Azure Key Vault Key client library for .NET

Azure Key Vault is a cloud service that provides secure storage of keys for encrypting your data. Multiple keys, and multiple versions of the same key, can be kept in the Key Vault. Cryptographic keys in Key Vault are represented as JSON Web Key (JWK) objects.

The Azure Key Vault keys library client supports RSA keys and Elliptic Curve (EC) keys, each with corresponding support in hardware security modules (HSM). It offers operations to create, retrieve, update, delete, purge, backup, restore and list the keys and its versions.

Source code | Package (NuGet) | API reference documentation | Product documentation | Samples

Getting started

Install the package

Install the Azure Key Vault Keys client library for .NET with NuGet:

Install-Package Azure.Security.KeyVault.Keys -IncludePrerelease

Prerequisites

An Azure subscription.
An existing Key Vault. If you need to create a Key Vault, you can use the Azure Portal or Azure CLI.

If you use the Azure CLI, replace <your-resource-group-name> and <your-key-vault-name> with your own, unique names:

az keyvault create --resource-group <your-resource-group-name> --name <your-key-vault-name>

Authenticate the client

In order to interact with the Key Vault service, you'll need to create an instance of the KeyClient class. You would need a vault url and client secret credentials (client id, client secret, tenant id) to instantiate a client object.

Client secret credential authentication is being used in this getting started section but you can find more ways to authenticate with Azure identity.

Create/Get credentials

Use the Azure CLI snippet below to create/get client secret credentials.

Create a service principal and configure its access to Azure resources:

az ad sp create-for-rbac -n <your-application-name> --skip-assignment

Output:

{
    "appId": "generated-app-ID",
    "displayName": "dummy-app-name",
    "name": "http://dummy-app-name",
    "password": "random-password",
    "tenant": "tenant-ID"
}

Use the returned credentials above to set AZURE_CLIENT_ID(appId), AZURE_CLIENT_SECRET(password) and AZURE_TENANT_ID(tenant) environment variables. The following example shows a way to do this in Powershell:

$Env:AZURE_CLIENT_ID="generated-app-ID"
$Env:AZURE_CLIENT_SECRET="random-password"
$Env:AZURE_TENANT_ID="tenant-ID"

Grant the above mentioned application authorization to perform key operations on the key vault:
```
az keyvault set-policy --name <your-key-vault-name> --spn $AZURE_CLIENT_ID --key-permissions backup delete get list create
```
--key-permissions: Accepted values: backup, create, decrypt, delete, encrypt, get, import, list, purge, recover, restore, sign, unwrapKey, update, verify, wrapKey
Use the above mentioned Key Vault name to retrieve details of your Vault which also contains your Key Vault URL:
```
az keyvault show --name <your-key-vault-name> 
```

Create KeyClient

Once you've populated the AZURE_CLIENT_ID, AZURE_CLIENT_SECRET and AZURE_TENANT_ID environment variables and replaced your-vault-url with the above returned URI, you can create the KeyClient:

using Azure.Identity;
using Azure.Security.KeyVault.Keys;

// Create a new key client using the default credential from Azure.Identity
var client = new KeyClient(vaultUri: <your-vault-url>, credential: new DefaultAzureCredential());

// Create a new key using the key client
Key key = await Client.CreateKey("key-name", KeyType.EllipticCurve);

new DefaultAzureCredential(): Uses the environment variables previously set (AZURE_CLIENT_ID, AZURE_CLIENT_SECRET, and AZURE_TENANT_ID).

Key concepts

Keys

Azure Key Vault supports multiple key types and algorithms, and enables the use of Hardware Security Modules (HSM) for high value keys.

Key Client:

A KeyClient providing both synchronous and asynchronous operations exists in the SDK allowing for selection of a client based on an application's use case. Once you've initialized a KeyClient, you can interact with the primary resource types in Key Vault.

Examples

The Azure.Security.KeyVault.Keys package supports synchronous and asynchronous APIs.

The following section provides several code snippets using the above created client, covering some of the most common Azure Key Vault Key service related tasks:

Sync examples

Create a Key
Retrieve a Key
Update an existing Key
Delete a Key
List Keys

Async examples

Create a Key

Create a Key

Create a Key to be stored in the Azure Key Vault. If a key with the same name already exists, then a new version of the key is created.

// Create a key. Note that you can specify the type of key
// i.e. Elliptic curve, Hardware Elliptic Curve, RSA
Key key = client.CreateKey("key-name", KeyType.EllipticCurve);

Console.WriteLine(key.Name);
Console.WriteLine(key.KeyMaterial.KeyType);

// Create a software RSA key
var rsaCreateKey = new RsaKeyCreateOptions("rsa-key-name", hsm: false);
Key rsaKey = client.CreateRsaKey(rsaCreateKey);

Console.WriteLine(rsaKey.Name);
Console.WriteLine(rsaKey.KeyMaterial.KeyType);

// Create a hardware Elliptic Curve key
var echsmkey = new EcKeyCreateOptions("ec-key-name", hsm: true);
Key ecKey = client.CreateEcKey(echsmkey);

Console.WriteLine(ecKey.Name);
Console.WriteLine(ecKey.KeyMaterial.KeyType);

Retrieve a Key

GetKey retrieves a key previously stored in the Key Vault.

