When building software in C# and .NET we need to create secure codes to make sure that the software is running well. Here are some keys steps to implement secure code:
- Input validation. Always validate user input to prevent attacks like SQL injection and cross-site scripting (XSS).
using System.Text.RegularExpressions;
string userInput = GetUserInput();
if (!Regex.IsMatch(userInput, @"^[a-zA-Z0-9]*$"))
{
throw new ArgumentException("Invalid input");
}
- Use Parameterized Queries: When accessing a database, use parameterized queries to prevent SQL injection.
using (SqlConnection connection = new SqlConnection(connectionString))
{
string query = "SELECT * FROM Users WHERE Username = @Username";
SqlCommand command = new SqlCommand(query, connection);
command.Parameters.AddWithValue("@Username", username);
connection.Open();
SqlDataReader reader = command.ExecuteReader();
// ...
}
- Secure password. Store passwords using a strong hashing algorithm like SHA-256 or bcrypt.
using System.Security.Cryptography;
using System.Text;
string password = "YourPassword";
using (SHA256 sha256Hash = SHA256.Create())
{
byte[] bytes = sha256Hash.ComputeHash(Encoding.UTF8.GetBytes(password));
StringBuilder builder = new StringBuilder();
for (int i = 0; i < bytes.Length; i++)
{
builder.Append(bytes[i].ToString("x2"));
}
string hashedPassword = builder.ToString();
}
- always use HTTPS to encrypt data transmitted between the client and server. Configure your application to require HTTPS.
- Authentication and Authorization. Implement robust authentication and authorization mechanisms using frameworks like ASP.NET Identity.
- Handle Exceptions Securely. Avoid displaying detailed error messages to users. Log errors internally and provide generic error messages.
- Regular security audits. Conduct regular security audits and code reviews to identify and fix vulnerabilities.
- Keep dependencies up to date. Regularly update libraries and frameworks to patch known vulnerabilities.
- secure configuration management by using tools like Terraform or Azure Resource Manager (ARM) templates to define and manage cloud resources securely.
- Identity and Access Management (IAM) Use managed identities to secure access to cloud resources without hardcoding credentials.
- Store sensitive information like API keys, connection strings, and certificates in secure vaults such as Azure Key Vault or AWS Secrets Manager.
- Implement network security such as VNET isolation, network security group, and web application firewall