public void Save(AsymmetricCipherKeyPair keypair)
{
//create the notebook's directory if it doesn't exist
Directory.CreateDirectory(NotebookDirectory);
//create the metadata
StringWriter wtr = new StringWriter();
XmlWriter xmlWtr = XmlWriter.Create(wtr);
xmlWtr.WriteStartDocument();
xmlWtr.WriteStartElement("notebook");
xmlWtr.WriteElementString("title", m_title);
foreach (Section sec in m_sections)
{
xmlWtr.WriteElementString("section", sec.ID);
//also save the section
sec.Save(keypair);
}
xmlWtr.WriteEndElement();
xmlWtr.WriteEndDocument();
xmlWtr.Close();
//encrypt the metadata
byte[] rawMetadata = Encoding.UTF8.GetBytes(wtr.GetStringBuilder().ToString());
byte[] encMetadata = Crypto.AsymmetricEncrypt(rawMetadata, ref keypair);
Eraser.SecureErase(rawMetadata);
//write the encrypted metadata to a file
string absPathMetadata = Path.Combine(NotebookDirectory, (string)Application.Current.Resources["MetadataFile"]);
File.WriteAllBytes(absPathMetadata, encMetadata);
}
public void SecureErase()
{
Eraser.SecureErase(m_encPrivKey);
Eraser.SecureErase(m_pubKey);
Eraser.SecureErase(m_decPrivKey);
Eraser.SecureErase(m_mgr);
m_encPrivKey = null;
m_pubKey = null;
m_decPrivKey = null;
m_mgr.ClearHandlers();
}
public bool Load(AsymmetricCipherKeyPair keypair)
{
//load the encrypted metadata
string absPathMetadata = Path.Combine(NotebookDirectory, (string)Application.Current.Resources["MetadataFile"]);
byte[] encMetadata = File.ReadAllBytes(absPathMetadata);
//decrypt the metadata
byte[] decMetadata = Crypto.AsymmetricDecrypt(encMetadata, ref keypair);
if (decMetadata == null)
{
return(false);
}
//get the metadata
string metadata = Encoding.UTF8.GetString(decMetadata);
//start parsing the metadata
XmlReader rdr = XmlReader.Create(new StringReader(metadata));
//check for the root tag
if (!rdr.ReadToFollowing("notebook"))
{
return(false);
}
//get the notebook title
if (!rdr.ReadToFollowing("title"))
{
return(false);
}
rdr.Read();
this.Title = rdr.Value;
//get the sections
while (rdr.ReadToFollowing("section"))
{
rdr.Read();
Section newSection = new Section(NotebookDirectory, rdr.Value);
if (!newSection.Load(keypair))
{
return(false);
}
m_sections.Add(newSection);
}
Eraser.SecureErase(metadata);
Eraser.SecureErase(decMetadata);
return(true);
}
public bool Load(AsymmetricCipherKeyPair keypair)
{
//read the encrypted metadata from file
byte[] encMetadata = File.ReadAllBytes(PageFile);
//decrypt the metadata
byte[] decMetadata = Crypto.AsymmetricDecrypt(encMetadata, ref keypair);
if (decMetadata == null)
{
return(false);
}
//start parsing the metadata
string metadata = Encoding.UTF8.GetString(decMetadata);
XmlReader rdr = XmlReader.Create(new StringReader(metadata));
//check for page root tag
if (!rdr.ReadToFollowing("page"))
{
return(false);
}
//get the page title
if (!rdr.ReadToFollowing("title"))
{
return(false);
}
rdr.Read();
this.Title = rdr.Value;
//get the page content
if (!rdr.ReadToFollowing("content"))
{
return(false);
}
rdr.Read();
this.Content = rdr.Value;
//close the reader
rdr.Close();
Eraser.SecureErase(decMetadata);
Eraser.SecureErase(metadata);
return(true);
}
public void Save(AsymmetricCipherKeyPair keypair)
{
//create the metadata
StringWriter wtr = new StringWriter();
XmlWriter xmlWtr = XmlWriter.Create(wtr);
xmlWtr.WriteStartDocument();
xmlWtr.WriteStartElement("page");
xmlWtr.WriteElementString("title", m_title);
xmlWtr.WriteElementString("content", m_content);
xmlWtr.WriteEndElement();
xmlWtr.WriteEndDocument();
xmlWtr.Close();
//encrypt the metadata
byte[] rawMetadata = Encoding.UTF8.GetBytes(wtr.GetStringBuilder().ToString());
byte[] encMetadata = Crypto.AsymmetricEncrypt(rawMetadata, ref keypair);
Eraser.SecureErase(rawMetadata);
//write the encrypted metadata to a file
File.WriteAllBytes(PageFile, encMetadata);
}
/*
* Decrypt the private key and start the app
*/
public void ResumeApp()
{
//attempt to load the keys if not already loaded
if (!m_ln.Loaded)
