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
- CTreeGenerator.cs
- User.cs
- X509CertificateClaimSet.cs
- DetailsViewRowCollection.cs
- ContentDisposition.cs
- InputElement.cs
- QueryContinueDragEvent.cs
- XmlTextEncoder.cs
- AtlasWeb.Designer.cs
- Geometry3D.cs
- BinHexEncoding.cs
- CursorInteropHelper.cs
- AuthorizationSection.cs
- MimeTypePropertyAttribute.cs
- CapabilitiesRule.cs
- QueryConverter.cs
- BrowsableAttribute.cs
- WebSysDisplayNameAttribute.cs
- ClientSideProviderDescription.cs
- ServiceContractListItem.cs
- PageRanges.cs
- SafeThreadHandle.cs
- NetworkInformationException.cs
- JsonXmlDataContract.cs
- FileReader.cs
- ProvideValueServiceProvider.cs
- UriTemplateTrieNode.cs
- ToolBarOverflowPanel.cs
- DecodeHelper.cs
- _SSPIWrapper.cs
- ConcurrencyBehavior.cs
- InkPresenterAutomationPeer.cs
- UnsafePeerToPeerMethods.cs
- WindowClosedEventArgs.cs
- ItemsPresenter.cs
- MetadataItem_Static.cs
- UniqueID.cs
- WebScriptMetadataInstanceContextProvider.cs
- ColorConverter.cs
- ProgressBar.cs
- ByteStreamMessageUtility.cs
- TrackingLocation.cs
- DocobjHost.cs
- BamlResourceDeserializer.cs
- DataSpaceManager.cs
- HierarchicalDataBoundControl.cs
- PickBranch.cs
- SqlDataSourceQueryConverter.cs
- EntityConnectionStringBuilderItem.cs
- SocketElement.cs
- DesignTable.cs
- BaseCodePageEncoding.cs
- Facet.cs
- SmtpNetworkElement.cs
- Int16AnimationBase.cs
- SelectionRangeConverter.cs
- WindowsUpDown.cs
- LineGeometry.cs
- PropertyChangedEventManager.cs
- EntitySqlQueryBuilder.cs
- TypefaceMap.cs
- ArcSegment.cs
- OdbcInfoMessageEvent.cs
- GlyphsSerializer.cs
- SqlTopReducer.cs
- ListItem.cs
- MsmqBindingElementBase.cs
- CodeAssignStatement.cs
- DataPagerFieldItem.cs
- ProfileService.cs
- ObjectAssociationEndMapping.cs
- CodePrimitiveExpression.cs
- ParseChildrenAsPropertiesAttribute.cs
- MSAAEventDispatcher.cs
- PersistChildrenAttribute.cs
- RtfNavigator.cs
- RuntimeIdentifierPropertyAttribute.cs
- Suspend.cs
- SmiEventSink_DeferedProcessing.cs
- CompiledQueryCacheEntry.cs
- ProfileGroupSettingsCollection.cs
- SqlClientWrapperSmiStream.cs
- PtsHost.cs
- GetBrowserTokenRequest.cs
- FontSizeConverter.cs
- RelatedView.cs
- TypeElement.cs
- GradientSpreadMethodValidation.cs
- DbConnectionFactory.cs
- MetadataItem.cs
- PackageRelationship.cs
- Walker.cs
- Vector3DAnimationUsingKeyFrames.cs
- WpfSharedBamlSchemaContext.cs
- MarkupExtensionReturnTypeAttribute.cs
- CompiledXpathExpr.cs
- SettingsPropertyCollection.cs
- DocumentProperties.cs
- ColumnWidthChangingEvent.cs
- DesignerActionKeyboardBehavior.cs