asyncpoll: refactor Sectigo / Entrust / GlobalSign to bounded polling (Phase 2)

Phase 2 of the #5 acquisition-readiness fix from the 2026-05-01 issuer
coverage audit. Phase 1 (commit 711265b) shipped the shared asyncpoll
package and refactored DigiCert as the reference. This commit applies
the same pattern to the remaining three async-CA connectors and adds
the operator-facing docs.

Per-connector refactors:

- Sectigo (sectigo.go): GetOrderStatus now wraps pollEnrollmentOnce in
  asyncpoll.Poll. The collectNotReady sentinel (cert approved by SCM
  but not yet retrievable from the collect endpoint) maps to
  StillPending and rides the backoff schedule rather than the prior
  "return pending immediately" branch. Added isPermanentStatusError
  helper to distinguish transient HTTP errors (5xx / 429 / network)
  from permanent ones (4xx / parse failure) — the wrapped checkStatus
  errors get triaged at the poll closure boundary.

- Entrust (entrust.go): GetOrderStatus wraps pollEnrollmentOnce. The
  AWAITING_APPROVAL status maps to StillPending; operators using
  approval-pending workflows where humans approve enrollments should
  bump CERTCTL_ENTRUST_POLL_MAX_WAIT_SECONDS to 86400 (24h) so a
  single scheduler tick can wait through the approval window. The
  default 10-minute deadline matches the other three connectors.

- GlobalSign (globalsign.go): GetOrderStatus wraps pollCertificateOnce.
  GlobalSign tracks orders by serial number rather than order ID, but
  the polling shape is identical to the other three. Status-code
  triage matches DigiCert: 4xx (not 429) is permanent, 5xx / 429 /
  network is transient.

Per-connector Config field added:
- DigiCert.PollMaxWaitSeconds (env CERTCTL_DIGICERT_POLL_MAX_WAIT_SECONDS)
- Sectigo.PollMaxWaitSeconds (env CERTCTL_SECTIGO_POLL_MAX_WAIT_SECONDS)
- Entrust.PollMaxWaitSeconds (env CERTCTL_ENTRUST_POLL_MAX_WAIT_SECONDS)
- GlobalSign.PollMaxWaitSeconds (env CERTCTL_GLOBALSIGN_POLL_MAX_WAIT_SECONDS)

internal/config/config.go env-var loaders updated for all four. Default
is 600 seconds (10 minutes); zero falls back to the asyncpoll package
default.

Test-helper updates: every existing test that exercises the pending
branch (collectNotReady, AWAITING_APPROVAL, status="pending", etc.)
now sets PollMaxWaitSeconds=1 in its Config so the test doesn't block
on the production-default 10-minute deadline. Tests that exercise
permanent-error branches (404, 401, malformed JSON, etc.) continue
to return immediately.

Test sites updated:
- buildSectigoConnector helper + GetOrderStatus_CollectNotReady test
- buildEntrustConnector helper + GetOrderStatus_Pending test
- buildGlobalsignConnector helper + GetOrderStatus_Pending test +
  the GetHTTPClient_NoMTLSCertPaths test (network failure now rides
  the backoff schedule rather than returning immediately)

Documentation:
- docs/async-polling.md: new operator reference covering the backoff
  schedule, status-code triage, the four env vars, failure modes, and
  where the implementation lives. Audit blocker citation included.
- docs/connectors.md: per-issuer sections for DigiCert, Sectigo,
  Entrust, GlobalSign each gain the PollMaxWaitSeconds env var row
  and a cross-link to async-polling.md.

Lint cleanup: simplified the isPermanentStatusError branch to satisfy
staticcheck S1008 (single-line return for a final boolean check).

Verified locally:
- gofmt -l . clean
- go vet ./... clean
- staticcheck ./... clean
- golangci-lint run --timeout 5m ./... → 0 issues
- go test -short -count=1 across all 4 connector packages + config + asyncpoll: green

Audit reference: cowork/issuer-coverage-audit-2026-05-01/RESULTS.md
Top-10 fix #5 — Phase 2.

internal/connector/issuer/entrust/entrust.go

@@ -34,6 +34,7 @@ import (
 	"time"
 
 	"github.com/shankar0123/certctl/internal/connector/issuer"
+	"github.com/shankar0123/certctl/internal/connector/issuer/asyncpoll"
 )
 
