Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Net / System / Net / Mail / WhitespaceReader.cs / 1305376 / WhitespaceReader.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Net.Mail { using System; using System.Text; using System.Net.Mime; using System.Globalization; using System.Collections; using System.Diagnostics; // FWS, CFWS, and Comments are defined in RFC 2822 section 3.2.3. // // FWS is a Folding White Space, or a series of spaces and tabs that may also contain a CRLF. // // CFWS is a FWS that also allows for nested comments enclosed in parenthesis. (comment (nested)) // // Valid values for these are declared in MailBnfHelper.cs and are explained in MailBNF.cs. // internal static class WhitespaceReader { // // This skips all folding and whitespace characters // // Preconditions: // - The data string must not be null or empty. // - The index must be within the upper bounds of the data string. // // Return value: // - The index of the next character that is NOT a whitespace character. // - -1 if the beginning of the data string is reached. // // A FormatException will be thrown if a CR or LF is found NOT in the sequence CRLF. internal static int ReadFwsReverse(string data, int index) { Debug.Assert(!String.IsNullOrEmpty(data), "data was null or empty"); Debug.Assert(index < data.Length, "index was outside the bounds of the string"); bool expectCR = false; for ( ; index >= 0; index--) { // Check for a valid CRLF pair if (data[index] == MailBnfHelper.CR && expectCR) { expectCR = false; // valid pair } // LF without CR, or CR without LF, invalid else if (data[index] == MailBnfHelper.CR || expectCR) { throw new FormatException(SR.GetString(SR.MailAddressInvalidFormat)); } // LF is only valid if preceded by a CR. // Skip both if they're found together. else if (data[index] == MailBnfHelper.LF) { expectCR = true; } // Skip whitespace else if (data[index] == MailBnfHelper.Space || data[index] == MailBnfHelper.Tab) { // No-op } else { // Neither check hit so we must be on something that is not whitespace break; } } if (expectCR) { // We found a LF without an immediately preceding CR, invalid. throw new FormatException(SR.GetString(SR.MailAddressInvalidFormat)); } return index; } // This method functions similarly to ReadFwsReverse but will also skip any comments. // // Comments are text within '(' and ')' and may be nested. There may also be consecutive comments. Unicode is // allowed, as the comments are not transmitted. // // This method was explicitly written in a non-recursive fashion to avoid malicious or accidental // stack-overflows from user input. // // Preconditions: // - The data string must not be null or empty // - The index must be within the upper bounds of the data string. // // Return value: // - The given index if it data[index] was not a ')' or white space // - The index of the next non comment or white space character // e.g. " d ( ( c o mment) )" returns index 1 // - -1 if skipping the comments and/or whitespace moves you to the beginning of the data string. // e.g. " (comment) " returns -1 // // Throws a FormatException for mismatched '(' and ')', or for unescaped characters not allowed in comments. internal static int ReadCfwsReverse(string data, int index) { Debug.Assert(!String.IsNullOrEmpty(data), "data was null or empty"); Debug.Assert(index < data.Length, "index was outside the bounds of the string"); int commentDepth = 0; // Check for valid whitespace index = ReadFwsReverse(data, index); while (index >= 0) { // Check for escaped characters. They must be within comments. int quotedCharCount = QuotedPairReader.CountQuotedChars(data, index, true); if (commentDepth > 0 && quotedCharCount > 0) { index = index - quotedCharCount; } // Start a new comment else if (data[index] == MailBnfHelper.EndComment) { commentDepth++; index--; } // Finish a comment else if (data[index] == MailBnfHelper.StartComment) { commentDepth--; if (commentDepth < 0) { // Mismatched '(' throw new FormatException(SR.GetString(SR.MailHeaderFieldInvalidCharacter, MailBnfHelper.StartComment)); } index--; } // Check for valid characters within comments. Allow Unicode, as we won't transmit any comments. else if (commentDepth > 0 && (data[index] > MailBnfHelper.Ascii7bitMaxValue || MailBnfHelper.Ctext[data[index]])) { index--; } // If we're still in a comment, this must be an invalid char else if (commentDepth > 0) { throw new FormatException(SR.GetString(SR.MailHeaderFieldInvalidCharacter, data[index])); } // We must no longer be in a comment, and this is not a whitespace char, return else { break; } // Check for valid whitespace index = ReadFwsReverse(data, index); } if (commentDepth > 0) { // Mismatched ')', throw throw new FormatException(SR.GetString(SR.MailHeaderFieldInvalidCharacter, MailBnfHelper.EndComment)); } return index; } } } // 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
- ResourceExpressionBuilder.cs
- Control.cs
- EmptyControlCollection.cs
- IdentityModelDictionary.cs
- ApplicationFileCodeDomTreeGenerator.cs
- TemplateControlBuildProvider.cs
- FunctionQuery.cs
- ConnectionPoint.cs
- OleDbInfoMessageEvent.cs
- ScaleTransform3D.cs
- ThicknessAnimationUsingKeyFrames.cs
- BinaryUtilClasses.cs
- EtwProvider.cs
- LayoutDump.cs
- QuerySettings.cs
- InfiniteIntConverter.cs
- NavigatorInput.cs
- Compensate.cs
- HtmlFormParameterWriter.cs
- Model3DGroup.cs
- QuadraticBezierSegment.cs
- ButtonAutomationPeer.cs
- ProxyWebPart.cs
- FixedNode.cs
- PrinterSettings.cs
- OutputCacheSettingsSection.cs
- XmlSecureResolver.cs
- XmlILOptimizerVisitor.cs
- CommandLineParser.cs
- AdapterUtil.cs
- WinEventWrap.cs
- DataControlFieldCell.cs
- WriteableBitmap.cs
- LeafCellTreeNode.cs
- TraceSwitch.cs
- SelectionItemProviderWrapper.cs
- XmlCharCheckingWriter.cs
- iisPickupDirectory.cs
- RequestedSignatureDialog.cs
- StylusSystemGestureEventArgs.cs
- SlipBehavior.cs
- HtmlTitle.cs
- PreviewPrintController.cs
- BuildResultCache.cs
- HitTestResult.cs
- WebServiceParameterData.cs
- SectionRecord.cs
- TypeLoadException.cs
- IIS7UserPrincipal.cs
- JsonReaderWriterFactory.cs
- ListViewInsertEventArgs.cs
- OracleBFile.cs
- IBuiltInEvidence.cs
- InputBinder.cs
- DbConnectionFactory.cs
- _ConnectStream.cs
- HyperlinkAutomationPeer.cs
- GridViewColumnHeader.cs
- MenuCommands.cs
- _IPv6Address.cs
- MetadataCache.cs
- ZoneButton.cs
- BrowserCapabilitiesCompiler.cs
- Window.cs
- BlobPersonalizationState.cs
- Geometry.cs
- OptimalTextSource.cs
- GPStream.cs
- MobilePage.cs
- DataGridViewRowStateChangedEventArgs.cs
- EdmToObjectNamespaceMap.cs
- FrameworkContentElementAutomationPeer.cs
- Canvas.cs
- manifestimages.cs
- BrowserDefinition.cs
- Function.cs
- LockedHandleGlyph.cs
- _IPv4Address.cs
- SiteMapNodeItem.cs
- DocumentOrderQuery.cs
- ResourceSetExpression.cs
- ObjectToIdCache.cs
- BitmapDownload.cs
- FormViewDeleteEventArgs.cs
- RequestQueryProcessor.cs
- CounterCreationData.cs
- IntPtr.cs
- AppearanceEditorPart.cs
- WindowsFormsLinkLabel.cs
- ModuleConfigurationInfo.cs
- SqlBuilder.cs
- XamlClipboardData.cs
- EdmRelationshipRoleAttribute.cs
- TextTrailingCharacterEllipsis.cs
- PersistStreamTypeWrapper.cs
- VirtualizingStackPanel.cs
- HtmlInputControl.cs
- X509Certificate2.cs
- AttributeProviderAttribute.cs
- StackBuilderSink.cs