/// <summary>
/// Finds a secret key out of the given secret keyring that is able
/// to decrypt the current encrypted message and returns its KeyID.
/// If such a key is not found, 0 is returned.
/// </summary>
/// <param name="skrRing">Secret keyring containing all secret keys
/// known to the system.</param>
/// <returns>Returns the KeyID of the key that is able to decrypt the
/// encrypted message.</returns>
/// <remarks>No remarks</remarks>
public ulong GetFittingKeyID(SecretKeyRing skrRing)
{
bool bFound = false;
IEnumerator ieSessionkeys = esKeys.AsymKeys.GetEnumerator();
while (ieSessionkeys.MoveNext())
{
if (!(ieSessionkeys.Current is AsymSessionKeyPacket))
{
throw new Exception("Strange Error!");
}
AsymSessionKeyPacket askpKey = (AsymSessionKeyPacket)ieSessionkeys.Current;
ulong lKeyID = askpKey.KeyID;
TransportableSecretKey tskKey = skrRing.Find(lKeyID);
if (tskKey != null)
{
return(lKeyID);
}
}
if (!bFound)
{
throw new Exception("No fitting secret key was found to decrypt the message!");
}
return(0);
}
/// <summary>
/// Decrypts the current encrypted message using the secret keys
/// in skrKeyRing and the given passphrase.
/// </summary>
/// <param name="skrKeyRing">The secret keyring containing all the
/// secret keys know to the sytem.</param>
/// <param name="strPassphrase">The passphrase that was used to
/// encrypt the secret key material in the key that decrypts
/// the message.</param>
/// <returns>Returns the message that was encrypted. Usually this is
/// an compressed or literal message.</returns>
/// <remarks>No remarks</remarks>
public Message Decrypt(SecretKeyRing skrKeyRing, string strPassphrase)
{
TransportableSecretKey tskSecretKey = new TransportableSecretKey();
AsymSessionKeyPacket askpSessionKey = new AsymSessionKeyPacket();
bool bFound = false;
// let's see, if we can find a fitting Sessionkey packet
IEnumerator ieSessionkeys = esKeys.AsymKeys.GetEnumerator();
while (ieSessionkeys.MoveNext())
{
if (!(ieSessionkeys.Current is AsymSessionKeyPacket))
{
throw new Exception("Strange Error!");
}
AsymSessionKeyPacket askpKey = (AsymSessionKeyPacket)ieSessionkeys.Current;
ulong lKeyID = askpKey.KeyID;
TransportableSecretKey tskKey = skrKeyRing.Find(lKeyID);
if (tskKey != null)
{
bFound = true;
tskSecretKey = tskKey;
askpSessionKey = askpKey;
}
}
if (!bFound)
{
throw new Exception("No fitting secret key was found to decrypt the message!");
}
askpSessionKey.DecryptSessionKey(tskSecretKey, strPassphrase);
byte[] bKey = askpSessionKey.SessionKey;
Packet[] pContent = new Packet[0];
try {
SymmetricAlgorithm saAlgo = CipherHelper.CreateSymAlgorithm(askpSessionKey.SymmetricAlgorithm);
pContent = sepData.Decrypt(bKey, saAlgo);
} catch (Exception e) {
throw new System.Exception("Decryption of the Message failed: " + e.Message);
}
// now we need to look what kind of message was hidden in the
// encrypted data
// it can be either a literal message
LiteralMessage lmLiteral = new LiteralMessage();
try {
int iPos = lmLiteral.ParseMessage(pContent);
return(lmLiteral);
} catch (Exception) {}
// or an compressed Message
CompressedMessage cmCompressed = new CompressedMessage();
try {
int iPos = cmCompressed.ParseMessage(pContent);
return(cmCompressed);
} catch (Exception) {}
throw new System.ArgumentException("Encrypted package content is not a valid message!");
}
/// <summary>
/// Finds a secret key out of the given secret keyring that is able
/// to decrypt the current encrypted message and returns its KeyID.
/// If such a key is not found, 0 is returned.
