Add Managed Identity Support (#552)

* Added Managed Identity support for multiple sources (IMDS, App Service, CloudShell, AzureML, Service Fabric, Azure Arc)
* Updated tests
* Updated documentation
* Added new Managed Identity client that currently supports cache and retry policies

.github/workflows/go.yml

@@ -39,7 +39,7 @@ jobs:
         run: go build ./apps/...
 
       - name: Unit Tests
-        run: go test -race -short ./apps/cache/... ./apps/confidential/... ./apps/public/... ./apps/internal/...
+        run: go test -race -short ./apps/cache/... ./apps/confidential/... ./apps/public/... ./apps/internal/... ./apps/managedidentity/...
       # Intergration tests runs on ADO
       # - name: Integration Tests
       #   run: go test -race ./apps/tests/integration/...

README.md

@@ -50,6 +50,28 @@ Acquiring tokens with MSAL Go follows this general pattern. There might be some
     }
     confidentialClient, err := confidential.New("https://login.microsoftonline.com/your_tenant", "client_id", cred)
     ```
+    * Initializing a Managed Identity client for SystemAssigned:
+
+    ```go
+    import mi "github.com/AzureAD/microsoft-authentication-library-for-go/apps/managedidentity"
+
+    // Managed identity client have a type of ID required, SystemAssigned or UserAssigned
+	miSystemAssigned, err := mi.New(mi.SystemAssigned())
+    if err != nil {
+        // TODO: handle error
+    }
+    ```
+    * Initializing a Managed Identity client for UserAssigned:
+
+    ```go
+    import mi "github.com/AzureAD/microsoft-authentication-library-for-go/apps/managedidentity"
+
+    // Managed identity client have a type of ID required, SystemAssigned or UserAssigned
+	miSystemAssigned, err := mi.New(mi.UserAssignedClientID("YOUR_CLIENT_ID"))
+    if err != nil {
+        // TODO: handle error
+    }
+    ```
 
 1. Call `AcquireTokenSilent()` to look for a cached token. If `AcquireTokenSilent()` returns an error, call another `AcquireToken...` method to authenticate.
 
@@ -96,6 +118,16 @@ Acquiring tokens with MSAL Go follows this general pattern. There might be some
     accessToken := result.AccessToken
     ```
 
+    * ManagedIdentity clietn can simply call `AcquireToken()`:
+    ```go
+    resource := "<Your resource>"
+	result, err := miSystemAssigned.AcquireToken(context.TODO(), resource)
+	if err != nil {
+        // TODO: handle error
+	}
+    accessToken := result.AccessToken
+    ```
+
 ## Community Help and Support
 
 We use [Stack Overflow](http://stackoverflow.com/questions/tagged/msal) to work with the community on supporting Azure Active Directory and its SDKs, including this one! We highly recommend you ask your questions on Stack Overflow (we're all on there!) Also browse existing issues to see if someone has had your question before. Please use the "msal" tag when asking your questions.

apps/confidential/confidential_test.go

@@ -10,7 +10,6 @@ import (
 	"crypto/x509"
 	"encoding/base64"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -25,6 +24,7 @@ import (
 	"github.com/kylelemons/godebug/pretty"
 
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/cache"
+	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/errors"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/exported"
 	internalTime "github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/json/types/time"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/mock"
@@ -35,6 +35,7 @@ import (
 
 // errorClient is an HTTP client for tests that should fail when confidential.Client sends a request
 type errorClient struct{}
+type contextKey struct{}
 
 func (*errorClient) Do(req *http.Request) (*http.Response, error) {
 	return nil, fmt.Errorf("expected no requests but received one for %s", req.URL.String())
@@ -138,7 +139,7 @@ func TestAcquireTokenByCredential(t *testing.T) {
 		}
 		client, err := fakeClient(accesstokens.TokenResponse{
 			AccessToken:   token,
-			ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
+			ExpiresOn:     time.Now().Add(1 * time.Hour),
 			ExtExpiresOn:  internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
 			GrantedScopes: accesstokens.Scopes{Slice: tokenScope},
 			TokenType:     "Bearer",
@@ -305,7 +306,7 @@ func TestAcquireTokenOnBehalfOf(t *testing.T) {
 
 func TestAcquireTokenByAssertionCallback(t *testing.T) {
 	calls := 0
-	key := struct{}{}
+	key := contextKey{}
 	ctx := context.WithValue(context.Background(), key, true)
 	getAssertion := func(c context.Context, o AssertionRequestOptions) (string, error) {
 		if v := c.Value(key); v == nil || !v.(bool) {
@@ -358,7 +359,7 @@ func TestAcquireTokenByAuthCode(t *testing.T) {
 			tr := accesstokens.TokenResponse{
 				AccessToken:   token,
 				RefreshToken:  refresh,
-				ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
+				ExpiresOn:     time.Now().Add(1 * time.Hour),
 				ExtExpiresOn:  internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
 				GrantedScopes: accesstokens.Scopes{Slice: tokenScope},
 				IDToken: accesstokens.IDToken{
@@ -427,6 +428,40 @@ func TestAcquireTokenByAuthCode(t *testing.T) {
 	}
 }
 
