Replace ErrAuthenticationRequired with AuthenticationRequiredError

sdk/azidentity/CHANGELOG.md

@@ -5,6 +5,10 @@
 ### Features Added
 
 ### Breaking Changes
+> These changes affect only code written against a beta version such as v1.6.0-beta.1
+* Replaced `ErrAuthenticationRequired` with `AuthenticationRequiredError`, a struct
+  type that carries the `TokenRequestOptions` passed to the `GetToken` call which
+  returned the error.
 
 ### Bugs Fixed
 * Fixed more cases in which credential chains like `DefaultAzureCredential`

sdk/azidentity/azidentity_test.go

@@ -21,6 +21,7 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore"
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/cloud"
@@ -114,6 +115,7 @@ func TestUserAuthentication(t *testing.T) {
 			name: credNameBrowser,
 			new: func(tcpo *TokenCachePersistenceOptions, co azcore.ClientOptions, ar AuthenticationRecord, disableAutoAuth bool) (authenticater, error) {
 				return NewInteractiveBrowserCredential(&InteractiveBrowserCredentialOptions{
+					AdditionallyAllowedTenants:     []string{"*"},
 					AuthenticationRecord:           ar,
 					ClientOptions:                  co,
 					DisableAutomaticAuthentication: disableAutoAuth,
@@ -126,6 +128,7 @@ func TestUserAuthentication(t *testing.T) {
 			name: credNameDeviceCode,
 			new: func(tcpo *TokenCachePersistenceOptions, co azcore.ClientOptions, ar AuthenticationRecord, disableAutoAuth bool) (authenticater, error) {
 				o := DeviceCodeCredentialOptions{
+					AdditionallyAllowedTenants:     []string{"*"},
 					AuthenticationRecord:           ar,
 					ClientOptions:                  co,
 					DisableAutomaticAuthentication: disableAutoAuth,
@@ -143,6 +146,7 @@ func TestUserAuthentication(t *testing.T) {
 			name: credNameUserPassword,
 			new: func(tcpo *TokenCachePersistenceOptions, co azcore.ClientOptions, ar AuthenticationRecord, disableAutoAuth bool) (authenticater, error) {
 				opts := UsernamePasswordCredentialOptions{
+					AdditionallyAllowedTenants:   []string{"*"},
 					AuthenticationRecord:         ar,
 					ClientOptions:                co,
 					TokenCachePersistenceOptions: tcpo,
@@ -264,8 +268,19 @@ func TestUserAuthentication(t *testing.T) {
 			t.Run("DisableAutomaticAuthentication/"+credential.name, func(t *testing.T) {
 				cred, err := credential.new(nil, policy.ClientOptions{Transport: &mockSTS{}}, AuthenticationRecord{}, true)
 				require.NoError(t, err)
-				_, err = cred.GetToken(context.Background(), testTRO)
-				require.ErrorIs(t, err, ErrAuthenticationRequired)
+				expected := policy.TokenRequestOptions{
+					Claims:    "claims",
+					EnableCAE: true,
+					Scopes:    []string{"scope"},
+					TenantID:  "tenant",
+				}
+				_, err = cred.GetToken(context.Background(), expected)
+				require.Contains(t, err.Error(), credential.name)
+				require.Contains(t, err.Error(), "Call Authenticate")
+				var actual *AuthenticationRequiredError
+				require.ErrorAs(t, err, &actual)
+				require.Equal(t, expected, actual.TokenRequestOptions)
+
 				if credential.name != credNameBrowser || runManualTests {
 					_, err = cred.Authenticate(context.Background(), &testTRO)
 					require.NoError(t, err)
@@ -274,6 +289,20 @@ func TestUserAuthentication(t *testing.T) {
 					require.NoError(t, err)
 				}
 			})
+			t.Run("DisableAutomaticAuthentication/ChainedTokenCredential/"+credential.name, func(t *testing.T) {
+				cred, err := credential.new(nil, policy.ClientOptions{}, AuthenticationRecord{}, true)
+				require.NoError(t, err)
+				expected := azcore.AccessToken{ExpiresOn: time.Now().UTC(), Token: tokenValue}
+				fake := NewFakeCredential()
+				fake.SetResponse(expected, nil)
+				chain, err := NewChainedTokenCredential([]azcore.TokenCredential{cred, fake}, nil)
+				require.NoError(t, err)
+				// ChainedTokenCredential should continue iterating when a credential returns
+				// AuthenticationRequiredError i.e., it should call fake.GetToken() and return the expected token
+				actual, err := chain.GetToken(context.Background(), testTRO)
+				require.NoError(t, err)
+				require.Equal(t, expected, actual)
+			})
 		}
 	}
 }
@@ -635,7 +664,8 @@ func TestAdditionallyAllowedTenants(t *testing.T) {
 				// tenant resolution should have succeeded because the specified tenant is allowed,
 				// however the credential should have returned a different error because automatic
 				// authentication is disabled
-				require.ErrorIs(t, ErrAuthenticationRequired, err)
+				var e *AuthenticationRequiredError
+				require.ErrorAs(t, err, &e)
 			}
 		})
 

