Azure Key Vault Keys client library for Python - Version 4.3.0

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

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:

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.

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