/// <summary>
/// Uploads selected file. File is first encrypted after which is stored on the specified path on encrypted file system.
/// </summary>
/// <param name="originalFile">Original, unencrypted file.</param>
/// <param name="pathOnEfs">Path on the encrypted file system where the file will be stored.</param>
/// <param name="algorithmNameSignature">Name of the algorithm used for file encryption.</param>
/// <param name="hashAlgorithmName">Name of the hashing algorithm used to create a file signature.</param>
/// <returns>Encrypted name of the file.</returns>
public string Upload(OriginalFile originalFile, string pathOnEfs, string algorithmNameSignature, string hashAlgorithmName)
{
CertificateCheck("You cannot import any new files.");
string encryptedName;
if (originalFile.FileSize > 1_900_000_000)
{
throw new Exception("File can't be larger than 2 GB.");
}
if (CanItBeStored(originalFile.FileSize))
{
var encryptedFile = new EncryptedFile(originalFile.GetOriginalFileFullName(), (uint)currentUser.Id, algorithmNameSignature, hashAlgorithmName, currentUser.PublicKey, currentUser.PrivateKey);
var encryptedFileRaw = encryptedFile.Encrypt(originalFile, currentUser.Id, currentUser.PrivateKey);
encryptedName = encryptedFile.EncryptedName;
// var userPrivateKey = currentUser.GetPrivateKey(privateKeyPath, password);
if (CanItBeStored(encryptedFileRaw.Length))
{
CreateFile(encryptedFileRaw, pathOnEfs + "\\" + encryptedFile.GetEncryptedFileFullName());
}
else
{
throw new Exception("Insufficient storage available. File can't be uploaded.");
}
}
else
{
throw new Exception("Insufficient storage available. File can't be uploaded.");
}
return(encryptedName);
}
/// <summary>
/// Shares a file with other specific user on EnigmaEfs.
/// </summary>
/// <param name="pathOnEfs">The name of the shared file.</param>
/// <param name="shareUser">User you are sharing a file with.</param>
public void Share(string pathOnEfs, UserInformation shareUser)
{
CertificateCheck($"You cannot share files with {shareUser.Username}.");
var encryptedFile = new EncryptedFile(pathOnEfs.Substring(pathOnEfs.LastIndexOf('\\') + 1).Split('.')[0]);
var updatedEncryptedFileRaw = encryptedFile.Share(File.ReadAllBytes(pathOnEfs), currentUser.Id, shareUser.Id, currentUser.PrivateKey, shareUser.PublicKey);
if (CanItBeStored(updatedEncryptedFileRaw.Length))
{
CreateFile(updatedEncryptedFileRaw, SharedDir + "\\" + encryptedFile.GetEncryptedFileFullName());
// When first sharing a file from user folder to shared folder.
if (pathOnEfs.Substring(0, pathOnEfs.LastIndexOf('\\')) != SharedDir)
{
DeleteFile(pathOnEfs);
}
}
else
{
throw new Exception("Insufficient storage available. File can't be updated.");
}
}
/// <summary>
/// Unshares a file with specific user on EnigmaEfs.
/// </summary>
/// <param name="pathOnEfs">The name of the shared file.</param>
/// <param name="userId">Unique user identifier from the database.</param>
public void Unshare(string pathOnEfs, int userId)
{
var encryptedFile = new EncryptedFile(pathOnEfs.Substring(pathOnEfs.LastIndexOf('\\') + 1).Split('.')[0]);
var updatedEncryptedFileRaw = encryptedFile.Unshare(File.ReadAllBytes(pathOnEfs), currentUser.Id, userId, out var numberOfSharedUsers);
if (CanItBeStored(updatedEncryptedFileRaw.Length))
{
// File is moved from shared folder to user's folder.
if (numberOfSharedUsers != 1)
{
CreateFile(updatedEncryptedFileRaw, SharedDir + "\\" + encryptedFile.GetEncryptedFileFullName());
}
// If no other user other than file owner can access a file, it's moved from shared folder to file owner's folder.
else
{
CreateFile(updatedEncryptedFileRaw, RootDir + "\\" + UserDir + "\\" + encryptedFile.GetEncryptedFileFullName());
DeleteFile(pathOnEfs);
}
}
else
{
throw new Exception("Insufficient storage available. File can't be updated.");
}
}
/// <summary>
/// Unshares a file with all shared users on EnigmaEfs.
/// </summary>
/// <param name="pathOnEfs"></param>
public void Unshare(string pathOnEfs)
{
var encryptedFile = new EncryptedFile(pathOnEfs.Substring(pathOnEfs.LastIndexOf('\\') + 1).Split('.')[0]);
var updatedEncryptedFileRaw = encryptedFile.Unshare(File.ReadAllBytes(pathOnEfs), currentUser.Id);
if (CanItBeStored(updatedEncryptedFileRaw.Length))
{
CreateFile(updatedEncryptedFileRaw, RootDir + "\\" + UserDir + "\\" + encryptedFile.GetEncryptedFileFullName());
DeleteFile(pathOnEfs);
}
else
{
throw new Exception("Insufficient storage available. File can't be updated.");
}
}
/// <summary>
/// Updates selected encrypted file with a specified unencrypted file.
/// </summary>
/// <param name="pathOnEfs">The name of the file to update.</param>
/// <param name="updateFile">Updated, unencrypted file.</param>
public void Update(string pathOnEfs, OriginalFile updateFile)
{
CertificateCheck("You cannot update files.");
if (updateFile.FileSize > 2_000_000_000)
{
throw new Exception("File can't be larger than 2 GB.");
}
if (!CanItBeStored(updateFile.FileSize))
{
throw new Exception("Insufficient storage available. File can't be uploaded.");
}
var encryptedFile = new EncryptedFile(pathOnEfs.Substring(pathOnEfs.LastIndexOf('\\') + 1).Split('.')[0]);
var updatedEncryptedFileRaw = encryptedFile.Update(updateFile, File.ReadAllBytes(pathOnEfs), currentUser.Id, currentUser.PrivateKey);
// Name update is always necessary because file's IV has been changed and possibly a new file has a different name.
encryptedFile.NameEncryption(updateFile.GetOriginalFileFullName(),
new AesAlgorithm(((SecurityDescriptor)encryptedFile.Headers[1]).GetKey((int)currentUser.Id, currentUser.PrivateKey),
((SecurityDescriptor)encryptedFile.Headers[1]).IV, "OFB"));
// delete the old encrypted file
DeleteFile(pathOnEfs);
if (CanItBeStored(updatedEncryptedFileRaw.Length))
{
CreateFile(updatedEncryptedFileRaw, pathOnEfs.Substring(0, pathOnEfs.LastIndexOf('\\')) + "\\" + encryptedFile.GetEncryptedFileFullName());
}
else
{
throw new Exception("Insufficient storage available. File can't be updated.");
}
}