Secure user worker operations

PLAN.md

@@ -872,7 +872,9 @@ workload logic into the service.
 
 **Acceptance criteria:**
 
-- the service has a versioned, documented API and owns user identity data;
+- the service has a versioned, documented API in
+  [`docs/user-service-api-contract.md`](docs/user-service-api-contract.md) and
+  owns user identity data;
 - credentials and authentication tokens are stored and handled securely; they
   are never logged or exposed to workers;
 - authenticated identity is propagated to coordinator requests through an

coordinator/cmd/coordinator/main.go

@@ -78,10 +78,10 @@ func run() error {
 		RenewLease:       usecase.NewRenewLease(taskRepo, workerRepo, tx, clk, cfg.LeaseDuration),
 		CompleteTask:     usecase.NewCompleteTask(taskRepo, jobRepo, artifactRepo, workerRepo, taskResultRepo, tx, clk, cfg.QuorumSize),
 		ReduceJob:        usecase.NewReduceJob(jobRepo, taskRepo, artifactRepo, blobStore, tx, clk),
-		FailTask:         usecase.NewFailTask(taskRepo, jobRepo, tx, clk),
+		FailTask:         usecase.NewFailTask(taskRepo, jobRepo, workerRepo, tx, clk),
 		GetJobStatus:     usecase.NewGetJobStatus(jobRepo, taskRepo),
 		CancelJob:        usecase.NewCancelJob(jobRepo, taskRepo, tx, clk),
-		UploadArtifact:   usecase.NewUploadArtifact(taskRepo, artifactRepo, blobStore, tx, clk),
+		UploadArtifact:   usecase.NewUploadArtifact(taskRepo, workerRepo, artifactRepo, blobStore, tx, clk),
 		DownloadArtifact: usecase.NewDownloadArtifact(artifactRepo, blobStore),
 		GetJobResult:     usecase.NewGetJobResult(jobRepo, usecase.NewDownloadArtifact(artifactRepo, blobStore)),
 		GetTaskInput:     usecase.NewGetTaskInput(taskRepo, artifactRepo, blobStore),

coordinator/internal/transport/http/server_test.go

@@ -52,11 +52,11 @@ func newEnvWithUIToken(t *testing.T, ready func(context.Context) error, configur
 		RenewLease:       usecase.NewRenewLease(tasks, work, tx, clk, lease),
 		CompleteTask:     usecase.NewCompleteTask(tasks, jobs, arts, work, memstore.NewTaskResultRepo(), tx, clk, 2),
 		ReduceJob:        usecase.NewReduceJob(jobs, tasks, arts, blobs, tx, clk),
-		FailTask:         usecase.NewFailTask(tasks, jobs, tx, clk),
+		FailTask:         usecase.NewFailTask(tasks, jobs, work, tx, clk),
 		GetJobStatus:     usecase.NewGetJobStatus(jobs, tasks),
 		GetJobResult:     usecase.NewGetJobResult(jobs, downloadArtifact),
 		CancelJob:        usecase.NewCancelJob(jobs, tasks, tx, clk),
-		UploadArtifact:   usecase.NewUploadArtifact(tasks, arts, blobs, tx, clk),
+		UploadArtifact:   usecase.NewUploadArtifact(tasks, work, arts, blobs, tx, clk),
 		DownloadArtifact: downloadArtifact,
 		GetTaskInput:     usecase.NewGetTaskInput(tasks, arts, blobs),
 		Dashboard:        usecase.NewDashboard(memstore.NewUIReadRepo(jobs, tasks, work, arts)),

coordinator/internal/usecase/artifact.go

@@ -12,18 +12,22 @@ import (
 // UploadArtifact stores a worker's partial-result bytes and records the metadata.
 type UploadArtifact struct {
 	tasks     TaskRepository
+	workers   WorkerRepository
 	artifacts ArtifactRepository
 	blobs     BlobStore
 	tx        TxManager
 	clk       Clock
 }
 