sdk/azidentity/azure_cli_credential_test.go

@@ -53,9 +53,9 @@ func TestAzureCLICredential_DefaultChainError(t *testing.T) {
 		t.Fatal(err)
 	}
 	_, err = cred.GetToken(context.Background(), testTRO)
-	var ue *credentialUnavailableError
-	if !errors.As(err, &ue) {
-		t.Fatalf("expected credentialUnavailableError, got %T: %q", err, err)
+	var cu credentialUnavailable
+	if !errors.As(err, &cu) {
+		t.Fatalf("expected %T, got %T: %q", cu, err, err)
 	}
 }
 

sdk/azidentity/azure_developer_cli_credential_test.go

@@ -35,9 +35,9 @@ func TestAzureDeveloperCLICredential_DefaultChainError(t *testing.T) {
 		t.Fatal(err)
 	}
 	_, err = cred.GetToken(context.Background(), testTRO)
-	var ue *credentialUnavailableError
-	if !errors.As(err, &ue) {
-		t.Fatalf("expected credentialUnavailableError, got %T: %q", err, err)
+	var cu credentialUnavailable
+	if !errors.As(err, &cu) {
+		t.Fatalf("expected %T, got %T: %q", cu, err, err)
 	}
 }
 

sdk/azidentity/chained_token_credential.go

@@ -86,7 +86,7 @@ func (c *ChainedTokenCredential) GetToken(ctx context.Context, opts policy.Token
 		errs                 []error
 		successfulCredential azcore.TokenCredential
 		token                azcore.AccessToken
-		unavailableErr       *credentialUnavailableError
+		unavailableErr       credentialUnavailable
 	)
 	for _, cred := range c.sources {
 		token, err = cred.GetToken(ctx, opts)

sdk/azidentity/chained_token_credential_test.go

@@ -139,8 +139,8 @@ func TestChainedTokenCredential_MultipleCredentialsGetTokenUnavailable(t *testin
 		t.Fatal(err)
 	}
 	_, err = cred.GetToken(context.Background(), testTRO)
-	if _, ok := err.(*credentialUnavailableError); !ok {
-		t.Fatalf("expected credentialUnavailableError, received %T", err)
+	if _, ok := err.(credentialUnavailable); !ok {
+		t.Fatalf("expected credentialUnavailable, received %T", err)
 	}
 	expectedError := `ChainedTokenCredential: failed to acquire a token.
 Attempted credentials:
@@ -186,8 +186,8 @@ func TestChainedTokenCredential_MultipleCredentialsGetTokenCustomName(t *testing
 	}
 	cred.name = "CustomNameCredential"
 	_, err = cred.GetToken(context.Background(), testTRO)
-	if _, ok := err.(*credentialUnavailableError); !ok {
-		t.Fatalf("expected credentialUnavailableError, received %T", err)
+	if _, ok := err.(credentialUnavailable); !ok {
+		t.Fatalf("expected credentialUnavailable, received %T", err)
 	}
 	expectedError := `CustomNameCredential: failed to acquire a token.
 Attempted credentials:

sdk/azidentity/confidential_client.go

@@ -109,7 +109,7 @@ func (c *confidentialClient) GetToken(ctx context.Context, tro policy.TokenReque
 	if err != nil {
 		// We could get a credentialUnavailableError from managed identity authentication because in that case the error comes from our code.
 		// We return it directly because it affects the behavior of credential chains. Otherwise, we return AuthenticationFailedError.
-		var unavailableErr *credentialUnavailableError
+		var unavailableErr credentialUnavailable
 		if !errors.As(err, &unavailableErr) {
 			res := getResponseFromError(err)
 			err = newAuthenticationFailedError(c.name, err.Error(), res, err)

sdk/azidentity/default_azure_credential.go

@@ -158,7 +158,7 @@ type defaultCredentialErrorReporter struct {
 }
 
 func (d *defaultCredentialErrorReporter) GetToken(ctx context.Context, opts policy.TokenRequestOptions) (azcore.AccessToken, error) {
-	if _, ok := d.err.(*credentialUnavailableError); ok {
+	if _, ok := d.err.(credentialUnavailable); ok {
 		return azcore.AccessToken{}, d.err
 	}
 	return azcore.AccessToken{}, newCredentialUnavailableError(d.credType, d.err.Error())

sdk/azidentity/default_azure_credential_test.go

@@ -277,8 +277,8 @@ func TestDefaultAzureCredential_timeoutWrapper(t *testing.T) {
 	for i := 0; i < 2; i++ {
 		// expecting credentialUnavailableError because delay exceeds the wrapper's timeout
 		_, err = chain.GetToken(context.Background(), testTRO)
-		if _, ok := err.(*credentialUnavailableError); !ok {
-			t.Fatalf("expected credentialUnavailableError, got %T: %v", err, err)
+		if _, ok := err.(credentialUnavailable); !ok {
+			t.Fatalf("expected credentialUnavailable, got %T: %v", err, err)
 		}
 	}
 

sdk/azidentity/developer_credential_util.go

@@ -19,7 +19,7 @@ const cliTimeout = 10 * time.Second
 // the next credential in its chain (another developer credential).
 func unavailableIfInChain(err error, inDefaultChain bool) error {
 	if err != nil && inDefaultChain {
-		var unavailableErr *credentialUnavailableError
+		var unavailableErr credentialUnavailable
 		if !errors.As(err, &unavailableErr) {
 			err = newCredentialUnavailableError(credNameAzureDeveloperCLI, err.Error())
 		}

sdk/azidentity/device_code_credential.go

@@ -34,8 +34,8 @@ type DeviceCodeCredentialOptions struct {
 	ClientID string
 
 	// DisableAutomaticAuthentication prevents the credential from automatically prompting the user to authenticate.
-	// When this option is true, [DeviceCodeCredential.GetToken] will return [ErrAuthenticationRequired] when user
-	// interaction is necessary to acquire a token.
+	// When this option is true, GetToken will return AuthenticationRequiredError when user interaction is necessary
+	// to acquire a token.
 	DisableAutomaticAuthentication bool
 
 	// DisableInstanceDiscovery should be set true only by applications authenticating in disconnected clouds, or

sdk/azidentity/errors.go

@@ -13,15 +13,12 @@ import (
 	"fmt"
 	"net/http"
 
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/policy"
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/runtime"
 	"github.com/Azure/azure-sdk-for-go/sdk/internal/errorinfo"
 	msal "github.com/AzureAD/microsoft-authentication-library-for-go/apps/errors"
 )
 
-// ErrAuthenticationRequired indicates a credential's Authenticate method must be called to acquire a token
-// because user interaction is required and the credential is configured not to automatically prompt the user.
-var ErrAuthenticationRequired error = &credentialUnavailableError{"can't acquire a token without user interaction. Call Authenticate to interactively authenticate a user"}
-
 // getResponseFromError retrieves the response carried by
 // an AuthenticationFailedError or MSAL CallErr, if any
 func getResponseFromError(err error) *http.Response {
@@ -110,8 +107,34 @@ func (*AuthenticationFailedError) NonRetriable() {
 
 var _ errorinfo.NonRetriable = (*AuthenticationFailedError)(nil)
 