/// </summary>
/// <param name="skrRing">Secret keyring containing all secret keys
/// known to the system.</param>
/// <returns>Returns the KeyID of the key that is able to decrypt the
/// encrypted message.</returns>
/// <remarks>No remarks</remarks>
public ulong GetFittingKeyID(SecretKeyRing skrRing)
{
bool bFound = false;
IEnumerator ieSessionkeys = esKeys.AsymKeys.GetEnumerator();
while (ieSessionkeys.MoveNext()) {
if (!(ieSessionkeys.Current is AsymSessionKeyPacket))
throw new Exception("Strange Error!");
AsymSessionKeyPacket askpKey = (AsymSessionKeyPacket)ieSessionkeys.Current;
ulong lKeyID = askpKey.KeyID;
TransportableSecretKey tskKey = skrRing.Find(lKeyID);
if (tskKey != null) {
return lKeyID;
}
}
if (!bFound)
throw new Exception("No fitting secret key was found to decrypt the message!");
return 0;
}
private static void DecryptAndVerify(SecretKeyRing skrSecretKeyRing, PublicKeyRing pkrPublicKeyRing, byte[] bData)
{
string strMessage = System.Text.Encoding.UTF8.GetString(bData);
ArmorTypes atType = new ArmorTypes();
string strRest = "";
string strRadix64 = Armor.RemoveArmor(strMessage, ref atType, ref strRest);
if (strRadix64.Length > 0)
bData = Radix64.Decode(strRadix64);
SharpPrivacy.OpenPGP.Messages.Message mContent = null;
if (atType == ArmorTypes.OpenPGPSignature) {
string strSignature = "";
string strSignedMessage = Armor.RemoveClearSignatureArmor(strMessage, ref atType, ref strSignature);
strSignedMessage = Radix64.DashUnescape(strSignedMessage);
strSignedMessage = Radix64.TrimMessage(strSignedMessage);
SignedMessage smMessage = new SignedMessage();
Packet[] pPackets = Packet.ParsePackets(strSignature);
if (!(pPackets[0] is SignaturePacket)) {
MessageBox.Show("Not a valid cleartext signature!");
return;
}
smMessage.Signature = (SignaturePacket)pPackets[0];
LiteralMessage lmMessage = new LiteralMessage(DataFormatTypes.Text);
lmMessage.Text = strSignedMessage;
smMessage.MessageSigned = lmMessage;
mContent = smMessage;
} else {
// let us see what kind of message this is
EncryptedMessage emMessage = new EncryptedMessage();
try {
Packet[] pPackets = Packet.ParsePackets(bData);
emMessage.ParseMessage(pPackets);
if (emMessage.SymmetricallyEncrypted) {
// Query passphrase for symmetrically encrypted message
QueryPassphrase qpPassphrase = new QueryPassphrase();
qpPassphrase.ShowMyDialog();
string strPassphrase = qpPassphrase.Passphrase;
mContent = emMessage.Decrypt(strPassphrase);
} else {
ulong lKeyID = emMessage.GetFittingKeyID(skrSecretKeyRing);
QueryPassphrase qpPassphrase = new QueryPassphrase();
qpPassphrase.ShowMyDialog(skrSecretKeyRing.Find(lKeyID));
string strPassphrase = qpPassphrase.Passphrase;
mContent = emMessage.Decrypt(skrSecretKeyRing, strPassphrase);
}
while ((!(mContent is LiteralMessage)) && (!(mContent is SignedMessage))) {
if (mContent is CompressedMessage) {
mContent = ((CompressedMessage)mContent).Uncompress();
} else {
MessageBox.Show("This is not a valid OpenPGP message!");
return;
}
}
} catch (Exception ee) {
MessageBox.Show("There was an error decrypting your message: " + ee.Message);
return;
}
}
LiteralMessage lmContent = new LiteralMessage();
string strDisplay = "";
if (mContent is SignedMessage) {
SignedMessage smContent = (SignedMessage)mContent;
lmContent = smContent.MessageSigned;
strDisplay += "*** OpenPGP Signed Message ***\r\n";
strDisplay += "*** Signature Status: " + smContent.Verify(pkrPublicKeyRing) + " ***\r\n";
strDisplay += "*** Signing Key: " + smContent.Signature.KeyID.ToString("x") + " ***\r\n";
