Identity server 4 token not validate in .NetFramework Api that use Identity Server 3

Question

In my identityserver app that use idsv4 and run on port "5000" have a client

            new Client
           {
            ClientId = "client",

            // no interactive user, use the clientid/secret for authentication
            AllowedGrantTypes = GrantTypes.ClientCredentials,

            // secret for authentication
            ClientSecrets =
            {
                new Secret("secret".Sha256())
            },

            // scopes that client has access to
            AllowedScopes = { "api1" }
        }`

and in my .Net Framework Api's startup class that use port no "7001" :

app.UseIdentityServerBearerTokenAuthentication(
new IdentityServerBearerTokenAuthenticationOptions
{
  Authority = "http://localhost:5000",
  ValidationMode = ValidationMode.ValidationEndpoint,

        RequiredScopes = new[] { "api1" }
    });`

and finally in my client catch token successfully:

    static TokenResponse GetClientToken()
    {
       var client = new TokenClient(
       "http://localhost:5000/connect/token",
       "client",
       "secret");

    return client.RequestClientCredentialsAsync("api1").Result;
}`

but when i use this token to call api:

static void CallApi(TokenResponse response)
{
   var client = new HttpClient();
   client.SetBearerToken(response.AccessToken);

   Console.WriteLine(client.GetStringAsync("http://localhost:7001/api/identity/get").Result);
}

client throw an exception:

Response status code does not indicate success: 401 (Unauthorized). I have done all of them in core api and every things are ok!!

Answer 1

After switching to X509 certificate instead of the certificate that comes with the samples, everything started working fine.

Get rid of .AddDeveloperSigningCredential() and use .AddSigningCredential(GET_THE_CERT_FROM_YOUR_CERT_STORE)