IDForwading: cache based on expires in (#81136)

* IDFowarding: Cache based on expires in

* IDFowarding: Change default expires in

---------

Co-authored-by: Victor Cinaglia <victor@grafana.com>

pkg/services/auth/idimpl/service_test.go

@@ -2,9 +2,10 @@ package idimpl
 
 import (
 	"context"
-	"encoding/json"
 	"testing"
 
+	"github.com/go-jose/go-jose/v3"
+	"github.com/go-jose/go-jose/v3/jwt"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -53,11 +54,14 @@ func Test_ProvideService(t *testing.T) {
 func TestService_SignIdentity(t *testing.T) {
 	signer := &idtest.MockSigner{
 		SignIDTokenFn: func(_ context.Context, claims *auth.IDClaims) (string, error) {
-			data, err := json.Marshal(claims)
-			if err != nil {
-				return "", err
-			}
-			return string(data), nil
+			key := []byte("key")
+			s, err := jose.NewSigner(jose.SigningKey{Algorithm: jose.HS256, Key: key}, nil)
+			require.NoError(t, err)
+
+			token, err := jwt.Signed(s).Claims(claims).CompactSerialize()
+			require.NoError(t, err)
+
+			return token, nil
 		},
 	}
 
@@ -81,8 +85,11 @@ func TestService_SignIdentity(t *testing.T) {
 		token, err := s.SignIdentity(context.Background(), &authn.Identity{ID: "user:1"})
 		require.NoError(t, err)
 
+		parsed, err := jwt.ParseSigned(token)
+		require.NoError(t, err)
+
 		claims := &auth.IDClaims{}
-		require.NoError(t, json.Unmarshal([]byte(token), claims))
+		require.NoError(t, parsed.UnsafeClaimsWithoutVerification(&claims))
 		assert.Equal(t, login.AzureADAuthModule, claims.AuthenticatedBy)
 	})
 }