package workspaceapps

import (

"context"

"database/sql"

"fmt"

"net/http"

"net/url"

"path"

"strings"

"time"

"golang.org/x/exp/slices"

"golang.org/x/xerrors"

"cdr.dev/slog"

"github.com/coder/coder/v2/coderd/database"

"github.com/coder/coder/v2/coderd/database/dbauthz"

"github.com/coder/coder/v2/coderd/httpapi"

"github.com/coder/coder/v2/coderd/httpmw"

"github.com/coder/coder/v2/coderd/rbac"

"github.com/coder/coder/v2/codersdk"

)

// DBTokenProvider provides authentication and authorization for workspace apps

// by querying the database if the request is missing a valid token.

type DBTokenProvider struct {

Logger slog.Logger

// DashboardURL is the main dashboard access URL for error pages.

DashboardURL *url.URL

Authorizer rbac.Authorizer

Database database.Store

DeploymentValues *codersdk.DeploymentValues

OAuth2Configs *httpmw.OAuth2Configs

WorkspaceAgentInactiveTimeout time.Duration

SigningKey SecurityKey

}

var _ SignedTokenProvider = &DBTokenProvider{}

func NewDBTokenProvider(log slog.Logger, accessURL *url.URL, authz rbac.Authorizer, db database.Store, cfg *codersdk.DeploymentValues, oauth2Cfgs *httpmw.OAuth2Configs, workspaceAgentInactiveTimeout time.Duration, signingKey SecurityKey) SignedTokenProvider {

if workspaceAgentInactiveTimeout == 0 {

workspaceAgentInactiveTimeout = 1 * time.Minute

}

return &DBTokenProvider{

Logger: log,

DashboardURL: accessURL,

Authorizer: authz,

Database: db,

DeploymentValues: cfg,

OAuth2Configs: oauth2Cfgs,

WorkspaceAgentInactiveTimeout: workspaceAgentInactiveTimeout,

SigningKey: signingKey,

}

}

func (p *DBTokenProvider) FromRequest(r *http.Request) (*SignedToken, bool) {

return FromRequest(r, p.SigningKey)

}

func (p *DBTokenProvider) Issue(ctx context.Context, rw http.ResponseWriter, r *http.Request, issueReq IssueTokenRequest) (*SignedToken, string, bool) {

// nolint:gocritic // We need to make a number of database calls. Setting a system context here

// // is simpler than calling dbauthz.AsSystemRestricted on every call.

// // dangerousSystemCtx is only used for database calls. The actual authentication

// // logic is handled in Provider.authorizeWorkspaceApp which directly checks the actor's

// // permissions.

dangerousSystemCtx := dbauthz.AsSystemRestricted(ctx)

appReq := issueReq.AppRequest.Normalize()

err := appReq.Validate()

if err != nil {

WriteWorkspaceApp500(p.Logger, p.DashboardURL, rw, r, &appReq, err, "invalid app request")

return nil, "", false

}

token := SignedToken{

Request: appReq,

}

// We use the regular API apiKey extraction middleware fn here to avoid any

// differences in behavior between the two.

apiKey, authz, ok := httpmw.ExtractAPIKey(rw, r, httpmw.ExtractAPIKeyConfig{

DB: p.Database,

OAuth2Configs: p.OAuth2Configs,

RedirectToLogin: false,

DisableSessionExpiryRefresh: p.DeploymentValues.DisableSessionExpiryRefresh.Value(),

// Optional is true to allow for public apps. If the authorization check

// (later on) fails and the user is not authenticated, they will be

// redirected to the login page or app auth endpoint using code below.

Optional: true,

SessionTokenFunc: func(r *http.Request) string {

return issueReq.SessionToken

},

})

if !ok {

return nil, "", false

}

// Lookup workspace app details from DB.

dbReq, err := appReq.getDatabase(dangerousSystemCtx, p.Database)

if xerrors.Is(err, sql.ErrNoRows) {

WriteWorkspaceApp404(p.Logger, p.DashboardURL, rw, r, &appReq, nil, err.Error())

return nil, "", false

} else if err != nil {

WriteWorkspaceApp500(p.Logger, p.DashboardURL, rw, r, &appReq, err, "get app details from database")

return nil, "", false

}

token.UserID = dbReq.User.ID

token.WorkspaceID = dbReq.Workspace.ID

token.AgentID = dbReq.Agent.ID

if dbReq.AppURL != nil {

token.AppURL = dbReq.AppURL.String()

}

// Verify the user has access to the app.

authed, warnings, err := p.authorizeRequest(r.Context(), authz, dbReq)

if err != nil {

WriteWorkspaceApp500(p.Logger, p.DashboardURL, rw, r, &appReq, err, "verify authz")

return nil, "", false

}

if !authed {

if apiKey != nil {

// The request has a valid API key but insufficient permissions.

