Using Keyvault with client credentials

KVClientCredentialsProgram.cs

// create app registration in AAD and secret
// Go to Keyvault and add app in access policies
// give sign permissions!
//
using Azure.Identity;
using Azure.Security.KeyVault.Keys;
using Azure.Security.KeyVault.Keys.Cryptography;
using Azure.Security.KeyVault.Secrets;
using System;
using System.Diagnostics;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace KeyVaultDIDTest
{
    internal class Program
    {
        static async Task Main(string[] args)
        {
            const string keyVaultClientId = "APPID";
            const string keyVaultClientSecret = "SECRET";
            const string TenantId = "TENANTID";
            const string kvURI = "https://YOURKEYVAULT.vault.azure.net/";

            Console.WriteLine("Hello World!");

            var cc = new ClientSecretCredential(TenantId, keyVaultClientId, keyVaultClientSecret);
            var secretClient = new SecretClient(new Uri(kvURI), cc);
            var keyClient = new KeyClient(new Uri(kvURI), cc);

            var kvKey = await keyClient.GetKeyAsync("YOURKEYNAME");
            var cryptoClient = new CryptographyClient(keyId: kvKey.Value.Id, cc);

            byte[] data = Encoding.UTF8.GetBytes("This is some sample data which we will use to demonstrate sign and verify");
            byte[] digest = null;

            using (HashAlgorithm hashAlgo = SHA256.Create())
            {
                digest = hashAlgo.ComputeHash(data);
            }

            SignResult ecSignResult = cryptoClient.Sign(SignatureAlgorithm.ES256K, digest);
            Console.WriteLine($"Signed digest using the algorithm {ecSignResult.Algorithm}, with key {ecSignResult.KeyId}. The resulting signature is {Convert.ToBase64String(ecSignResult.Signature)}");

            VerifyResult ecVerifyResult = cryptoClient.Verify(SignatureAlgorithm.ES256K, digest, ecSignResult.Signature);
            Console.WriteLine($"Verified the signature using the algorithm {ecVerifyResult.Algorithm}, with key {ecVerifyResult.KeyId}. Signature is valid: {ecVerifyResult.IsValid}");
            Console.ReadLine();
        }
    }
}