Create azure-ad-sso-service-principal.cs (oracle#333)

Author: alexkeh

samples/azure-active-directory/sso/azure-ad-sso-service-principal.cs

@@ -0,0 +1,71 @@
+//This application demonstrates connecting .NET to Oracle database using Microsoft Entra ID/Azure Active
+// Directory single sign-on (SSO). It uses service principal authentication with either managed ODP.NET or
+// ODP.NET Core 23c or higher.
+
+// ODP.NET Azure AD SSO requires Oracle.ManagedDataAccess.Azure package from NuGet Gallery
+using Oracle.ManagedDataAccess.Azure;
+using Oracle.ManagedDataAccess.Client;
+using System.Security;
+
+//Set your Azure Active Directory parameters below and ODP.NET data source value
+string clientId = "<AZURE AD APP REGISTRATION CLIENT ID>";
+string tenantId = "<AZURE AD TENANT ID>";
+string clientSecret = "<AZURE AD APP REGISTRATION SECRET VALUE>";
+string dbAppIdUri = "<AZURE AD PROTECTED RESOURCE ID>";
+var conn = new OracleConnection("User Id=/;Data Source=<DATA SOURCE>;Connection Timeout=900;");
+
+var secureSecret = new SecureString();
+foreach (char c in clientSecret)
+{
+    secureSecret.AppendChar(c);
+}
+secureSecret.MakeReadOnly();
+
+//Create Azure authentication token object and set its values.
+var tokenConfig = new AzureTokenAuthentication
+{
+    ClientId = clientId,
+    TenantId = tenantId,
+    ClientSecret = secureSecret,
+    DatabaseApplicationIdUri = dbAppIdUri,
+};
+
+//Set token authentication mode to Azure Service Principal and use Azure token authentication
+conn.TokenAuthentication = OracleTokenAuth.AzureServicePrincipal;
+conn.UseAzureTokenAuthentication(tokenConfig);
+
+try
+{
+    conn.Open();
+    Console.WriteLine("Connection opened successfully!");
+    using (OracleCommand cmd = conn.CreateCommand())
+    {
+        //Retrieve authenticated identity value from database
+        cmd.CommandText = "SELECT SYS_CONTEXT('USERENV', 'AUTHENTICATED_IDENTITY') FROM DUAL";
+        Console.WriteLine($"Authenticated identity: {cmd.ExecuteScalar().ToString()}");
+    }
+}
+catch (Exception ex)
+{
+    Console.WriteLine("Error: " + ex.Message);
+}
+conn.Dispose();
+
+/* Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved. */
+
+/******************************************************************************
+ *
+ * You may not use the identified files except in compliance with The MIT
+ * License (the "License.")
+ *
+ * You may obtain a copy of the License at
+ * https://github.com/oracle/dotnet-db-samples/blob/master/LICENSE.txt
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ *****************************************************************************/