Azure Key Vault Quickstart fails to provide key vault client - azure-keyvault

Question

I am learning the Azure Key Vault. I am trying to follow https://learn.microsoft.com/en-us/azure/key-vault/secrets/quick-create-net. I have created a vault in the portal, assigned an access policy for a user account. I have seen the vault in the protal, and I have seen that the user has I have set the environment variable value. I use an 'az login' command at a prompt to use that account. From the prompt I run the code in the quickstart. It prompts for a secret. I enter 'bob.' It throws an exception.
"Creating a secret in [...]-key-vault called 'mySecret' with the value 'bob' ...Unhandled exception. Azure.Identity.AuthenticationFailedException: SharedTokenCacheCredential authentication failed: A configuration issue is preventing authentication - check the error message from the server for details.You can modify the configuration in the application registration portal. See https://aka.ms/msal-net-invalid-client for details. Original exception: AADSTS70002: The client does not exist or is not enabled for consumers. If you are the application developer, configure a new application through the App Registrations in the Azure Portal at https://go.microsoft.com/fwlink/?linkid=2083908."
The exception is at
await client.SetSecretAsync(secretName, secretValue);
I think the problem is coming from
var client = new SecretClient(new Uri(kvUri), new DefaultAzureCredential());
The client is not able to send tokens that the vault accepts. I am at a loss. I have had a couple of people with some expertise in using the Vault review this code and they haven't been able to provide insight. Any help?
Here is the code, from the example:
using System;
using System.Threading.Tasks;
using Azure.Identity;
using Azure.Security.KeyVault.Secrets;
namespace key_vault_console_app
{
class Program
{
static async Task Main(string[] args)
{
const string secretName = "mySecret";
var keyVaultName = Environment.GetEnvironmentVariable("KEY_VAULT_NAME");
var kvUri = $"https://{keyVaultName}.vault.azure.net";
var client = new SecretClient(new Uri(kvUri), new DefaultAzureCredential());
Console.Write("Input the value of your secret > ");
var secretValue = Console.ReadLine();
Console.Write($"Creating a secret in {keyVaultName} called '{secretName}' with the value '{secretValue}' ...");
await client.SetSecretAsync(secretName, secretValue);
Console.WriteLine(" done.");
Console.WriteLine("Forgetting your secret.");
secretValue = string.Empty;
Console.WriteLine($"Your secret is '{secretValue}'.");
Console.WriteLine($"Retrieving your secret from {keyVaultName}.");
var secret = await client.GetSecretAsync(secretName);
Console.WriteLine($"Your secret is '{secret.Value}'.");
Console.Write($"Deleting your secret from {keyVaultName} ...");
DeleteSecretOperation operation = await client.StartDeleteSecretAsync(secretName);
// You only need to wait for completion if you want to purge or recover the secret.
await operation.WaitForCompletionAsync();
Console.WriteLine(" done.");
Console.Write($"Purging your secret from {keyVaultName} ...");
await client.PurgeDeletedSecretAsync(secretName);
Console.WriteLine(" done.");
}
}
}

Answer 1

Not Sure the root reason for it. But If you want to use a user account to login to Azure and access your key vault, using UsernamePasswordCredential() could be a workaround here.
To use UsernamePasswordCredential(), you should register a client application in Azure AD: Go to Azure portal =>Azure Active Directory => New registration
Note its application ID:
Go to API permissioms, and grant key vault user_impersonation permission so that users could access key vault via this app.
Click "Grant admin consent for.." to finish the permission grant process.
Go to the "Authentication" blade, turn on "Allow public client flows" so that Azure will consider this app as a public client:
Try the code below to create a secret:
using System;
using System.Threading.Tasks;
using Azure.Identity;
using Azure.Security.KeyVault.Secrets;
namespace key_vault_console_app
{
class Program
{
static async Task Main(string[] args)
{
const string secretName = "mySecret2";
var keyVaultName = "<your kv name>";
var kvUri = $"https://{keyVaultName}.vault.azure.net";
var userCred = new UsernamePasswordCredential("<user account name>", "<user password>", "<your tenant name/id>", "<client application ID WHCIH we created above>");
var client = new SecretClient(new Uri(kvUri), userCred);
Console.Write("Input the value of your secret > ");
var secretValue = Console.ReadLine();
Console.Write($"Creating a secret in {keyVaultName} called '{secretName}' with the value '{secretValue}' ...");
await client.SetSecretAsync(secretName, secretValue);
Console.WriteLine(" done.");
}
}
}
Result: