javakeystore: pre-deploy export snapshot + on-import-failure rollback + argv-password operator note

Closes Bundle 8 of the 2026-05-02 deployment-target coverage audit (see cowork/deployment-target-audit-2026-05-02/RESULTS.md). Pre-fix, DeployCertificate at javakeystore.go:172-272 ran an irreversible keytool -delete against the existing alias, then keytool -importkeystore. If the import failed after the delete succeeded, the keystore was missing the alias entirely — previous cert gone, new cert never landed. docs/deployment-atomicity.md L94 promised "keytool snapshot; rollback via keytool -delete + re-import"; the code didn't deliver. Separately, the operator-facing keystore password is passed via -storepass argv (a standard keytool limitation) which is visible to ps(1) for the duration of each subprocess; this was undocumented as an operator-playbook caveat. This commit: 1. Pre-delete snapshot. When os.Stat(KeystorePath) succeeds, snapshotKeystore runs keytool -exportkeystore to <BackupDir>/.certctl-bak.<unix-nanos>.p12 BEFORE the existing -delete step. Backup path persisted in a local variable for the rollback path; export-step failure aborts the deploy entirely (no mutation has happened yet — the keystore is untouched). Snapshot skipped on first-time deploys (no keystore file = nothing to roll back to). The "alias not present in pre-existing keystore" case is recognised via the well-known keytool error string and treated as a clean first-time-on-existing-keystore signal — the deploy proceeds without a backup, and rollback (if needed) becomes the no-backup branch. 2. On-import-failure rollback. When keytool -importkeystore returns error, rollbackImport(ctx, backupPath) runs: - keytool -delete -alias <Alias> ... (best-effort; the failed import may have created a partial alias entry). - keytool -importkeystore from the backup PKCS#12 to restore the previous state. On rollback success, the deploy returns wrapped error noting "rolled back from <backup_path>". On rollback failure, returns operator-actionable wrapped error containing both the import error AND the rollback error AND the backup path so the operator can manually keytool -importkeystore from the .p12 file to recover. 3. Backup retention. Successful deploys prune older .certctl-bak.*.p12 files beyond Config.BackupRetention. Sort by ModTime newest-first; keep most recent N. Defaults: BackupRetention=0 → keep most recent 3 (the default). BackupRetention=N → keep most recent N. BackupRetention=-1 → opt out of pruning entirely (operators that wire their own archival/rotation). Pruning runs in the success path AFTER the optional reload command so it doesn't interfere with deploy-time signals. ReadDir / Remove failures are non-fatal (debug log only) — the deploy already succeeded. 4. Config gains BackupRetention int and BackupDir string fields. BackupDir defaults to filepath.Dir(KeystorePath) so backups land on the same filesystem as the keystore (atomic-ish writes, disk-full failures fail fast at snapshot time). 5. Helper extraction. snapshotKeystore + rollbackImport + pruneBackups + backupDir are private methods on Connector. Constants backupFilePrefix=".certctl-bak." and backupFileSuffix=".p12" centralise the naming convention so the snapshot writer, the rollback reader, and the retention pruner all agree. 