// // Acquire Server Side Certificate information and set it on the class. // private bool AcquireServerCredentials(ref byte[] thumbPrint) { GlobalLog.Enter("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireServerCredentials"); X509Certificate localCertificate = null; bool cachedCred = false; if (_certSelectionDelegate != null) { X509CertificateCollection tempCollection = new X509CertificateCollection(); tempCollection.Add(_serverCertificate); localCertificate = _certSelectionDelegate(string.Empty, tempCollection, null, Array.Empty <string>()); GlobalLog.Print("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireServerCredentials() Use delegate selected Cert"); } else { localCertificate = _serverCertificate; } if (localCertificate == null) { throw new NotSupportedException(SR.net_ssl_io_no_server_cert); } // SECURITY: Accessing X509 cert Credential is disabled for semitrust. // We no longer need to demand for unmanaged code permissions. // EnsurePrivateKey should do the right demand for us. X509Certificate2 selectedCert = EnsurePrivateKey(localCertificate); if (selectedCert == null) { throw new NotSupportedException(SR.net_ssl_io_no_server_cert); } GlobalLog.Assert(localCertificate.Equals(selectedCert), "AcquireServerCredentials()|'selectedCert' does not match 'localCertificate'."); // // Note selectedCert is a safe ref possibly cloned from the user passed Cert object // byte[] guessedThumbPrint = selectedCert.GetCertHash(); try { SafeFreeCredentials cachedCredentialHandle = SslSessionsCache.TryCachedCredential(guessedThumbPrint, _sslProtocols, _serverMode, _encryptionPolicy); if (cachedCredentialHandle != null) { _credentialsHandle = cachedCredentialHandle; _serverCertificate = localCertificate; cachedCred = true; } else { _credentialsHandle = SslStreamPal.AcquireCredentialsHandle(selectedCert, _sslProtocols, _encryptionPolicy, _serverMode); thumbPrint = guessedThumbPrint; _serverCertificate = localCertificate; } } finally { // An extra cert could have been created, dispose it now. if ((object)localCertificate != (object)selectedCert) { selectedCert.Dispose(); } } GlobalLog.Leave("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireServerCredentials, cachedCreds = " + cachedCred.ToString(), LoggingHash.ObjectToString(_credentialsHandle)); return(cachedCred); }
//------------------------------------------------------------------- internal unsafe static int AcceptSecurityContext( ref SafeFreeCredentials inCredentials, ref SafeDeleteContext refContext, Interop.Secur32.ContextFlags inFlags, Interop.Secur32.Endianness endianness, SecurityBuffer inSecBuffer, SecurityBuffer[] inSecBuffers, SecurityBuffer outSecBuffer, ref Interop.Secur32.ContextFlags outFlags) { #if TRACE_VERBOSE GlobalLog.Enter("SafeDeleteContext::AcceptSecurityContex"); GlobalLog.Print(" credential = " + inCredentials.ToString()); GlobalLog.Print(" refContext = " + LoggingHash.ObjectToString(refContext)); GlobalLog.Print(" inFlags = " + inFlags); if (inSecBuffers == null) { GlobalLog.Print(" inSecBuffers = (null)"); } else { GlobalLog.Print(" inSecBuffers[] = length:" + inSecBuffers.Length); } #endif GlobalLog.Assert(outSecBuffer != null, "SafeDeleteContext::AcceptSecurityContext()|outSecBuffer != null"); GlobalLog.Assert(inSecBuffer == null || inSecBuffers == null, "SafeDeleteContext::AcceptSecurityContext()|inSecBuffer == null || inSecBuffers == null"); if (inCredentials == null) { throw new ArgumentNullException("inCredentials"); } Interop.Secur32.SecurityBufferDescriptor inSecurityBufferDescriptor = null; if (inSecBuffer != null) { inSecurityBufferDescriptor = new Interop.Secur32.SecurityBufferDescriptor(1); } else if (inSecBuffers != null) { inSecurityBufferDescriptor = new Interop.Secur32.SecurityBufferDescriptor(inSecBuffers.Length); } Interop.Secur32.SecurityBufferDescriptor outSecurityBufferDescriptor = new Interop.Secur32.SecurityBufferDescriptor(1); // Actually, this is returned in outFlags. bool isSspiAllocated = (inFlags & Interop.Secur32.ContextFlags.AllocateMemory) != 0 ? true : false; int errorCode = -1; Interop.Secur32.SSPIHandle contextHandle = new Interop.Secur32.SSPIHandle(); if (refContext != null) { contextHandle = refContext._handle; } // These are pinned user byte arrays passed along with SecurityBuffers. GCHandle[] pinnedInBytes = null; GCHandle pinnedOutBytes = new GCHandle(); // Optional output buffer that may need to be freed. SafeFreeContextBuffer outFreeContextBuffer = null; try { pinnedOutBytes = GCHandle.Alloc(outSecBuffer.token, GCHandleType.Pinned); var inUnmanagedBuffer = new Interop.Secur32.SecurityBufferStruct[inSecurityBufferDescriptor == null ? 1 : inSecurityBufferDescriptor.Count]; fixed(void *inUnmanagedBufferPtr = inUnmanagedBuffer) { if (inSecurityBufferDescriptor != null) { // Fix Descriptor pointer that points to unmanaged SecurityBuffers. inSecurityBufferDescriptor.UnmanagedPointer = inUnmanagedBufferPtr; pinnedInBytes = new GCHandle[inSecurityBufferDescriptor.Count]; SecurityBuffer securityBuffer; for (int index = 0; index < inSecurityBufferDescriptor.Count; ++index) { securityBuffer = inSecBuffer != null ? inSecBuffer : inSecBuffers[index]; if (securityBuffer != null) { // Copy the SecurityBuffer content into unmanaged place holder. inUnmanagedBuffer[index].count = securityBuffer.size; inUnmanagedBuffer[index].type = securityBuffer.type; // Use the unmanaged token if it's not null; otherwise use the managed buffer. if (securityBuffer.unmanagedToken != null) { inUnmanagedBuffer[index].token = securityBuffer.unmanagedToken.DangerousGetHandle(); } else if (securityBuffer.token == null || securityBuffer.token.Length == 0) { inUnmanagedBuffer[index].token = IntPtr.Zero; } else { pinnedInBytes[index] = GCHandle.Alloc(securityBuffer.token, GCHandleType.Pinned); inUnmanagedBuffer[index].token = Marshal.UnsafeAddrOfPinnedArrayElement(securityBuffer.token, securityBuffer.offset); } #if TRACE_VERBOSE GlobalLog.Print("SecBuffer: cbBuffer:" + securityBuffer.size + " BufferType:" + securityBuffer.type); #endif } } } var outUnmanagedBuffer = new Interop.Secur32.SecurityBufferStruct[1]; fixed(void *outUnmanagedBufferPtr = outUnmanagedBuffer) { // Fix Descriptor pointer that points to unmanaged SecurityBuffers. outSecurityBufferDescriptor.UnmanagedPointer = outUnmanagedBufferPtr; // Copy the SecurityBuffer content into unmanaged place holder. outUnmanagedBuffer[0].count = outSecBuffer.size; outUnmanagedBuffer[0].type = outSecBuffer.type; if (outSecBuffer.token == null || outSecBuffer.token.Length == 0) { outUnmanagedBuffer[0].token = IntPtr.Zero; } else { outUnmanagedBuffer[0].token = Marshal.UnsafeAddrOfPinnedArrayElement(outSecBuffer.token, outSecBuffer.offset); } if (isSspiAllocated) { outFreeContextBuffer = SafeFreeContextBuffer.CreateEmptyHandle(); } if (refContext == null || refContext.IsInvalid) { refContext = new SafeDeleteContext_SECURITY(); } errorCode = MustRunAcceptSecurityContext_SECURITY( ref inCredentials, contextHandle.IsZero ? null : &contextHandle, inSecurityBufferDescriptor, inFlags, endianness, refContext, outSecurityBufferDescriptor, ref outFlags, outFreeContextBuffer); GlobalLog.Print("SafeDeleteContext:AcceptSecurityContext Marshalling OUT buffer"); // Get unmanaged buffer with index 0 as the only one passed into PInvoke. outSecBuffer.size = outUnmanagedBuffer[0].count; outSecBuffer.type = outUnmanagedBuffer[0].type; if (outSecBuffer.size > 0) { outSecBuffer.token = new byte[outSecBuffer.size]; Marshal.Copy(outUnmanagedBuffer[0].token, outSecBuffer.token, 0, outSecBuffer.size); } else { outSecBuffer.token = null; } } } } finally { if (pinnedInBytes != null) { for (int index = 0; index < pinnedInBytes.Length; index++) { if (pinnedInBytes[index].IsAllocated) { pinnedInBytes[index].Free(); } } } if (pinnedOutBytes.IsAllocated) { pinnedOutBytes.Free(); } if (outFreeContextBuffer != null) { outFreeContextBuffer.Dispose(); } } GlobalLog.Leave("SafeDeleteContext::AcceptSecurityContex() unmanaged AcceptSecurityContex()", "errorCode:0x" + errorCode.ToString("x8") + " refContext:" + LoggingHash.ObjectToString(refContext)); return(errorCode); }
/*++ * AcquireCredentials - Attempts to find Client Credential * Information, that can be sent to the server. In our case, * this is only Client Certificates, that we have Credential Info. * * How it works: * case 0: Cert Selection delegate is present * Always use its result as the client cert answer. * Try to use cached credential handle whenever feasible. * Do not use cached anonymous creds if the delegate has returned null * and the collection is not empty (allow responding with the cert later). * * case 1: Certs collection is empty * Always use the same statically acquired anonymous SSL Credential * * case 2: Before our Connection with the Server * If we have a cached credential handle keyed by first X509Certificate **content** in the passed collection, then we use that cached * credential and hoping to restart a session. * * Otherwise create a new anonymous (allow responding with the cert later). * * case 3: After our Connection with the Server (i.e. during handshake or re-handshake) * The server has requested that we send it a Certificate then * we Enumerate a list of server sent Issuers trying to match against * our list of Certificates, the first match is sent to the server. * * Once we got a cert we again try to match cached credential handle if possible. * This will not restart a session but helps minimizing the number of handles we create. * * In the case of an error getting a Certificate or checking its private Key we fall back * to the behavior of having no certs, case 1. * * Returns: True if cached creds were used, false otherwise. * * --*/ private bool AcquireClientCredentials(ref byte[] thumbPrint) { GlobalLog.Enter("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials"); // Acquire possible Client Certificate information and set it on the handle. X509Certificate clientCertificate = null; // This is a candidate that can come from the user callback or be guessed when targeting a session restart. ArrayList filteredCerts = new ArrayList(); // This is an intermediate client certs collection that try to use if no selectedCert is available yet. string[] issuers = null; // This is a list of issuers sent by the server, only valid is we do know what the server cert is. bool sessionRestartAttempt = false; // If true and no cached creds we will use anonymous creds. if (_certSelectionDelegate != null) { issuers = GetRequestCertificateAuthorities(); GlobalLog.Print("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials() calling CertificateSelectionCallback"); X509Certificate2 remoteCert = null; try { X509Certificate2Collection dummyCollection; remoteCert = CertificateValidationPal.GetRemoteCertificate(_securityContext, out dummyCollection); clientCertificate = _certSelectionDelegate(_hostName, ClientCertificates, remoteCert, issuers); } finally { if (remoteCert != null) { remoteCert.Dispose(); } } if (clientCertificate != null) { if (_credentialsHandle == null) { sessionRestartAttempt = true; } filteredCerts.Add(clientCertificate); if (SecurityEventSource.Log.IsEnabled()) { SecurityEventSource.Log.CertificateFromDelegate(LoggingHash.HashInt(this)); } } else { if (ClientCertificates.Count == 0) { if (SecurityEventSource.Log.IsEnabled()) { SecurityEventSource.Log.NoDelegateNoClientCert(LoggingHash.HashInt(this)); } sessionRestartAttempt = true; } else { if (SecurityEventSource.Log.IsEnabled()) { SecurityEventSource.Log.NoDelegateButClientCert(LoggingHash.HashInt(this)); } } } } else if (_credentialsHandle == null && _clientCertificates != null && _clientCertificates.Count > 0) { // This is where we attempt to restart a session by picking the FIRST cert from the collection. // Otherwise it is either server sending a client cert request or the session is renegotiated. clientCertificate = ClientCertificates[0]; sessionRestartAttempt = true; if (clientCertificate != null) { filteredCerts.Add(clientCertificate); } if (SecurityEventSource.Log.IsEnabled()) { SecurityEventSource.Log.AttemptingRestartUsingCert(clientCertificate == null ? "null" : clientCertificate.ToString(true), LoggingHash.HashInt(this)); } } else if (_clientCertificates != null && _clientCertificates.Count > 0) { // // This should be a server request for the client cert sent over currently anonymous sessions. // issuers = GetRequestCertificateAuthorities(); if (SecurityEventSource.Log.IsEnabled()) { if (issuers == null || issuers.Length == 0) { SecurityEventSource.Log.NoIssuersTryAllCerts(LoggingHash.HashInt(this)); } else { SecurityEventSource.Log.LookForMatchingCerts(issuers.Length, LoggingHash.HashInt(this)); } } for (int i = 0; i < _clientCertificates.Count; ++i) { // // Make sure we add only if the cert matches one of the issuers. // If no issuers were sent and then try all client certs starting with the first one. // if (issuers != null && issuers.Length != 0) { X509Certificate2 certificateEx = null; X509Chain chain = null; try { certificateEx = MakeEx(_clientCertificates[i]); if (certificateEx == null) { continue; } GlobalLog.Print("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials() root cert:" + certificateEx.Issuer); chain = new X509Chain(); chain.ChainPolicy.RevocationMode = X509RevocationMode.NoCheck; chain.ChainPolicy.VerificationFlags = X509VerificationFlags.IgnoreInvalidName; chain.Build(certificateEx); bool found = false; // // We ignore any errors happened with chain. // if (chain.ChainElements.Count > 0) { for (int ii = 0; ii < chain.ChainElements.Count; ++ii) { string issuer = chain.ChainElements[ii].Certificate.Issuer; found = Array.IndexOf(issuers, issuer) != -1; if (found) { GlobalLog.Print("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials() matched:" + issuer); break; } GlobalLog.Print("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials() no match:" + issuer); } } if (!found) { continue; } } finally { if (chain != null) { chain.Dispose(); } if (certificateEx != null && (object)certificateEx != (object)_clientCertificates[i]) { certificateEx.Dispose(); } } } if (SecurityEventSource.Log.IsEnabled()) { SecurityEventSource.Log.SelectedCert(_clientCertificates[i].ToString(true), LoggingHash.HashInt(this)); } filteredCerts.Add(_clientCertificates[i]); } } bool cachedCred = false; // This is a return result from this method. X509Certificate2 selectedCert = null; // This is a final selected cert (ensured that it does have private key with it). clientCertificate = null; if (SecurityEventSource.Log.IsEnabled()) { SecurityEventSource.Log.CertsAfterFiltering(filteredCerts.Count, LoggingHash.HashInt(this)); if (filteredCerts.Count != 0) { SecurityEventSource.Log.FindingMatchingCerts(LoggingHash.HashInt(this)); } } // // ATTN: When the client cert was returned by the user callback OR it was guessed AND it has no private key, // THEN anonymous (no client cert) credential will be used. // // SECURITY: Accessing X509 cert Credential is disabled for semitrust. // We no longer need to demand for unmanaged code permissions. // EnsurePrivateKey should do the right demand for us. for (int i = 0; i < filteredCerts.Count; ++i) { clientCertificate = filteredCerts[i] as X509Certificate; if ((selectedCert = EnsurePrivateKey(clientCertificate)) != null) { break; } clientCertificate = null; selectedCert = null; } GlobalLog.Assert(((object)clientCertificate == (object)selectedCert) || clientCertificate.Equals(selectedCert), "AcquireClientCredentials()|'selectedCert' does not match 'clientCertificate'."); GlobalLog.Print("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials() Selected Cert = " + (selectedCert == null ? "null" : selectedCert.Subject)); try { // Try to locate cached creds first. // // SECURITY: selectedCert ref if not null is a safe object that does not depend on possible **user** inherited X509Certificate type. // byte[] guessedThumbPrint = selectedCert == null ? null : selectedCert.GetCertHash(); SafeFreeCredentials cachedCredentialHandle = SslSessionsCache.TryCachedCredential(guessedThumbPrint, _sslProtocols, _serverMode, _encryptionPolicy); // We can probably do some optimization here. If the selectedCert is returned by the delegate // we can always go ahead and use the certificate to create our credential // (instead of going anonymous as we do here). if (sessionRestartAttempt && cachedCredentialHandle == null && selectedCert != null) { GlobalLog.Print("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials() Reset to anonymous session."); // IIS does not renegotiate a restarted session if client cert is needed. // So we don't want to reuse **anonymous** cached credential for a new SSL connection if the client has passed some certificate. // The following block happens if client did specify a certificate but no cached creds were found in the cache. // Since we don't restart a session the server side can still challenge for a client cert. if ((object)clientCertificate != (object)selectedCert) { selectedCert.Dispose(); } guessedThumbPrint = null; selectedCert = null; clientCertificate = null; } if (cachedCredentialHandle != null) { if (SecurityEventSource.Log.IsEnabled()) { SecurityEventSource.Log.UsingCachedCredential(LoggingHash.HashInt(this)); } _credentialsHandle = cachedCredentialHandle; _selectedClientCertificate = clientCertificate; cachedCred = true; } else { _credentialsHandle = SslStreamPal.AcquireCredentialsHandle(selectedCert, _sslProtocols, _encryptionPolicy, _serverMode); thumbPrint = guessedThumbPrint; // Delay until here in case something above threw. _selectedClientCertificate = clientCertificate; } } finally { // An extra cert could have been created, dispose it now. if (selectedCert != null && (object)clientCertificate != (object)selectedCert) { selectedCert.Dispose(); } } GlobalLog.Leave("SecureChannel#" + LoggingHash.HashString(this) + "::AcquireClientCredentials, cachedCreds = " + cachedCred.ToString(), LoggingHash.ObjectToString(_credentialsHandle)); return(cachedCred); }
internal unsafe static int CompleteAuthToken( ref SafeDeleteContext refContext, SecurityBuffer[] inSecBuffers) { GlobalLog.Enter("SafeDeleteContext::CompleteAuthToken"); GlobalLog.Print(" refContext = " + LoggingHash.ObjectToString(refContext)); #if TRACE_VERBOSE GlobalLog.Print(" inSecBuffers[] = length:" + inSecBuffers.Length); #endif GlobalLog.Assert(inSecBuffers != null, "SafeDeleteContext::CompleteAuthToken()|inSecBuffers == null"); var inSecurityBufferDescriptor = new Interop.Secur32.SecurityBufferDescriptor(inSecBuffers.Length); int errorCode = (int)Interop.SecurityStatus.InvalidHandle; // These are pinned user byte arrays passed along with SecurityBuffers. GCHandle[] pinnedInBytes = null; var inUnmanagedBuffer = new Interop.Secur32.SecurityBufferStruct[inSecurityBufferDescriptor.Count]; fixed(void *inUnmanagedBufferPtr = inUnmanagedBuffer) { // Fix Descriptor pointer that points to unmanaged SecurityBuffers. inSecurityBufferDescriptor.UnmanagedPointer = inUnmanagedBufferPtr; pinnedInBytes = new GCHandle[inSecurityBufferDescriptor.Count]; SecurityBuffer securityBuffer; for (int index = 0; index < inSecurityBufferDescriptor.Count; ++index) { securityBuffer = inSecBuffers[index]; if (securityBuffer != null) { inUnmanagedBuffer[index].count = securityBuffer.size; inUnmanagedBuffer[index].type = securityBuffer.type; // Use the unmanaged token if it's not null; otherwise use the managed buffer. if (securityBuffer.unmanagedToken != null) { inUnmanagedBuffer[index].token = securityBuffer.unmanagedToken.DangerousGetHandle(); } else if (securityBuffer.token == null || securityBuffer.token.Length == 0) { inUnmanagedBuffer[index].token = IntPtr.Zero; } else { pinnedInBytes[index] = GCHandle.Alloc(securityBuffer.token, GCHandleType.Pinned); inUnmanagedBuffer[index].token = Marshal.UnsafeAddrOfPinnedArrayElement(securityBuffer.token, securityBuffer.offset); } #if TRACE_VERBOSE GlobalLog.Print("SecBuffer: cbBuffer:" + securityBuffer.size + " BufferType:" + securityBuffer.type); #endif } } Interop.Secur32.SSPIHandle contextHandle = new Interop.Secur32.SSPIHandle(); if (refContext != null) { contextHandle = refContext._handle; } try { if (refContext == null || refContext.IsInvalid) { refContext = new SafeDeleteContext_SECURITY(); } try { bool ignore = false; refContext.DangerousAddRef(ref ignore); errorCode = Interop.Secur32.CompleteAuthToken(contextHandle.IsZero ? null : &contextHandle, inSecurityBufferDescriptor); } finally { refContext.DangerousRelease(); } } finally { if (pinnedInBytes != null) { for (int index = 0; index < pinnedInBytes.Length; index++) { if (pinnedInBytes[index].IsAllocated) { pinnedInBytes[index].Free(); } } } } } GlobalLog.Leave("SafeDeleteContext::CompleteAuthToken() unmanaged CompleteAuthToken()", "errorCode:0x" + errorCode.ToString("x8") + " refContext:" + LoggingHash.ObjectToString(refContext)); return(errorCode); }