Fix AcquireCredentialHandle parameter lifetime (#113540)

* Fix lifetime of data passed to native code during SslStream handshake on Windows.

* Remove unnecessary init

* Fix init

Author: rzikm

src/libraries/System.Net.Security/src/System/Net/Security/SslStreamPal.Windows.cs

@@ -353,10 +353,11 @@ public static unsafe SafeFreeCredentials AcquireCredentialsHandleSchannelCred(Ss
                 secureCredential.dwSessionLifespan = -1;
             }
 
+            Interop.Crypt32.CERT_CONTEXT* certificateHandle;
             if (certificate != null)
             {
                 secureCredential.cCreds = 1;
-                Interop.Crypt32.CERT_CONTEXT* certificateHandle = (Interop.Crypt32.CERT_CONTEXT*)certificate.Handle;
+                certificateHandle = (Interop.Crypt32.CERT_CONTEXT*)certificate.Handle;
                 secureCredential.paCred = &certificateHandle;
             }
 
@@ -434,19 +435,21 @@ public static unsafe SafeFreeCredentials AcquireCredentialsHandleSchCredentials(
                 credential.dwSessionLifespan = -1;
             }
 
+            Interop.Crypt32.CERT_CONTEXT* certificateHandle;
             if (certificate != null)
             {
                 credential.cCreds = 1;
-                Interop.Crypt32.CERT_CONTEXT* certificateHandle = (Interop.Crypt32.CERT_CONTEXT*)certificate.Handle;
+                certificateHandle = (Interop.Crypt32.CERT_CONTEXT*)certificate.Handle;
                 credential.paCred = &certificateHandle;
             }
 
             if (NetEventSource.Log.IsEnabled()) NetEventSource.Info($"flags=({flags}), ProtocolFlags=({protocolFlags}), EncryptionPolicy={policy}");
 
+            Interop.SspiCli.TLS_PARAMETERS tlsParameters;
             if (protocolFlags != 0)
             {
                 // If we were asked to do specific protocol we need to fill TLS_PARAMETERS.
-                Interop.SspiCli.TLS_PARAMETERS tlsParameters = default;
+                tlsParameters = default;
                 tlsParameters.grbitDisabledProtocols = (uint)protocolFlags ^ uint.MaxValue;
 
                 credential.cTlsParameters = 1;