Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / clr / src / BCL / System / Security / Cryptography / DESCryptoServiceProvider.cs / 1305376 / DESCryptoServiceProvider.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== //[....] // // // DESCryptoServiceProvider.cs // namespace System.Security.Cryptography { [System.Runtime.InteropServices.ComVisible(true)] public sealed class DESCryptoServiceProvider : DES { // // public constructors // [System.Security.SecuritySafeCritical] // auto-generated public DESCryptoServiceProvider () { if (!Utils.HasAlgorithm(Constants.CALG_DES, 0)) throw new CryptographicException(Environment.GetResourceString("Cryptography_CSP_AlgorithmNotAvailable")); // Since the CSP only supports a CFB feedback of 8, make that the default FeedbackSizeValue = 8; } // // public methods // [System.Security.SecuritySafeCritical] // auto-generated public override ICryptoTransform CreateEncryptor (byte[] rgbKey, byte[] rgbIV) { if (IsWeakKey(rgbKey)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKey_Weak"),"DES"); if (IsSemiWeakKey(rgbKey)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKey_SemiWeak"),"DES"); return _NewEncryptor(rgbKey, ModeValue, rgbIV, FeedbackSizeValue, CryptoAPITransformMode.Encrypt); } [System.Security.SecuritySafeCritical] // auto-generated public override ICryptoTransform CreateDecryptor (byte[] rgbKey, byte[] rgbIV) { if (IsWeakKey(rgbKey)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKey_Weak"),"DES"); if (IsSemiWeakKey(rgbKey)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKey_SemiWeak"),"DES"); return _NewEncryptor(rgbKey, ModeValue, rgbIV, FeedbackSizeValue, CryptoAPITransformMode.Decrypt); } public override void GenerateKey () { KeyValue = new byte[8]; Utils.StaticRandomNumberGenerator.GetBytes(KeyValue); // Never hand back a weak or semi-weak key while (DES.IsWeakKey(KeyValue) || DES.IsSemiWeakKey(KeyValue)) { Utils.StaticRandomNumberGenerator.GetBytes(KeyValue); } } public override void GenerateIV () { IVValue = new byte[8]; Utils.StaticRandomNumberGenerator.GetBytes(IVValue); } // // private methods // [System.Security.SecurityCritical] // auto-generated private ICryptoTransform _NewEncryptor (byte[] rgbKey, CipherMode mode, byte[] rgbIV, int feedbackSize, CryptoAPITransformMode encryptMode) { int cArgs = 0; int[] rgArgIds = new int[10]; Object[] rgArgValues = new Object[10]; // Check for bad values // 1) we don't support OFB mode in DESCryptoServiceProvider if (mode == CipherMode.OFB) throw new CryptographicException(Environment.GetResourceString("Cryptography_CSP_OFBNotSupported")); // 2) we only support CFB with a feedback size of 8 bits if ((mode == CipherMode.CFB) && (feedbackSize != 8)) throw new CryptographicException(Environment.GetResourceString("Cryptography_CSP_CFBSizeNotSupported")); // Build the key if one does not already exist if (rgbKey == null) { rgbKey = new byte[8]; Utils.StaticRandomNumberGenerator.GetBytes(rgbKey); } // Set the mode for the encryptor (defaults to CBC) if (mode != CipherMode.CBC) { rgArgIds[cArgs] = Constants.KP_MODE; rgArgValues[cArgs] = mode; cArgs += 1; } // If not ECB mode -- pass in an IV if (mode != CipherMode.ECB) { if (rgbIV == null) { rgbIV = new byte[8]; Utils.StaticRandomNumberGenerator.GetBytes(rgbIV); } // // We truncate IV's that are