Azure key vault: access denied

Question

I have the following code for obtaining a secret from the Azure key vault:

public static async Task<string> GetToken(string authority, string resource, string scope)
    {
        var authContext = new AuthenticationContext(authority);
        ClientCredential clientCred = new ClientCredential(...); //app id, app secret
        AuthenticationResult result = await authContext.AcquireTokenAsync(resource, clientCred);

        if (result == null)
            throw new InvalidOperationException("Failed to obtain the JWT token");

        return result.AccessToken;
    }

    public static string GetSecret(string secretName)
    {
        KeyVaultClient keyVaultClient = new KeyVaultClient(GetToken);
        try
        {
            return keyVaultClient.GetSecretAsync("my-key-vault-url", secretName).Result.Value;
        }
        catch(Exception ex)
        {
            return "Error";
        }
    }

The error I am getting is "access denied", which (I think) means that the id, secret and the vault's url are fine. However, I don't know what I can do differently to fix this error, is there maybe a setting in the Azure portal which is preventing me from reading a secret?

Answer 1

To fix access denied you need to configure Active Directory permissions. Grant access to KeyVault.

1. Using PowerShell Run next command:

Set-AzureRmKeyVaultAccessPolicy -VaultName 'XXXXXXX' -ServicePrincipalName XXXXX -PermissionsToKeys decrypt,sign,get,unwrapKey

2. Using the Azure portal

1. Open Key Vaults
2. Select Access Policies from the Key Vault resource blade
3. Click the [+ Add Access Policy] button at the top of the blade
4. Click Select Principal to select the application you created earlier
5. From the Key permissions drop down, select "Decrypt", "Sign", "Get", "UnwrapKey" permissions
6. Save changes

Authorize the application to use the key or secret