+func TestInvalidJsonErrFromResponse(t *testing.T) {
+	cred, err := NewCredFromSecret(fakeSecret)
+	if err != nil {
+		t.Fatal(err)
+	}
+	tenant := "A"
+	lmo := "login.microsoftonline.com"
+	mockClient := mock.Client{}
+	mockClient.AppendResponse(mock.WithBody(mock.GetInstanceDiscoveryBody(lmo, tenant)))
+	client, err := New(fmt.Sprintf(authorityFmt, lmo, tenant), fakeClientID, cred, WithHTTPClient(&mockClient))
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctx := context.Background()
+	// cache an access token for each tenant. To simplify determining their provenance below, the value of each token is the ID of the tenant that provided it.
+	if _, err = client.AcquireTokenSilent(ctx, tokenScope, WithTenantID(tenant)); err == nil {
+		t.Fatal("silent auth should fail because the cache is empty")
+	}
+	mockClient.AppendResponse(mock.WithBody(mock.GetTenantDiscoveryBody(lmo, tenant)))
+	body := fmt.Sprintf(
+		`{"access_token": "%s","expires_in": %d,"expires_on": %d,"token_type": "Bearer"`,
+		tenant, 3600, time.Now().Add(time.Duration(3600)*time.Second).Unix(),
+	)
+	mockClient.AppendResponse(mock.WithBody([]byte(body)))
+	_, err = client.AcquireTokenByCredential(ctx, tokenScope, WithTenantID(tenant))
+	if err == nil {
+		t.Fatal("should have failed with InvalidJsonErr Response")
+	}
+	var ie errors.InvalidJsonErr
+	if !errors.As(err, &ie) {
+		t.Fatal("should have revieved a InvalidJsonErr, but got", err)
+	}
+}
+
 func TestAcquireTokenSilentTenants(t *testing.T) {
 	cred, err := NewCredFromSecret(fakeSecret)
 	if err != nil {
@@ -478,7 +513,7 @@ func TestADFSTokenCaching(t *testing.T) {
 			AccessToken:   "at1",
 			RefreshToken:  "rt",
 			TokenType:     "bearer",
-			ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(time.Hour)},
+			ExpiresOn:     time.Now().Add(time.Hour),
 			ExtExpiresOn:  internalTime.DurationTime{T: time.Now().Add(time.Hour)},
 			GrantedScopes: accesstokens.Scopes{Slice: tokenScope},
 			IDToken: accesstokens.IDToken{
@@ -608,7 +643,7 @@ func TestNewCredFromCert(t *testing.T) {
 			t.Run(fmt.Sprintf("%s/%v", filepath.Base(file.path), sendX5c), func(t *testing.T) {
 				client, err := fakeClient(accesstokens.TokenResponse{
 					AccessToken:   token,
-					ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(time.Hour)},
+					ExpiresOn:     time.Now().Add(time.Hour),
 					GrantedScopes: accesstokens.Scopes{Slice: tokenScope},
 				}, cred, fakeAuthority, opts...)
 				if err != nil {
@@ -724,7 +759,7 @@ func TestNewCredFromTokenProvider(t *testing.T) {
 	expectedToken := "expected token"
 	called := false
 	expiresIn := 4200
-	key := struct{}{}
+	key := contextKey{}
 	ctx := context.WithValue(context.Background(), key, true)
 	cred := NewCredFromTokenProvider(func(c context.Context, tp exported.TokenProviderParameters) (exported.TokenProviderResult, error) {
 		if called {
@@ -982,7 +1017,7 @@ func TestWithClaims(t *testing.T) {
 				case "password":
 					ar, err = client.AcquireTokenByUsernamePassword(ctx, tokenScope, "username", "password", WithClaims(test.claims))
 				default:
-					t.Fatalf("test bug: no test for " + method)
+					t.Fatalf("test bug: no test for %s", method)
 				}
 				if err != nil {
 					t.Fatal(err)
@@ -1092,7 +1127,7 @@ func TestWithTenantID(t *testing.T) {
 				case "obo":
 					ar, err = client.AcquireTokenOnBehalfOf(ctx, "assertion", tokenScope, WithTenantID(test.tenant))
 				default:
-					t.Fatalf("test bug: no test for " + method)
+					t.Fatalf("test bug: no test for %s", method)
 				}
 				if err != nil {
 					if test.expectError {
@@ -1402,7 +1437,7 @@ func TestWithAuthenticationScheme(t *testing.T) {
 	}
 	client, err := fakeClient(accesstokens.TokenResponse{
 		AccessToken:   token,
-		ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
+		ExpiresOn:     time.Now().Add(1 * time.Hour),
 		ExtExpiresOn:  internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
 		GrantedScopes: accesstokens.Scopes{Slice: tokenScope},
 		TokenType:     "TokenType",
@@ -1442,7 +1477,7 @@ func TestAcquireTokenByCredentialFromDSTS(t *testing.T) {
 			}
 			client, err := fakeClient(accesstokens.TokenResponse{
 				AccessToken:   token,
-				ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
+				ExpiresOn:     time.Now().Add(1 * time.Hour),
 				ExtExpiresOn:  internalTime.DurationTime{T: time.Now().Add(1 * time.Hour)},
 				GrantedScopes: accesstokens.Scopes{Slice: tokenScope},
 				TokenType:     "Bearer",

apps/errors/errors.go

@@ -64,11 +64,20 @@ type CallErr struct {
 	Err  error
 }
 
+type InvalidJsonErr struct {
+	Err error
+}
+
 // Errors implements error.Error().
 func (e CallErr) Error() string {
 	return e.Err.Error()
 }
 
+// Errors implements error.Error().
+func (e InvalidJsonErr) Error() string {
+	return e.Err.Error()
+}
+
 // Verbose prints a versbose error message with the request or response.
 func (e CallErr) Verbose() string {
 	e.Resp.Request = nil // This brings in a bunch of TLS crap we don't need

apps/internal/base/base.go

@@ -14,7 +14,7 @@ import (
 	"time"
 
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/cache"
-	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/base/internal/storage"
+	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/base/storage"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/oauth"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/oauth/ops/accesstokens"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/oauth/ops/authority"
@@ -111,7 +111,6 @@ func AuthResultFromStorage(storageTokenResponse storage.TokenResponse) (AuthResu
 	if err := storageTokenResponse.AccessToken.Validate(); err != nil {
 		return AuthResult{}, fmt.Errorf("problem with access token in StorageTokenResponse: %w", err)
 	}
-
 	account := storageTokenResponse.Account
 	accessToken := storageTokenResponse.AccessToken.Secret
 	grantedScopes := strings.Split(storageTokenResponse.AccessToken.Scopes, scopeSeparator)
@@ -146,7 +145,7 @@ func NewAuthResult(tokenResponse accesstokens.TokenResponse, account shared.Acco
 		Account:       account,
 		IDToken:       tokenResponse.IDToken,
 		AccessToken:   tokenResponse.AccessToken,
-		ExpiresOn:     tokenResponse.ExpiresOn.T,
+		ExpiresOn:     tokenResponse.ExpiresOn,
 		GrantedScopes: tokenResponse.GrantedScopes.Slice,
 		Metadata: AuthResultMetadata{
 			TokenSource: IdentityProvider,

apps/internal/base/base_test.go

@@ -12,7 +12,7 @@ import (
 	"time"
 
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/cache"
-	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/base/internal/storage"
+	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/base/storage"
 	internalTime "github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/json/types/time"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/oauth"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/oauth/fake"
@@ -50,7 +50,7 @@ func fakeClient(t *testing.T, opts ...Option) Client {
 	client.Token.AccessTokens = &fake.AccessTokens{
 		AccessToken: accesstokens.TokenResponse{
 			AccessToken:   fakeAccessToken,
-			ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(time.Hour)},
+			ExpiresOn:     time.Now().Add(time.Hour),
 			FamilyID:      "family-id",
 			GrantedScopes: accesstokens.Scopes{Slice: testScopes},
 			IDToken:       fakeIDToken,
@@ -135,7 +135,7 @@ func TestAcquireTokenSilentScopes(t *testing.T) {
 				accesstokens.TokenResponse{
 					AccessToken:   fakeAccessToken,
 					ClientInfo:    accesstokens.ClientInfo{UID: "uid", UTID: "utid"},
-					ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(-time.Hour)},
+					ExpiresOn:     time.Now().Add(-time.Hour),
 					GrantedScopes: accesstokens.Scopes{Slice: test.cachedTokenScopes},
 					IDToken:       fakeIDToken,
 					RefreshToken:  fakeRefreshToken,
@@ -178,7 +178,7 @@ func TestAcquireTokenSilentGrantedScopes(t *testing.T) {
 		},
 		accesstokens.TokenResponse{
 			AccessToken:   expectedToken,
-			ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(time.Hour)},
+			ExpiresOn:     time.Now().Add(time.Hour),
 			GrantedScopes: accesstokens.Scopes{Slice: grantedScopes},
 			TokenType:     "Bearer",
 		},
@@ -335,7 +335,7 @@ func TestCreateAuthenticationResult(t *testing.T) {
 			desc: "no declined scopes",
 			input: accesstokens.TokenResponse{
 				AccessToken:    "accessToken",
-				ExpiresOn:      internalTime.DurationTime{T: future},
+				ExpiresOn:      future,
 				GrantedScopes:  accesstokens.Scopes{Slice: []string{"user.read"}},
 				DeclinedScopes: nil,
 			},
@@ -353,7 +353,7 @@ func TestCreateAuthenticationResult(t *testing.T) {
 			desc: "declined scopes",
 			input: accesstokens.TokenResponse{
 				AccessToken:    "accessToken",
-				ExpiresOn:      internalTime.DurationTime{T: future},
+				ExpiresOn:      future,
 				GrantedScopes:  accesstokens.Scopes{Slice: []string{"user.read"}},
 				DeclinedScopes: []string{"openid"},
 			},

