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//------------------------------------------------------------------------------
// <copyright file="PeerName.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Net.PeerToPeer
{
using System;
using System.Globalization;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Text.RegularExpressions;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.Serialization;
using System.Security.Permissions;
using Microsoft.Win32;
/// <remarks>
/// The PeerName class represents the native PeerName construct.
/// </remarks>
[Serializable]
public class PeerName : ISerializable, IEquatable<PeerName>
{
//===================================================
//constants
//===================================================
private const int PEER_MAX_CLASSIFIER_LENGTH = 149;
private const int SECURE_AUTHORITY_LENGTH = 40;
private const int INSECURE_AUTHORITY_LENGTH = 1;
private const int PEER_MAX_PEERNAME_LENGTH = SECURE_AUTHORITY_LENGTH + 1 + PEER_MAX_CLASSIFIER_LENGTH;
private const string PEERNAME_UNSECURED_AUTHORITY = "0";
//===================================================
//private member variables
//===================================================
private string m_PeerName;
private string m_Authority;
private string m_Classifier;
private string m_PeerHostName;
// ===================================================
// Constructors
// ===================================================
static PeerName()
{
//-------------------------------------------------
//Check for the availability of the simpler PNRP APIs
//-------------------------------------------------
if (!PeerToPeerOSHelper.SupportsP2P)
{
throw new PlatformNotSupportedException(SR.GetString(SR.P2P_NotAvailable));
}
}
/// <summary>
/// We use this constructor to create an PeerName
/// for internal implementation
/// </summary>
private PeerName(string peerName, string authority, string classifier) {
m_PeerName = peerName;
m_Classifier = classifier;
m_Authority = authority;
}
/// <summary>
/// This constructor is to create a peername from an
/// arbitrary string. The Identity is not necessarily
/// the same as the current user
/// </summary>
/// <param name="peerName">string form of the peer name</param>
/// <remarks>
/// 1. We assume that the peername is already normalized according to the
/// Unicode rules
/// 2. The PeerName given has nothig to do with the default Identity
/// It is just a way to create a PeerName instance given a string
/// </remarks>
public PeerName(string remotePeerName)
{
//-------------------------------------------------
//Check arguments
//-------------------------------------------------
if (remotePeerName == null)
throw new ArgumentNullException("remotePeerName");
//-------------------------------------------------
//Check PeerName format
//NOTE: Currentlt thre is no native API to check
//the format of the PeerName string. The
//StrongParsePeerName implements the logic
//-------------------------------------------------
string authority;
string classifier;
if (!StrongParsePeerName(remotePeerName, out authority, out classifier))
{
Logging.P2PTraceSource.TraceEvent(TraceEventType.Information, 0, "PeerName string {0} failed the check for a valid peer name", remotePeerName);
throw new ArgumentException(SR.GetString(SR.Pnrp_InvalidPeerName), "remotePeerName");
}
//authrority would have been lower cased
//so we must ste the m_PeerName to authority + classifier
if (classifier != null)
m_PeerName = authority + "." + classifier;
else
m_PeerName = authority;
m_Authority = authority;
m_Classifier = classifier;
Logging.P2PTraceSource.TraceEvent(TraceEventType.Information, 0, "PeerName instance created - PeerName {0} Authority {1} Classfier {2}", m_PeerName, m_Authority, ((m_Classifier == null)? "null" : m_Classifier));
}
/// <summary>
/// Given a classifier creates a secured or unsecured name
/// </summary>
/// <param name="classifier"></param>
/// <param name="secured"></param>
// <SecurityKernel Critical="True" Ring="0">
// <SatisfiesLinkDemand Name="SafeHandle.Dispose():System.Void" />
// <CallsSuppressUnmanagedCode Name="UnsafeP2PNativeMethods.PeerCreatePeerName(System.String,System.String,System.Net.PeerToPeer.SafePeerData&):System.Int32" />
// <CallsSuppressUnmanagedCode Name="UnsafeP2PNativeMethods.PeerIdentityGetDefault(System.Net.PeerToPeer.SafePeerData&):System.Int32" />
// <ReferencesCritical Name="Local shNewPeerName of type: SafePeerData" Ring="1" />
// <ReferencesCritical Name="Local shDefaultIdentity of type: SafePeerData" Ring="1" />
