PeerName.cs source code in C# .NET

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Code:

/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / SystemNet / Net / PeerToPeer / PeerName.cs / 1305376 / PeerName.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 
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;
    /// 
    /// The PeerName class represents the native PeerName construct.
    ///  
    [Serializable]
    public class PeerName : ISerializable, IEquatable 
    { 
        //===================================================
        //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)); 
            }
        }

        ///  
        /// We use this constructor to create an PeerName
        /// for internal implementation 
        ///  
        private PeerName(string peerName, string authority, string classifier) {
            m_PeerName = peerName; 
            m_Classifier = classifier;
            m_Authority = authority;
        }
 
        /// 
        /// This constructor is to create a peername from an 
        /// arbitrary string. The Identity is not necessarily 
        /// the same as the current user
        ///  
        /// string form of the peer name
        /// 
        ///     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 
        ///  
        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));
        }

        ///  
        /// Given a classifier creates a secured or unsecured name
        ///  
        ///  
        /// 
        //  
        // 
        // 
        // 
        //  
        // 
        //  
        //  
        // 
        [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); 
        }

        /// 
        /// Given a peerHostName string [the dns safe version of the PeerName] 
        /// Get the PeerName for it
        ///  
        /// string form (dns safe form) of the peer name 
        /// a PeerName instance
        //  
        // 
        // 
        // 
        //  
        // 
        //  
        [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; 
        }
 
        ///  
        /// 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
        /// 
        /// a PeerName instance 
        /// a new classfier string
        ///  
        //  
        // 
        //  
        // 
        // 
        // 
        //  
        [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;
        } 

        /// 
        /// Friendly string
        ///  
        /// 
        public override string ToString() 
        { 
            return m_PeerName;
        } 

        /// 
        /// Notionb of equals is based on same peer name string content
        ///  
        /// 
        ///  
        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); 

        }
        /// 
        /// Hash code comes from m_PeerName since the others are just components of this 
        /// 
        ///  
        public override int GetHashCode() 
        {
            return m_PeerName.GetHashCode(); 
        }

        /// 
        /// Authroity 
        /// 
        public string Authority 
        { 
            get
            { 
                return m_Authority;
            }
        }
        ///  
        /// Classifier
        ///  
        public string Classifier 
        {
            get 
            {
                return m_Classifier;
            }
        } 

        ///  
        /// A DNS Safe version of the Peer Name 
        /// 
        public string PeerHostName 
        {
            // 
            // 
            //  
            // 
            //  
            //  
            // 
            [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; 
            }
        } 

        /// 
        /// Basically if the authority == 0 or not [unsecured or secured respectively]
        ///  
        public bool IsSecured
        { 
            get 
            {
                return m_Authority != PEERNAME_UNSECURED_AUTHORITY; 
            }
        }

 
        // ===================================================
        // Private methods 
        // ==================================================== 
        /// 
        /// 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
        /// - [....] 6/6/2005
        ///  
        /// 
        ///  
        ///  
        /// 
        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')); 
        }
 
        /// 
        /// 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 
        /// 
        /// in: peerName to parse 
        /// out: parsed authority value 
        /// out: parsed classfier value
        /// none 
        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 
        } 

        ///  
        /// Constructor to enable serialization
        /// 
        /// 
        ///  
        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"); 
        }
 
 
        // 
        //  
        // 
        [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); 
        }
 
        /// 
        /// This is made virtual so that derived types can be implemented correctly
        /// 
        ///  
        /// 
        [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);
        }
 		 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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