apps/internal/base/internal/storage/items.go → apps/internal/base/storage/items.go

@@ -102,8 +102,9 @@ func NewAccessToken(homeID, env, realm, clientID string, cachedAt, expiresOn, ex
 
 // Key outputs the key that can be used to uniquely look up this entry in a map.
 func (a AccessToken) Key() string {
+	ks := []string{a.HomeAccountID, a.Environment, a.CredentialType, a.ClientID, a.Realm, a.Scopes}
 	key := strings.Join(
-		[]string{a.HomeAccountID, a.Environment, a.CredentialType, a.ClientID, a.Realm, a.Scopes},
+		ks,
 		shared.CacheKeySeparator,
 	)
 	// add token type to key for new access tokens types. skip for bearer token type to

apps/internal/base/internal/storage/items_test.go → apps/internal/base/storage/items_test.go

@@ -305,7 +305,7 @@ func TestContractUnmarshalJSON(t *testing.T) {
 	}
 	if diff := pretty.Compare(want, got); diff != "" {
 		t.Errorf("TestContractUnmarshalJSON: -want/+got:\n%s", diff)
-		t.Errorf(string(got.AdditionalFields["unknownEntity"].(stdJSON.RawMessage)))
+		t.Errorf("%s", string(got.AdditionalFields["unknownEntity"].(stdJSON.RawMessage)))
 	}
 }
 

apps/internal/base/internal/storage/partitioned_storage.go → apps/internal/base/storage/partitioned_storage.go

@@ -114,7 +114,7 @@ func (m *PartitionedManager) Write(authParameters authority.AuthParams, tokenRes
 			realm,
 			clientID,
 			cachedAt,
-			tokenResponse.ExpiresOn.T,
+			tokenResponse.ExpiresOn,
 			tokenResponse.ExtExpiresOn.T,
 			target,
 			tokenResponse.AccessToken,

apps/internal/base/internal/storage/partitioned_storage_test.go → apps/internal/base/storage/partitioned_storage_test.go

@@ -10,7 +10,6 @@ import (
 	"testing"
 	"time"
 
-	internalTime "github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/json/types/time"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/oauth/ops/accesstokens"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/oauth/ops/authority"
 	"github.com/AzureAD/microsoft-authentication-library-for-go/apps/internal/shared"
@@ -59,7 +58,7 @@ func TestOBOAccessTokenScopes(t *testing.T) {
 			accesstokens.TokenResponse{
 				AccessToken:   scope[0] + "-at",
 				ClientInfo:    accesstokens.ClientInfo{UID: upn, UTID: idt.TenantID},
-				ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(time.Hour)},
+				ExpiresOn:     time.Now().Add(time.Hour),
 				GrantedScopes: accesstokens.Scopes{Slice: scope},
 				IDToken:       idt,
 				RefreshToken:  upn + "-rt",
@@ -121,7 +120,7 @@ func TestOBOPartitioning(t *testing.T) {
 			accesstokens.TokenResponse{
 				AccessToken:   upn + "-at",
 				ClientInfo:    accesstokens.ClientInfo{UID: upn, UTID: idt.TenantID},
-				ExpiresOn:     internalTime.DurationTime{T: time.Now().Add(time.Hour)},
+				ExpiresOn:     time.Now().Add(time.Hour),
 				GrantedScopes: accesstokens.Scopes{Slice: scopes},
 				IDToken:       idt,
 				RefreshToken:  upn + "-rt",