Azure Key Vault Keys client library for Python

Azure Key Vault allows you to create and store keys in the Key Vault. Azure Key Vault client supports RSA keys and elliptic curve keys, each with corresponding support in hardware security modules (HSM).

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. This library offers operations to create, retrieve, update, delete, purge, backup, restore and list the keys and its versions.

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

Getting started

Install the package

Install the Azure Key Vault Keys client library for Python with pip:

pip install azure-keyvault-keys

Prerequisites

• An Azure subscription.

• Python 2.7, 3.5 or later to use this package.

• An existing Key Vault. If you need to create a Key Vault, you can use the Azure Cloud Shell to create one with this Azure CLI command. 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 for using the DefaultAzureCredential examples in the README. DefaultAzureCredential authentication by providing client secret credentials 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 Cloud Shell 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 credentials returned 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 Bash:

   export AZURE_CLIENT_ID="generated-app-ID"
   export AZURE_CLIENT_SECRET="random-password"
   export AZURE_TENANT_ID="tenant-ID"
  

• Grant the above mentioned application authorization to perform key operations on the keyvault:

  az keyvault set-policy --name <your-key-vault-name> --spn $AZURE_CLIENT_ID --key-permissions backup delete get list set
  

  --key-permissions: Accepted values: backup, delete, get, list, purge, recover, restore, set

• 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 Key client

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 for example "https://myvault.vault.azure.net", you can create the KeyClient:

from azure.identity import DefaultAzureCredential
from azure.keyvault.keys import KeyClient

credential = DefaultAzureCredential()

# Create a new Key client using the default credential
key_client = KeyClient(vault_url=<your-vault-url>, credential=credential)

Key concepts

Key

Azure Key Vault supports multiple key types and algorithms, and enables the use of Hardware Security Modules (HSM) for high value keys. In addition to the key value, the following attributes may be specified:

• enabled: Specifies whether the key is enabled and useable for cryptographic operations.
• not_before: Identifies the time before which the key must not be used for cryptographic operations.
• expires: Identifies the expiration time on or after which the key MUST NOT be used for cryptographic operation.
• created: Indicates when this version of the key was created.
• updated: Indicates when this version of the key was updated.

Key Client:

The Key client performs the interactions with the Azure Key Vault service for getting, setting, updating, deleting,and listing keys and its versions. An asynchronous and synchronous, KeyClient, client exists in the SDK allowing for selection of a client based on an application's use case. Once you've initialized a Key, you can interact with the primary resource types in Key Vault.

Examples

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

• Create a Key
• Retrieve a Key
• Update an existing Key
• Delete a Key
• List Keys
• Asynchronously create a Key
• Asynchronously list Keys

Create a Key

create_rsa_key and create_ec_key create RSA and elliptic curve keys in the vault, respectively. If a key with the same name already exists, a new version of the key is created.

# Create an RSA key
rsa_key = key_client.create_rsa_key("rsa-key-name", hsm=False, size=2048)
print(rsa_key.name)
print(rsa_key.key_material.kty)

# Create an elliptic curve key
ec_key = key_client.create_ec_key("ec-key-name", hsm=False, curve="P-256")
print(ec_key.name)
print(ec_key.key_material.kty)

Retrieve a Key

get_key retrieves a key previously stored in the Key Vault.

key = key_client.get_key("key-name")

print(key.name)
print(key.value)

Update an existing Key

update_key updates a key previously stored in the Key Vault.

# Clients may specify additional application-specific metadata in the form of tags.
tags = {"foo": "updated tag"}

updated_key = key_client.update_key("key-name", tags=tags)

print(updated_key.name)
print(updated_key.version)
print(updated_key.updated)
print(updated_key.tags)

Delete a Key

delete_key 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.

deleted_key = key_client.delete_key("key-name")

print(deleted_key.name)
print(deleted_key.deleted_date)

List keys

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

keys = key_client.list_keys()

for key in keys:
    # the list doesn't include values or versions of the keys
    print(key.name)

Cryptographic operations

CryptographyClient enables cryptographic operations (encrypt/decrypt, wrap/unwrap, sign/verify) using a particular key.

from azure.identity import DefaultAzureCredential
from azure.keyvault.keys import KeyClient
from azure.keyvault.keys.crypto import EncryptionAlgorithm

credential = DefaultAzureCredential()
key_client = KeyClient(vault_url=vault_url, credential=credential)

key = key_client.get_key("my-key")
crypto_client = key_client.get_cryptography_client(key)

result = crypto_client.encrypt(EncryptionAlgorithm.rsa_oaep, plaintext)
crypto_client.decrypt(result.algorithm, result.ciphertext)

See the reference documentation for more information.

Async operations

This library includes a complete async API supported on Python 3.5+. To use it, you must first install an async transport, such as aiohttp. See azure-core documentation for more information.

