Azure Key Vault Key client library for JavaScript

Azure Key Vault is a service that allows you to encrypt authentication keys, storage account keys, data encryption keys, .pfx files, and passwords by using secured keys. If you would like to know more about Azure Key Vault, you may want to review: What is Azure Key Vault?

Azure Key Vault Key management allows you to create and control encryption keys that encrypt your data.

Use the client library for Azure Key Vault Keys in your Node.js application to:

Create keys using elliptic curve or RSA encryption, optionally backed by Hardware Security Modules (HSM).
Import, Delete, and Update keys.
Get one or more keys and deleted keys, with their attributes.
Recover a deleted key and restore a backed up key.
Get the versions of a key.

Using the cryptography client available in this library you also have access to:

Encrypting
Decrypting
Signing
Verifying
Wrapping keys
Unwrapping keys

Note: This package cannot be used in the browser due to Azure Key Vault service limitations.

Source code | Package (npm) | API Reference Documentation | Product documentation | Samples

Getting started

Prerequisites: You must have an Azure subscription and a Key Vault resource to use this package.

If you are using this package in a Node.js application, then use Node.js 8.x or higher.

Install the package

Install the Azure Key Vault Key client library using npm

npm install @azure/keyvault-keys

Install the identity library

Key Vault clients authenticate using the Azure identity library. Install it as well using npm

npm install @azure/identity

Configure TypeScript

TypeScript users need to have Node type definitions installed:

npm install @types/node

You also need to enable compilerOptions.allowSyntheticDefaultImports in your tsconfig.json. Note that if you have enabled compilerOptions.esModuleInterop, allowSyntheticDefaultImports is enabled by default. See TypeScript's compiler options handbook for more information.

Configuring your Key Vault

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 above returned credentials information 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 create decrypt delete encrypt get import list purge recover restore sign unwrapKey update verify wrapKey
```
--secret-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>
```

Key concepts

The Key client is the primary interface to interact with the API methods related to keys in the Azure Key Vault API from a JavaScript application. Once initialized, it provides a basic set of methods that can be used to create, read, update and delete keys.
A Key version is a version of a key in the Key Vault. Each time a user assigns a value to a unique key name, a new version of that key is created. Retrieving a key by a name will always return the latest value assigned, unless a specific version is provided to the query.
Soft delete allows Key Vaults to support deletion and purging as two separate steps, so deleted keys are not immediately lost. This only happens if the Key Vault has soft-delete enabled.
A Key backup can be generated from any created key. These backups come as binary data, and can only be used to regenerate a previously deleted key.
The Cryptography client is a separate interface that interacts with the keys API methods in the Key Vault API. This client focuses only in the cryptography operations that can be executed using a key that has been already created in the Key Vault. More about this client in the Cryptography section.

Authenticating with Azure Active Directory

The Key Vault service relies on Azure Active Directory to authenticate requests to its APIs. The @azure/identity package provides a variety of credential types that your application can use to do this. The README for @azure/identity provides more details and samples to get you started.

Here's a quick example. First, import DefaultAzureCredential and KeyClient:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

Once these are imported, we can next connect to the Key Vault service. To do this, we'll need to copy some settings from the key vault we are connecting to into our environment variables. Once they are in our environment, we can access them with the following code:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

// DefaultAzureCredential expects the following three environment variables:
// * AZURE_TENANT_ID: The tenant ID in Azure Active Directory
// * AZURE_CLIENT_ID: The application (client) ID registered in the AAD tenant
// * AZURE_CLIENT_SECRET: The client secret for the registered application
const credential = new DefaultAzureCredential();

// Build the URL to reach your key vault
const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

// Lastly, create our keys client and connect to the service
const client = new KeyClient(url, credential);

Specifying the Azure Key Vault service API version

By default, this package uses the latest Azure Key Vault service version which is 7.1. The only other version that is supported is 7.0. You can change the service version being used by setting the option serviceVersion in the client constructor as shown below:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

// Change the Azure Key Vault service API version being used via the `serviceVersion` option
const client = new KeyClient(url, credential, {
  serviceVersion: "7.0"
});

Examples

The following sections provide code snippets that cover some of the common tasks using Azure Key Vault Keys. The scenarios that are covered here consist of:

Creating a key.
Getting a key.
Creating and updating keys with attributes.
Deleting a key.
Iterating lists of keys.