{
m_ln.LoadKeys();
}
//prompt the user to enter a password to decrypt the private key
PasswordPrompt p = new PasswordPrompt()
{
NegativeButtonVisible = false, PositiveButtonText = "Decrypt"
};
p.OnPromptSaved += new Prompt.PromptClosedEventListener(() =>
{
if (p.Password == null || p.Password.Length == 0)
{
return;
}
//attempt to decrypt the public key
if (!m_ln.DecryptPrivateKey(p.Password))
{ //decryption failed, incorrect password was entered
NotificationFactory.ShortAlert("Password is incorrect");
p.Show();
return;
}
//erase the entered password
Eraser.SecureErase(p.Password);
p.Password = "";
//private key decrypted, start the app normally
StartAppFinal();
});
//check if fingerprint auth is enabled
if (m_config.UseFingerprint && m_config.EncryptedPassword.Length > 1)
{
//prompt for fingerprint
IFingerprint fp = FingerprintFactory.GetInstance();
fp.InitReader();
if (fp.IsReady())
{
Application.Current.MainPage = new FingerprintPage(new EventHandler((oo, ee) =>
{
byte[] data = (byte[])oo; //page returns the decrypted password
//go to password entry if skipped
if (data == null)
{
p.Show();
return;
}
//decrypt the password
string pass = Encoding.UTF8.GetString(data);
//attempt to decrypt the private key
if (!m_ln.DecryptPrivateKey(pass))
{ //decryption failed
return;
}
//erase the decrypted password
Eraser.SecureErase(pass);
p.Password = "";
//private key decrypted, start the app normally
StartAppFinal();
}), fp, "");
}
}
else
{
p.Show();
}
}
public FirstTimeSetup()
{
InitializeComponent();
//create the password entry view
PasswordEntryView pep = new PasswordEntryView();
pep.OnSave += new EventHandler((o, e) =>
{
//get the public key ASN1
SubjectPublicKeyInfo pubki = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(m_keypair.Public);
//get the private key ASN1
PrivateKeyInfo privki = PrivateKeyInfoFactory.CreatePrivateKeyInfo(m_keypair.Private);
//encrypt the private key
byte[] encPrivKey = Crypto.EncryptKey(privki.GetDerEncoded(), pep.Text);
m_keypair = null;
//delete the old notebooks
if (Directory.Exists(NoteManager.GetNotebookDir()))
{
Directory.Delete(NoteManager.GetNotebookDir(), true);
}
//save the keys to file
KeyManager.SaveKeys(encPrivKey, pubki.GetDerEncoded());
//erase the data
Eraser.SecureErase(encPrivKey);
//ask if the user wants to use a fingerprint
IFingerprint fp = FingerprintFactory.GetInstance();
fp.InitReader();
if (fp.IsReady())
{
Application.Current.MainPage = new FingerprintPage(new EventHandler((oo, ee) =>
{
byte[] data = (byte[])oo; //page returns the encrypted password
if (data != null)
{ //only if was not skipped
//encrypt the password and save it
ConfigFactory.GetInstance().EncryptedPassword = data;
ConfigFactory.GetInstance().UseFingerprint = true;
}
else
{
ConfigFactory.GetInstance().EncryptedPassword = new byte[] { 0 };
ConfigFactory.GetInstance().UseFingerprint = false;
}
//trigger the setup complete event
if (OnSetupComplete != null)
{
OnSetupComplete(this, new EventArgs());
}
}), fp, pep.Text);
}
else
{
//trigger the setup complete event
if (OnSetupComplete != null)
{
OnSetupComplete(this, new EventArgs());
}
}
});
//create the activity indicator layout
StackLayout actLayout = new StackLayout()
{
VerticalOptions = LayoutOptions.CenterAndExpand
};
ActivityIndicator actInd = new ActivityIndicator();;
actLayout.Children.Add(actInd);
actLayout.Children.Add(new Label()
{
Text = "Generating key pair", TextColor = Color.DarkGray, HorizontalTextAlignment = TextAlignment.Center
});
TapRandomizer tapRnd = new TapRandomizer();
tapRnd.OnRandomized += new EventHandler((o, e) =>
{
m_seed = tapRnd.Seed;
//show wait animation
actInd.IsRunning = true;
this.Content = actLayout;
//generate the key pair
Crypto.StartGenerateKeypair(m_seed, new Crypto.GenCompleteEventHandler((keypair) =>
{
m_keypair = keypair;
//hide wait animation
actInd.IsRunning = false;
//show the password entry page
this.Content = pep;
}));
});
this.Content = tapRnd;
}
