pvNugsSecretManagerNc9Azure 9.0.0

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PvNugs Azure Key Vault Secret Manager

A robust, production-ready Azure Key Vault integration library for .NET applications that provides secure secret management with built-in caching, comprehensive logging, and support for both Managed Identity and Service Principal authentication.

✨ Features

• 🔐 Secure Secret Retrieval: Direct integration with Azure Key Vault for secure secret storage and retrieval
• 🚀 Performance Optimized: Built-in caching layer to minimize API calls and improve response times
• 🔑 Flexible Authentication: Support for both Azure Managed Identity (recommended) and Service Principal authentication
• 📊 Comprehensive Logging: Detailed logging integration with customizable log levels
• ⚡ Async/Await Support: Fully asynchronous operations with cancellation token support
• 🛡️ Exception Handling: Robust error handling with detailed exception information
• 🏗️ Dependency Injection: Seamless integration with .NET's built-in dependency injection container
• 🔧 Configuration Driven: Flexible configuration through .NET's IConfiguration system
• 🧪 Thread Safe: Designed for concurrent access in multi-threaded applications

📦 Installation

Install the package via NuGet Package Manager:

bash
dotnet add package pvNugsSecretManagerNc9Azure

Or via Package Manager Console:

powershell
Install-Package pvNugsSecretManagerNc9Azure

🔧 Dependencies

This package requires the following companion packages:

bash
# Cache provider (required)
dotnet add package pvNugsCacheNc9Local

# Logger service (required)
dotnet add package pvNugsLoggerNc9Seri

🚀 Quick Start

1. Configuration Setup

Using Managed Identity (Recommended for Azure environments)

appsettings.json:

json
{
"PvNugsAzureSecretManagerConfig": {
"KeyVaultUrl": "https://your-keyvault.vault.azure.net/"
}
}

Using Service Principal (for local development or non-Azure environments)

appsettings.json:

json
{
  "PvNugsAzureSecretManagerConfig": {
  "KeyVaultUrl": "https://your-keyvault.vault.azure.net/",
  "Credential": {
    "TenantId": "12345678-1234-1234-1234-123456789012",
    "ClientId": "87654321-4321-4321-4321-210987654321",
    "ClientSecret": "your-client-secret-here"
    }
  }
}

2. Service Registration

Program.cs:

csharp
using pvNugsSecretManagerNc9Azure;
using pvNugsCacheNc9Local;
using pvNugsLoggerNc9Seri;

var builder = WebApplication.CreateBuilder(args);

// Register dependencies
builder.Services.TryAddPvNugsCacheNc9Local(builder.Configuration);
builder.Services.TryAddPvNugsLoggerSeriService(builder.Configuration);

// Register Azure Key Vault secret manager
builder.Services.TryAddPvNugsAzureStaticSecretManager(builder.Configuration);

var app = builder.Build();

3. Usage in Your Application

csharp
using pvNugsSecretManagerNc9Abstractions;

public class DatabaseService
{
private readonly IPvNugsStaticSecretManager _secretManager;

    public DatabaseService(IPvNugsStaticSecretManager secretManager)
    {
        _secretManager = secretManager;
    }
    
    public async Task<string> GetConnectionStringAsync()
    {
        var password = await _secretManager.GetStaticSecretAsync("database-password");
        
        if (password == null)
            throw new InvalidOperationException("Database password not found");
            
        return $"Server=myserver;Database=mydb;Password={password};";
    }
}

🔐 Authentication Methods

Managed Identity (Recommended)

For applications running in Azure (App Service, Functions, VMs, etc.), use Managed Identity for secure, keyless authentication:

json
{
  "PvNugsAzureSecretManagerConfig": {
  "KeyVaultUrl": "https://your-keyvault.vault.azure.net/",
    "Credential": null
  }
}

Benefits:

• No credentials to manage or rotate
• Automatic credential management by Azure
• Enhanced security posture
• Simplified deployment process

Service Principal

For local development, testing, or non-Azure environments:

json
{
  "PvNugsAzureSecretManagerConfig": {
    "KeyVaultUrl": "https://your-keyvault.vault.azure.net/",
    "Credential": {
      "TenantId": "your-tenant-id",
      "ClientId": "your-client-id",
      "ClientSecret": "your-client-secret"
    }
  }
}

