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
• Vault administration (azure-keyvault-administration) - role-based access control (RBAC), and vault-level backup and restore options

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

Getting started

Install packages

Install azure-keyvault-keys and azure-identity with pip:

pip install azure-keyvault-keys azure-identity

azure-identity is used for Azure Active Directory authentication as demonstrated below.

Prerequisites

• An Azure subscription

• Python 2.7, 3.5.3, or later

• A Key Vault. If you need to create one, you can use the Azure Cloud Shell to create one with these commands (replace "my-resource-group" and "my-key-vault" with your own, unique names):

  (Optional) if you want a new resource group to hold the Key Vault:

  az group create --name my-resource-group --location westus2
  

  Create the Key Vault:

  az keyvault create --resource-group my-resource-group --name my-key-vault
  

  Output:

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

  The "vaultUri" property is the vault_url used by KeyClient

Authenticate the client

This document demonstrates using DefaultAzureCredential to authenticate as a service principal. However, KeyClient accepts any azure-identity credential. See the azure-identity documentation for more information about other credentials.

Create a service principal (optional)

This Azure Cloud Shell snippet shows how to create a new service principal. Before using it, replace "your-application-name" with a more appropriate name for your service principal.

Create a service principal:

az ad sp create-for-rbac --name http://my-application --skip-assignment

Output:

{
    "appId": "generated app id",
    "displayName": "my-application",
    "name": "http://my-application",
    "password": "random password",
    "tenant": "tenant id"
}

Use the output to set AZURE_CLIENT_ID ("appId" above), AZURE_CLIENT_SECRET ("password" above) and AZURE_TENANT_ID ("tenant" above) 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 my-key-vault --spn $AZURE_CLIENT_ID --key-permissions backup delete get list create update decrypt encrypt

Possible permissions:

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

Create a client

Once the AZURE_CLIENT_ID, AZURE_CLIENT_SECRET and AZURE_TENANT_ID environment variables are set, DefaultAzureCredential will be able to authenticate the KeyClient.

Constructing the client also requires your vault's URL, which you can get from the Azure CLI or the Azure Portal. In the Azure Portal, this URL is the vault's "DNS Name".

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

credential = DefaultAzureCredential()

key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)

Key concepts

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.

KeyClient can create keys in the vault, get existing keys from the vault, update key metadata, and delete keys, as shown in the examples below.

Examples

This section contains code snippets covering common tasks:

• Create a Key
• Retrieve a Key
• Update an existing Key
• Delete a Key
• List Keys
• Perform cryptographic operations
• 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 that key is created.

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

credential = DefaultAzureCredential()

key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)

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

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

Retrieve a Key

get_key retrieves a key previously stored in the Vault.

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

credential = DefaultAzureCredential()

key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)
key = key_client.get_key("key-name")
print(key.name)

Update an existing Key

update_key_properties updates the properties of a key previously stored in the Key Vault.

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

credential = DefaultAzureCredential()

key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)

# we will now disable the key for further use
updated_key = key_client.update_key_properties("key-name", enabled=False)

print(updated_key.name)
print(updated_key.properties.enabled)

Delete a Key

begin_delete_key requests Key Vault delete a key, returning a poller which allows you to wait for the deletion to finish. Waiting is helpful when the vault has soft-delete enabled, and you want to purge (permanently delete) the key as soon as possible. When soft-delete is disabled, begin_delete_key itself is permanent.

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

credential = DefaultAzureCredential()

key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)
deleted_key = key_client.begin_delete_key("key-name").result()

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

List keys

list_properties_of_keys lists the properties of all of the keys in the client's vault.

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

credential = DefaultAzureCredential()

key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)
keys = key_client.list_properties_of_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 CryptographyClient, EncryptionAlgorithm

credential = DefaultAzureCredential()
key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)

key = key_client.get_key("key-name")
crypto_client = CryptographyClient(key, credential=credential)
plaintext = b"plaintext"

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 API

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.

Async clients should be closed when they're no longer needed. Each async client is an async context manager and defines an async close method. For example:

from azure.keyvault.keys import KeyClient

# call close when the client is no longer needed
client = KeyClient()
...
await client.close()

# alternatively, use the client as an async context manager
client = KeyClient()
async with client:
  ...

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="https://my-key-vault.vault.azure.net/", credential=credential)

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

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

Asynchronously list keys

list_properties_of_keys lists the properties of all of the keys in the client's vault.

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

credential = DefaultAzureCredential()
key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)
keys = key_client.list_properties_of_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.identity import DefaultAzureCredential
from azure.keyvault.keys import KeyClient
from azure.core.exceptions import ResourceNotFoundError

credential = DefaultAzureCredential()
key_client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential)

try:
    key_client.get_key("which-does-not-exist")
except ResourceNotFoundError as e:
    print(e.message)

Logging

This library uses the standard logging library for logging. Basic information about HTTP sessions (URLs, headers, etc.) is logged at INFO level.