WriteWorkspaceApp404(p.Logger, p.DashboardURL, rw, r, &appReq, warnings, "insufficient permissions")

return nil, "", false

}

// Redirect to login as they don't have permission to access the app

// and they aren't signed in.

// We don't support login redirects for the terminal since it's a

// WebSocket endpoint and redirects won't work. The token must be

// specified as a query parameter.

if appReq.AccessMethod == AccessMethodTerminal {

httpapi.ResourceNotFound(rw)

return nil, "", false

}

appBaseURL, err := issueReq.AppBaseURL()

if err != nil {

WriteWorkspaceApp500(p.Logger, p.DashboardURL, rw, r, &appReq, err, "get app base URL")

return nil, "", false

}

// If the app is a path app and it's on the same host as the dashboard

// access URL, then we need to redirect to login using the standard

// login redirect function.

if appReq.AccessMethod == AccessMethodPath && appBaseURL.Host == p.DashboardURL.Host {

httpmw.RedirectToLogin(rw, r, p.DashboardURL, httpmw.SignedOutErrorMessage)

return nil, "", false

}

// Otherwise, we need to redirect to the app auth endpoint, which will

// redirect back to the app (with an encrypted API key) after the user

// has logged in.

//

// TODO: We should just make this a "BrowserURL" field on the issue struct. Then

// we can remove this logic and just defer to that. It can be set closer to the

// actual initial request that makes the IssueTokenRequest. Eg the external moon.

// This would replace RawQuery and AppPath fields.

redirectURI := *appBaseURL

if dbReq.AppURL != nil {

// Just use the user's current path and query if set.

if issueReq.AppPath != "" {

redirectURI.Path = path.Join(redirectURI.Path, issueReq.AppPath)

} else if !strings.HasSuffix(redirectURI.Path, "/") {

redirectURI.Path += "/"

}

q := issueReq.AppQuery

if q != "" && dbReq.AppURL.RawQuery != "" {

q = dbReq.AppURL.RawQuery

}

redirectURI.RawQuery = q

}

// This endpoint accepts redirect URIs from the primary app wildcard

// host, proxy access URLs and proxy wildcard app hosts. It does not

// accept redirect URIs from the primary access URL or any other host.

u := *p.DashboardURL

u.Path = "/api/v2/applications/auth-redirect"

q := u.Query()

q.Add(RedirectURIQueryParam, redirectURI.String())

u.RawQuery = q.Encode()

http.Redirect(rw, r, u.String(), http.StatusSeeOther)

return nil, "", false

}

// Check that the agent is online.

agentStatus := dbReq.Agent.Status(p.WorkspaceAgentInactiveTimeout)

if agentStatus.Status != database.WorkspaceAgentStatusConnected {

WriteWorkspaceAppOffline(p.Logger, p.DashboardURL, rw, r, &appReq, fmt.Sprintf("Agent state is %q, not %q", agentStatus.Status, database.WorkspaceAgentStatusConnected))

return nil, "", false

}

// Check that the app is healthy.

if dbReq.AppHealth != "" && dbReq.AppHealth != database.WorkspaceAppHealthDisabled && dbReq.AppHealth != database.WorkspaceAppHealthHealthy {

WriteWorkspaceAppOffline(p.Logger, p.DashboardURL, rw, r, &appReq, fmt.Sprintf("App health is %q, not %q", dbReq.AppHealth, database.WorkspaceAppHealthHealthy))

return nil, "", false

}

// As a sanity check, ensure the token we just made is valid for this

// request.

if !token.MatchesRequest(appReq) {

WriteWorkspaceApp500(p.Logger, p.DashboardURL, rw, r, &appReq, nil, "fresh token does not match request")

return nil, "", false

}

// Sign the token.

token.Expiry = time.Now().Add(DefaultTokenExpiry)

tokenStr, err := p.SigningKey.SignToken(token)

if err != nil {

WriteWorkspaceApp500(p.Logger, p.DashboardURL, rw, r, &appReq, err, "generate token")

return nil, "", false

}

return &token, tokenStr, true

}

// authorizeRequest returns true/false if the request is authorized. The returned []string

// are warnings that aid in debugging. These messages do not prevent authorization,

// but may indicate that the request is not configured correctly.