longer than the block size to 8 bytes : this is // done to maintain backward compatibility with the behavior shipped in V1.x. // The call to set the IV in CryptoAPI will ignore any bytes after the first 8 // bytes. We'll still reject IV's that are shorter than the block size though. // if (rgbIV.Length < 8) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidIVSize")); rgArgIds[cArgs] = Constants.KP_IV; rgArgValues[cArgs] = rgbIV; cArgs += 1; } // If doing OFB or CFB, then we need to set the feed back loop size if ((mode == CipherMode.OFB) || (mode == CipherMode.CFB)) { rgArgIds[cArgs] = Constants.KP_MODE_BITS; rgArgValues[cArgs] = feedbackSize; cArgs += 1; } // Create the encryptpr/decryptor object return new CryptoAPITransform(Constants.CALG_DES, cArgs, rgArgIds, rgArgValues, rgbKey, PaddingValue, mode, BlockSizeValue, feedbackSize, false, encryptMode); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- RowToParametersTransformer.cs
- XPathDocumentBuilder.cs
- ChangeNode.cs
- SchemeSettingElementCollection.cs
- DefaultProxySection.cs
- RuntimeConfigLKG.cs
- MultipleViewPatternIdentifiers.cs
- UIntPtr.cs
- PlainXmlDeserializer.cs
- ServiceContractListItem.cs
- designeractionlistschangedeventargs.cs
- StorageEntityTypeMapping.cs
- StrokeNodeData.cs
- PackageRelationship.cs
- SafeNativeMethods.cs
- Duration.cs
- PageCatalogPartDesigner.cs
- Soap12ServerProtocol.cs
- ListViewItem.cs
- PeerCredential.cs
- ArgumentNullException.cs
- Terminate.cs
- DBCommand.cs
- ListMarkerSourceInfo.cs
- FocusChangedEventArgs.cs
- MimeTypePropertyAttribute.cs
- ListViewSortEventArgs.cs
- Math.cs
- RootCodeDomSerializer.cs
- XmlName.cs
- ResourceContainer.cs
- DataTableNewRowEvent.cs
- XamlStyleSerializer.cs
- WebPartEventArgs.cs
- CreateParams.cs
- SqlException.cs
- ParameterRetriever.cs
- FixedTextView.cs
- EventDrivenDesigner.cs
- SqlDataSourceFilteringEventArgs.cs
- XmlObjectSerializerReadContextComplex.cs
- FlowDocumentReader.cs
- TempFiles.cs
- FastEncoder.cs
- InvokeGenerator.cs
- JapaneseLunisolarCalendar.cs
- MetadataSerializer.cs
- Int32CollectionConverter.cs
- SHA256Managed.cs
- HtmlInputCheckBox.cs
- ExtendedProperty.cs
- InputElement.cs
- BindingsSection.cs
- DetailsViewCommandEventArgs.cs
- QilUnary.cs
- MaskedTextBoxDesigner.cs
- FullTextBreakpoint.cs
- CryptoKeySecurity.cs
- TrackingRecordPreFilter.cs
- BlurBitmapEffect.cs
- SubordinateTransaction.cs
- KerberosSecurityTokenProvider.cs
- WebPartEditVerb.cs
- SessionStateModule.cs
- UserControl.cs
- HashCryptoHandle.cs
- DataControlReferenceCollection.cs
- ToolboxItemCollection.cs
- WebPartConnectionsCloseVerb.cs
- FragmentNavigationEventArgs.cs
- IPCCacheManager.cs
- CommandEventArgs.cs
- RegisteredScript.cs
- EventMappingSettingsCollection.cs
- PrintPreviewControl.cs
- MsmqQueue.cs
- XmlSerializationGeneratedCode.cs
- Part.cs
- HtmlInputSubmit.cs
- FilterQueryOptionExpression.cs
- Menu.cs
- BindingContext.cs
- EventLogPermissionEntry.cs
- MaskDescriptors.cs
- EntityCommand.cs
- ArgumentException.cs
- Stream.cs
- versioninfo.cs
- XsltCompileContext.cs
- SqlAliaser.cs
- HandlerFactoryWrapper.cs
- DelimitedListTraceListener.cs
- WebPartHeaderCloseVerb.cs
- ProxyGenerationError.cs
- WeakKeyDictionary.cs
- X509WindowsSecurityToken.cs
- COMException.cs
- DeclarativeCatalogPart.cs
- shaper.cs
- SchemaImporterExtension.cs