-// credentialUnavailableError indicates a credential can't attempt authentication because it lacks required
-// data or state
+// AuthenticationRequiredError indicates a credential's Authenticate method must be called to acquire a token
+// because the credential requires user interaction and is configured not to request it automatically.
+type AuthenticationRequiredError struct {
+	credentialUnavailableError
+
+	// TokenRequestOptions for the required token. Pass this to the credential's Authenticate method.
+	TokenRequestOptions policy.TokenRequestOptions
+}
+
+func newAuthenticationRequiredError(credType string, tro policy.TokenRequestOptions) error {
+	return &AuthenticationRequiredError{
+		credentialUnavailableError: credentialUnavailableError{
+			credType + " can't acquire a token without user interaction. Call Authenticate to authenticate a user interactively",
+		},
+		TokenRequestOptions: tro,
+	}
+}
+
+var (
+	_ credentialUnavailable  = (*AuthenticationRequiredError)(nil)
+	_ errorinfo.NonRetriable = (*AuthenticationRequiredError)(nil)
+)
+
+type credentialUnavailable interface {
+	error
+	credentialUnavailable()
+}
+
 type credentialUnavailableError struct {
 	message string
 }
@@ -135,6 +158,11 @@ func (e *credentialUnavailableError) Error() string {
 }
 
 // NonRetriable is a marker method indicating this error should not be retried. It has no implementation.
-func (e *credentialUnavailableError) NonRetriable() {}
+func (*credentialUnavailableError) NonRetriable() {}
+
+func (*credentialUnavailableError) credentialUnavailable() {}
 
-var _ errorinfo.NonRetriable = (*credentialUnavailableError)(nil)
+var (
+	_ credentialUnavailable  = (*credentialUnavailableError)(nil)
+	_ errorinfo.NonRetriable = (*credentialUnavailableError)(nil)
+)

sdk/azidentity/example_shared_test.go

@@ -12,12 +12,13 @@ import (
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore"
 )
 
-// Helpers and variables to keep the examples tidy
+// Helpers, variables, fakes to keep the examples tidy
 
 const (
-	certPath = "testdata/certificate.pem"
-	clientID = "fake-client-id"
-	tenantID = "fake-tenant"
+	authRecordPath = "fake/path"
+	certPath       = "testdata/certificate.pem"
+	clientID       = "fake-client-id"
+	tenantID       = "fake-tenant"
 )
 
 func handleError(err error) {
@@ -28,3 +29,13 @@ func handleError(err error) {
 
 var cred azcore.TokenCredential
 var err error
+
+type exampleServiceClient struct{}
+
+func newServiceClient(azcore.TokenCredential) (exampleServiceClient, error) {
+	return exampleServiceClient{}, nil
+}
+
+func (exampleServiceClient) Method() error {
+	return nil
+}

sdk/azidentity/example_test.go

@@ -7,11 +7,49 @@
 package azidentity_test
 
 import (
+	"context"
+	"errors"
 	"os"
 
 	"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
 )
 
+// Credentials that require user interaction such as [InteractiveBrowserCredential] and [DeviceCodeCredential]
+// can optionally return this error instead of automatically prompting for user interaction. This allows applications
+// to decide when to request user interaction. This example shows how to handle the error and authenticate a user
+// interactively. It shows [InteractiveBrowserCredential] but the same pattern applies to [DeviceCodeCredential].
+func ExampleAuthenticationRequiredError() {
+	cred, err := azidentity.NewInteractiveBrowserCredential(
+		&azidentity.InteractiveBrowserCredentialOptions{
+			// This option is useful only for applications that need to control when to prompt users to
+			// authenticate. If the timing of user interaction isn't important, don't set this option.
+			DisableAutomaticAuthentication: true,
+		},
+	)
+	if err != nil {
+		// TODO: handle error
+	}
+	// this could be any client that authenticates with an azidentity credential
+	client, err := newServiceClient(cred)
+	if err != nil {
+		// TODO: handle error
+	}
+	err = client.Method()
+	if err != nil {
+		var are *azidentity.AuthenticationRequiredError
+		if errors.As(err, &are) {
+			// The client requested a token and the credential requires user interaction. Whenever it's convenient
+			// for the application, call Authenticate to prompt the user. Pass the error's TokenRequestOptions to
+			// request a token with the parameters the client specified.
+			_, err = cred.Authenticate(context.TODO(), &are.TokenRequestOptions)
+			if err != nil {
+				// TODO: handle error
+			}
+			// TODO: retry the client method; it should succeed because the credential now has the required token
+		}
+	}
+}
+
 func ExampleNewOnBehalfOfCredentialWithCertificate() {
 	data, err := os.ReadFile(certPath)
 	if err != nil {