-func NewUploadArtifact(tasks TaskRepository, artifacts ArtifactRepository,
+func NewUploadArtifact(tasks TaskRepository, workers WorkerRepository, artifacts ArtifactRepository,
 	blobs BlobStore, tx TxManager, clk Clock) *UploadArtifact {
-	return &UploadArtifact{tasks: tasks, artifacts: artifacts, blobs: blobs, tx: tx, clk: clk}
+	return &UploadArtifact{tasks: tasks, workers: workers, artifacts: artifacts, blobs: blobs, tx: tx, clk: clk}
 }
 
 func (uc *UploadArtifact) Execute(ctx context.Context, in UploadArtifactInput) (*domain.Artifact, error) {
+	if err := authorizeWorkerOwner(ctx, uc.workers, in.WorkerID); err != nil {
+		return nil, err
+	}
 	task, err := uc.tasks.Get(ctx, in.TaskID)
 	if err != nil {
 		return nil, err

coordinator/internal/usecase/task.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/google/uuid"
 
-	"github.com/emil28092005/SciMesh/coordinator/internal/authctx"
 	"github.com/emil28092005/SciMesh/coordinator/internal/domain"
 )
 
@@ -59,11 +58,8 @@ func (uc *ClaimTask) Execute(ctx context.Context, in ClaimTaskInput) (*domain.Cl
 		// tier would be read off a caller-supplied worker_id, letting anyone who
 		// knows a trusted worker's id claim as it. A shared-token caller (no
 		// requester) is a lab operator and may act as any worker.
-		if r, ok := authctx.From(ctx); ok {
-			if worker.OwnerID == nil || *worker.OwnerID != r.UserID {
-				// Don't disclose that another user's worker exists.
-				return nil, domain.ErrWorkerNotFound
-			}
+		if err := authorizeWorkerOwner(ctx, uc.workers, in.WorkerID); err != nil {
+			return nil, err
 		}
 		// An untrusted volunteer may claim, but never a chunk its owner has
 		// already voted on — so quorum needs genuinely independent computations.
@@ -126,6 +122,9 @@ func NewRenewLease(tasks TaskRepository, workers WorkerRepository, tx TxManager,
 // locked: two concurrent heartbeats must not interleave into a lost update.
 // Whether the caller may renew at all is decided by the entity, not here.
 func (uc *RenewLease) Execute(ctx context.Context, in RenewLeaseInput) (*domain.ClaimedTask, error) {
+	if err := authorizeWorkerOwner(ctx, uc.workers, in.WorkerID); err != nil {
+		return nil, err
+	}
 	var claimed domain.ClaimedTask
 
 	err := uc.tx.WithinTx(ctx, func(ctx context.Context) error {
@@ -186,6 +185,9 @@ func NewCompleteTask(tasks TaskRepository, jobs JobRepository, artifacts Artifac
 // Lease ownership, staleness, and idempotent replays are all decided by
 // Task.CompleteWith; this use case only orchestrates.
 func (uc *CompleteTask) Execute(ctx context.Context, in CompleteTaskInput) (*domain.Task, error) {
+	if err := authorizeWorkerOwner(ctx, uc.workers, in.WorkerID); err != nil {
+		return nil, err
+	}
 	var out *domain.Task
 
 	err := uc.tx.WithinTx(ctx, func(ctx context.Context) error {
@@ -317,19 +319,23 @@ func (uc *CompleteTask) verifyResultArtifact(ctx context.Context, taskID uuid.UU
 // --- FailTask ------------------------------------------------------------
 
 type FailTask struct {
-	tasks TaskRepository
-	jobs  JobRepository
-	tx    TxManager
-	clock Clock
+	tasks   TaskRepository
+	jobs    JobRepository
+	workers WorkerRepository
+	tx      TxManager
+	clock   Clock
 }
 
-func NewFailTask(tasks TaskRepository, jobs JobRepository, tx TxManager, clock Clock) *FailTask {
-	return &FailTask{tasks: tasks, jobs: jobs, tx: tx, clock: clock}
+func NewFailTask(tasks TaskRepository, jobs JobRepository, workers WorkerRepository, tx TxManager, clock Clock) *FailTask {
+	return &FailTask{tasks: tasks, jobs: jobs, workers: workers, tx: tx, clock: clock}
 }
 
 // Execute delegates the requeue-or-terminate decision to Task.Fail, then keeps
 // the parent job's status consistent in the same transaction.
 func (uc *FailTask) Execute(ctx context.Context, in FailTaskInput) (*domain.Task, error) {
+	if err := authorizeWorkerOwner(ctx, uc.workers, in.WorkerID); err != nil {
+		return nil, err
+	}
 	var out *domain.Task
 
 	err := uc.tx.WithinTx(ctx, func(ctx context.Context) error {

coordinator/internal/usecase/usecase_test.go

@@ -77,11 +77,11 @@ func newHarness() *harness {
 	h.claim = usecase.NewClaimTask(h.tasks, h.jobs, h.work, tx, h.clk, lease)
 	h.renew = usecase.NewRenewLease(h.tasks, h.work, tx, h.clk, lease)
 	h.complete = usecase.NewCompleteTask(h.tasks, h.jobs, h.arts, h.work, h.taskResults, tx, h.clk, 2)
-	h.fail = usecase.NewFailTask(h.tasks, h.jobs, tx, h.clk)
+	h.fail = usecase.NewFailTask(h.tasks, h.jobs, h.work, tx, h.clk)
 	h.status = usecase.NewGetJobStatus(h.jobs, h.tasks)
 	h.results = usecase.NewListResults(h.tasks)
 	h.register = usecase.NewRegisterWorker(h.work, h.clk)
-	h.uploadArt = usecase.NewUploadArtifact(h.tasks, h.arts, h.blobs, tx, h.clk)
+	h.uploadArt = usecase.NewUploadArtifact(h.tasks, h.work, h.arts, h.blobs, tx, h.clk)
 	h.downloadArt = usecase.NewDownloadArtifact(h.arts, h.blobs)
 	h.getInput = usecase.NewGetTaskInput(h.tasks, h.arts, h.blobs)
 	h.expire = usecase.NewExpireLeases(h.tasks, h.jobs, tx, h.clk)
@@ -318,6 +318,36 @@ func TestJWTCallerCannotClaimAsAnotherUsersWorker(t *testing.T) {
 	}
 }
 
+func TestJWTCallerCannotMutateAnotherUsersWorkerLease(t *testing.T) {
+	h := newHarness()
+	h.seedJob(t, "w", 1)
+	victimOwner := uuid.New()
+	victim, err := h.register.Execute(ctx, usecase.RegisterWorkerInput{
+		Name: "victim", Capabilities: []string{"w"}, OwnerID: &victimOwner, TrustLevel: domain.WorkerTrusted,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	claimed, err := h.claim.Execute(ctx, usecase.ClaimTaskInput{WorkerID: victim.ID.String()})
+	if err != nil || claimed == nil {
+		t.Fatalf("claim = (%v, %v)", claimed, err)
+	}
+	attacker := authctx.With(ctx, authctx.Requester{UserID: uuid.New(), Role: "user"})
+
+	if _, err := h.renew.Execute(attacker, usecase.RenewLeaseInput{TaskID: claimed.TaskID, WorkerID: victim.ID.String(), Attempt: claimed.Attempt}); !errors.Is(err, domain.ErrWorkerNotFound) {
+		t.Errorf("foreign heartbeat err = %v, want ErrWorkerNotFound", err)
+	}
+	if _, err := h.fail.Execute(attacker, usecase.FailTaskInput{TaskID: claimed.TaskID, WorkerID: victim.ID.String(), Attempt: claimed.Attempt, ErrorCode: "x"}); !errors.Is(err, domain.ErrWorkerNotFound) {
+		t.Errorf("foreign failure err = %v, want ErrWorkerNotFound", err)
+	}
+	if _, err := h.uploadArt.Execute(attacker, usecase.UploadArtifactInput{TaskID: claimed.TaskID, WorkerID: victim.ID.String(), Attempt: claimed.Attempt, Filename: "x.csv", ContentType: "text/csv", Body: strings.NewReader("x")}); !errors.Is(err, domain.ErrWorkerNotFound) {
+		t.Errorf("foreign upload err = %v, want ErrWorkerNotFound", err)
+	}
+	if _, err := h.complete.Execute(attacker, usecase.CompleteTaskInput{TaskID: claimed.TaskID, WorkerID: victim.ID.String(), Attempt: claimed.Attempt, ResultArtifactID: uuid.New()}); !errors.Is(err, domain.ErrWorkerNotFound) {
+		t.Errorf("foreign result err = %v, want ErrWorkerNotFound", err)
+	}
+}
+
 func TestJWTCallerClaimsAsOwnTrustedWorker(t *testing.T) {
 	h := newHarness()
 	h.seedJob(t, "w", 1)
@@ -551,7 +581,7 @@ func TestUploadRejectsLeaseThatExpiresDuringStreaming(t *testing.T) {
 	h.seedJob(t, "w", 1)
 	taskID, attempt := h.leaseOne(t, "w1", "w")
 	h.uploadArt = usecase.NewUploadArtifact(
-		h.tasks, h.arts, expiringBlobStore{BlobStore: h.blobs, clock: h.clk}, memstore.Tx{}, h.clk,
+		h.tasks, h.work, h.arts, expiringBlobStore{BlobStore: h.blobs, clock: h.clk}, memstore.Tx{}, h.clk,
 	)
 
