Azure Identity Rust

Azure Identity library for Rust

Microsoft Entra ID authentication for Azure SDK clients.

Use this skill when:

• An app needs to authenticate to Azure services from Rust
• You need DeveloperToolsCredential for local development
• You need ManagedIdentityCredential for Azure-hosted workloads
• You need service principal auth with secret or certificate

IMPORTANT: Only use official azure_* crates published by the azure-sdk crates.io user. Do NOT use the deprecated azure_sdk_* crates (MindFlavor/AzureSDKForRust) or community crates. Official crates use underscores in names and none have version 0.21.0.

Note: The Rust SDK does not have DefaultAzureCredential. Use DeveloperToolsCredential for local development and ManagedIdentityCredential for production.

Installation

cargo add azure_identity tokio

Do not add azure_core directly to Cargo.toml. It is re-exported by service crates.

Environment Variables

AZURE_TENANT_ID=<your-tenant-id>         # Required for service principal auth
AZURE_CLIENT_ID=<your-client-id>         # Required for service principal or user-assigned managed identity
AZURE_CLIENT_SECRET=<your-client-secret> # Required for ClientSecretCredential

Authentication

DeveloperToolsCredential (Local Development)

Tries Azure CLI then Azure Developer CLI:

use azure_identity::DeveloperToolsCredential;
use azure_security_keyvault_secrets::SecretClient;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Local dev: DeveloperToolsCredential. Production: use ManagedIdentityCredential.
    let credential = DeveloperToolsCredential::new(None)?;
    let client = SecretClient::new(
        "https://<vault-name>.vault.azure.net/",
        credential.clone(),
        None,
    )?;

    let secret = client.get_secret("secret-name", None).await?.into_model()?;
    println!("Secret: {:?}", secret.value);
    Ok(())
}

Ensure you are logged in:

az login        # Azure CLI
azd auth login  # or Azure Developer CLI

ManagedIdentityCredential (Production)

For Azure-hosted resources (VMs, App Service, Functions, AKS):

use azure_identity::ManagedIdentityCredential;

// System-assigned managed identity
let credential = ManagedIdentityCredential::new(None)?;

// User-assigned managed identity
let options = ManagedIdentityCredentialOptions {
    client_id: Some("<managed-identity-client-id>".into()),
    ..Default::default()
};
let credential = ManagedIdentityCredential::new(Some(options))?;

ClientSecretCredential (Service Principal)

For CI/CD pipelines and service accounts:

use azure_identity::ClientSecretCredential;

let credential = ClientSecretCredential::new(
    "<tenant-id>",
    "<client-id>",
    "<client-secret>",
    None,
)?;

Credential Types

Best Practices

1. Use DeveloperToolsCredential for local development and ManagedIdentityCredential for production. The Rust SDK does not support DefaultAzureCredential, so explicitly use the appropriate credential in each environment.
2. Never hardcode credentials — use environment variables or managed identity for all authentication
3. Assign appropriate RBAC roles for Entra ID auth. For production authentication using Entra ID, ensure the identity has the necessary RBAC role assigned for the target service (e.g., "Key Vault Secrets User" for secret reads).
4. Always verify package versions using crates.io. Before using a package, check its version on crates.io to ensure you are using a stable and supported release.
5. Clone credentials — pass credential.clone() when constructing multiple clients; credentials are Arc-wrapped and thread-safe
6. Reuse clients — clients are thread-safe; create once, share across tasks

Reference Links