/// ----------------------------------------------------------------------------------------
/// <summary>
/// Helper method: Get preferences dictionary from decrypted data.
/// In editing mode, users have to enter the right SEB administrator password
/// before they can access the settings contents
/// and returns the decrypted bytes
/// </summary>
/// ----------------------------------------------------------------------------------------
private static DictObj GetPreferencesDictFromConfigData(byte[] sebData, bool forEditing)
{
DictObj sebPreferencesDict = null;
try
{
// Get preferences dictionary from decrypted data
sebPreferencesDict = (DictObj)Plist.readPlist(sebData);
}
catch (Exception readPlistException)
{
MessageBox.Show(SEBUIStrings.loadingSettingsFailed, SEBUIStrings.loadingSettingsFailedReason, MessageBoxButtons.OK, MessageBoxIcon.Error);
Console.WriteLine(readPlistException.Message);
return(null);
}
// In editing mode, the user has to enter the right SEB administrator password used in those settings before he can access their contents
if (forEditing)
{
// Get the admin password set in these settings
string sebFileHashedAdminPassword = (string)SEBSettings.valueForDictionaryKey(sebPreferencesDict, SEBSettings.KeyHashedAdminPassword);
// If there was no or empty admin password set in these settings, the user can access them anyways
if (!String.IsNullOrEmpty(sebFileHashedAdminPassword))
{
// Get the current hashed admin password
string hashedAdminPassword = (string)SEBSettings.valueForDictionaryKey(SEBSettings.settingsCurrent, SEBSettings.KeyHashedAdminPassword);
if (hashedAdminPassword == null)
{
hashedAdminPassword = "";
}
// If the current hashed admin password is same as the hashed admin password from the settings file
// then the user is allowed to access the settings
if (String.Compare(hashedAdminPassword, sebFileHashedAdminPassword, StringComparison.OrdinalIgnoreCase) != 0)
{
// otherwise we have to ask for the SEB administrator password used in those settings and
// allow opening settings only if the user enters the right one
if (!askForPasswordAndCompareToHashedPassword(sebFileHashedAdminPassword, forEditing))
{
return(null);
}
}
}
}
// Reading preferences was successful!
return(sebPreferencesDict);
}
///// ----------------------------------------------------------------------------------------
///// <summary>
///// Show SEB Password Dialog Form.
///// </summary>
///// ----------------------------------------------------------------------------------------
//public static string ShowPasswordDialogForm(string title, string passwordRequestText)
//{
// // Set the title of the dialog window
// sebPasswordDialogForm.Text = title;
// // Set the text of the dialog
// sebPasswordDialogForm.LabelText = passwordRequestText;
// sebPasswordDialogForm.txtSEBPassword.Focus();
// // If we are running in SebWindowsClient we need to activate it before showing the password dialog
// if (SEBClientInfo.SebWindowsClientForm != null) SebWindowsClientForm.SEBToForeground(); //SEBClientInfo.SebWindowsClientForm.Activate();
// // Show password dialog as a modal dialog and determine if DialogResult = OK.
// if (sebPasswordDialogForm.ShowDialog() == DialogResult.OK)
// {
// // Read the contents of testDialog's TextBox.
