private void AddRecord(string fileName, CryptoChoice settings, string fileHash)
{
byte[] encryptedDataFile = ReadDataFile();
byte[] fileBytes = DecryptDataFile(encryptedDataFile);
SHA1Hasher sha1 = new SHA1Hasher();
sha1.ComputeHash(Encoding.UTF8.GetBytes(IdentificationUsername));
SHA1Hasher sha2 = new SHA1Hasher();
sha2.ComputeHash(Encoding.UTF8.GetBytes(fileName));
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.AppendLine($"{sha2.HashedString}:{sha1.HashedString}:{fileHash}:{settings.Choice.ToString()}:{Encoding.UTF8.GetString(settings.Key)}:{settings.Depad}");
byte[] recordBytes = Encoding.UTF8.GetBytes(stringBuilder.ToString());
byte[] newFileBytes = new byte[fileBytes.Length + recordBytes.Length];
Array.Copy(fileBytes, 0, newFileBytes, 0, fileBytes.Length);
Array.Copy(recordBytes, 0, newFileBytes, fileBytes.Length, recordBytes.Length);
encryptedDataFile = EncryptDataFile(newFileBytes);
WriteDataFile(encryptedDataFile);
}
internal byte[] DecryptFileExplicit(byte[] encryptedBytes, CryptoChoice settings)
{
byte[] fileBytes;
switch (settings.Choice)
{
case CryptoChoices.OneTimePad:
OneTimePadCrypter otp = new OneTimePadCrypter(settings.Key);
fileBytes = otp.Decrypt(encryptedBytes);
break;
case CryptoChoices.TEA:
TEACrypter tea = new TEACrypter(settings.Key);
fileBytes = tea.Decrypt(encryptedBytes);
if (settings.Depad)
{
fileBytes = TEACrypter.DepadData(fileBytes);
}
break;
default:
throw new InvalidOperationException("Cryption settings are not valid: Desired cryption algorithm doesn't exist.");
}
return(fileBytes);
}
public void RequestFileUpload(string filePath, CryptoChoice answer, bool replaceOnConflict = false)
{
string fileName = Path.GetFileName(filePath);
byte[] fileBytes = File.ReadAllBytes(filePath);
SHA1Hasher sha1 = new SHA1Hasher();
sha1.ComputeHash(fileBytes);
string hashValue = sha1.HashedString;
byte[] encryptedBytes;
try
{
encryptedBytes = cryptionController.EncryptFile(fileName, fileBytes, answer, replaceOnConflict);
}
catch (Exception e)
{
throw new InvalidOperationException("Couldn't encrypt the file: " + e.Message);
}
HttpWebResponse resp = null;
try
{
string FileManagerServiceUrl = "http://localhost:56082/MyCloudStore/CloudStoreService.svc";
var serviceUrl = string.Format($"{FileManagerServiceUrl}/UploadFile/{fileName}/{hashValue}");
var request = (HttpWebRequest)WebRequest.Create(serviceUrl);
request.Method = "POST";
request.ContentType = "text/plain";
System.IO.Stream reqStream = request.GetRequestStream();
reqStream.Write(encryptedBytes, 0, encryptedBytes.Length);
reqStream.Close();
resp = (HttpWebResponse)request.GetResponse();
System.Windows.Forms.MessageBox.Show(string.Format("Client: Receive Response HTTP/{0} {1} {2}", resp.ProtocolVersion, (int)resp.StatusCode, resp.StatusDescription));
}
catch (Exception e)
{
throw new Exception("Error uploading the file to the service: " + e.GetFullMessage());
}
finally
{
if (resp != null && resp.StatusCode != HttpStatusCode.OK)
{
cryptionController.RemoveFileRecord(fileName);
}
resp.Dispose();
}
}
public byte[] EncryptFile(string fileName, byte[] fileBytes, CryptoChoice settings, bool replaceRecordIfConflict = false)
{
if (ReadRecord(fileName) != null)
{
if (replaceRecordIfConflict)
{
RemoveRecord(fileName);
}
else
{
throw new InvalidOperationException("The record for a file with this name already exists. If you want to replace it, pass another bool as an argument to the method.");
}
}
SHA1Hasher sha1 = new SHA1Hasher();
sha1.ComputeHash(fileBytes);
string fileHash = sha1.HashedString;
byte[] encryptedBytes;
switch (settings.Choice)
{
case CryptoChoices.OneTimePad:
OneTimePadCrypter otp = new OneTimePadCrypter(settings.Key);
encryptedBytes = otp.Encrypt(fileBytes);
break;
case CryptoChoices.TEA:
TEACrypter tea = new TEACrypter(settings.Key);
if (TEACrypter.CheckIfDataNeedsPadding(fileBytes))
{
fileBytes = TEACrypter.PadData(fileBytes);
settings.Depad = true;
}
encryptedBytes = tea.Encrypt(fileBytes);
break;
default:
throw new InvalidOperationException("Cryption settings are not valid: Desired cryption algorithm doesn't exist.");
}
AddRecord(fileName, settings, fileHash);
return(encryptedBytes);
}
public byte[] DecryptFile(byte[] encryptedBytes, string fileName)
{
var foundRecord = ReadRecord(fileName);
if (foundRecord == null)
{
throw new ArgumentException("There is no record for this file.");
}
CryptoChoice settings = foundRecord.Item1;
string originalFileHash = foundRecord.Item2;
byte[] fileBytes;
switch (settings.Choice)
{
case CryptoChoices.OneTimePad:
OneTimePadCrypter otp = new OneTimePadCrypter(settings.Key);
fileBytes = otp.Decrypt(encryptedBytes);
break;
case CryptoChoices.TEA:
TEACrypter tea = new TEACrypter(settings.Key);
fileBytes = tea.Decrypt(encryptedBytes);
if (settings.Depad)
{
fileBytes = TEACrypter.DepadData(fileBytes);
}
break;
default:
throw new InvalidOperationException("Cryption settings are not valid: Desired cryption algorithm doesn't exist.");
}
SHA1Hasher sha1 = new SHA1Hasher();
sha1.ComputeHash(fileBytes);
if (originalFileHash != sha1.HashedString)
{
throw new Exception("The hash value of the decrypted file and the original file hash value do not match. Access denied.");
}
return(fileBytes);
}
