Add user autoprovisioning via libreGraph

When removing the accounts service we lost the user autoprovision
feature. This re-introduces it. When autoprovisioning is enabled (via
PROXY_AUTOPROVISION_ACCOUNTS, as in the past) accounts that are not
resolvable via cs3 will be provsioned via the libregraph API.

Closes: owncloud#3540

extensions/ocs/pkg/service/v0/service.go

@@ -118,7 +118,7 @@ func (o Ocs) getCS3Backend() backend.UserBackend {
 	if err != nil {
 		o.logger.Fatal().Msgf("could not get reva client at address %s", o.config.Reva.Address)
 	}
-	return backend.NewCS3UserBackend(nil, revaClient, o.config.MachineAuthAPIKey, o.logger)
+	return backend.NewCS3UserBackend(nil, revaClient, o.config.MachineAuthAPIKey, "", nil, o.logger)
 }
 
 // NotImplementedStub returns a not implemented error

extensions/proxy/pkg/command/server.go

@@ -8,9 +8,8 @@ import (
 	"os"
 	"time"
 
-	storesvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/store/v0"
-
 	"github.com/coreos/go-oidc/v3/oidc"
+	"github.com/cs3org/reva/v2/pkg/token/manager/jwt"
 	chimiddleware "github.com/go-chi/chi/v5/middleware"
 	"github.com/justinas/alice"
 	"github.com/oklog/run"
@@ -30,6 +29,7 @@ import (
 	"github.com/owncloud/ocis/v2/ocis-pkg/service/grpc"
 	"github.com/owncloud/ocis/v2/ocis-pkg/version"
 	settingssvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/settings/v0"
+	storesvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/store/v0"
 	"github.com/urfave/cli/v2"
 	"golang.org/x/oauth2"
 )
@@ -135,7 +135,15 @@ func loadMiddlewares(ctx context.Context, logger log.Logger, cfg *config.Config)
 	var userProvider backend.UserBackend
 	switch cfg.AccountBackend {
 	case "cs3":
-		userProvider = backend.NewCS3UserBackend(rolesClient, revaClient, cfg.MachineAuthAPIKey, logger)
+		tokenManager, err := jwt.New(map[string]interface{}{
+			"secret": cfg.TokenManager.JWTSecret,
+		})
+		if err != nil {
+			logger.Error().Err(err).
+				Msg("Failed to create token manager")
+		}
+
+		userProvider = backend.NewCS3UserBackend(rolesClient, revaClient, cfg.MachineAuthAPIKey, cfg.OIDC.Issuer, tokenManager, logger)
 	default:
 		logger.Fatal().Msgf("Invalid accounts backend type '%s'", cfg.AccountBackend)
 	}

extensions/proxy/pkg/config/config.go

@@ -25,13 +25,13 @@ type Config struct {
 	TokenManager          *TokenManager   `yaml:"token_manager"`
 	PolicySelector        *PolicySelector `yaml:"policy_selector"`
 	PreSignedURL          PreSignedURL    `yaml:"pre_signed_url"`
-	AccountBackend        string          `yaml:"account_backend" env:"PROXY_ACCOUNT_BACKEND_TYPE"`
-	UserOIDCClaim         string          `yaml:"user_oidc_claim" env:"PROXY_USER_OIDC_CLAIM"`
-	UserCS3Claim          string          `yaml:"user_cs3_claim" env:"PROXY_USER_CS3_CLAIM"`
-	MachineAuthAPIKey     string          `yaml:"machine_auth_api_key" env:"OCIS_MACHINE_AUTH_API_KEY;PROXY_MACHINE_AUTH_API_KEY"`
-	AutoprovisionAccounts bool            `yaml:"auto_provision_accounts" env:"PROXY_AUTOPROVISION_ACCOUNTS"`
-	EnableBasicAuth       bool            `yaml:"enable_basic_auth" env:"PROXY_ENABLE_BASIC_AUTH"`
-	InsecureBackends      bool            `yaml:"insecure_backends" env:"PROXY_INSECURE_BACKENDS"`
+	AccountBackend        string          `yaml:"account_backend" env:"PROXY_ACCOUNT_BACKEND_TYPE" desc:"Account backend the proxy should use, currenly only 'cs3' is possible here."`
+	UserOIDCClaim         string          `yaml:"user_oidc_claim" env:"PROXY_USER_OIDC_CLAIM" desc:"The name of an OpenID Connect claim that should be used for resolving users with the account backend. Currently defaults to 'email'."`
+	UserCS3Claim          string          `yaml:"user_cs3_claim" env:"PROXY_USER_CS3_CLAIM" desc:"The name of a CS3 user attribute (claim) that should be mapped to the 'user_oidc_claim'. Currently defaults to 'mail' (other possible values are: 'username', 'displayname')"`
+	MachineAuthAPIKey     string          `yaml:"machine_auth_api_key" env:"OCIS_MACHINE_AUTH_API_KEY;PROXY_MACHINE_AUTH_API_KEY" desc: "Machine auth API key used for accessing the 'auth-machine' service."`
+	AutoprovisionAccounts bool            `yaml:"auto_provision_accounts" env:"PROXY_AUTOPROVISION_ACCOUNTS" desc:"Set this to 'true' to automatically provsion users that do not yet exist in the users service on-demand upon first signin. To use this a write-enabled libregraph user backend needs to be setup an running."`
+	EnableBasicAuth       bool            `yaml:"enable_basic_auth" env:"PROXY_ENABLE_BASIC_AUTH" desc:"Set this to true to enable 'basic' (username/password) authentication. (Default: false)"`
+	InsecureBackends      bool            `yaml:"insecure_backends" env:"PROXY_INSECURE_BACKENDS" desc:"Disable TLS certificate validation for all http backend connections. (Default: false)"`
 	AuthMiddleware        AuthMiddleware  `yaml:"auth_middleware"`
 