// string password = sebPasswordDialogForm.txtSEBPassword.Text;
// sebPasswordDialogForm.txtSEBPassword.Text = "";
// //sebPasswordDialogForm.txtSEBPassword.Focus();
// return password;
// }
// else
// {
// return null;
// }
//}
/// Generate Encrypted .seb Settings Data
/// ----------------------------------------------------------------------------------------
/// <summary>
/// Read SEB settings from UserDefaults and encrypt them using provided security credentials
/// </summary>
/// ----------------------------------------------------------------------------------------
public static byte[] EncryptSEBSettingsWithCredentials(string settingsPassword, bool passwordIsHash, X509Certificate2 certificateRef, bool useAsymmetricOnlyEncryption, SEBSettings.sebConfigPurposes configPurpose, bool forEditing)
{
// Get current settings dictionary and clean it from empty arrays and dictionaries
//DictObj cleanedCurrentSettings = SEBSettings.CleanSettingsDictionary();
// Serialize preferences dictionary to an XML string
string sebXML = Plist.writeXml(SEBSettings.settingsCurrent);
string cleanedSebXML = sebXML.Replace("<array />", "<array></array>");
cleanedSebXML = cleanedSebXML.Replace("<dict />", "<dict></dict>");
cleanedSebXML = cleanedSebXML.Replace("<data />", "<data></data>");
byte[] encryptedSebData = Encoding.UTF8.GetBytes(cleanedSebXML);
string encryptingPassword = null;
// Check for special case: .seb configures client, empty password
if (String.IsNullOrEmpty(settingsPassword) && configPurpose == SEBSettings.sebConfigPurposes.sebConfigPurposeConfiguringClient)
{
encryptingPassword = "";
}
else
{
// in all other cases:
// Check if no password entered and no identity selected
if (String.IsNullOrEmpty(settingsPassword) && certificateRef == null)
{
if (MessageBox.Show(SEBUIStrings.noEncryptionChosen, SEBUIStrings.noEncryptionChosenSaveUnencrypted, MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
{
// OK: save .seb config data unencrypted
return(encryptedSebData);
}
else
{
return(null);
}
}
}
// gzip the serialized XML data
encryptedSebData = GZipByte.Compress(encryptedSebData);
// Check if password for encryption is provided and use it then
if (!String.IsNullOrEmpty(settingsPassword))
{
encryptingPassword = settingsPassword;
}
// So if password is empty (special case) or provided
if (!(encryptingPassword == null))
{
// encrypt with password
encryptedSebData = EncryptDataUsingPassword(encryptedSebData, encryptingPassword, passwordIsHash, configPurpose);
}
else
{
// Create byte array large enough to hold prefix and data
byte[] encryptedData = new byte[encryptedSebData.Length + PREFIX_LENGTH];
// if no encryption with password: Add a 4-char prefix identifying plain data
string prefixString = PLAIN_DATA_MODE;
Buffer.BlockCopy(Encoding.UTF8.GetBytes(prefixString), 0, encryptedData, 0, PREFIX_LENGTH);
// append plain data
Buffer.BlockCopy(encryptedSebData, 0, encryptedData, PREFIX_LENGTH, encryptedSebData.Length);
encryptedSebData = (byte[])encryptedData.Clone();
}
// Check if cryptographic identity for encryption is selected
if (certificateRef != null)
{
// Encrypt preferences using a cryptographic identity
encryptedSebData = EncryptDataUsingIdentity(encryptedSebData, certificateRef, useAsymmetricOnlyEncryption);
}
// gzip the encrypted data
encryptedSebData = GZipByte.Compress(encryptedSebData);
return(encryptedSebData);
}
/// ----------------------------------------------------------------------------------------
/// <summary>
/// Helper method which decrypts the byte array using an empty password,
/// or the administrator password currently set in SEB
/// or asks for the password used for encrypting this SEB file
/// for configuring the client
/// </summary>
/// ----------------------------------------------------------------------------------------
private static DictObj DecryptDataWithPasswordForConfiguringClient(byte[] sebData, bool forEditing, ref string sebFilePassword, ref bool passwordIsHash)
{
passwordIsHash = false;
string password;
// First try to decrypt with the current admin password
// get admin password hash
string hashedAdminPassword = (string)SEBSettings.valueForDictionaryKey(SEBSettings.settingsCurrent, SEBSettings.KeyHashedAdminPassword);
if (hashedAdminPassword == null)
{
hashedAdminPassword = "";
}
// We use always uppercase letters in the base16 hashed admin password used for encrypting
hashedAdminPassword = hashedAdminPassword.ToUpper();
DictObj sebPreferencesDict = null;
byte[] decryptedSebData = SEBProtectionController.DecryptDataWithPassword(sebData, hashedAdminPassword);
if (decryptedSebData == null)
{
// If decryption with admin password didn't work, try it with an empty password
decryptedSebData = SEBProtectionController.DecryptDataWithPassword(sebData, "");
if (decryptedSebData == null)
{
// If decryption with empty and admin password didn't work, ask for the password the .seb file was encrypted with