Creating a key

createKey creates 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.

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const result = await client.createKey(keyName, "RSA");
  console.log("result: ", result);
}

main();

The second parameter sent to createKey is the type of the key. Keys can either be of either one of the following types:

EC for a key generated using Elliptic Curve cryptography.
EC-HSM for a key generated with Elliptic Curve cryptography with Hardware Security Modules.
RSA for Rivest, Shamir, and Adelman cryptography.
RSA-HSM for Rivest, Shamir, and Adelman cryptography with Hardware Security Modules.

Getting a key

The simplest way to read keys back from the vault is to get a key by name. This will retrieve the most recent version of the key. You can optionally get a different version of the key if you specify it as part of the optional parameters.

getKey retrieves a key previous stores in the Key Vault.

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const latestKey = await client.getKey(keyName);
  console.log(`Latest version of the key ${keyName}: `, latestKey);
  const specificKey = await client.getKey(keyName, { version: latestKey.properties.version! });
  console.log(`The key ${keyName} at the version ${latestKey.properties.version!}: `, specificKey);
}

main();

Creating and updating keys with attributes

The following attributes can also be assigned to any key in a Key Vault:

tags: Any set of key-values that can be used to search and filter keys.
keyOps: An array of the operations that this key will be able to perform (encrypt, decrypt, sign, verify, wrapKey, unwrapKey).
enabled: A boolean value that determines whether the key value can be read or not.
notBefore: A given date after which the key value can be retrieved.
expires: A given date after which the key value cannot be retrieved.

An object with these attributes can be sent as the third parameter of createKey, right after the key's name and value, as follows:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const result = await client.createKey(keyName, "RSA", {
    enabled: false
  });
  console.log("result: ", result);
}

main();

This will create a new version of the same key, which will have the latest provided attributes.

Attributes can also be updated to an existing key version with updateKeyProperties, as follows:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const result = await client.createKey(keyName, "RSA");
  await client.updateKeyProperties(keyName, result.properties.version, {
    enabled: false
  });
}

main();

Deleting a key

The beginDeleteKey method starts the deletion of a key. This process will happen in the background as soon as the necessary resources are available.

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const poller = await client.beginDeleteKey(keyName);
  await poller.pollUntilDone();
}

main();

If soft-delete is enabled for the Key Vault, this operation will only label the key as a deleted key. A deleted key can't be updated. They can only be either read, recovered or purged.

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const poller = await client.beginDeleteKey(keyName)

  // You can use the deleted key immediately:
  const deletedKey = poller.getResult();

  // The key is being deleted. Only wait for it if you want to restore it or purge it.
  await poller.pollUntilDone();

  // You can also get the deleted key this way:
  await client.getDeletedKey(keyName);

  // Deleted keys can also be recovered or purged:

  // recoverDeletedKey also returns a poller, just like beginDeleteKey.
  const recoverPoller = await client.beginRecoverDeletedKey(keyName)
  await recoverPoller.pollUntilDone();

  // And here is how to purge a deleted key
  await client.purgeDeletedKey(keyName);
}

main();

Since Keys take some time to get fully deleted, beginDeleteKey returns a Poller object that keeps track of the underlying Long Running Operation according to our guidelines: https://azure.github.io/azure-sdk/typescript_design.html#ts-lro

The received poller will allow you to get the deleted key by calling to poller.getResult(). You can also wait until the deletion finishes, either by running individual service calls until the key is deleted, or by waiting until the process is done:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const poller = await client.beginDeleteKey(keyName);

