/// <summary>
/// Validates the masterkey by decrypting the given fortress and flushing the memory afterwards.
/// </summary>
/// <param name="fortressFullPath"></param>
/// <param name="fortressName"></param>
/// <param name="password"></param>
internal void ValidateMasterKey(string fortressFullPath, string fortressName, string password)
{
try
{
Logger.log.Info($"Start validating the masterkey of fortress {fortressFullPath}...");
var aesHelper = new AesHelper();
// =========================================================== Unzip the fortress - Read salt
var unzippedFortress = ZipHelper.UnzipSavedZip(fortressFullPath);
using (unzippedFortress)
{
var entryOfSalt = fortressName + "/salt" + TermHelper.GetTextFileEnding();
var saltEntry = unzippedFortress.GetEntry(entryOfSalt);
var saltBytes = new byte[32];
using (var stream = saltEntry.Open())
{
saltBytes = ByteHelper.ReadBytesOfStream(stream);
}
Logger.log.Debug("Unzipped fortress - Salt bytes read.");
// =========================================================== Create masterkey
var hashedKey = aesHelper.CreateKey(password, 256, saltBytes);
password = string.Empty; // Delete the password in plaintext from RAM
var masterKey = new Masterkey(hashedKey);
Logger.log.Debug("Masterkey created.");
// =========================================================== Decrypt database
var entryOfDatabase = fortressName + "/" + TermHelper.GetDatabaseTerm() + TermHelper.GetDatabaseEnding();
var databaseEntry = unzippedFortress.GetEntry(entryOfDatabase);
var aesAlg = new AesAlgorithm();
using (var stream = databaseEntry.Open())
{
var dbBytes = ByteHelper.ReadBytesOfStream(stream);
var decryptedDb = aesAlg.Decrypt(dbBytes, masterKey.Value, saltBytes);
Logger.log.Info($"Validated {TermHelper.GetDatabaseTerm()}");
decryptedDb = null;
}
}
}
catch (Exception ex)
{
ex.SetUserMessage(WellKnownExceptionMessages.DataExceptionMessage());
throw ex;
}
}
/// <summary>
/// Do NOT use this unless a salt is stored in a single file.
/// </summary>
internal void StoreSalt(string path, byte[] salt)
{
CheckDatacache();
File.WriteAllBytes(Path.Combine(path, $"salt{TermHelper.GetTextFileEnding()}"), salt);
}
/// <summary>
/// Opens a <see cref="Fortress"/> and loads the database.
/// </summary>
public void BuildFortress(string fortressFullPath, string fortressName, string password)
{
try
{
Logger.log.Info($"Start opening the fortress {fortressFullPath}...");
var aesHelper = new AesHelper();
// =========================================================== Unzip the fortress - Read salt
var unzippedFortress = ZipHelper.UnzipSavedZip(fortressFullPath);
using (unzippedFortress)
{
var entryOfSalt = fortressName + "/salt" + TermHelper.GetTextFileEnding();
var saltEntry = unzippedFortress.GetEntry(entryOfSalt);
var saltBytes = new byte[32];
using (var stream = saltEntry.Open())
{
saltBytes = ByteHelper.ReadBytesOfStream(stream);
}
CurrentFortressData.Salt = saltBytes;
Logger.log.Debug("Unzipped fortress - Salt bytes read.");
// =========================================================== Create masterkey
var hashedKey = aesHelper.CreateKey(password, 256, saltBytes);
password = string.Empty; // Delete the password in plaintext from RAM
var masterKey = new Masterkey(hashedKey);
hashedKey = null; // Hash also
Logger.log.Debug("Masterkey created.");
// =========================================================== Decrypt database
var entryOfDatabase = fortressName + "/" + TermHelper.GetDatabaseTerm() + TermHelper.GetDatabaseEnding();
var databaseEntry = unzippedFortress.GetEntry(entryOfDatabase);
var aesAlg = new AesAlgorithm();
using (var stream = databaseEntry.Open())
{
var dbBytes = ByteHelper.ReadBytesOfStream(stream);
var decryptedDb = aesAlg.Decrypt(dbBytes, masterKey.Value, saltBytes);
Logger.log.Info($"Decrypted {TermHelper.GetDatabaseTerm()}");
// =========================================================== Unzip database
// We distinguish between sensible data and normal data. We put the sensible data into the secureDatacache.
var unzippedByteEntriesOfDb = ZipHelper.GetEntriesFromZipArchive(decryptedDb); // These are the entries in byte arrays
decryptedDb = null;
// Add to secureDC.
foreach (var sensibleBytes in unzippedByteEntriesOfDb.Item2.Item2.ToList()) // ToList() otherwise the iterations throws exception
{
AddToSecureMemoryDC(unzippedByteEntriesOfDb.Item2.Item1.Pop(), unzippedByteEntriesOfDb.Item2.Item2.Pop());
}
foreach (var bytes in unzippedByteEntriesOfDb.Item1.ToList()) // Add not sensible data to the "unsecure" DC.
{
AddToUnsecureMemoryDC(BuildModelsOutOfBytes <ModelBase>(unzippedByteEntriesOfDb.Item1.Pop()));
}
unzippedByteEntriesOfDb = null;
}
// Track the security parameters for scans later.
SecurityParameterProvider.Instance.UpdateHash(nameof(Fortress), fortressFullPath);
}
}
catch (Exception ex)
{
ex.SetUserMessage(WellKnownExceptionMessages.DataExceptionMessage());
throw ex;
}
}