// Allow up to 5 attempts for entering decoding password
int i = 5;
password = null;
string enterPasswordString = SEBUIStrings.enterEncryptionPassword;
do
{
i--;
// Prompt for password
password = SebPasswordDialogForm.ShowPasswordDialogForm(SEBUIStrings.reconfiguringLocalSettings, enterPasswordString);
// If cancel was pressed, abort
if (password == null)
{
return(null);
}
string hashedPassword = SEBProtectionController.ComputePasswordHash(password);
// we try to decrypt with the hashed password
decryptedSebData = SEBProtectionController.DecryptDataWithPassword(sebData, hashedPassword);
// in case we get an error we allow the user to try it again
enterPasswordString = SEBUIStrings.enterEncryptionPasswordAgain;
} while (decryptedSebData == null && i > 0);
if (decryptedSebData == null)
{
//wrong password entered in 5th try: stop reading .seb file
MessageBox.Show(SEBUIStrings.reconfiguringLocalSettingsFailed, SEBUIStrings.reconfiguringLocalSettingsFailedWrongPassword, MessageBoxButtons.OK, MessageBoxIcon.Error);
return(null);
}
else
{
// Decrypting with entered password worked: We save it for returning it later
if (forEditing)
{
sebFilePassword = password;
}
}
}
}
else
{
//decrypting with hashedAdminPassword worked: we save it for returning as decryption password
sebFilePassword = hashedAdminPassword;
// identify that password as hash
passwordIsHash = true;
}
/// Decryption worked
// Ungzip the .seb (according to specification >= v14) decrypted serialized XML plist data
decryptedSebData = GZipByte.Decompress(decryptedSebData);
// Check if the openend reconfiguring seb file has the same admin password inside like the current one
try
{
sebPreferencesDict = (DictObj)Plist.readPlist(decryptedSebData);
}
catch (Exception readPlistException)
{
// Error when deserializing the decrypted configuration data
// We abort reading the new settings here
MessageBox.Show(SEBUIStrings.loadingSettingsFailed, SEBUIStrings.loadingSettingsFailedReason, MessageBoxButtons.OK, MessageBoxIcon.Error);
Console.WriteLine(readPlistException.Message);
return(null);
}
// Get the admin password set in these settings
string sebFileHashedAdminPassword = (string)SEBSettings.valueForDictionaryKey(sebPreferencesDict, SEBSettings.KeyHashedAdminPassword);
if (sebFileHashedAdminPassword == null)
{
sebFileHashedAdminPassword = "";
}
// Has the SEB config file the same admin password inside as the current settings have?
if (String.Compare(hashedAdminPassword, sebFileHashedAdminPassword, StringComparison.OrdinalIgnoreCase) != 0)
{
//No: The admin password inside the .seb file wasn't the same as the current one
if (forEditing)
{
// If the file is openend for editing (and not to reconfigure SEB)
// we have to ask the user for the admin password inside the file
if (!askForPasswordAndCompareToHashedPassword(sebFileHashedAdminPassword, forEditing))
{
// If the user didn't enter the right password we abort
return(null);
}
}
else
{
// The file was actually opened for reconfiguring the SEB client:
// we have to ask for the current admin password and
// allow reconfiguring only if the user enters the right one
// We don't check this for the case the current admin password was used to encrypt the new settings
// In this case there can be a new admin pw defined in the new settings and users don't need to enter the old one
if (passwordIsHash == false && hashedAdminPassword.Length > 0)
{
// Allow up to 5 attempts for entering current admin password
int i = 5;
password = null;
string hashedPassword;
string enterPasswordString = SEBUIStrings.enterCurrentAdminPwdForReconfiguring;
bool passwordsMatch;
do
{
i--;
// Prompt for password
password = SebPasswordDialogForm.ShowPasswordDialogForm(SEBUIStrings.reconfiguringLocalSettings, enterPasswordString);
// If cancel was pressed, abort
if (password == null)
{
return(null);
}
if (password.Length == 0)
{
hashedPassword = "";
}
else
{
hashedPassword = SEBProtectionController.ComputePasswordHash(password);
}
passwordsMatch = (String.Compare(hashedPassword, hashedAdminPassword, StringComparison.OrdinalIgnoreCase) == 0);
// in case we get an error we allow the user to try it again
enterPasswordString = SEBUIStrings.enterCurrentAdminPwdForReconfiguringAgain;
} while (!passwordsMatch && i > 0);
if (!passwordsMatch)
{
//wrong password entered in 5th try: stop reading .seb file
MessageBox.Show(SEBUIStrings.reconfiguringLocalSettingsFailed, SEBUIStrings.reconfiguringLocalSettingsFailedWrongCurrentAdminPwd, MessageBoxButtons.OK, MessageBoxIcon.Error);
return(null);
}
}
}
}
// We need to set the right value for the key sebConfigPurpose to know later where to store the new settings
sebPreferencesDict[SEBSettings.KeySebConfigPurpose] = (int)SEBSettings.sebConfigPurposes.sebConfigPurposeConfiguringClient;
// Reading preferences was successful!
return(sebPreferencesDict);
}