 	Context context.Context `yaml:"-"`
@@ -83,8 +83,8 @@ type AuthMiddleware struct {
 // OIDC is the config for the OpenID-Connect middleware. If set the proxy will try to authenticate every request
 // with the configured oidc-provider
 type OIDC struct {
-	Issuer        string        `yaml:"issuer" env:"OCIS_URL;OCIS_OIDC_ISSUER;PROXY_OIDC_ISSUER"`
-	Insecure      bool          `yaml:"insecure" env:"OCIS_INSECURE;PROXY_OIDC_INSECURE"`
+	Issuer        string        `yaml:"issuer" env:"OCIS_URL;OCIS_OIDC_ISSUER;PROXY_OIDC_ISSUER" desc:"URL of the OpenID connect identity provider."`
+	Insecure      bool          `yaml:"insecure" env:"OCIS_INSECURE;PROXY_OIDC_INSECURE" desc:"Disable TLS certificate validation for connections to the IDP. (not recommended for production environments."`
 	UserinfoCache UserinfoCache `yaml:"user_info_cache"`
 }
 

extensions/proxy/pkg/middleware/account_resolver.go

@@ -73,8 +73,9 @@ func (m accountResolver) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 			}
 			m.logger.Debug().Interface("claims", claims).Msg("Autoprovisioning user")
 			user, err = m.userProvider.CreateUserFromClaims(req.Context(), claims)
-			// TODO instead of creating an account create a personal storage via the CS3 admin api?
-			// see https://cs3org.github.io/cs3apis/#cs3.admin.user.v1beta1.CreateUserRequest
+			if err != nil {
+				m.logger.Error().Err(err).Msg("Autoprovisioning user failed")
+			}
 		}
 
 		if errors.Is(err, backend.ErrAccountDisabled) {

extensions/proxy/pkg/user/backend/cs3.go

@@ -2,30 +2,49 @@ package backend
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
+	"io"
+	"net/http"
 
 	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
 	cs3 "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
 	rpcv1beta1 "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	types "github.com/cs3org/go-cs3apis/cs3/types/v1beta1"
+	"github.com/cs3org/reva/v2/pkg/auth/scope"
+	revactx "github.com/cs3org/reva/v2/pkg/ctx"
+	"github.com/cs3org/reva/v2/pkg/token"
+	libregraph "github.com/owncloud/libre-graph-api-go"
+	"github.com/owncloud/ocis/v2/extensions/graph/pkg/service/v0/errorcode"
 	settingsService "github.com/owncloud/ocis/v2/extensions/settings/pkg/service/v0"
 	"github.com/owncloud/ocis/v2/ocis-pkg/log"
+	"github.com/owncloud/ocis/v2/ocis-pkg/oidc"
+	"github.com/owncloud/ocis/v2/ocis-pkg/registry"
 	settingssvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/settings/v0"
+	"go-micro.dev/v4/selector"
 )
 
 type cs3backend struct {
+	graphSelector       selector.Selector
 	settingsRoleService settingssvc.RoleService
 	authProvider        RevaAuthenticator
+	oidcISS             string
 	machineAuthAPIKey   string
+	tokenManager        token.Manager
 	logger              log.Logger
 }
 
