Azure Key Vault Keys client library for Python

Azure Key Vault helps solve the following problems:

• Cryptographic key management (this library) - create, store, and control access to the keys used to encrypt your data
• Secrets management (azure-keyvault-secrets) - securely store and control access to tokens, passwords, certificates, API keys, and other secrets
• Certificate management (azure-keyvault-certificates) - create, manage, and deploy public and private SSL/TLS certificates

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

• A Key Vault. If you need to create one, you can use the Azure Cloud Shell to create one with this 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>
  

  Output:

  {
      "id": "...",
      "location": "westus2",
      "name": "<your key vault name>",
      "properties": {
          "accessPolicies": [...],
          "createMode": null,
          "enablePurgeProtection": null,
          "enableSoftDelete": null,
          "enabledForDeployment": false,
          "enabledForDiskEncryption": null,
          "enabledForTemplateDeployment": null,
          "networkAcls": null,
          "provisioningState": "Succeeded",
          "sku": { "name": "standard" },
          "tenantId": "...",
          "vaultUri": "https://<your key vault name>.vault.azure.net/"
      },
      "resourceGroup": "<your resource group name>",
      "type": "Microsoft.KeyVault/vaults"
  }
  

  The "vaultUri" property is the vault_url used by KeyClient.

Authenticate the client

To interact with a Key Vault's keys, you'll need an instance of the KeyClient class. Creating one requires a vault url and credential. This document demonstrates using DefaultAzureCredential as the credential, authenticating with a service principal's client id, secret, and tenant id. Other authentication methods are supported. See the azure-identity documentation for more details.

Create a service principal

Use this Azure Cloud Shell snippet to create a service principal:

• 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": "your-application-name",
      "name": "http://your-application-name",
      "password": "random password",
      "tenant": "tenant id"
  }
  

• Use the output 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"
  

• Authorize the service principal to perform key operations in your Key Vault:

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

  Possible key permissions:

  • Key management: backup, delete, get, list, purge, recover, restore, create, update, import
  • Cryptographic operations: decrypt, encrypt, unwrapKey, wrapKey, verify, sign

Create a client

After setting the AZURE_CLIENT_ID, AZURE_CLIENT_SECRET and AZURE_TENANT_ID environment variables, you can create the KeyClient:

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

credential = DefaultAzureCredential()

key_client = KeyClient(vault_url=<your-vault-url>, credential=credential)

Key concepts

With a KeyClient, you can get keys from the vault, create new keys and new versions of existing keys, update key metadata, and delete keys, as shown in the examples below.

Keys

Azure Key Vault can create and store RSA and elliptic curve keys. Both can optionally be protected by hardware security modules (HSMs). Azure Key Vault can also perform cryptographic operations with them. For more information about keys and supported operations and algorithms, see the Key Vault documentation .

Examples

This section contains code snippets covering common tasks:

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

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 that 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 vault.

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

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. If soft-delete is not enabled for the vault, this 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 client's 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("mykey")
crypto_client = key_client.get_cryptography_client(key)

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

See the package documentation for more details of the cryptography API.

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 client's 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 example, if you try to get a key that doesn't exist in the vault, KeyClient raises ResourceNotFoundError:

from azure.core.exceptions import ResourceNotFoundError

key_client.delete_key("my-key")

try:
    key_client.get_key("my-key")
except ResourceNotFoundError as e:
    print(e.message)

Logging

Network trace logging is disabled by default for this library. When enabled, HTTP requests will be logged at DEBUG level using the logging library. You can configure logging to print debugging information to stdout or write it to a file:

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 to log all HTTP requests at DEBUG level
config = KeyClient.create_config(credential, logging_enable=True)
client = KeyClient(vault_url, credential, config=config)

Network trace logging can also be enabled for any single operation:

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

Next steps

Several samples are available in the Azure SDK for Python GitHub repository. These provide example code for additional Key Vault scenarios:

• test_samples_keys.py and test_samples_keys_async.py - code snippets from the library's documentation
• hello_world.py and hello_world_async.py - create/get/update/delete keys
• backup_restore_operations.py and backup_restore_operations_async.py - backup and recover keys

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

4.0.0b3 (2019-09-11)

Breaking changes:

• CryptographyClient methods wrap and unwrap are renamed wrap_key and unwrap_key, respectively.

New features:

• CryptographyClient performs encrypt, verify and wrap operations locally when its key's public material is available (i.e., when it has keys/get permission).

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