Detailed DEBUG level logging, including request/response bodies and unredacted headers, can be enabled on a client with the logging_enable argument:

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

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

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

credential = DefaultAzureCredential()

# This client will log detailed information about its HTTP sessions, at DEBUG level
client = KeyClient(vault_url="https://my-key-vault.vault.azure.net/", credential=credential, logging_enable=True)

Similarly, logging_enable can enable detailed logging for a single operation, even when it isn't enabled for the client:

client.get_key("my-key", 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:

• hello_world.py and hello_world_async.py - create/get/update/delete keys
• list_operations.py and list_operations_async.py - basic list operations for keys
• backup_restore_operations.py and backup_restore_operations_async.py - backup and recover keys
• recover_purge_operations.py and recover_purge_operations_async.py - recovering and purging 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

4.3.0 (2020-10-06)

Changed

• CryptographyClient can perform decrypt and sign operations locally (#9754)

Fixed

• Correct typing for async paging methods

4.2.0 (2020-08-11)

Fixed

• Values of x-ms-keyvault-region and x-ms-keyvault-service-version headers are no longer redacted in logging output
• CryptographyClient will no longer perform encrypt or wrap operations when its key has expired or is not yet valid

Changed

• Key Vault API version 7.1 is now the default
• Updated minimum azure-core version to 1.7.0

Added

• At construction, clients accept a CustomHookPolicy through the optional keyword argument custom_hook_policy
• All client requests include a unique ID in the header x-ms-client-request-id
• Dependency on azure-common for multiapi support

4.2.0b1 (2020-03-10)

• Support for Key Vault API version 7.1-preview (#10124)
  • Added import_key to KeyOperation
  • Added recoverable_days to CertificateProperties
  • Added ApiVersion enum identifying Key Vault versions supported by this package

4.1.0 (2020-03-10)

• KeyClient instances have a close method which closes opened sockets. Used as a context manager, a KeyClient closes opened sockets on exit. (#9906)
• Pollers no longer sleep after operation completion (#9991)

4.0.1 (2020-02-11)

• azure.keyvault.keys defines __version__
• Challenge authentication policy preserves request options (#8999)
• Updated msrest requirement to >=0.6.0
• Challenge authentication policy requires TLS (#9457)
• Methods no longer raise the internal error KeyVaultErrorException (#9690)
• Fix AttributeError in async CryptographyClient when verifying signatures remotely (#9734)

2019-10-31 4.0.0

Breaking changes:

• Removed KeyClient.get_cryptography_client() and CryptographyClient.get_key()
• Moved the optional parameters of several methods into kwargs ( docs detail the new keyword arguments):
  • create_key now has positional parameters name and key_type
  • create_ec_key and create_rsa_key now have one positional parameter, name
  • update_key_properties now has two positional parameters, name and (optional) version
  • import_key now has positional parameters name and key
• CryptographyClient operations return class instances instead of tuples and renamed the following properties
  • Renamed the decrypted_bytes property of DecryptResult to plaintext
  • Renamed the unwrapped_bytes property of UnwrapResult to key
  • Renamed the result property of VerifyResult to is_valid
• Renamed the UnwrapKeyResult and WrapKeyResult classes to UnwrapResult and WrapResult
• Renamed list_keys to list_properties_of_keys
• Renamed list_key_versions to list_properties_of_key_versions
• Renamed sync method delete_key to begin_delete_key
• The sync method begin_delete_key and async delete_key now return pollers that return a DeletedKey
• Renamed Key to KeyVaultKey
• KeyVaultKey properties created, expires, and updated renamed to created_on, expires_on, and updated_on
• The vault_endpoint parameter of KeyClient has been renamed to vault_url
• The property vault_endpoint has been renamed to vault_url in all models

New features:

• Now all CryptographyClient returns include key_id and algorithm properties

4.0.0b4 (2019-10-08)

• Enums JsonWebKeyCurveName, JsonWebKeyOperation, and JsonWebKeyType have been renamed to KeyCurveName, KeyOperation, and KeyType, respectively.

• Key now has attribute properties, which holds certain properties of the key, such as version. This changes the shape of the returned Key type, as certain properties of Key (such as version) have to be accessed through the properties property.

• update_key has been renamed to update_key_properties

• The vault_url parameter of KeyClient has been renamed to vault_endpoint

• The property vault_url has been renamed to vault_endpoint in all models

Fixes and improvements:

• The key argument to import_key should be an instance of azure.keyvault.keys.JsonWebKey (#7590)

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