// <ReferencesCritical Name="Method: PeerToPeerException.CreateFromHr(System.String,System.Int32):System.Net.PeerToPeer.PeerToPeerException" Ring="1" />
// <ReferencesCritical Name="Method: SafePeerData.get_UnicodeString():System.String" Ring="1" />
// </SecurityKernel>
[System.Security.SecurityCritical]
public PeerName(string classifier, PeerNameType peerNameType)
{
//-------------------------------------------------
//Check arguments
//-------------------------------------------------
if ((classifier == null || classifier.Length == 0)&&
peerNameType == PeerNameType.Unsecured)
{
throw new ArgumentNullException("classifier");
}
if (classifier != null && classifier.Length > PEER_MAX_CLASSIFIER_LENGTH)
{
throw new ArgumentException(SR.GetString(SR.Pnrp_InvalidClassifier), "classifier");
}
//--------------------------------------------------
//Normalize using NFC
//--------------------------------------------------
if (classifier != null && classifier.Length > 0)
{
classifier = classifier.Normalize(NormalizationForm.FormC);
}
//-------------------------------------------------
//call the helper to create the PeerName
//-------------------------------------------------
Int32 result;
SafePeerData shNewPeerName = null;
SafePeerData shDefaultIdentity = null;
try
{
if (peerNameType == PeerNameType.Unsecured)
{
result = UnsafeP2PNativeMethods.PeerCreatePeerName((string)null, classifier, out shNewPeerName);
if (result != 0)
{
throw PeerToPeerException.CreateFromHr(SR.GetString(SR.Pnrp_CouldNotCreateUnsecuredPeerName), result);
}
m_Authority = PEERNAME_UNSECURED_AUTHORITY;
}
else
{
result = UnsafeP2PNativeMethods.PeerIdentityGetDefault(out shDefaultIdentity);
if (result != 0)
{
throw PeerToPeerException.CreateFromHr(SR.GetString(SR.Pnrp_CouldNotGetDefaultIdentity), result);
}
m_Authority = shDefaultIdentity.UnicodeString;
//}
result = UnsafeP2PNativeMethods.PeerCreatePeerName(m_Authority, classifier, out shNewPeerName);
if (result != 0)
{
throw PeerToPeerException.CreateFromHr(SR.GetString(SR.Pnrp_CouldNotCreateSecuredPeerName), result);
}
}
m_PeerName = shNewPeerName.UnicodeString;
m_Classifier = classifier;
}
finally
{
if (shNewPeerName != null) shNewPeerName.Dispose();
if (shDefaultIdentity != null) shDefaultIdentity.Dispose();
}
Logging.P2PTraceSource.TraceEvent(TraceEventType.Information, 0, "PeerName instance created - PeerName {0} Authority {1} Classfier {2}", m_PeerName, m_Authority, m_Classifier);
}
/// <summary>
/// Given a peerHostName string [the dns safe version of the PeerName]
/// Get the PeerName for it
/// </summary>
/// <param name="peerHostName">string form (dns safe form) of the peer name</param>
/// <returns>a PeerName instance</returns>
// <SecurityKernel Critical="True" Ring="0">
// <SatisfiesLinkDemand Name="SafeHandle.Dispose():System.Void" />
// <CallsSuppressUnmanagedCode Name="UnsafeP2PNativeMethods.PeerHostNameToPeerName(System.String,System.Net.PeerToPeer.SafePeerData&):System.Int32" />
// <ReferencesCritical Name="Local shPeerName of type: SafePeerData" Ring="1" />
// <ReferencesCritical Name="Method: PeerToPeerException.CreateFromHr(System.String,System.Int32):System.Net.PeerToPeer.PeerToPeerException" Ring="1" />
// <ReferencesCritical Name="Method: SafePeerData.get_UnicodeString():System.String" Ring="1" />
// </SecurityKernel>
[System.Security.SecurityCritical]
public static PeerName CreateFromPeerHostName(string peerHostName)
{
//-------------------------------------------------
//Check arguments
//-------------------------------------------------
if (peerHostName == null)
throw new ArgumentNullException("peerHostName");
if (peerHostName.Length == 0)
throw new ArgumentException(SR.GetString(SR.Pnrp_InvalidPeerHostName), "peerHostName");
Int32 result;
SafePeerData shPeerName = null;
string peerName = null;
try
{
result = UnsafeP2PNativeMethods.PeerHostNameToPeerName(peerHostName, out shPeerName);
if (result != 0)
{
throw PeerToPeerException.CreateFromHr(SR.GetString(SR.Pnrp_CouldNotGetPeerNameFromPeerHostName), result);
}
peerName = shPeerName.UnicodeString;
}
finally
{
if (shPeerName != null) shPeerName.Dispose();
}
string authority;
string classifier;
WeakParsePeerName(peerName, out authority, out classifier);
PeerName p = new PeerName(peerName, authority, classifier);
Logging.P2PTraceSource.TraceEvent(TraceEventType.Information, 0, "PeerName created from PeerHostName - PeerHostName {0} to PeerName PeerName {1} Authority {2} Classfier {3}", peerHostName, peerName, authority, classifier);
return p;
}
/// <summary>
/// Given a PeerName, change the classifier.