🎯 Advanced Usage Examples

Error Handling with Retry Logic

csharp
public async Task<string> GetSecretWithRetryAsync(string secretName, int maxRetries = 3)
{
for (int attempt = 1; attempt <= maxRetries; attempt++)
{
try
{
var secret = await _secretManager.GetStaticSecretAsync(secretName);
return secret ?? throw new SecretNotFoundException($"Secret '{secretName}' not found");
}
catch (PvNugsStaticSecretManagerException ex) when (IsTransientError(ex) && attempt < maxRetries)
{
var delay = TimeSpan.FromSeconds(Math.Pow(2, attempt)); // Exponential backoff
_logger.LogWarning(ex, "Transient error on attempt {Attempt}, retrying in {Delay}ms",
attempt, delay.TotalMilliseconds);
await Task.Delay(delay);
}
}
throw new InvalidOperationException($"Failed to retrieve secret after {maxRetries} attempts");
}

private static bool IsTransientError(PvNugsStaticSecretManagerException ex)
{
return ex.InnerException is HttpRequestException or TimeoutException;
}

Batch Secret Retrieval

csharp
public async Task<Dictionary<string, string>> GetMultipleSecretsAsync(
string[] secretNames,
CancellationToken cancellationToken = default)
{
var tasks = secretNames.Select(async name => new
{
Name = name,
Value = await _secretManager.GetStaticSecretAsync(name, cancellationToken)
});

    var results = await Task.WhenAll(tasks);
    
    return results
        .Where(r => r.Value != null)
        .ToDictionary(r => r.Name, r => r.Value!);
}

Environment-Specific Configuration

// Program.cs - Different configuration per environment
if (builder.Environment.IsDevelopment())
{
    // Local development with service principal
    builder.Services.Configure<PvNugsAzureSecretManagerConfig>(options =>
    {
        options.KeyVaultUrl = "https://dev-keyvault.vault.azure.net/";
        options.Credential = new PvNugsAzureServicePrincipalCredential
        {
            TenantId = builder.Configuration["AzureAd:TenantId"]!,
            ClientId = builder.Configuration["AzureAd:ClientId"]!,
            ClientSecret = builder.Configuration["AzureAd:ClientSecret"]!
        };
    });
}
else
{
    // Production with managed identity
    builder.Services.Configure<PvNugsAzureSecretManagerConfig>(options =>
    {
        options.KeyVaultUrl = builder.Configuration["KeyVault:ProductionUrl"]!;
        options.Credential = null; // Use managed identity
    });
}

builder.Services.TryAddPvNugsAzureStaticSecretManager(builder.Configuration);

🔧 Configuration Options

*Required only when using Service Principal authentication

🛡️ Security Best Practices

1. Use Managed Identity in Production: Always prefer Managed Identity over Service Principal in Azure environments
2. Secure Secret Storage: Store service principal credentials securely (Key Vault, environment variables, etc.)
3. Regular Credential Rotation: Implement regular rotation for service principal secrets
4. Principle of Least Privilege: Grant minimal required permissions to Key Vault
5. Network Security: Use Key Vault firewall and private endpoints when possible
6. Audit Logging: Enable Key Vault audit logging for compliance and monitoring

📊 Performance Characteristics

• Cache Hit Response Time: < 1ms (in-memory cache)
• Cache Miss Response Time: 100-500ms (depends on network latency to Azure)
• Concurrent Request Support: Unlimited (thread-safe singleton pattern)
• Memory Footprint: Minimal (lazy-loaded client, efficient caching)

🐛 Troubleshooting

Common Issues and Solutions

Authentication Errors (401/403)

PvNugsStaticSecretManagerException: Unauthorized

Solutions:

• Verify Key Vault access policies or RBAC permissions
• Check service principal credentials if using Service Principal auth
• Ensure Managed Identity is enabled and properly configured

Secret Not Found (404)

PvNugsStaticSecretManagerException: Secret not found

Solutions:

• Verify the secret exists in the specified Key Vault
• Check secret name spelling and casing
• Ensure the secret is not disabled or expired

Network Connectivity Issues

PvNugsStaticSecretManagerException: Network error

Solutions:

• Check network connectivity to Azure
• Verify Key Vault URL is correct and accessible
• Check firewall and network security group rules

📚 API Reference

IPvNugsStaticSecretManager

public interface IPvNugsStaticSecretManager
{
    Task<string?> GetStaticSecretAsync(string secretName, CancellationToken cancellationToken = default);
}

PvNugsStaticSecretManagerException

Custom exception thrown for all secret management errors, wrapping underlying Azure SDK exceptions while preserving original error details.

🤝 Contributing

We welcome contributions! Please see our Contributing Guidelines for details.

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🔗 Related Packages

• pvNugsCacheNc9Local - Local caching provider
• pvNugsLoggerNc9Seri - Serilog-based logging provider
• pvNugsSecretManagerNc9Abstractions - Core abstractions and interfaces

📞 Support

• 📖 Documentation: Wiki
• 🐛 Bug Reports: Issues
• 💡 Feature Requests: Discussions
• 📧 Email Support: Contact Us

Made with ❤️ by the PvNugs Team

Secure your secrets with confidence! 🔐