  // You can use the deleted key immediately:
  let deletedKey = poller.getResult();

  // Or you can wait until the key finishes being deleted:
  deletedKey = await poller.pollUntilDone();
  console.log(deletedKey);
}

main();

Another way to wait until the key is fully deleted is to do individual calls, as follows:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");
const { delay } = require("@azure/core-http");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  const poller = await client.beginDeleteKey(keyName);

  while (!poller.isDone()) {
    await poller.poll();
    await delay(5000);
  }

  console.log(`The key ${keyName} is fully deleted`);
}

main();

Iterating lists of keys

Using the KeyClient, you can retrieve and iterate through all of the keys in a Key Vault, as well as through all of the deleted keys and the versions of a specific key. The following API methods are available:

listPropertiesOfKeys will list all of your non-deleted keys by their names, only at their latest versions.
listDeletedKeys will list all of your deleted keys by their names, only at their latest versions.
listPropertiesOfKeyVersions will list all the versions of a key based on a key name.

Which can be used as follows:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  for await (let keyProperties of client.listPropertiesOfKeys()) {
    console.log("Key properties: ", keyProperties);
  }
  for await (let deletedKey of client.listDeletedKeys()) {
    console.log("Deleted: ", deletedKey);
  }
  for await (let versionProperties of client.listPropertiesOfKeyVersions(keyName)) {
    console.log("Version properties: ", versionProperties);
  }
}

main();

All of these methods will return all of the available results at once. To retrieve them by pages, add .byPage() right after invoking the API method you want to use, as follows:

const { DefaultAzureCredential } = require("@azure/identity");
const { KeyClient } = require("@azure/keyvault-keys");

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const client = new KeyClient(url, credential);

const keyName = "MyKeyName";

async function main() {
  for await (let page of client.listPropertiesOfKeys().byPage()) {
    for (let keyProperties of page) {
      console.log("Key properties: ", keyProperties);
    }
  }
  for await (let page of client.listDeletedKeys().byPage()) {
    for (let deletedKey of page) {
      console.log("Deleted key: ", deletedKey);
    }
  }
  for await (let page of client.listPropertiesOfKeyVersions(keyName).byPage()) {
    for (let versionProperties of page) {
      console.log("Version: ", versionProperties);
    }
  }
}

Cryptography

This library also offers a set of cryptographic utilities available through CryptographyClient. Similar to the KeyClient, CryptographyClient will connect to Azure Key Vault with the provided set of credentials. Once connected, CryptographyClient can encrypt, decrypt, sign, verify, wrap keys, and unwrap keys.

We can next connect to the key vault service just as we do with the KeyClient. We'll need to copy some settings from the key vault we are connecting to into our environment variables. Once they are in our environment, we can access them with the following code:

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  // Create or retrieve a key from the keyvault
  let myKey = await keysClient.createKey("MyKey", "RSA");

  // Lastly, create our cryptography client and connect to the service
  // This example uses the URL that is part of the key we created (called key ID)
  const cryptographyClient = new CryptographyClient(myKey.id, credential);
}

Encrypt

encrypt will encrypt a message. The following algorithms are currently supported: "RSA-OAEP", "RSA-OAEP-256", and "RSA1_5".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const encryptResult = await cryptographyClient.encrypt("RSA1_5", Buffer.from("My Message"));
  console.log("encrypt result: ", encryptResult.result);
}

main();

Decrypt

decrypt will decrypt an encrypted message. The following algorithms are currently supported: "RSA-OAEP", "RSA-OAEP-256", and "RSA1_5".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const encryptResult = await cryptographyClient.encrypt("RSA1_5", Buffer.from("My Message"));
  console.log("encrypt result: ", encryptResult.result);

  const decryptResult = await cryptographyClient.decrypt("RSA1_5", encryptResult.result);
  console.log("decrypt result: ", decryptResult.result.toString());
}

main();