/// This is simply replacing the classifier, but we will
/// let the native APIs do the right thing since they
/// might change the concept in future
/// </summary>
/// <param name="peerName">a PeerName instance</param>
/// <param name="classifier">a new classfier string</param>
/// <returns></returns>
// <SecurityKernel Critical="True" Ring="0">
// <SatisfiesLinkDemand Name="SafeHandle.Dispose():System.Void" />
// <CallsSuppressUnmanagedCode Name="UnsafeP2PNativeMethods.PeerCreatePeerName(System.String,System.String,System.Net.PeerToPeer.SafePeerData&):System.Int32" />
// <ReferencesCritical Name="Local shNewPeerName of type: SafePeerData" Ring="1" />
// <ReferencesCritical Name="Method: PeerToPeerException.CreateFromHr(System.String,System.Int32):System.Net.PeerToPeer.PeerToPeerException" Ring="1" />
// <ReferencesCritical Name="Method: SafePeerData.get_UnicodeString():System.String" Ring="1" />
// </SecurityKernel>
[System.Security.SecurityCritical]
public static PeerName CreateRelativePeerName(
PeerName peerName,
string classifier)
{
//-------------------------------------------------
//Check arguments
//-------------------------------------------------
if (peerName == null)
{
throw new ArgumentNullException("peerName", SR.GetString(SR.Pnrp_PeerNameCantBeNull));
}
if (!peerName.IsSecured && (classifier == null || classifier.Length == 0))
{
throw new ArgumentException(SR.GetString(SR.Pnrp_InvalidClassifier), "classifier");
}
if (classifier != null && classifier.Length > PEER_MAX_CLASSIFIER_LENGTH)
{
throw new ArgumentException(SR.GetString(SR.Pnrp_InvalidClassifier), "classifier");
}
//--------------------------------------------------
//Normalize using NFC
//--------------------------------------------------
if (classifier != null && classifier.Length > 0)
{
classifier = classifier.Normalize(NormalizationForm.FormC);
}
Int32 result;
SafePeerData shNewPeerName = null;
string newPeerName = null;
try
{
//Here there is change made on the native side
//when passing secured peer names, it takes string of the form [40hexdigits].claasisifer and a newclassifier
//returns [40hexdigits.newclassifier]
//But for unsecured peer names it does not take 0.clasfier and newclassfier to return 0.newclassfier.
//It expects NULL as the first param. To satisfy this broken finctionality, we are passing null if the
//peer name is unsecured.