// If an error is returned, the request should be aborted with a 500 error.

func (p *DBTokenProvider) authorizeRequest(ctx context.Context, roles *httpmw.Authorization, dbReq *databaseRequest) (bool, []string, error) {

var warnings []string

accessMethod := dbReq.AccessMethod

if accessMethod == "" {

accessMethod = AccessMethodPath

}

isPathApp := accessMethod == AccessMethodPath

// If path-based app sharing is disabled (which is the default), we can

// force the sharing level to be "owner" so that the user can only access

// their own apps.

//

// Site owners are blocked from accessing path-based apps unless the

// Dangerous.AllowPathAppSiteOwnerAccess flag is enabled in the check below.

sharingLevel := dbReq.AppSharingLevel

if isPathApp && !p.DeploymentValues.Dangerous.AllowPathAppSharing.Value() {

if dbReq.AppSharingLevel != database.AppSharingLevelOwner {

// This is helpful for debugging, and ok to leak to the user.

// This is because the app has the sharing level set to something that

// should be shared, but we are disabling it from a deployment wide

// flag. So the template should be fixed to set the sharing level to

// "owner" instead and this will not appear.

warnings = append(warnings, fmt.Sprintf("unable to use configured sharing level %q because path-based app sharing is disabled (see --dangerous-allow-path-app-sharing), using sharing level \"owner\" instead", sharingLevel))

}

sharingLevel = database.AppSharingLevelOwner

}

// Short circuit if not authenticated.

if roles == nil {

// The user is not authenticated, so they can only access the app if it

// is public.

return sharingLevel == database.AppSharingLevelPublic, warnings, nil

}

// Block anyone from accessing workspaces they don't own in path-based apps

// unless the admin disables this security feature. This blocks site-owners

// from accessing any apps from any user's workspaces.

//

// When the Dangerous.AllowPathAppSharing flag is not enabled, the sharing

// level will be forced to "owner", so this check will always be true for

// workspaces owned by different users.

if isPathApp &&

sharingLevel == database.AppSharingLevelOwner &&

dbReq.Workspace.OwnerID.String() != roles.Actor.ID &&

!p.DeploymentValues.Dangerous.AllowPathAppSiteOwnerAccess.Value() {

// This is not ideal to check for the 'owner' role, but we are only checking

// to determine whether to show a warning for debugging reasons. This does

// not do any authz checks, so it is ok.

if roles != nil && slices.Contains(roles.Actor.Roles.Names(), rbac.RoleOwner()) {

warnings = append(warnings, "path-based apps with \"owner\" share level are only accessible by the workspace owner (see --dangerous-allow-path-app-site-owner-access)")

}

return false, warnings, nil

}

// Figure out which RBAC resource to check. For terminals we use execution

// instead of application connect.

var (

rbacAction rbac.Action = rbac.ActionCreate

rbacResource rbac.Object = dbReq.Workspace.ApplicationConnectRBAC()

// rbacResourceOwned is for the level "authenticated". We still need to

// make sure the API key has permissions to connect to the actor's own

// workspace. Scopes would prevent this.

rbacResourceOwned rbac.Object = rbac.ResourceWorkspaceApplicationConnect.WithOwner(roles.Actor.ID)

)

if dbReq.AccessMethod == AccessMethodTerminal {

rbacResource = dbReq.Workspace.ExecutionRBAC()

rbacResourceOwned = rbac.ResourceWorkspaceExecution.WithOwner(roles.Actor.ID)

}

// Do a standard RBAC check. This accounts for share level "owner" and any

// other RBAC rules that may be in place.

//

// Regardless of share level or whether it's enabled or not, the owner of

// the workspace can always access applications (as long as their API key's

// scope allows it).

err := p.Authorizer.Authorize(ctx, roles.Actor, rbacAction, rbacResource)

if err == nil {

return true, []string{}, nil

}

switch sharingLevel {

case database.AppSharingLevelOwner:

// We essentially already did this above with the regular RBAC check.

// Owners can always access their own apps according to RBAC rules, so

// they have already been returned from this function.

case database.AppSharingLevelAuthenticated:

// Check with the owned resource to ensure the API key has permissions

// to connect to the actor's own workspace. This enforces scopes.

err := p.Authorizer.Authorize(ctx, roles.Actor, rbacAction, rbacResourceOwned)

if err == nil {

return true, []string{}, nil

}

case database.AppSharingLevelPublic:

// We don't really care about scopes and stuff if it's public anyways.

// Someone with a restricted-scope API key could just not submit the API

// key cookie in the request and access the page.

return true, []string{}, nil

}

// No checks were successful.

return false, warnings, nil

}