private void btnOpen_Click(object sender, EventArgs e)
{
// Select a file to open - we only want to pick one XML file
openFileDialog1.Filter = "XML files|*.xml";
openFileDialog1.Multiselect = false;
openFileDialog1.FileName = string.Empty;
if (openFileDialog1.ShowDialog() != DialogResult.OK)
{
// User pressed Cancel so don't take any action, just exit
return;
}
// User pressed OK so we need to clear any previous status
_signable = false;
clearInfo();
_edsig = null;
enableControls();
// Now attempt to open the specified file
try
{
addInfo("Opening file " + openFileDialog1.FileName);
_edsig = new eDataSig(openFileDialog1.FileName);
}
catch (XmlException x)
{
// An XML parsing error occurred
addInfo("The file contains invalid XML");
Debug.WriteLine(x);
return;
}
catch (Exception x)
{
// Some other error occurred, don't go any further
addInfo("The file could not be read");
Debug.WriteLine(x);
return;
}
// XML format is OK
addInfo("The XML format is valid");
// Validate the document format against the XSD Schema and display any errors/warnings
bool _valid = _edsig.ValidateFormat();
if (_valid)
{
addInfo("The eData format is valid");
}
else
{
addInfo("The eData format is not valid");
}
if (_edsig.ValidationErrors.Length > 0)
{
addInfo("eData format errors: " + _edsig.ValidationErrors);
}
if (_edsig.ValidationWarnings.Length > 0)
{
addInfo("eData format warnings: " + _edsig.ValidationWarnings);
}
if (!_valid)
{
return;
}
// Determine number of MaterialData elements present
addInfo(_edsig.MaterialDataCount + " MaterialData elements found");
// Determine the type of digital signature.
switch (_edsig.SignatureType)
{
case eDataSig.SignatureTypes.None:
addInfo("File has no digital signature");
_signable = true;
break;
case eDataSig.SignatureTypes.DSA:
addInfo("File has a DSA digital signature");
X509Certificate2 cert = selectCert("Select a certificate to use for digital signature verification:");
if (cert != null)
{
// Verify the trust chain of the certificate
if (cert.Verify())
{
addInfo("The certificate trust chain is valid");
}
else
{
addInfo("The certificate trust chain cannot be verified");
}
// Retrieve the DSA public key from the certificate
DSA key = DSACertificateExtensions.GetDSAPublicKey(cert);
if (key == null)
{
addInfo("The DSA public key cannot be retrieved from the certificate");
}
else
{
// Public key retrieved, now attempt to verify the signature
if (_edsig.VerifySignature(key))
{
// Digital signature valid
addInfo("The digital signature is valid.");
}
else
{
// Digital signature not valid
addInfo("Either the digital signature is not valid or the wrong certificate was selected");
// All we can do now is try to validate using public key embedded in the signature.
if (_edsig.VerifySignature())
{
addInfo("The digital signature is valid according to the embedded public key but the integrity of the data cannot be guaranteed");
}
else
{
addInfo("The digital signature is not valid according to the embedded public key");
}
}
}
}
else
{
// Certificate not supplied
addInfo("The digital signature was not checked because no certificate was selected");
// All we can do now is try to validate using public key embedded in the signature.
if (_edsig.VerifySignature())
{
addInfo("The digital signature is valid according to the embedded public key but the integrity of the data cannot be guaranteed");
}
else
{
addInfo("The digital signature is not valid according to the embedded public key");
}
}
break;
case eDataSig.SignatureTypes.HMACSHA1:
addInfo("File has HMAC-SHA1 digital signature");
PasswordDialog frmPwd = new PasswordDialog();
if (frmPwd.ShowDialog() == DialogResult.OK)
{
// Password supplied
if (_edsig.VerifySignature(frmPwd.Password))
{
// Digital signature valid
addInfo("Digital signature is valid");
}
else
{
// Digital signature not valid
addInfo("Digital signature is not valid or the password is incorrect");
}
}
else
{
// Password not supplied
addInfo("Digital signature was not checked because no password was provided");
}
break;
case eDataSig.SignatureTypes.Invalid:
default:
addInfo("File has invalid digital signature");
break;
}
// Enable/disable controls as needed
enableControls();
}
// Sign button event handler
private void btnSign_Click(object sender, EventArgs e)
{
// Set up save file dialog - this is common to either algorithm
saveFileDialog1.OverwritePrompt = true;
saveFileDialog1.CheckPathExists = true;
saveFileDialog1.AddExtension = true;
saveFileDialog1.Filter = "XML files|*.xml";
// For HMAC-SHA1
if (radPassword.Checked)
{
PasswordDialog pwd = new PasswordDialog();
pwd.Prompt = "Enter password:"******"Password must be at least 6 characters.");
return;
}
pwd.Prompt = "Re-enter password:"******"Passwords do not match!");
return;
}
// Everything is good, now sign and save the file
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
try
{
// Sign and save to a new file
_edsig.Sign(pwd1, saveFileDialog1.FileName);
// Success!
MessageBox.Show("Signing and saving were successful.");
}
catch (System.Exception x)
{
// There was an error during the sign/save operation.
Debug.WriteLine(x);
MessageBox.Show("Error while signing and saving.");
}
}
}
}
}
// For DSA
else if (radCertificate.Checked)
{
X509Certificate2 cert = selectCert("Select certificate to use for digital signature:");
if (cert != null)
{
// Grab the private key from the cert so that it can be signed.
DSA key = cert.GetDSAPrivateKey();
// Everything is good, now sign and save the file
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
try
{
// Sign and save to a new file
_edsig.Sign(key, saveFileDialog1.FileName);
// Success!
MessageBox.Show("Signing and saving were successful.");
}
catch (System.Exception x)
{
// There was an error during the sign/save operation.
Debug.WriteLine(x);
MessageBox.Show("Error while signing and saving.");
}
}
}
}
}