result = UnsafeP2PNativeMethods.PeerCreatePeerName(peerName.IsSecured? peerName.m_PeerName : null, classifier, out shNewPeerName);
if (result != 0)
{
throw PeerToPeerException.CreateFromHr(SR.GetString(SR.Pnrp_CouldNotCreateRelativePeerName), result);
}
newPeerName = shNewPeerName.UnicodeString;
}
finally
{
if (shNewPeerName != null) shNewPeerName.Dispose();
}
string authority;
string newClassifier;
WeakParsePeerName(newPeerName, out authority, out newClassifier);
PeerName p = new PeerName(newPeerName, authority, newClassifier);
Logging.P2PTraceSource.TraceEvent(TraceEventType.Information, 0, "A new PeerName created from existing PeerName with a new classfier. Existing PeerName {0} Classifier {1} New PeerName {2}", peerName, classifier, p);
return p;
}
/// <summary>
/// Friendly string
/// </summary>
/// <returns></returns>
public override string ToString()
{
return m_PeerName;
}
/// <summary>
/// Notionb of equals is based on same peer name string content
/// </summary>
/// <param name="comparand"></param>
/// <returns></returns>
public bool Equals(PeerName other)
{
if(other == null) return false;
return string.Compare(other.m_PeerName, m_PeerName, StringComparison.Ordinal) == 0;
}
public override bool Equals(object obj)
{
if (obj == null) return false;
PeerName other = obj as PeerName;
if (other == null) return false;
return Equals(other);
}
/// <summary>
/// Hash code comes from m_PeerName since the others are just components of this
/// </summary>
/// <returns></returns>
public override int GetHashCode()
{
return m_PeerName.GetHashCode();
}
/// <summary>
/// Authroity
/// </summary>
public string Authority
{
get
{
return m_Authority;
}
}
/// <summary>
/// Classifier
/// </summary>
public string Classifier
{
get
{
return m_Classifier;
}
}
/// <summary>
/// A DNS Safe version of the Peer Name
/// </summary>
public string PeerHostName
{
// <SecurityKernel Critical="True" Ring="0">
// <SatisfiesLinkDemand Name="SafeHandle.Dispose():System.Void" />
// <CallsSuppressUnmanagedCode Name="UnsafeP2PNativeMethods.PeerNameToPeerHostName(System.String,System.Net.PeerToPeer.SafePeerData&):System.Int32" />
// <ReferencesCritical Name="Local shPeerHostName of type: SafePeerData" Ring="1" />
// <ReferencesCritical Name="Method: PeerToPeerException.CreateFromHr(System.String,System.Int32):System.Net.PeerToPeer.PeerToPeerException" Ring="1" />
// <ReferencesCritical Name="Method: SafePeerData.get_UnicodeString():System.String" Ring="1" />
// </SecurityKernel>
[System.Security.SecurityCritical]
get
{
if (m_PeerHostName == null)
{
Int32 result;
SafePeerData shPeerHostName = null;
try
{
//This API gives HRESULT > 0 for success instead of S_OK == 0
//WINDOWS OS
result = UnsafeP2PNativeMethods.PeerNameToPeerHostName( m_PeerName, out shPeerHostName);
if (result < 0)
{
throw PeerToPeerException.CreateFromHr(SR.GetString(SR.Pnrp_CouldNotGetPeerHostNameFromPeerName), result);
}
m_PeerHostName = shPeerHostName.UnicodeString;
}
finally
{
if (shPeerHostName != null) shPeerHostName.Dispose();
}
}
Logging.P2PTraceSource.TraceEvent(TraceEventType.Information, 0, "PeerHostName created for PeerName PeerHostName {0} PeerName {1}", m_PeerHostName, this);
return m_PeerHostName;
}
}
/// <summary>
/// Basically if the authority == 0 or not [unsecured or secured respectively]
/// </summary>
public bool IsSecured
{
get
{
return m_Authority != PEERNAME_UNSECURED_AUTHORITY;
}
}
// ===================================================
// Private methods
// ===================================================
/// <summary>
/// I have considered using regular expressions. However, the regular expressions offer
/// poor performance and or startup cost. Really there is no substiture for custom
/// parsing logic. I decided to write this piece of code to parse the peername for now
/// - Microsoft 6/6/2005
/// </summary>
/// <param name="peerName"></param>
/// <param name="authority"></param>
/// <param name="classifier"></param>
/// <returns></returns>
private static bool StrongParsePeerName(string peerName, out string authority, out string classifier)
{
authority = null;
classifier = null;
//Rule 0. The max length must not be exeeded
if (peerName == null ||
peerName.Length == 0 ||
peerName.Length > PEER_MAX_PEERNAME_LENGTH) return false;
//Rule 1. The length of the string must be at least 3
//as in 0.C for unsecured PeerName with classifier "C"
if (peerName.Length < 3) return false;
string tempAuthority = null;
int IndexOfPeriod = peerName.IndexOf('.');
if (IndexOfPeriod == 0) return false;
if (IndexOfPeriod < 0)
{
//Rule 2. Secure PeerNames can have just the authority
//or Authority. or Authority.Classifier
//if there is no period, we have to treat the entire string as the authority
tempAuthority = peerName;
}
else if (IndexOfPeriod == peerName.Length - 1)
{
//May be this is of the form Authority.