 // Config represents the Entrust Certificate Services issuer connector configuration.
@@ -58,6 +59,25 @@ type Config struct {
 	// If set, constrains enrollments to use this profile.
 	// Set via CERTCTL_ENTRUST_PROFILE_ID environment variable.
 	ProfileId string `json:"profile_id,omitempty"`
+
+	// PollMaxWaitSeconds caps how long GetOrderStatus blocks doing
+	// internal exponential-backoff polling before returning
+	// StillPending. Default 600 (10 minutes); operators using
+	// approval-pending workflows where humans approve enrollments
+	// should bump this to a higher value (e.g., 86400 = 24h) so a
+	// single scheduler tick can wait through the approval window.
+	//
+	// Set via CERTCTL_ENTRUST_POLL_MAX_WAIT_SECONDS. Audit fix #5.
+	PollMaxWaitSeconds int `json:"poll_max_wait_seconds,omitempty"`
+}
+
+// pollMaxWait returns the configured PollMaxWait as a time.Duration,
+// or the asyncpoll package default if unset.
+func (c *Config) pollMaxWait() time.Duration {
+	if c.PollMaxWaitSeconds <= 0 {
+		return asyncpoll.DefaultMaxWait
+	}
+	return time.Duration(c.PollMaxWaitSeconds) * time.Second
 }
 
 // Connector implements the issuer.Connector interface for Entrust Certificate Services.
@@ -336,56 +356,102 @@ func (c *Connector) RevokeCertificate(ctx context.Context, request issuer.Revoca
 	return nil
 }
 
-// GetOrderStatus checks the status of an Entrust enrollment.
-// If the enrollment is "ISSUED", returns the certificate.
-// If still pending, returns pending status for continued polling.
+// GetOrderStatus checks the status of an Entrust enrollment using
+// bounded internal polling (asyncpoll.Poll). One call blocks for up
+// to PollMaxWait (default 10m; operators using approval-pending
+// workflows can raise to 24h) doing exponential backoff with jitter.
+//
+// Audit fix #5 Phase 2: previously each scheduler tick made one HTTP
+// call. Approval-pending enrollments now ride the backoff schedule
+// rather than tight-loop polling.
 func (c *Connector) GetOrderStatus(ctx context.Context, orderID string) (*issuer.OrderStatus, error) {
 	c.logger.Debug("checking Entrust enrollment status", "tracking_id", orderID)
 
+	var done *issuer.OrderStatus
+	var lastPendingMsg string
+	cfg := asyncpoll.Config{MaxWait: c.config.pollMaxWait()}
+
+	res, err := asyncpoll.Poll(ctx, cfg, func(ctx context.Context) (asyncpoll.Result, error) {
+		status, result, pollErr := c.pollEnrollmentOnce(ctx, orderID)
+		if status != nil {
+			switch result {
+			case asyncpoll.Done:
+				done = status
+			case asyncpoll.StillPending:
+				if status.Message != nil {
+					lastPendingMsg = *status.Message
+				}
+			}
+		}
+		return result, pollErr
+	})
+
+	now := time.Now()
+	switch res {
+	case asyncpoll.Done:
+		return done, nil
+	case asyncpoll.Failed:
+		return nil, err
+	default:
+		msg := lastPendingMsg
+		if msg == "" {
+			msg = fmt.Sprintf("enrollment %s still pending after PollMaxWait", orderID)
+		}
+		return &issuer.OrderStatus{
+			OrderID:   orderID,
+			Status:    "pending",
+			Message:   &msg,
+			UpdatedAt: now,
+		}, nil
+	}
+}
+
+// pollEnrollmentOnce makes one HTTP GET against the Entrust enrollment
+// status endpoint. 4xx (not 429) is permanent; 5xx / 429 / network is
+// transient and rides the backoff schedule.
+func (c *Connector) pollEnrollmentOnce(ctx context.Context, orderID string) (*issuer.OrderStatus, asyncpoll.Result, error) {
 	statusURL := fmt.Sprintf("%s/v1/certificate-authorities/%s/enrollments/%s",
 		c.config.APIUrl, c.config.CAId, orderID)
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, statusURL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to create status request: %w", err)
+		return nil, asyncpoll.Failed, fmt.Errorf("failed to create status request: %w", err)
 	}
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("Entrust status request failed: %w", err)
+		return nil, asyncpoll.StillPending, fmt.Errorf("Entrust status request failed: %w", err)
 	}
 	defer resp.Body.Close()
 
 	respBody, err := io.ReadAll(resp.Body)
 	if err != nil {
-		return nil, fmt.Errorf("failed to read status response: %w", err)
+		return nil, asyncpoll.StillPending, fmt.Errorf("failed to read status response: %w", err)
 	}
 
