4.0.0.0_it_b77a5c561934e089\mscorlib.resources.dll'+
in BerkeleyDB.DatabaseException.ThrowException(Int32 err) in D:\work\releases\db-5.3.21\lang\csharp\src\DatabaseException.cs:riga 72
in BerkeleyDB.Internal.DB.open(DB_TXN txn, String file, String database, DBTYPE type, UInt32 flags, Int32 mode) in D:\work\releases\db-5.3.21\lang\csharp\src\Internal\DB.cs:riga 261
in BerkeleyDB.BTreeDatabase.Open(String Filename, String DatabaseName, BTreeDatabaseConfig cfg, Transaction txn) in D:\work\releases\db-5.3.21\lang\csharp\src\BTreeDatabase.cs:riga 230
in BerkeleyDB.BTreeDatabase.Open(String Filename, BTreeDatabaseConfig cfg) in D:\work\releases\db-5.3.21\lang\csharp\src\BTreeDatabase.cs:riga 97
+in [...]+
It's my mistake?
Thank you.
Massimiliano.

Answer 1

Hi Massimiliano,
We had a bug related to encrypting database when using the C# API, bug #18891, but that was fixed in 5.2 (see the entry in the 5.2 change log)
+Fixed a bug where encryption could not be enabled for individual databases in an encrypted environment. [#18891]+
, hence the fix is part of Berkeley DB 5.3.21.
You haven't posted a complete stack trace or a small stand-alone testcase, so I cannot know exactly what is the problem.
But, here are the rules around using encryption:
A. When the database is part of an environment
- you will need to specify the encryption password and encryption algorithm using the DatabaseEnvironmentConfig.SetEncryption() method
- if you want a database in the environment to be encrypted (using the password and algorithm specified for the environment), you will need to set the DatabaseConfig.Encrypted property to true
- note that it is an error to try to set an encryption password/algorithm using the DatabaseConfig.SetEncryption() method for a database that is part of an environment, because the database will use the encryption password/algorithm specified for the environment
- here is a snippet of code showing how to correctly encrypt a database that is part of an environment:
     DatabaseEnvironmentConfig envCfg;
     envCfg = new DatabaseEnvironmentConfig();
     envCfg.Create = true;
     envCfg.UseMPool = true;
     envCfg.SetEncryption("123456789", EncryptionAlgorithm.DEFAULT);
     env = DatabaseEnvironment.Open(envHome, envCfg);
     BTreeDatabaseConfig btreeCfg = new BTreeDatabaseConfig();
     btreeCfg.Creation = CreatePolicy.IF_NEEDED;
     btreeCfg.Env = env;
     btreeCfg.Encrypted = true;
     db = BTreeDatabase.Open(dbName, btreeCfg);
     ...B. When the database is NOT part of an environment
     BTreeDatabaseConfig btreeCfg2 = new BTreeDatabaseConfig();
     btreeCfg2.Creation = CreatePolicy.IF_NEEDED;
     btreeCfg2.Encrypted = true;
     btreeCfg2.SetEncryption("123456789", EncryptionAlgorithm.DEFAULT);
     db2 = BTreeDatabase.Open(db2Name, btreeCfg2);This should clarify things. If not or you have additional questions let me know.
Regards,
Andrei