Dotnet core Oracle 23c SSL connection not working on Linux environment and works on Windows

The issue you're encountering with SSL/TLS connections in a .NET Core application on Linux, while it works on Windows, is not uncommon. There are several potential reasons for this discrepancy, and here are some steps and considerations to help you troubleshoot and resolve the issue:

1. SSL/TLS Version and Cipher Suites

• Windows and Linux Differences: Windows and Linux might have different default SSL/TLS versions and cipher suites. Ensure that the SSL/TLS version and cipher suites supported by the Oracle 23c server are also supported by the .NET Core runtime on Linux.
• Configuration: You can configure the SSL/TLS protocols and cipher suites in your .NET Core application. For example, you can explicitly set the SSL/TLS version in your code:
  ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls13;
  
  

  2. Certificates

  • Certificate Validation: Ensure that the SSL certificate used by the Oracle 23c server is trusted by the Linux environment. You might need to install the CA certificate in the Linux certificate store.
  • Certificate Chain: Sometimes, the certificate chain might not be fully trusted on Linux. You can use tools like openssl to verify the certificate chain:
    openssl s_client -connect <oracle_server>:<port> -showcerts
    

    3. Oracle Data Provider for .NET (ODP.NET)

    • Driver Version: Ensure you are using the latest version of the Oracle Data Provider for .NET (ODP.NET) that supports .NET Core and Oracle 23c.
    • Configuration: Check the ODP.NET configuration for any platform-specific settings. Sometimes, the TNS_ADMIN environment variable or the tnsnames.ora file might need to be correctly set up on Linux.

    4. Network and Firewall

    • Firewall Rules: Ensure that there are no firewall rules or network policies that might be causing the connection to be reset on Linux.
    • Network Configuration: Verify that the network configuration on Linux allows outbound connections to the Oracle server on the required port.

    5. .NET Core Runtime

    • Runtime Version: Ensure that you are using a compatible version of the .NET Core runtime on Linux. Some versions might have bugs or limitations related to SSL/TLS.
    • Patches and Updates: Make sure your .NET Core runtime is up-to-date with the latest patches.

    6. Environment Variables

    • SSL/TLS Environment Variables: Sometimes, setting specific environment variables can help. For example, you can set the DOTNET_SYSTEM_NET_SECURITY_ENABLESSLV3 or DOTNET_SYSTEM_NET_SECURITY_TLS13 environment variables to control SSL/TLS behavior.

    7. Logging and Diagnostics

    • Enable Detailed Logging: Enable detailed logging in your .NET Core application to get more insights into what might be going wrong. You can enable logging for System.Net.Security to get more details about the SSL/TLS handshake.
    • Oracle Trace: Enable Oracle client tracing to get more details about the connection attempt.

    Example Code to Set SSL/TLS Version:

    using System;
    using System.Net;
    using System.Net.Security;
    using System.Security.Authentication;
    using Oracle.ManagedDataAccess.Client;

    class Program
    {
        static void Main()
        {
            // Set the SSL/TLS version
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls13;

            // Your connection string
            string connectionString = "User Id=your_user;Password=your_password;Data Source=your_tnsname;";

            using (OracleConnection conn = new OracleConnection(connectionString))
            {
                try
                {
                    conn.Open();
                    Console.WriteLine("Connection successful!");
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Connection failed: " + ex.Message);
                }
            }
        }
    }

    
    

    The issue is likely related to differences in SSL/TLS configuration or certificate handling between Windows and Linux. By ensuring that the SSL/TLS versions, cipher suites, and certificates are correctly configured, you should be able to resolve the connection issue on Linux. If the problem persists, consider reaching out to Oracle support or the .NET community for further assistance. https://stylishnamegenerator.in/