ComponentFactory.Krypton.Ribbon.EncryptedLicenseProvider.LoadLicense C# (CSharp) Method

        private EncryptedLicense LoadLicense(LicenseContext context, Type type, string licenseKey)
        {
            // check that validation parameters have been set by the client
            //
            if (_rsaParameters == null || _designSignature == null || _runtimeSignature == null)
                throw new InvalidOperationException("EncryptedLicenseProvider.SetParameters must be called prior to using the EncryptedLicenseProvider");
            if (licenseKey == null) return null;

            try
            {
                byte[] encData = FromHex(licenseKey);

                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                des.Key = _desKey;
                des.IV = _desIV;

                byte[] data = des.CreateDecryptor().TransformFinalBlock(encData, 0, encData.Length);

                // extract the encryption key and encrypted product data - note that the encryption
                // key has only 7 significant bytes
                //
                byte[] encryptionKey = new byte[ArraySize(8)];
                byte[] encPayload = new byte[ArraySize(data.Length - keyLength)];

                Array.Copy(data, 0, encryptionKey, 0, keyLength);
                Array.Copy(data, keyLength, encPayload, 0, encPayload.Length);

                // validate that the password matches what the client is expecting
                //
                RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
                rsa.FromXmlString(_rsaParameters);

                if (context.UsageMode == LicenseUsageMode.Designtime)
                {
                    // if design time license requested then the license MUST be a design license
                    //
                    if (!rsa.VerifyData(encryptionKey, new SHA1CryptoServiceProvider(), _designSignature)) return null;
                }
                else
                {
                    // if runtime license requested then first check if the license is a runtime license
                    // also allow design licenses to work at runtime
                    //
                    if (!rsa.VerifyData(encryptionKey, new SHA1CryptoServiceProvider(), _runtimeSignature))
                    {
                        if (!rsa.VerifyData(encryptionKey, new SHA1CryptoServiceProvider(), _designSignature)) return null;
                    }
                }

                // decrypt the payload using the encryption key
                //
                des.IV = encryptionKey;
                byte[] payload = des.CreateDecryptor().TransformFinalBlock(encPayload, 0, encPayload.Length);
                byte[] productData = new byte[ArraySize(payload.Length - 2)];
                Array.Copy(payload, 2, productData, 0, productData.Length);

                UInt16 serialNo = BitConverter.ToUInt16(payload, 0);
                string product = System.Text.ASCIIEncoding.UTF8.GetString(productData);

                // if in design time then create a runtime license and save it
                //
                if (context.UsageMode == LicenseUsageMode.Designtime && type != null)
                {
                    // create the runtime password by encrypting the design time license
                    //
                    byte[] encKey = des.CreateEncryptor().TransformFinalBlock(encryptionKey, 0, encryptionKey.Length);
                    byte[] runtimeKey = new byte[ArraySize(8)];
                    Array.Copy(encKey, 0, runtimeKey, 0, keyLength);

                    // encrypt the payload using the runtime key
                    //
                    des.IV = runtimeKey;
                    encPayload = des.CreateEncryptor().TransformFinalBlock(payload, 0, payload.Length);

                    // Combine the runtime key and encrypted payload
                    // Note that only the first 7 bytes of the key contain information so we
                    // only pack this much information - this enables us to reduce the size of
                    // the final key by 8 bytes.
                    //
                    data = new byte[ArraySize(keyLength + encPayload.Length)];
                    runtimeKey.CopyTo(data, 0);
                    encPayload.CopyTo(data, keyLength);

                    // encrypt again to obscure the password - this time using preset encryption key
                    //
                    des.IV = _desIV;
                    encData = des.CreateEncryptor().TransformFinalBlock(data, 0, data.Length);

                    string runtimeLicenseKey = ToHex(encData);

                    // save the runtime key into the context
                    //
                    context.SetSavedLicenseKey(type, runtimeLicenseKey);
                }
                return new EncryptedLicense(licenseKey, serialNo, product);
            }
            catch
            {
                return null;
            }
        }