strDisplay += "*** Signing Date: " + smContent.Signature.TimeCreated.ToString() + "***\r\n\r\n";
} else if (mContent is LiteralMessage) {
lmContent = (LiteralMessage)mContent;
strDisplay += "*** OpenPGP Encrypted Message ***\r\n\r\n";
} else {
MessageBox.Show("An error occured: Could not find an encrypted or signed message!", "Error...");
return;
}
if (lmContent.DataFormat == DataFormatTypes.Text) {
strDisplay += lmContent.Text;
strDisplay += "\r\n\r\n*** End OpenPGP Message ***\r\n";
PlaintextViewer pvViewer = new PlaintextViewer();
pvViewer.MessageText = strDisplay;
pvViewer.Show();
} else {
if (MessageBox.Show(strDisplay, "Signature Status...", MessageBoxButtons.OKCancel, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1) == DialogResult.OK) {
System.Windows.Forms.SaveFileDialog sfdSave = new SaveFileDialog();
sfdSave.OverwritePrompt = true;
sfdSave.Filter = "All Files (*.*)|*.*";
sfdSave.FileName = lmContent.Filename;
sfdSave.ShowDialog();
if (sfdSave.FileName.Length > 0) {
System.IO.FileStream fsOut = new FileStream(sfdSave.FileName, FileMode.CreateNew);
System.IO.BinaryWriter bwOut = new BinaryWriter(fsOut);
bwOut.Write(lmContent.Binary);
bwOut.Close();
fsOut.Close();
}
}
}
}
/// <summary>
/// Decrypts the current encrypted message using the secret keys
/// in skrKeyRing and the given passphrase.
/// </summary>
/// <param name="skrKeyRing">The secret keyring containing all the
/// secret keys know to the sytem.</param>
/// <param name="strPassphrase">The passphrase that was used to
/// encrypt the secret key material in the key that decrypts
/// the message.</param>
/// <returns>Returns the message that was encrypted. Usually this is
/// an compressed or literal message.</returns>
/// <remarks>No remarks</remarks>
public Message Decrypt(SecretKeyRing skrKeyRing, string strPassphrase)
{
TransportableSecretKey tskSecretKey = new TransportableSecretKey();
AsymSessionKeyPacket askpSessionKey = new AsymSessionKeyPacket();
bool bFound = false;
// let's see, if we can find a fitting Sessionkey packet
IEnumerator ieSessionkeys = esKeys.AsymKeys.GetEnumerator();
while (ieSessionkeys.MoveNext()) {
if (!(ieSessionkeys.Current is AsymSessionKeyPacket))
throw new Exception("Strange Error!");
AsymSessionKeyPacket askpKey = (AsymSessionKeyPacket)ieSessionkeys.Current;
ulong lKeyID = askpKey.KeyID;
TransportableSecretKey tskKey = skrKeyRing.Find(lKeyID);
if (tskKey != null) {
bFound = true;
tskSecretKey = tskKey;
askpSessionKey = askpKey;
}
}
if (!bFound)
throw new Exception("No fitting secret key was found to decrypt the message!");
askpSessionKey.DecryptSessionKey(tskSecretKey, strPassphrase);
byte[] bKey = askpSessionKey.SessionKey;
Packet[] pContent = new Packet[0];
try {
SymmetricAlgorithm saAlgo = CipherHelper.CreateSymAlgorithm(askpSessionKey.SymmetricAlgorithm);
pContent = sepData.Decrypt(bKey, saAlgo);
} catch (Exception e) {
throw new System.Exception("Decryption of the Message failed: " + e.Message);
}
// now we need to look what kind of message was hidden in the
// encrypted data
// it can be either a literal message
LiteralMessage lmLiteral = new LiteralMessage();
try {
int iPos = lmLiteral.ParseMessage(pContent);
return lmLiteral;
} catch (Exception) {}
// or an compressed Message
CompressedMessage cmCompressed = new CompressedMessage();
try {
int iPos = cmCompressed.ParseMessage(pContent);
return cmCompressed;
} catch (Exception) {}
throw new System.ArgumentException("Encrypted package content is not a valid message!");
}
