public override void LoadXml(XmlElement value) { _encryptedKey = new EncryptedKey(); _encryptedKey.LoadXml(value); }
// default behaviour is to look for keys defined by an EncryptedKey clause // either directly or through a KeyInfoRetrievalMethod, and key names in the key mapping public virtual SymmetricAlgorithm GetDecryptionKey(EncryptedData encryptedData, string symmetricAlgorithmUri) { if (encryptedData == null) { throw new ArgumentNullException(nameof(encryptedData)); } if (encryptedData.KeyInfo == null) { return(null); } IEnumerator keyInfoEnum = encryptedData.KeyInfo.GetEnumerator(); KeyInfoRetrievalMethod kiRetrievalMethod; KeyInfoName kiName; KeyInfoEncryptedKey kiEncKey; EncryptedKey ek = null; while (keyInfoEnum.MoveNext()) { kiName = keyInfoEnum.Current as KeyInfoName; if (kiName != null) { // Get the decryption key from the key mapping string keyName = kiName.Value; if ((SymmetricAlgorithm)_keyNameMapping[keyName] != null) { return((SymmetricAlgorithm)_keyNameMapping[keyName]); } // try to get it from a CarriedKeyName XmlNamespaceManager nsm = new XmlNamespaceManager(_document.NameTable); nsm.AddNamespace("enc", EncryptedXml.XmlEncNamespaceUrl); XmlNodeList encryptedKeyList = _document.SelectNodes("//enc:EncryptedKey", nsm); if (encryptedKeyList != null) { foreach (XmlNode encryptedKeyNode in encryptedKeyList) { XmlElement encryptedKeyElement = encryptedKeyNode as XmlElement; EncryptedKey ek1 = new EncryptedKey(); ek1.LoadXml(encryptedKeyElement); if (ek1.CarriedKeyName == keyName && ek1.Recipient == Recipient) { ek = ek1; break; } } } break; } kiRetrievalMethod = keyInfoEnum.Current as KeyInfoRetrievalMethod; if (kiRetrievalMethod != null) { string idref = Utils.ExtractIdFromLocalUri(kiRetrievalMethod.Uri); ek = new EncryptedKey(); ek.LoadXml(GetIdElement(_document, idref)); break; } kiEncKey = keyInfoEnum.Current as KeyInfoEncryptedKey; if (kiEncKey != null) { ek = kiEncKey.EncryptedKey; break; } } // if we have an EncryptedKey, decrypt to get the symmetric key if (ek != null) { // now process the EncryptedKey, loop recursively // If the Uri is not provided by the application, try to get it from the EncryptionMethod if (symmetricAlgorithmUri == null) { if (encryptedData.EncryptionMethod == null) { throw new CryptographicException(SR.Cryptography_Xml_MissingAlgorithm); } symmetricAlgorithmUri = encryptedData.EncryptionMethod.KeyAlgorithm; } byte[] key = DecryptEncryptedKey(ek); if (key == null) { throw new CryptographicException(SR.Cryptography_Xml_MissingDecryptionKey); } SymmetricAlgorithm symAlg = CryptoHelpers.CreateFromName <SymmetricAlgorithm>(symmetricAlgorithmUri); if (symAlg == null) { throw new CryptographicException(SR.Cryptography_Xml_MissingAlgorithm); } symAlg.Key = key; return(symAlg); } return(null); }
public KeyInfoEncryptedKey(EncryptedKey encryptedKey) { _encryptedKey = encryptedKey; }