public IAuthenticatedEncryptorConfiguration FromXml([NotNull] XElement element)
{
// <cbcEncryptor reader="{TYPE}">
// <encryption algorithm="{STRING}" provider="{STRING}" keyLength="{INT}" />
// <validation algorithm="{STRING}" provider="{STRING}" />
// <secret>...</secret>
// </cbcEncryptor>
CryptoUtil.Assert(element.Name == CngCbcAuthenticatedEncryptorConfiguration.CbcEncryptorElementName,
@"TODO: Bad element.");
var options = new CngCbcAuthenticatedEncryptorConfigurationOptions();
// read <encryption> element
var encryptionElement = element.Element(CngCbcAuthenticatedEncryptorConfiguration.EncryptionElementName);
options.EncryptionAlgorithm = (string)encryptionElement.Attribute("algorithm");
options.EncryptionAlgorithmProvider = (string)encryptionElement.Attribute("provider");
options.EncryptionAlgorithmKeySize = (int)encryptionElement.Attribute("keyLength");
// read <validation> element
var validationElement = element.Element(CngCbcAuthenticatedEncryptorConfiguration.ValidationElementName);
options.HashAlgorithm = (string)validationElement.Attribute("algorithm");
options.HashAlgorithmProvider = (string)validationElement.Attribute("provider");
// read the child of the <secret> element, then decrypt it
var encryptedSecretElement = element.Element(CngCbcAuthenticatedEncryptorConfiguration.SecretElementName).Elements().Single();
var secretElementDecryptorTypeName = (string)encryptedSecretElement.Attribute("decryptor");
var secretElementDecryptorType = Type.GetType(secretElementDecryptorTypeName, throwOnError: true);
var secretElementDecryptor = (IXmlDecryptor)_typeActivator.CreateInstance(_serviceProvider, secretElementDecryptorType);
var decryptedSecretElement = secretElementDecryptor.Decrypt(encryptedSecretElement);
CryptoUtil.Assert(decryptedSecretElement.Name == CngCbcAuthenticatedEncryptorConfiguration.SecretElementName,
@"TODO: Bad element.");
byte[] decryptedSecretBytes = Convert.FromBase64String((string)decryptedSecretElement);
try
{
var protectedMemoryBlob = new ProtectedMemoryBlob(decryptedSecretBytes);
return(new CngCbcAuthenticatedEncryptorConfiguration(options, protectedMemoryBlob));
}
finally
{
Array.Clear(decryptedSecretBytes, 0, decryptedSecretBytes.Length);
}
}
public CngCbcAuthenticatedEncryptorConfigurationFactory([NotNull] IOptions <CngCbcAuthenticatedEncryptorConfigurationOptions> optionsAccessor)
{
_options = optionsAccessor.Options.Clone();
}
public CngCbcAuthenticatedEncryptorConfiguration(CngCbcAuthenticatedEncryptorConfigurationOptions options, ISecret secret)
{
_options = options;
_secret = secret;
}