Add handling of many typical input errors and cert only export (no key)

georg-jung · Mar 11, 2020 · c88e83a · c88e83a
1 parent 0cb32bc
commit c88e83a
Showing 1 changed file with 39 additions and 6 deletions.
diff --git a/PfxCreator/MainForm.cs b/PfxCreator/MainForm.cs
@@ -1,4 +1,4 @@
-using Org.BouncyCastle.Asn1.Pkcs;
+using Org.BouncyCastle.Asn1.Pkcs;
 using Org.BouncyCastle.Crypto;
 using Org.BouncyCastle.Pkcs;
 using Org.BouncyCastle.X509;
@@ -52,26 +52,56 @@ private AsymmetricKeyParameter ReadPrivateKey(string keyPem)
             return ReadPem<AsymmetricKeyParameter>(keyPem);
         }
 
-        private void WritePfx(string certPem, string keyPem, string password, string filePath)
+        /// <returns>True if a private key was written, false if just the certificate was written.</returns>
+        private bool WritePfx(string certPem, string keyPem, string password, string filePath)
         {
             var cert = ReadCertificate(certPem);
             var certEntry = new X509CertificateEntry(cert);
-            var chain = new X509CertificateEntry[] { certEntry };
 
-            var privKey = ReadPrivateKey(keyPem);
+            if (certEntry?.Certificate == null)
+                throw new ArgumentException("The string given as a PEM representation of the certificate could not be read accordingly.", nameof(certPem));
+
+            AsymmetricKeyParameter privKey = null;
+            if (!string.IsNullOrEmpty(keyPem))
+            {
+                privKey = ReadPrivateKey(keyPem);
+                if (privKey == null)
+                    throw new ArgumentException("The string given as a PEM representation of the private key could not be read accordingly.", nameof(keyPem));
+            }
 
             var store = new Pkcs12StoreBuilder().Build();
-            store.SetKeyEntry("", new AsymmetricKeyEntry(privKey), chain);
+            if (privKey != null)
+            {
+                var chain = new X509CertificateEntry[] { certEntry };
+                store.SetKeyEntry("", new AsymmetricKeyEntry(privKey), chain);
+            }
+            else
+                store.SetCertificateEntry("", certEntry);
 
             using (var p12file = File.Create(filePath))
             {
                 store.Save(p12file, password.ToCharArray(), new SecureRandom());
             }
+            return privKey != null;
         }
 
         private void savePfxButton_Click(object sender, EventArgs e)
         {
             string fileName;
+            var certPem = certTextBox.Text;
+            var psw = pfxPasswordTextBox.Text;
+            if (string.IsNullOrEmpty(certPem))
+            {
+                MessageBox.Show("You did not specify a certificate. To export a PFX file, at least the certificate is needed.",
+                        "Invalid input", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+                return;
+            }
+            if (string.IsNullOrEmpty(psw))
+                if (MessageBox.Show("You did not specify a password. If you continue saving the PFX file, it will be " +
+                    "saved encrypted but with an empty string as passphrase. Do you want to continue?",
+                    "No password specified", MessageBoxButtons.YesNo, MessageBoxIcon.Warning) != DialogResult.Yes)
+                    return;
+
             using (var sfd = new SaveFileDialog())
             {
                 sfd.Filter = "PKCS #12 files (*.pfx)|*.pfx|PKCS #12 files (*.p12)|*.p12";
@@ -83,7 +113,10 @@ private void savePfxButton_Click(object sender, EventArgs e)
 
             try
             {
-                WritePfx(certTextBox.Text, privateKeyTextBox.Text, pfxPasswordTextBox.Text, fileName);
+                var keyWritten = WritePfx(certPem, privateKeyTextBox.Text, psw, fileName);
+                if (!keyWritten)
+                    MessageBox.Show("You did not specify a private key. The exported PFX file contains just the certificate.",
+                        "PFX without private key", MessageBoxButtons.OK, MessageBoxIcon.Information);
             }
             catch (Exception ex)
             {