 // NewCS3UserBackend creates a user-provider which fetches users from a CS3 UserBackend
-func NewCS3UserBackend(rs settingssvc.RoleService, ap RevaAuthenticator, machineAuthAPIKey string, logger log.Logger) UserBackend {
+func NewCS3UserBackend(rs settingssvc.RoleService, ap RevaAuthenticator, machineAuthAPIKey string, oidcISS string, tokenManager token.Manager, logger log.Logger) UserBackend {
+	reg := registry.GetRegistry()
+	sel := selector.NewSelector(selector.Registry(reg))
 	return &cs3backend{
+		graphSelector:       sel,
 		settingsRoleService: rs,
 		authProvider:        ap,
+		oidcISS:             oidcISS,
 		machineAuthAPIKey:   machineAuthAPIKey,
+		tokenManager:        tokenManager,
 		logger:              logger,
 	}
 }
@@ -72,7 +91,7 @@ func (c *cs3backend) GetUserByClaims(ctx context.Context, claim, value string, w
 				RoleId:      settingsService.BundleUUIDRoleUser,
 			})
 			if err != nil {
-				c.logger.Error().Err(err).Msg("Could not add default role")
+				c.logger.Warn().Err(err).Msg("Could not add default role")
 			}
 			roleIDs = append(roleIDs, settingsService.BundleUUIDRoleUser)
 		}
@@ -113,10 +132,191 @@ func (c *cs3backend) Authenticate(ctx context.Context, username string, password
 	return res.User, res.Token, nil
 }
 
+// CreateUserFromClaims creates a new user via libregraph users API, taking the
+// attributes from the provided `claims` map. On success it returns the new
+// user. If the user already exist this is not considered an error and the
+// function will just return the existing user.
 func (c *cs3backend) CreateUserFromClaims(ctx context.Context, claims map[string]interface{}) (*cs3.User, error) {
-	return nil, fmt.Errorf("CS3 Backend does not support creating users from claims")
+	newctx := context.Background()
+	token, err := c.generateAutoProvisionAdminToken(newctx)
+	if err != nil {
+		c.logger.Error().Err(err).Msg("Error generating token for autoprovisioning user.")
+		return nil, err
+	}
+	lgClient, err := c.setupLibregraphClient(ctx, token)
+	if err != nil {
+		c.logger.Error().Err(err).Msg("Error setting up libregraph client.")
+		return nil, err
+	}
+
+	newUser, err := c.libregraphUserFromClaims(newctx, claims)
+	if err != nil {
+		c.logger.Error().Err(err).Interface("claims", claims).Msg("Error creating user from claims")
+		return nil, fmt.Errorf("Error creating user from claims: %w", err)
+	}
+
+	req := lgClient.UsersApi.CreateUser(newctx).User(newUser)
+
+	created, resp, err := req.Execute()
+	var reread bool
+	if err != nil {
+		if resp == nil {
+			return nil, err
+		}
+
+		// If the user already exists here, some other request did already create it in parallel.
+		// So just issue a Debug message and ignore the libregraph error otherwise
+		var lerr error
+		if reread, lerr = c.isAlreadyExists(resp); lerr != nil {
+			c.logger.Error().Err(lerr).Msg("extracting error from ibregraph response body failed.")
+			return nil, err
+		}
+		if !reread {
+			c.logger.Error().Err(err).Msg("Error creating user")
+			return nil, err
+		}
+	}
+
+	// User has been created meanwhile, re-read it to get the user id
+	if reread {
+		c.logger.Debug().Msg("User already exist, re-reading via libregraph")
+		gureq := lgClient.UserApi.GetUser(newctx, newUser.GetOnPremisesSamAccountName())
+		created, resp, err = gureq.Execute()
+		if err != nil {
+			c.logger.Error().Err(err).Msg("Error trying to re-read user from graphAPI")
+			return nil, err
+		}
+	}
+
+	cs3UserCreated := c.cs3UserFromLibregraph(newctx, created)
+
+	return &cs3UserCreated, nil
 }
 