Asynchronously create a Key

create_rsa_key and create_ec_key create RSA and elliptic curve keys in the vault, respectively. If a key with the same name already exists, a new version of the key is created.

from azure.identity.aio import DefaultAzureCredential
from azure.keyvault.keys.aio import KeyClient

credential = DefaultAzureCredential()
key_client = KeyClient(vault_url=vault_url, credential=credential)

# Create an RSA key
rsa_key = await key_client.create_rsa_key("rsa-key-name", hsm=False, size=2048)
print(rsa_key.name)
print(rsa_key.key_material.kty)

# Create an elliptic curve key
ec_key = await key_client.create_ec_key("ec-key-name", hsm=False, curve="P-256")
print(ec_key.name)
print(ec_key.key_material.kty)

Asynchronously list keys

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

keys = key_client.list_keys()

async for key in keys:
    print(key.name)

Troubleshooting

General

Key Vault clients raise exceptions defined in azure-core. For more detailed infromation about exceptions and how to deal with them, see Azure Core exceptions.

For example, if you try to retrieve a key after it is deleted a 404 error is returned, indicating resource not found. In the following snippet, the error is handled gracefully by catching the exception and displaying additional information about the error.

try:
    key_client.get_key("deleted_key")
except ResourceNotFoundError as e:
    print(e.message)

Output: "Key not found:deleted_key"

Logging

Network trace logging is disabled by default for this library. When enabled, this will be logged at DEBUG level. The logging policy is used to output the HTTP network trace to the configured logger. You can configure logging to print out debugging information to the stdout or write it to a file using the following example:

import sys
import logging

# Create a logger for the 'azure' SDK
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)

# Configure a console output
handler = logging.StreamHandler(stream=sys.stdout)
logger.addHandler(handler)

# Configure a file output
file_handler = logging.FileHandler(filename)
logger.addHandler(file_handler)

# Enable network trace logging. This will be logged at DEBUG level.
# By default, network tracing logging is disabled.
config = KeyClient.create_config(credential, logging_enable=True)
client = KeyClient(url, credential, config=config)

The logger can also be enabled per operation.

key = key_client.get_key("key-name", logging_enable=True)

Next steps

Several KeyVault Python SDK samples are available to you in the SDK's GitHub repository. These samples provide example code for additional scenarios commonly encountered while working with Key Vault:

• test_samples_keys.py and test_samples_keys_async.py - Contains the code snippets working with Key Vault keys.
• hello_world.py and hello_world_async.py - Python code for working with Azure Key Vault, including:
  • Create a key
  • Get an existing key
  • Update an existing key
  • Delete key
• backup_restore_operations.py and backup_restore_operations_async.py - Example code for working with Key Vault keys backup and recovery, including:
  • Create key
  • Backup a key
  • Delete the key
  • Use backed up key bytes to restore the deleted key

Additional Documentation

For more extensive documentation on Azure Key Vault, see the API reference documentation.

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.

Release History

4.0.0b2 (2019-08-06)

Breaking changes:

• Removed azure.core.Configuration from the public API in preparation for a revamped configuration API. Static create_config methods have been renamed _create_config, and will be removed in a future release.
• Removed wrap_key and unwrap_key from KeyClient. These are now available through CryptographyClient.
• This version of the library requires azure-core 1.0.0b2
  • If you later want to revert to a version requiring azure-core 1.0.0b1, of this or another Azure SDK library, you must explicitly install azure-core 1.0.0b1 as well. For example: pip install azure-core==1.0.0b1 azure-keyvault-keys==4.0.0b1

New features:

• Added CryptographyClient, a client for performing cryptographic operations (encrypt/decrypt, wrap/unwrap, sign/verify) with a key.
• Distributed tracing framework OpenCensus is now supported
• Added support for HTTP challenge based authentication, allowing clients to interact with vaults in sovereign clouds.

Other changes:

• Async clients use aiohttp for transport by default. See azure-core documentation for more information about using other transports.

4.0.0b1 (2019-06-28)

Version 4.0.0b1 is the first preview of our efforts to create a user-friendly and Pythonic client library for Azure Key Vault. For more information about preview releases of other Azure SDK libraries, please visit https://aka.ms/azure-sdk-preview1-python.

This library is not a direct replacement for azure-keyvault. Applications using that library would require code changes to use azure-keyvault-keys. This package's documentation and samples demonstrate the new API.

Major changes from azure-keyvault

• Packages scoped by functionality
  • azure-keyvault-keys contains a client for key operations, azure-keyvault-secrets contains a client for secret operations
• Client instances are scoped to vaults (an instance interacts with one vault only)
• Asynchronous API supported on Python 3.5.3+
  • the azure.keyvault.keys.aio namespace contains an async equivalent of the synchronous client in azure.keyvault.keys
• Authentication using azure-identity credentials
  • see this package's documentation , and the Azure Identity documentation for more information

azure-keyvault features not implemented in this release

• Certificate management APIs
• Cryptographic operations, e.g. sign, un/wrap_key, verify, en- and decrypt
• National cloud support. This release supports public global cloud vaults, e.g. https://{vault-name}.vault.azure.net