Code:
/ FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / clr / src / BCL / System / Security / Cryptography / SymmetricAlgorithm.cs / 1 / SymmetricAlgorithm.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // // SymmetricAlgorithm.cs // namespace System.Security.Cryptography { [System.Runtime.InteropServices.ComVisible(true)] public abstract class SymmetricAlgorithm : IDisposable { protected int BlockSizeValue; protected int FeedbackSizeValue; protected byte[] IVValue; protected byte[] KeyValue; protected KeySizes[] LegalBlockSizesValue; protected KeySizes[] LegalKeySizesValue; protected int KeySizeValue; protected CipherMode ModeValue; protected PaddingMode PaddingValue; // // protected constructors // protected SymmetricAlgorithm() { // Default to cipher block chaining (CipherMode.CBC) and // PKCS-style padding (pad n bytes with value n) ModeValue = CipherMode.CBC; PaddingValue = PaddingMode.PKCS7; } // SymmetricAlgorithm implements IDisposable ///void IDisposable.Dispose() { Dispose(true); GC.SuppressFinalize(this); } public void Clear() { ((IDisposable) this).Dispose(); } protected virtual void Dispose(bool disposing) { if (disposing) { // Note: we always want to zeroize the sensitive key material if (KeyValue != null) { Array.Clear(KeyValue, 0, KeyValue.Length); KeyValue = null; } if (IVValue != null) { Array.Clear(IVValue, 0, IVValue.Length); IVValue = null; } } } // // public properties // public virtual int BlockSize { get { return BlockSizeValue; } set { int i; int j; for (i=0; i BlockSizeValue || (value % 8) != 0) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidFeedbackSize")); FeedbackSizeValue = value; } } public virtual byte[] IV { get { if (IVValue == null) GenerateIV(); return (byte[]) IVValue.Clone(); } set { if (value == null) throw new ArgumentNullException("value"); if (value.Length != BlockSizeValue / 8) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidIVSize")); IVValue = (byte[]) value.Clone(); } } public virtual byte[] Key { get { if (KeyValue == null) GenerateKey(); return (byte[]) KeyValue.Clone(); } set { if (value == null) throw new ArgumentNullException("value"); if (!ValidKeySize(value.Length * 8)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKeySize")); // must convert bytes to bits KeyValue = (byte[]) value.Clone(); KeySizeValue = value.Length * 8; } } public virtual KeySizes[] LegalBlockSizes { get { return (KeySizes[]) LegalBlockSizesValue.Clone(); } } public virtual KeySizes[] LegalKeySizes { get { return (KeySizes[]) LegalKeySizesValue.Clone(); } } public virtual int KeySize { get { return KeySizeValue; } set { if (!ValidKeySize(value)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKeySize")); KeySizeValue = value; KeyValue = null; } } public virtual CipherMode Mode { get { return ModeValue; } set { if ((value < CipherMode.CBC) || (CipherMode.CFB < value)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidCipherMode")); ModeValue = value; } } public virtual PaddingMode Padding { get { return PaddingValue; } set { if ((value < PaddingMode.None) || (PaddingMode.ISO10126 < value)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidPaddingMode")); PaddingValue = value; } } // // public methods // // The following method takes a bit length input and returns whether that length is a valid size // according to LegalKeySizes public bool ValidKeySize(int bitLength) { KeySizes[] validSizes = this.LegalKeySizes; int i,j; if (validSizes == null) return