Key key = client.GetKey("key-name");

Console.WriteLine(key.Name);
Console.WriteLine(key.KeyMaterial.KeyType);

Update an existing Key

UpdateKey updates a key previously stored in the Key Vault.

Key key = client.CreateKey("key-name", KeyType.EllipticCurve);

// You can specify additional application-specific metadata in the form of tags.
key.Tags["foo"] = "updated tag";

KeyBase updatedKey = client.UpdateKey(key, key.KeyMaterial.KeyOps);

Console.WriteLine(updatedKey.Name);
Console.WriteLine(updatedKey.Version);
Console.WriteLine(updatedKey.Updated);

Delete a Key

DeleteKey deletes a key previously stored in the Key Vault. When soft-delete is not enabled for the Key Vault, this operation permanently deletes the key.

DeletedKey key = client.DeleteKey("key-name");

Console.WriteLine(key.Name);
Console.WriteLine(key.DeletedDate);

List Keys

This example lists all the keys in the specified Key Vault.

IEnumerable<Response<KeyBase>> allKeys = client.GetKeys();

  foreach (Key key in allKeys)
  {
    Console.WriteLine(key.Name);
  }

Async create a Key

Async APIs are identical to their synchronous counterparts. Note that all methods end with Async.

// Create a key of any type
Key key = await client.CreateKeyAsync("key-name", KeyType.EllipticCurve);

Console.WriteLine(key.Name);
Console.WriteLine(key.KeyMaterial.KeyType);

// Create a software RSA key
var rsaCreateKey = new RsaKeyCreateOptions("rsa-key-name", hsm: false);
Key rsaKey = await client.CreateRsaKeyAsync(rsarsaCreateKeyKey);

Console.WriteLine(rsaKey.Name);
Console.WriteLine(rsaKey.KeyMaterial.KeyType);

// Create a hardware Elliptic Curve key
var echsmkey = new EcKeyCreateOptions("ec-key-name", hsm: true);
Key ecKey = await client.CreateEcKeyAsync(echsmkey);

Console.WriteLine(ecKey.Name);
Console.WriteLine(ecKey.KeyMaterial.KeyType);

Troubleshooting

General

When you interact with the Azure Key Vault Key client library using the .NET SDK, errors returned by the service correspond to the same HTTP status codes returned for REST API requests.

For example, if you try to retrieve a Key that doesn't exist in your Key Vault, a 404 error is returned, indicating Not Found.

try
{
  Key key = await Client.GetKeyAsync("some_key");
}
catch (RequestFailedException ex)
{
  System.Console.WriteLine(ex.ToString());
}

You will notice that additional information is logged, like the Client Request ID of the operation.

Message: 
    Azure.RequestFailedException : Service request failed.
    Status: 404 (Not Found) 
Content:
    {"error":{"code":"KeyNotFound","message":"Key not found: some_key"}}
    
Headers:
    Cache-Control: no-cache
    Pragma: no-cache
    Server: Microsoft-IIS/10.0
    x-ms-keyvault-region: westus
    x-ms-request-id: 625f870e-10ea-41e5-8380-282e5cf768f2
    x-ms-keyvault-service-version: 1.1.0.866
    x-ms-keyvault-network-info: addr=131.107.174.199;act_addr_fam=InterNetwork;
    X-AspNet-Version: 4.0.30319
    X-Powered-By: ASP.NET
    Strict-Transport-Security: max-age=31536000;includeSubDomains
    X-Content-Type-Options: nosniff
    Date: Tue, 18 Jun 2019 16:02:11 GMT
    Content-Length: 75
    Content-Type: application/json; charset=utf-8
    Expires: -1

Next steps

Several Key Vault Keys client library samples are available to you in this GitHub repository. These samples provide example code for additional scenarios commonly encountered while working with Key Vault:

HelloWorld.cs and HelloWorldAsync.cs - for working with Azure Key Vault, including:
- Create a key
- Get an existing key
- Update an existing key
- Delete a key
BackupAndRestore.cs and BackupAndRestoreAsync.cs - Contains the code snippets working with Key Vault keys, including:
- Backup and recover a key
GetKeys.cs and GetKeysAsync.cs - Example code for working with Key Vault keys, including:
- Create keys
- List all keys in the Key Vault
- Update keys in the Key Vault
- List versions of a specified key
- Delete keys from the Key Vault
- List deleted keys in the Key Vault

Additional Documentation

For more extensive documentation on Azure Key Vault, see the API reference documentation.
For Secrets client library see Secrets client library.
For Certificates client library see Certificates client library.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

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Readme.md

Readme.md

Azure Key Vault Key client library for .NET

Getting started

Install the package

Prerequisites

Authenticate the client

Create/Get credentials

Create KeyClient

Key concepts

Keys

Key Client:

Examples

Sync examples

Async examples

Create a Key

Retrieve a Key

Update an existing Key

Delete a Key

List Keys

Async create a Key

Troubleshooting

General

Next steps

Additional Documentation

Contributing

Files

Readme.md

Latest commit

History

Readme.md

File metadata and controls

Azure Key Vault Key client library for .NET

Getting started

Install the package

Prerequisites

Authenticate the client

Create/Get credentials

Create KeyClient

Key concepts

Keys

Key Client:

Examples

Sync examples

Async examples

Create a Key

Retrieve a Key

Update an existing Key

Delete a Key

List Keys

Async create a Key

Troubleshooting

General

Next steps

Additional Documentation

Contributing