 	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("Entrust enrollment status returned %d: %s", resp.StatusCode, string(respBody))
+		err := fmt.Errorf("Entrust enrollment status returned %d: %s", resp.StatusCode, string(respBody))
+		if resp.StatusCode == http.StatusTooManyRequests || resp.StatusCode >= 500 {
+			return nil, asyncpoll.StillPending, err
+		}
+		return nil, asyncpoll.Failed, err
 	}
 
 	var statusResp enrollmentStatusResponse
 	if err := json.Unmarshal(respBody, &statusResp); err != nil {
-		return nil, fmt.Errorf("failed to parse status response: %w", err)
+		return nil, asyncpoll.Failed, fmt.Errorf("failed to parse status response: %w", err)
 	}
 
 	now := time.Now()
-
 	switch statusResp.Status {
 	case "ISSUED":
 		if statusResp.Certificate == "" {
-			return nil, fmt.Errorf("enrollment is ISSUED but certificate is missing")
+			return nil, asyncpoll.Failed, fmt.Errorf("enrollment is ISSUED but certificate is missing")
 		}
-
 		serial, notBefore, notAfter, err := parseCertMetadata(statusResp.Certificate)
 		if err != nil {
-			return nil, fmt.Errorf("failed to parse certificate metadata: %w", err)
+			return nil, asyncpoll.Failed, fmt.Errorf("failed to parse certificate metadata: %w", err)
 		}
-
-		c.logger.Info("Entrust enrollment completed",
-			"tracking_id", orderID,
-			"serial", serial)
-
+		c.logger.Info("Entrust enrollment completed", "tracking_id", orderID, "serial", serial)
 		return &issuer.OrderStatus{
 			OrderID:   orderID,
 			Status:    "completed",
@@ -395,7 +461,7 @@ func (c *Connector) GetOrderStatus(ctx context.Context, orderID string) (*issuer
 			NotBefore: &notBefore,
 			NotAfter:  &notAfter,
 			UpdatedAt: now,
-		}, nil
+		}, asyncpoll.Done, nil
 
 	case "PENDING", "PROCESSING", "AWAITING_APPROVAL":
 		msg := fmt.Sprintf("enrollment %s is %s", orderID, statusResp.Status)
@@ -404,7 +470,7 @@ func (c *Connector) GetOrderStatus(ctx context.Context, orderID string) (*issuer
 			Status:    "pending",
 			Message:   &msg,
 			UpdatedAt: now,
-		}, nil
+		}, asyncpoll.StillPending, nil
 
 	case "REJECTED", "DENIED", "FAILED":
 		msg := fmt.Sprintf("enrollment %s was %s", orderID, statusResp.Status)
@@ -413,7 +479,7 @@ func (c *Connector) GetOrderStatus(ctx context.Context, orderID string) (*issuer
 			Status:    "failed",
 			Message:   &msg,
 			UpdatedAt: now,
-		}, nil
+		}, asyncpoll.Done, nil
 
 	default:
 		msg := fmt.Sprintf("unknown enrollment status: %s", statusResp.Status)
@@ -422,7 +488,7 @@ func (c *Connector) GetOrderStatus(ctx context.Context, orderID string) (*issuer
 			Status:    "pending",
 			Message:   &msg,
 			UpdatedAt: now,
-		}, nil
+		}, asyncpoll.StillPending, nil
 	}
 }
 

internal/connector/issuer/entrust/entrust_failure_test.go

@@ -21,8 +21,9 @@ import (
 func buildEntrustConnector(t *testing.T, baseURL string) *Connector {
 	t.Helper()
 	cfg := &Config{
-		APIUrl: baseURL,
-		CAId:   "test-ca-id",
+		APIUrl:             baseURL,
+		CAId:               "test-ca-id",
+		PollMaxWaitSeconds: 1, // keep async-pending tests fast
 	}
 	httpClient := &http.Client{Transport: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}}} //nolint:gosec
 	return NewWithHTTPClient(cfg, slog.Default(), httpClient)

internal/connector/issuer/entrust/entrust_test.go

@@ -344,10 +344,11 @@ func TestEntrustConnector(t *testing.T) {
 		defer srv.Close()
 
 		config := &entrust.Config{
-			APIUrl:         srv.URL,
-			ClientCertPath: "/dev/null",
-			ClientKeyPath:  "/dev/null",
-			CAId:           "ca-123",
+			APIUrl:             srv.URL,
+			ClientCertPath:     "/dev/null",
+			ClientKeyPath:      "/dev/null",
+			CAId:               "ca-123",
+			PollMaxWaitSeconds: 1, // keep async-pending tests fast
 		}
 		connector := entrust.NewWithHTTPClient(config, logger, srv.Client())