internal static unsafe SafeFreeCredentials AcquireCredentialsHandle(string package, bool isServer, NetworkCredential credential)
{
SafeSspiAuthDataHandle authData = null;
try
{
Interop.SECURITY_STATUS result = Interop.SspiCli.SspiEncodeStringsAsAuthIdentity(
credential.UserName, credential.Domain,
credential.Password, out authData);
if (result != Interop.SECURITY_STATUS.OK)
{
if (NetEventSource.IsEnabled)
{
NetEventSource.Error(null, StringsHelper.Format(Strings.net_log_operation_failed_with_error, nameof(Interop.SspiCli.SspiEncodeStringsAsAuthIdentity), $"0x{(int)result:X}"));
}
throw new Win32Exception((int)result);
}
return(SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPIAuth,
package, (isServer ? Interop.SspiCli.CredentialUse.SECPKG_CRED_INBOUND : Interop.SspiCli.CredentialUse.SECPKG_CRED_OUTBOUND), ref authData));
}
finally
{
if (authData != null)
{
authData.Dispose();
}
}
}
private SafeFreeCredentials AcquireCredentialsHandle(CredentialUse credUsage, ref SecureCredential secureCredential)
{
SafeFreeCredentials credentials;
try
{
using (WindowsIdentity.Impersonate(IntPtr.Zero))
{
credentials = SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPISecureChannel, "Microsoft Unified Security Protocol Provider", credUsage, secureCredential);
}
}
catch
{
credentials = SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPISecureChannel, "Microsoft Unified Security Protocol Provider", credUsage, secureCredential);
}
return(credentials);
}
//
// Security: we temporarily reset thread token to open the handle under process account.
//
private static SafeFreeCredentials AcquireCredentialsHandle(Interop.SspiCli.CredentialUse credUsage, Interop.SspiCli.SCHANNEL_CRED secureCredential)
{
// First try without impersonation, if it fails, then try the process account.
// I.E. We don't know which account the certificate context was created under.
try
{
//
// For app-compat we want to ensure the credential are accessed under >>process<< account.
//
return(WindowsIdentity.RunImpersonated <SafeFreeCredentials>(SafeAccessTokenHandle.InvalidHandle, () =>
{
return SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPISecureChannel, SecurityPackage, credUsage, secureCredential);
}));
}
catch
{
return(SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPISecureChannel, SecurityPackage, credUsage, secureCredential));
}
}
internal unsafe static SafeFreeCredentials AcquireCredentialsHandle(string package, bool isServer, NetworkCredential credential)
{
SafeSspiAuthDataHandle authData = null;
try
{
Interop.SecurityStatus result = Interop.SspiCli.SspiEncodeStringsAsAuthIdentity(
credential.UserName, credential.Domain,
credential.Password, out authData);
if (result != Interop.SecurityStatus.OK)
{
if (NetEventSource.Log.IsEnabled())
{
NetEventSource.PrintError(
NetEventSource.ComponentType.Security,
SR.Format(
SR.net_log_operation_failed_with_error,
"SspiEncodeStringsAsAuthIdentity()",
String.Format(CultureInfo.CurrentCulture, "0x{0:X}", (int)result)));
}
throw new Win32Exception((int)result);
}
return(SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPIAuth,
package, (isServer ? Interop.SspiCli.CredentialUse.Inbound : Interop.SspiCli.CredentialUse.Outbound), ref authData));
}
finally
{
if (authData != null)
{
authData.Dispose();
}
}
}
//
// Acquire Server Side Certificate information and set it on the class.
//
private bool AcquireServerCredentials(ref byte[] thumbPrint)
{
GlobalLog.Enter("SecureChannel#" + Logging.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#" + Logging.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 = SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPISecureChannel, 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#" + Logging.HashString(this) + "::AcquireServerCredentials, cachedCreds = " + cachedCred.ToString(), Logging.ObjectToString(_credentialsHandle));
return(cachedCred);
}
/*++
* 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#" + Logging.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#" + Logging.HashString(this) + "::AcquireClientCredentials() calling CertificateSelectionCallback");
X509Certificate2 remoteCert = null;
try
{
X509Certificate2Collection dummyCollection;
remoteCert = CertWrapper.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 (Logging.On)
{
Logging.PrintInfo(Logging.Web, this, SR.net_log_got_certificate_from_delegate);
}
}
else
{
if (ClientCertificates.Count == 0)
{
if (Logging.On)
{
Logging.PrintInfo(Logging.Web, this, SR.net_log_no_delegate_and_have_no_client_cert);
}
sessionRestartAttempt = true;
}
else
{
if (Logging.On)
{
Logging.PrintInfo(Logging.Web, this, SR.net_log_no_delegate_but_have_client_cert);
}
}
}
}
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 (Logging.On)
{
Logging.PrintInfo(Logging.Web, this, SR.Format(SR.net_log_attempting_restart_using_cert, (clientCertificate == null ? "null" : clientCertificate.ToString(true))));
}
}
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 (Logging.On)
{
if (issuers == null || issuers.Length == 0)
{
Logging.PrintInfo(Logging.Web, this, SR.net_log_no_issuers_try_all_certs);
}
else
{
Logging.PrintInfo(Logging.Web, this, SR.Format(SR.net_log_server_issuers_look_for_matching_certs, issuers.Length));
}
}
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#" + Logging.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#" + Logging.HashString(this) + "::AcquireClientCredentials() matched:" + issuer);
break;
}
GlobalLog.Print("SecureChannel#" + Logging.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 (Logging.On)
{
Logging.PrintInfo(Logging.Web, this, SR.Format(SR.net_log_selected_cert, _clientCertificates[i].ToString(true)));
}
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 (Logging.On)
{
Logging.PrintInfo(Logging.Web, this, SR.Format(SR.net_log_n_certs_after_filtering, filteredCerts.Count));
if (filteredCerts.Count != 0)
{
Logging.PrintInfo(Logging.Web, this, SR.net_log_finding_matching_certs);
}
}
//
// 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#" + Logging.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#" + Logging.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 (Logging.On)
{
Logging.PrintInfo(Logging.Web, SR.net_log_using_cached_credential);
}
_credentialsHandle = cachedCredentialHandle;
_selectedClientCertificate = clientCertificate;
cachedCred = true;
}
else
{
_credentialsHandle = SSPIWrapper.AcquireCredentialsHandle(GlobalSSPI.SSPISecureChannel, 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#" + Logging.HashString(this) + "::AcquireClientCredentials, cachedCreds = " + cachedCred.ToString(), Logging.ObjectToString(_credentialsHandle));
return(cachedCred);
}