tempAuthority = peerName.Substring(0, peerName.Length - 1);
}
else
{
//Rule 2B. Unsecure peer names must have a classifier
//There must be a period separating the authority and classifier
//and must not be the first character and it must not be the last character
tempAuthority = peerName.Substring(0, IndexOfPeriod);
}
//Rule 3. Authority is either SECURE_AUTHORITY_LENGTH hex characters or "0"
if (tempAuthority.Length != SECURE_AUTHORITY_LENGTH &&
tempAuthority.Length != INSECURE_AUTHORITY_LENGTH) return false;
//Rule 4. If it is length 1 it must be 0
if (tempAuthority.Length == INSECURE_AUTHORITY_LENGTH && tempAuthority != PEERNAME_UNSECURED_AUTHORITY)
return false;
//Rule 5. the authority must be 40 hex characters
if(tempAuthority.Length == SECURE_AUTHORITY_LENGTH)
{
foreach (char c in tempAuthority)
{
if (!IsHexDigit(c)) return false;
}
}
//Rule 6. The maximum length of the classfier is PEER_MAX_CLASSIFIER_LENGTH
string tempClassifier = null;
if (IndexOfPeriod != peerName.Length - 1 && IndexOfPeriod > 0)
{
tempClassifier = peerName.Substring(IndexOfPeriod + 1);
}
if (tempClassifier != null && tempClassifier.Length > PEER_MAX_CLASSIFIER_LENGTH) return false;
//Finish
authority = tempAuthority.ToLower(CultureInfo.InvariantCulture); //Safe for Hex digits
classifier = tempClassifier;
return true;
}
private static bool IsHexDigit(char character)
{
return ((character >= '0') && (character <= '9'))
|| ((character >= 'A') && (character <= 'F'))
|| ((character >= 'a') && (character <= 'f'));
}
/// <summary>
/// WARNING: Don't call this unless you are sure that
/// the PeerName is a valid string. This is invoked only when
/// we are sure that the peername is valid and we need to components
/// </summary>
/// <param name="peerName">in: peerName to parse</param>
/// <param name="authority">out: parsed authority value</param>
/// <param name="classifier">out: parsed classfier value</param>
/// <returns>none</returns>
private static void WeakParsePeerName(string peerName, out string authority, out string classifier)
{
authority = null;
classifier = null;
int indexOfPeriod = peerName.IndexOf('.');
if (indexOfPeriod < 0)
{
authority = peerName;
}
else if (indexOfPeriod == peerName.Length - 1)
{
//May be this is of the form Authority.
authority = peerName.Substring(0, peerName.Length - 1);
}
else
{
authority = peerName.Substring(0, indexOfPeriod);
}
if (indexOfPeriod != peerName.Length - 1 && indexOfPeriod > 0)
{
classifier = peerName.Substring(indexOfPeriod + 1);
}
authority = authority.ToLower(CultureInfo.InvariantCulture); //safe for hex strings
}
/// <summary>
/// Constructor to enable serialization
/// </summary>
/// <param name="serializationInfo"></param>
/// <param name="streamingContext"></param>
[SecurityPermission(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.SerializationFormatter)]
protected PeerName(SerializationInfo info, StreamingContext context)
{
if (info == null)
{
throw new ArgumentNullException("info");
}
m_PeerName = info.GetString("_PeerName");
m_Authority = info.GetString("_Authority");
m_Classifier = info.GetString("_Classifier");
}
// <SecurityKernel Critical="True" Ring="0">
// <SatisfiesLinkDemand Name="GetObjectData(SerializationInfo, StreamingContext):Void" />
// </SecurityKernel>
[SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase", Justification = "System.Net.dll is still using pre-v4 security model and needs this demand")]
[System.Security.SecurityCritical]
[SecurityPermission(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.SerializationFormatter, SerializationFormatter = true)]
void ISerializable.GetObjectData(SerializationInfo info, StreamingContext context)
{
GetObjectData(info, context);
}
/// <summary>
/// This is made virtual so that derived types can be implemented correctly
/// </summary>
/// <param name="serializationInfo"></param>
/// <param name="streamingContext"></param>
[SecurityPermission(SecurityAction.LinkDemand, SerializationFormatter = true)]
protected virtual void GetObjectData(SerializationInfo info, StreamingContext context)
{
info.AddValue("_PeerName", m_PeerName);
info.AddValue("_Authority", m_Authority);
info.AddValue("_Classifier", m_Classifier);
}
}
}
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