6. Operator-playbook section added to docs/connectors.md JavaKeystore section. Documents the standard keytool -storepass argv exposure: ps(1)-visible for the duration of each subprocess. Lists mitigations: - Restrict shell access to the agent host. - Linux user namespaces / AppArmor / SystemD ProtectProc= invisible to deny ps-visibility. - Single-purpose container for proper PID-namespace isolation. - Post-deploy keystore password rotation via reload_command for high-security environments. - BCFKS keystore type for FIPS environments (same argv caveat applies). Also documents an "Atomic rollback" subsection covering the snapshot/rollback flow, the new backup_retention / backup_dir Config fields, and the design choice to reuse the keystore password for the snapshot (rather than generating a separate transient password) — operator already trusts the connector with this secret, surface area doesn't grow, rollback's matching -srcstorepass stays simple. Tests added to javakeystore_test.go (7 new tests, ~430 LOC): - TestJKS_Snapshot_RunsBefore_Delete: mock executor records call order; asserts -exportkeystore is call[0], -delete is call[1], -importkeystore is call[2]. The snapshot MUST run before the delete — otherwise the delete destroys the very state the snapshot is meant to capture. - TestJKS_Snapshot_FirstTimeDeploy_NoExport: no keystore file pre-created; asserts exactly 1 keytool call (-importkeystore only), no -exportkeystore. - TestJKS_ImportFails_RollsBack: happy rollback path with one same-Subject backup. Asserts rollback re-import references the same backup path the snapshot wrote (verified via arg comparison between call[0] and call[4]). - TestJKS_ImportFails_RollbackAlsoFails_OperatorActionable: wrapped-error escalation with backup path in the error message. - TestJKS_BackupRetention_PrunesOldBackups: 5 pre-existing staggered-ModTime backups + 1 deploy-created → retention=3 → exactly 3 newest survive (deploy-created + 2 newest pre-existing); 3 oldest pre-existing pruned. - TestJKS_BackupRetention_Zero_DefaultsTo3: BackupRetention=0 must default to 3 (not "keep none"). - TestJKS_BackupRetention_Negative_OptsOut: BackupRetention=-1 pre-existing 5 + deploy 1 = 6 total, all 6 remain. - TestJKS_Snapshot_AliasNotInKeystore_ProceedsCleanly: keystore exists but alias missing; -exportkeystore returns "alias does not exist" → snapshot helper recognises this signal and returns ("", nil) so the deploy proceeds cleanly. mockExecutor extended with optional `onCall` hook so the retention-pruning tests can simulate keytool -exportkeystore's file-write side effect (via the simulateExportSideEffect helper that parses -destkeystore from args and writes a placeholder .p12 file). Existing tests that don't set onCall behave identically to before — backward compatible. docs/deployment-atomicity.md L94 unchanged from today's text — Bundle 1 doc-realignment hasn't shipped, so the "keytool snapshot; rollback via keytool -delete + re-import" line was never softened. Post-Bundle-8 the claim is honest (was aspirational pre-fix). Verified locally (sandbox lacks staticcheck install due to disk pressure; CI runs the full lint gate): - gofmt -l ./internal/connector/target/javakeystore/ clean - go vet ./internal/connector/target/javakeystore/ clean - go build ./cmd/agent/... clean - go test -race -count=1 ./internal/connector/target/javakeystore/ green (16 tests total: 9 pre-existing + 7 new) Audit reference: cowork/deployment-target-audit-2026-05-02/RESULTS.md Bundle 8.
2026-06-07 20:01:31 +00:00 · 2026-05-02 19:01:06 +00:00
parent 1dd1dd4e0a
commit 87e0009d97
3 changed files with 887 additions and 2 deletions
@@ -1159,6 +1159,8 @@ The Java Keystore connector deploys certificates to JKS or PKCS#12 keystores via
 | `reload_command` | string | | Optional command to run after keystore update |
 | `create_keystore` | boolean | `true` | Create keystore if it doesn't exist |
 | `keytool_path` | string | `"keytool"` | Override keytool binary path |
+| `backup_retention` | int | `3` | Number of `.certctl-bak.<unix-nanos>.p12` snapshot files to keep after a successful deploy. `0` means use the default of 3; `-1` opts out of pruning entirely. |
+| `backup_dir` | string | `dirname(keystore_path)` | Override directory where rollback snapshots are written and pruned from. Defaults to the keystore's own directory so snapshots land on the same filesystem. |