false; for (i=0; i< validSizes.Length; i++) { if (validSizes[i].SkipSize == 0) { if (validSizes[i].MinSize == bitLength) { // assume MinSize = MaxSize return true; } } else { for (j = validSizes[i].MinSize; j<= validSizes[i].MaxSize; j += validSizes[i].SkipSize) { if (j == bitLength) { return true; } } } } return false; } static public SymmetricAlgorithm Create() { // use the crypto config system to return an instance of // the default SymmetricAlgorithm on this machine return Create("System.Security.Cryptography.SymmetricAlgorithm"); } static public SymmetricAlgorithm Create(String algName) { return (SymmetricAlgorithm) CryptoConfig.CreateFromName(algName); } public virtual ICryptoTransform CreateEncryptor() { return CreateEncryptor(Key, IV); } public abstract ICryptoTransform CreateEncryptor(byte[] rgbKey, byte[] rgbIV); public virtual ICryptoTransform CreateDecryptor() { return CreateDecryptor(Key, IV); } public abstract ICryptoTransform CreateDecryptor(byte[] rgbKey, byte[] rgbIV); public abstract void GenerateKey(); public abstract void GenerateIV(); } }
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- Type.cs
- PowerStatus.cs
- DataGridViewRowPostPaintEventArgs.cs
- ValidationUtility.cs
- ScrollBarAutomationPeer.cs
- RootBrowserWindowProxy.cs
- ApplicationGesture.cs
- AssociationSet.cs
- AutoCompleteStringCollection.cs
- EventWaitHandle.cs
- DependencyPropertyKey.cs
- DesignerSerializationOptionsAttribute.cs
- DataView.cs
- XmlSchemaValidator.cs
- NamespaceMapping.cs
- RadioButtonPopupAdapter.cs
- DataServiceRequestArgs.cs
- PerfService.cs
- CompoundFileStreamReference.cs
- StaticSiteMapProvider.cs
- PngBitmapDecoder.cs
- TextEffectCollection.cs
- AssociationSetEnd.cs
- ConversionHelper.cs
- ChangePassword.cs
- ParseChildrenAsPropertiesAttribute.cs
- TableAutomationPeer.cs
- ApplicationGesture.cs
- ThreadStateException.cs
- TreeBuilderBamlTranslator.cs
- ComplusTypeValidator.cs
- PriorityBindingExpression.cs
- RequestCacheValidator.cs
- TimerElapsedEvenArgs.cs
- Win32KeyboardDevice.cs
- DataGridViewRowDividerDoubleClickEventArgs.cs
- IteratorFilter.cs
- PackageStore.cs
- httpserverutility.cs
- SqlDataSourceCache.cs
- SimpleTextLine.cs
- BamlBinaryReader.cs
- OleTxTransaction.cs
- UpdateProgress.cs
- WindowsComboBox.cs
- WSMessageEncoding.cs
- RegionInfo.cs
- AstTree.cs
- Main.cs
- ItemAutomationPeer.cs
- List.cs
- EmbossBitmapEffect.cs
- SqlNamer.cs
- Properties.cs
- XmlAtomicValue.cs
- PrintPageEvent.cs
- ScriptResourceInfo.cs
- TrackBar.cs
- XpsResourceDictionary.cs
- DataControlCommands.cs
- WebResponse.cs
- AnnotationResource.cs
- elementinformation.cs
- RecognizerBase.cs
- ServiceModelExtensionCollectionElement.cs
- LinkClickEvent.cs
- IItemContainerGenerator.cs
- XPathAncestorIterator.cs
- AssociationTypeEmitter.cs
- QueryStringParameter.cs
- TdsParserHelperClasses.cs
- OAVariantLib.cs
- UInt16.cs
- InputBinding.cs
- CodeAttributeDeclaration.cs
- CompiledAction.cs
- EmptyCollection.cs
- ConfigXmlElement.cs
- WebBrowserBase.cs
- HttpListenerContext.cs
- DataGridViewColumnCollection.cs
- KeyInstance.cs
- ReaderOutput.cs
- UIElement3DAutomationPeer.cs
- WmlSelectionListAdapter.cs
- AssociationProvider.cs
- CheckBox.cs
- FileNotFoundException.cs
- Vector.cs
- StandardToolWindows.cs
- QilStrConcat.cs
- WebPartEditorApplyVerb.cs
- WSFederationHttpSecurity.cs
- Image.cs
- ObjectPropertyMapping.cs
- ColorBuilder.cs
- InstancePersistenceException.cs
- Adorner.cs
- ConvertEvent.cs
- XmlKeywords.cs