 func (c cs3backend) GetUserGroups(ctx context.Context, userID string) {
 	panic("implement me")
 }
+
+func (c cs3backend) setupLibregraphClient(ctx context.Context, cs3token string) (*libregraph.APIClient, error) {
+	// Use micro registry to resolve next graph service endpoint
+	next, err := c.graphSelector.Select("com.owncloud.graph.graph")
+	if err != nil {
+		c.logger.Debug().Err(err).Msg("setupLibregraphClient: error during Select")
+		return nil, err
+	}
+	node, err := next()
+	if err != nil {
+		c.logger.Debug().Err(err).Msg("setupLibregraphClient: error getting next Node")
+		return nil, err
+	}
+	lgconf := libregraph.NewConfiguration()
+	lgconf.Servers = libregraph.ServerConfigurations{
+		{
+			URL: fmt.Sprintf("%s://%s/graph/v1.0", node.Metadata["protocol"], node.Address),
+		},
+	}
+
+	lgconf.DefaultHeader = map[string]string{revactx.TokenHeader: cs3token}
+	return libregraph.NewAPIClient(lgconf), nil
+}
+
+func (c cs3backend) isAlreadyExists(resp *http.Response) (bool, error) {
+	oDataErr := libregraph.NewOdataErrorWithDefaults()
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		c.logger.Debug().Err(err).Msg("Error trying to read libregraph response")
+		return false, err
+	}
+	err = json.Unmarshal(body, oDataErr)
+	if err != nil {
+		c.logger.Debug().Err(err).Msg("Error unmarshalling libregraph response")
+		return false, err
+	}
+
+	if oDataErr.Error.Code == errorcode.NameAlreadyExists.String() {
+		return true, nil
+	}
+	return false, nil
+}
+
+func (c cs3backend) libregraphUserFromClaims(ctx context.Context, claims map[string]interface{}) (libregraph.User, error) {
+	var ok bool
+	var dn, mail, username string
+	user := libregraph.User{}
+	if dn, ok = claims[oidc.Name].(string); !ok {
+		return user, fmt.Errorf("Missing claim '%s'", oidc.Name)
+	}
+	if mail, ok = claims[oidc.Email].(string); !ok {
+		return user, fmt.Errorf("Missing claim '%s'", oidc.Email)
+	}
+	if username, ok = claims[oidc.PreferredUsername].(string); !ok {
+		c.logger.Warn().Str("claim", oidc.PreferredUsername).Msg("Missing claim for username, falling back to email address")
+		username = mail
+	}
+	user.DisplayName = &dn
+	user.OnPremisesSamAccountName = &username
+	user.Mail = &mail
+	return user, nil
+}
+
+func (c cs3backend) cs3UserFromLibregraph(ctx context.Context, lu *libregraph.User) cs3.User {
+	cs3id := cs3.UserId{
+		Type: cs3.UserType_USER_TYPE_PRIMARY,
+		Idp:  c.oidcISS,
+	}
+
+	cs3id.OpaqueId = lu.GetId()
+
+	cs3user := cs3.User{
+		Id: &cs3id,
+	}
+	cs3user.Username = lu.GetOnPremisesSamAccountName()
+	cs3user.DisplayName = lu.GetDisplayName()
+	cs3user.Mail = lu.GetMail()
+	return cs3user
+}
+
+// This returns an hardcoded internal User, that is privileged to create new User via
+// the Graph API. This user is needed for autoprovisioning of users from incoming OIDC
+// claims.
+func getAutoProvisionUserCreator() (*cs3.User, error) {
+	encRoleID, err := encodeRoleIDs([]string{settingsService.BundleUUIDRoleAdmin})
+	if err != nil {
+		return nil, err
+	}
+
+	autoProvisionUserCreator := &cs3.User{
+		DisplayName: "Autoprovision User",
+		Username:    "autoprovisioner",
+		Id: &cs3.UserId{
+			Idp:      "internal",
+			OpaqueId: "autoprov-user-id00-0000-000000000000",
+		},
+		Opaque: &types.Opaque{
+			Map: map[string]*types.OpaqueEntry{
+				"roles": encRoleID,
+			},
+		},
+	}
+	return autoProvisionUserCreator, nil
+}
+
+func (c cs3backend) generateAutoProvisionAdminToken(ctx context.Context) (string, error) {
+	userCreator, err := getAutoProvisionUserCreator()
+	if err != nil {
+		return "", err
+	}
+
+	s, err := scope.AddOwnerScope(nil)
+	if err != nil {
+		c.logger.Error().Err(err).Msg("could not get owner scope")
+		return "", err
+	}
+
+	token, err := c.tokenManager.MintToken(ctx, userCreator, s)
+	if err != nil {
+		c.logger.Error().Err(err).Msg("could not mint token")
+		return "", err
+	}
+	return token, nil
+}