 	_, err := h.uploadArt.Execute(ctx, usecase.UploadArtifactInput{

coordinator/internal/usecase/worker_authorization.go

@@ -0,0 +1,33 @@
+package usecase
+
+import (
+	"context"
+
+	"github.com/google/uuid"
+
+	"github.com/emil28092005/SciMesh/coordinator/internal/authctx"
+	"github.com/emil28092005/SciMesh/coordinator/internal/domain"
+)
+
+// authorizeWorkerOwner binds a JWT-authenticated requester to a worker. The
+// shared coordinator token intentionally has no requester and retains its
+// existing operator privileges.
+func authorizeWorkerOwner(ctx context.Context, workers WorkerRepository, workerID string) error {
+	requester, ok := authctx.From(ctx)
+	if !ok {
+		return nil
+	}
+	id, err := uuid.Parse(workerID)
+	if err != nil {
+		return domain.ErrWorkerNotFound
+	}
+	worker, err := workers.Get(ctx, id)
+	if err != nil {
+		return err
+	}
+	if worker.OwnerID == nil || *worker.OwnerID != requester.UserID {
+		// Mask ownership and existence from another user.
+		return domain.ErrWorkerNotFound
+	}
+	return nil
+}

docs/user-service-api-contract.md

@@ -0,0 +1,47 @@
+# SciMesh User Service API contract (v1)
+
+**Status:** `v1`. The User Service owns user accounts and issues access tokens.
+The coordinator never receives user passwords and never accesses the User
+Service database.
+
+## Authentication boundary
+
+- User Service signs access tokens; coordinator verifies them before accepting
+  user-scoped requests.
+- Tokens contain a UUID `sub`, `role` (`user` or `admin`), `verified`, `iat`,
+  and `exp` claims.
+- A user-authenticated caller may operate only workers whose `owner_id` equals
+  `sub`. This applies to claim, heartbeat, result, failure, and artifact upload.
+- Worker traffic authenticated with the coordinator's shared worker token has
+  no user identity and remains an operator-only compatibility path.
+- Role or verification changes take effect when the access token is renewed.
+  Deployments needing immediate revocation must use a short token lifetime or a
+  revocation mechanism before enabling volunteer-worker trust.
+
+## Endpoints
+
+All JSON request bodies reject unknown fields and are size-limited. Error
+responses are JSON with a stable `error` value and request ID.
+
+| Method | Path | Auth | Success |
+| --- | --- | --- | --- |
+| `GET` | `/health` | none | `200 {"status":"ok"}` |
+| `POST` | `/register` | none | `201` user object |
+| `POST` | `/login` | none | `200` user object and access token |
+| `GET` | `/me` | Bearer access token | `200` current user |
+| `POST` | `/users/{id}/verify` | Bearer admin token | `204` |
+| `POST` | `/users/{id}/unverify` | Bearer admin token | `204` |
+| `POST` | `/users/{id}/promote` | Bearer admin token | `204` |
+| `POST` | `/users/{id}/demote` | Bearer admin token | `204` |
+
+`POST /register` accepts `{ "email": string, "password": string }` and
+always creates role `user` with `verified: false`. `POST /login` accepts the
+same shape and returns `{ "token": string, "user": User }`. Password hashes,
+JWT signing material, and raw tokens must never be logged.
+
+## Coordinator integration tests
+
+The coordinator must test that a JWT user cannot claim or mutate another
+user's worker lease, including heartbeat, failure, result, and artifact upload.
+Job and artifact access is restricted to the job owner unless the caller has
+the admin role.

users/README.md

@@ -5,6 +5,9 @@ and issues the JWTs the coordinator trusts. It is a **separate bounded context**
 from the coordinator: its own database, its own binary. The only thing shared
 between the two services is the JWT signing secret.
 
+The versioned external contract is
+[`docs/user-service-api-contract.md`](../docs/user-service-api-contract.md).
+
 Built as a modular monolith following Clean Architecture — one binary, four
 layers, dependencies pointing strictly inward: