Azure Key Vault Keys SDK for TypeScript

Manage cryptographic keys with Azure Key Vault.

Installation

# Keys SDK
npm install @azure/keyvault-keys @azure/identity

Environment Variables

KEY_VAULT_URL=https://<vault-name>.vault.azure.net
# Or
AZURE_KEYVAULT_NAME=<vault-name>
AZURE_TOKEN_CREDENTIALS=prod # Required only if DefaultAzureCredential is used in production

Authentication

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

// Local dev: DefaultAzureCredential. Production: set AZURE_TOKEN_CREDENTIALS=prod or AZURE_TOKEN_CREDENTIALS=<specific_credential>
const credential = new DefaultAzureCredential({requiredEnvVars: ["AZURE_TOKEN_CREDENTIALS"]});
// Or use a specific credential directly in production:
// See https://learn.microsoft.com/javascript/api/overview/azure/identity-readme?view=azure-node-latest#credential-classes
// const credential = new ManagedIdentityCredential();
const vaultUrl = `https://${process.env.AZURE_KEYVAULT_NAME}.vault.azure.net`;

const keyClient = new KeyClient(vaultUrl, credential);
const secretClient = new SecretClient(vaultUrl, credential);

Secrets Operations

Create/Set Secret

const secret = await secretClient.setSecret("MySecret", "secret-value");

// With attributes
const secretWithAttrs = await secretClient.setSecret("MySecret", "value", {
  enabled: true,
  expiresOn: new Date("2025-12-31"),
  contentType: "application/json",
  tags: { environment: "production" }
});

Get Secret

// Get latest version
const secret = await secretClient.getSecret("MySecret");
console.log(secret.value);

// Get specific version
const specificSecret = await secretClient.getSecret("MySecret", {
  version: secret.properties.version
});

List Secrets

for await (const secretProperties of secretClient.listPropertiesOfSecrets()) {
  console.log(secretProperties.name);
}

// List versions
for await (const version of secretClient.listPropertiesOfSecretVersions("MySecret")) {
  console.log(version.version);
}

Delete Secret

// Soft delete
const deletePoller = await secretClient.beginDeleteSecret("MySecret");
await deletePoller.pollUntilDone();

// Purge (permanent)
await secretClient.purgeDeletedSecret("MySecret");

// Recover
const recoverPoller = await secretClient.beginRecoverDeletedSecret("MySecret");
await recoverPoller.pollUntilDone();

Keys Operations

Create Keys

// Generic key
const key = await keyClient.createKey("MyKey", "RSA");

// RSA key with size
const rsaKey = await keyClient.createRsaKey("MyRsaKey", { keySize: 2048 });

// Elliptic Curve key
const ecKey = await keyClient.createEcKey("MyEcKey", { curve: "P-256" });

// With attributes
const keyWithAttrs = await keyClient.createKey("MyKey", "RSA", {
  enabled: true,
  expiresOn: new Date("2025-12-31"),
  tags: { purpose: "encryption" },
  keyOps: ["encrypt", "decrypt", "sign", "verify"]
});

Get Key

const key = await keyClient.getKey("MyKey");
console.log(key.name, key.keyType);

List Keys

for await (const keyProperties of keyClient.listPropertiesOfKeys()) {
  console.log(keyProperties.name);
}

Rotate Key

// Manual rotation
const rotatedKey = await keyClient.rotateKey("MyKey");

// Set rotation policy
await keyClient.updateKeyRotationPolicy("MyKey", {
  lifetimeActions: [{ action: "Rotate", timeBeforeExpiry: "P30D" }],
  expiresIn: "P90D"
});

Delete Key

const deletePoller = await keyClient.beginDeleteKey("MyKey");
await deletePoller.pollUntilDone();

// Purge
await keyClient.purgeDeletedKey("MyKey");

Cryptographic Operations

Create CryptographyClient

import { CryptographyClient } from "@azure/keyvault-keys";

// From key object
const cryptoClient = new CryptographyClient(key, credential);

// From key ID
const cryptoClient = new CryptographyClient(key.id!, credential);

Encrypt/Decrypt

// Encrypt
const encryptResult = await cryptoClient.encrypt({
  algorithm: "RSA-OAEP",
  plaintext: Buffer.from("My secret message")
});

// Decrypt
const decryptResult = await cryptoClient.decrypt({
  algorithm: "RSA-OAEP",
  ciphertext: encryptResult.result
});

console.log(decryptResult.result.toString());

Sign/Verify

import { createHash } from "node:crypto";

// Create digest
const hash = createHash("sha256").update("My message").digest();

// Sign
const signResult = await cryptoClient.sign("RS256", hash);

// Verify
const verifyResult = await cryptoClient.verify("RS256", hash, signResult.result);
console.log("Valid:", verifyResult.result);

Wrap/Unwrap Keys

// Wrap a key (encrypt it for storage)
const wrapResult = await cryptoClient.wrapKey("RSA-OAEP", Buffer.from("key-material"));

// Unwrap
const unwrapResult = await cryptoClient.unwrapKey("RSA-OAEP", wrapResult.result);

Backup and Restore

// Backup
const keyBackup = await keyClient.backupKey("MyKey");
const secretBackup = await secretClient.backupSecret("MySecret");

// Restore (can restore to different vault)
const restoredKey = await keyClient.restoreKeyBackup(keyBackup!);
const restoredSecret = await secretClient.restoreSecretBackup(secretBackup!);

Key Types

import {
  KeyClient,
  KeyVaultKey,
  KeyProperties,
  DeletedKey,
  CryptographyClient,
  KnownEncryptionAlgorithms,
  KnownSignatureAlgorithms
} from "@azure/keyvault-keys";

import {
  SecretClient,
  KeyVaultSecret,
  SecretProperties,
  DeletedSecret
} from "@azure/keyvault-secrets";

Error Handling

try {
  const secret = await secretClient.getSecret("NonExistent");
} catch (error: any) {
  if (error.code === "SecretNotFound") {
    console.log("Secret does not exist");
  } else {
    throw error;
  }
}

Best Practices

1. Use DefaultAzureCredential for local development; use ManagedIdentityCredential or WorkloadIdentityCredential for production
2. Enable soft-delete - Required for production vaults
3. Set expiration dates - On both keys and secrets
4. Use key rotation policies - Automate key rotation
5. Limit key operations - Only grant needed operations (encrypt, sign, etc.)
6. Browser not supported - These SDKs are Node.js only