Sign

sign will cryptographically sign the digest (hash) of a message with a signature. The following algorithms are currently supported: "PS256", "PS384", "PS512", "RS256", "RS384", "RS512", "ES256","ES256K", "ES384", and "ES512".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";
import { createHash } from "crypto";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const signatureValue = "MySignature";
  let hash = createHash("sha256");

  let digest = hash.update(signatureValue).digest();
  console.log("digest: ", digest);

  const signResult = await cryptographyClient.signData("RS256", digest);
  console.log("sign result: ", signResult.result);
}

main();

Sign Data

signData will cryptographically sign a message with a signature. The following algorithms are currently supported: "PS256", "PS384", "PS512", "RS256", "RS384", "RS512", "ES256","ES256K", "ES384", and "ES512".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const signResult = await cryptographyClient.signData("RS256", Buffer.from("My Message"));
  console.log("sign result: ", signResult.result);
}

main();

Verify

verify will cryptographically verify that the signed digest was signed with the given signature. The following algorithms are currently supported: "PS256", "PS384", "PS512", "RS256", "RS384", "RS512", "ES256","ES256K", "ES384", and "ES512".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const hash = createHash("sha256");
  hash.update("My Message");
  const digest = hash.digest();

  const signResult = await cryptographyClient.signData("RS256", digest);
  console.log("sign result: ", signResult.result);

  const verifyResult = await cryptographyClient.verify("RS256", digest, signResult.result);
  console.log("verify result: ", verifyResult.result);
}

main();

Verify Data

verifyData will cryptographically verify that the signed message was signed with the given signature. The following algorithms are currently supported: "PS256", "PS384", "PS512", "RS256", "RS384", "RS512", "ES256","ES256K", "ES384", and "ES512".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const buffer = Buffer.from("My Message");

  const signResult = await cryptographyClient.signData("RS256", buffer);
  console.log("sign result: ", signResult.result);

  const verifyResult = await cryptographyClient.verifyData("RS256", buffer, signResult.result);
  console.log("verify result: ", verifyResult.result);
}

main();

Wrap Key

wrapKey will wrap a key with an encryption layer. The following algorithms are currently supported: "RSA-OAEP", "RSA-OAEP-256", and "RSA1_5".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const wrapResult = await cryptographyClient.wrapKey("RSA-OAEP", Buffer.from("My Key"));
  console.log("wrap result:", wrapResult.result);
}

main();

Unwrap Key

unwrapKey will unwrap a wrapped key. The following algorithms are currently supported: "RSA-OAEP", "RSA-OAEP-256", and "RSA1_5".

import { DefaultAzureCredential } from "@azure/identity";
import { KeyClient, CryptographyClient } from "@azure/keyvault-keys";

const credential = new DefaultAzureCredential();

const vaultName = "<YOUR KEYVAULT NAME>";
const url = `https://${vaultName}.vault.azure.net`;

const keysClient = new KeyClient(url, credential);

async function main() {
  let myKey = await keysClient.createKey("MyKey", "RSA");
  const cryptographyClient = new CryptographyClient(myKey.id, credential);

  const wrapResult = await cryptographyClient.wrapKey("RSA-OAEP", Buffer.from("My Key"));
  console.log("wrap result:", wrapResult.result);

  const unwrapResult = await cryptographyClient.unwrapKey("RSA-OAEP", wrapResult.result);
  console.log("unwrap result: ", unwrapResult.result);
}

main();

Troubleshooting

Enabling logging may help uncover useful information about failures. In order to see a log of HTTP requests and responses, set the AZURE_LOG_LEVEL environment variable to info. Alternatively, logging can be enabled at runtime by calling setLogLevel in the @azure/logger:

import { setLogLevel } from "@azure/logger";

setLogLevel("info");

Next steps

You can find more code samples through the following links:

Contributing

If you'd like to contribute to this library, please read the contributing guide to learn more about how to build and test the code.

Impressions