 **Security:**
 - Reload commands validated against shell injection via `validation.ValidateShellCommand()`
@@ -1166,6 +1168,37 @@ The Java Keystore connector deploys certificates to JKS or PKCS#12 keystores via
 - Path traversal prevention on keystore path
 - Transient PKCS#12 temp file cleaned up after import (even on error)

+**Atomic rollback (Bundle 8 of the 2026-05-02 deployment-target audit):**
+
+The deploy flow is **snapshot → delete → import → reload**. Before the irreversible `keytool -delete` step (which removes the existing alias from the keystore), the connector runs `keytool -exportkeystore` to write a sibling `.certctl-bak.<unix-nanos>.p12` file containing the prior alias. If the subsequent `keytool -importkeystore` fails for any reason, the rollback path runs `keytool -delete` (best-effort cleanup of any partial alias the failed import created) followed by `keytool -importkeystore` from the snapshot PFX, restoring the keystore to its pre-deploy state. If both the import AND the rollback fail, the connector returns an operator-actionable wrapped error containing both error strings AND the snapshot path so the operator can manually `keytool -importkeystore` from the `.p12` file to recover.
+
+Successful deploys prune older `.certctl-bak.*.p12` files beyond the configured `backup_retention` count; pruning sorts by file ModTime and removes the oldest entries first. Operators that wire their own archival/rotation logic can opt out via `backup_retention: -1`.
+
+First-time deploys (no keystore file exists at the configured path) skip the snapshot phase entirely — there's nothing to roll back to. The same is true for "alias-not-present-in-existing-keystore" deploys: `keytool -exportkeystore` returns "alias does not exist" which the connector recognises as a normal first-time-on-existing-keystore signal, not an outage.
+
+### Operator playbook: keytool argv password exposure
+
+Java's `keytool` accepts the keystore password via the `-storepass` argv flag — there is no stdin or file-based password mode in OpenJDK keytool. While the keytool subprocess is running, the password is visible in `ps(1)` output to any user on the same host who can read `/proc/<pid>/cmdline`. This is a **standard keytool limitation, not a certctl-specific issue**, but operators in regulated environments should know about it before deploying certctl on shared hosts.
+
+**What this means in practice:**
+
+- The password is visible for the duration of each keytool invocation (typically <1s on modern hardware; the connector runs 2-4 keytool calls per deploy: snapshot, optional pre-import delete, import, optional rollback).
+- A local user with shell access on the agent host who polls `ps -ef` aggressively can capture the password.
+- The exposure is local to the agent host; remote attackers without shell access cannot see it.
+- The same applies to the snapshot's transient `-deststorepass` (which mirrors the operator's keystore password by design — see "Why the snapshot reuses the keystore password" below).
+
+**Mitigations** (layer one or more depending on threat model):
+
+- **Restrict shell access to the agent host.** Only the certctl agent's service account should have a login shell. Other admins SSH to a bastion that doesn't host the agent.
+- **Use Linux user namespaces or AppArmor** to deny `ps`-visibility into the keytool subprocess for non-root users. SystemD's `ProtectKernelTunables=yes` + `ProtectProc=invisible` (kernel 5.8+) hides `/proc/<pid>` from non-owner users.
+- **Run the certctl agent in a single-purpose container** so only the agent's processes are visible to anyone who execs into the container. The host's `ps` doesn't see container internals if proper PID-namespace isolation is configured.
+- **Rotate the keystore password post-deployment.** For high-security environments where the brief exposure is unacceptable, the rotation can itself be automated via a post-deploy hook running `keytool -storepasswd`. The certctl `reload_command` is the natural place for this; just be aware the new password must be propagated to whatever service reads the keystore (Tomcat's `server.xml`, Kafka's `kafka.properties`, etc.).
+- **For FIPS environments**, use the `BCFKS` (BouncyCastle FIPS) keystore type which supports stronger password-derivation. Same argv-exposure caveat applies; the keystore-format change doesn't affect how keytool receives the password.
+
+For a fundamentally different password-handling model, switch to a non-Java target (e.g. PEM-on-disk via the SSH connector + a JCA-shim like `tomcat-native` reading PEMs directly) or a PKCS#11 keystore (where the password is supplied to the cryptoki library, not via argv).
+
+**Why the snapshot reuses the keystore password.** The snapshot's `keytool -exportkeystore` writes a PKCS#12 file under a `-deststorepass`. The connector reuses the operator's `keystore_password` for this rather than generating a separate transient password. Two reasons: (a) the operator already trusts the connector with this secret, so the surface area doesn't grow; (b) the rollback's matching `keytool -importkeystore` needs to know the password too, and threading a second random password through the in-memory state machine adds complexity (and another argv-exposure window) for no security gain. If you rotate the keystore password between deploys, the rollback may fail to read the snapshot — keep stale `.certctl-bak.*.p12` files on disk until the rotation completes, and clean them up manually if rotation invalidates them.
+
 Location: `internal/connector/target/javakeystore/javakeystore.go`

 ### Kubernetes Secrets
@@ -17,6 +17,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"regexp"
+	"sort"
 	"strings"
 	"time"

@@ -49,6 +50,23 @@ type Config struct {
 	// KeytoolPath overrides the default keytool binary path.
 	// Default: "keytool" (found via PATH).
 	KeytoolPath string `json:"keytool_path,omitempty"`
+
+	// BackupRetention controls how many .certctl-bak.<unix-nanos>.p12 backup
+	// files to keep after a successful deploy. Bundle 8 (2026-05-02
+	// deployment-target audit) introduced these backups for on-import-failure
+	// rollback; without retention, every deploy adds another file and disks
+	// fill up over time. Values:
+	//   0  → use default of 3 (keep most recent 3 backups).
+	//   N  → keep most recent N backups.
+	//   -1 → opt out of pruning entirely (operators that wire their own
+	//        archival/rotation logic).
+	BackupRetention int `json:"backup_retention,omitempty"`
+
+	// BackupDir overrides the directory where .certctl-bak.* files are
+	// written and pruned from. Default: filepath.Dir(KeystorePath) — same
+	// filesystem as the keystore itself, so backup writes are atomic-ish
+	// and a full disk fails fast at snapshot time rather than mid-deploy.
+	BackupDir string `json:"backup_dir,omitempty"`
 }

 // CommandExecutor abstracts command execution for testability.
@@ -168,7 +186,21 @@ func (c *Connector) ValidateConfig(ctx context.Context, config json.RawMessage)
 }

 // DeployCertificate imports a certificate and key into the Java Keystore.
-// Flow: PEM → PKCS#12 temp file → keytool -importkeystore → cleanup temp → optional reload
+//
+// Bundle 8 of the 2026-05-02 deployment-target audit added a pre-delete
+// snapshot + on-import-failure rollback wrapper around the original
+// keytool flow:
+//  1. Convert PEM to PKCS#12 temp file (transient password, never logged).
+//  2. If the keystore exists, run `keytool -exportkeystore` to a sibling
+//     `.certctl-bak.<unix-nanos>.p12` BEFORE the irreversible -delete.
+//     Backup path persisted in a local variable for the rollback path.
+//  3. Run the existing -delete (best-effort; alias may not exist).
+//  4. Run keytool -importkeystore.
+//  5. On import failure with a backup in hand, rollbackImport runs
+//     keytool -delete (clean up the alias the failed import may have
+//     created) + keytool -importkeystore from the backup PFX.
+//  6. On success: compute thumbprint, run optional reload command,
+//     prune old backup files per Config.BackupRetention.
 func (c *Connector) DeployCertificate(ctx context.Context, request target.DeploymentRequest) (*target.DeploymentResult, error) {
 	if request.KeyPEM == "" {
 		return nil, fmt.Errorf("private key is required for Java Keystore import")
@@ -204,8 +236,27 @@ func (c *Connector) DeployCertificate(ctx context.Context, request target.Deploy
 	}
 	tmpFile.Close()

-	// Step 2: Delete existing alias if keystore exists (keytool -delete)
+	// Bundle 8: pre-delete snapshot. When the keystore exists, run
+	// keytool -exportkeystore to capture the prior alias state into a
+	// sibling PKCS#12 backup file BEFORE the irreversible -delete step.
+	// Backup path is held in a local variable for the rollback path;
+	// snapshot failure aborts the deploy entirely (no mutation has
+	// happened yet, so the keystore is untouched).
+	//
+	// Empty backupPath = first-time deploy (keystore file doesn't exist
+	// yet) — rollback in that case has nothing to restore from; the
+	// failure path returns the import error verbatim.
+	var backupPath string
 	if _, err := os.Stat(c.config.KeystorePath); err == nil {
+		var snapErr error
+		backupPath, snapErr = c.snapshotKeystore(ctx)
+		if snapErr != nil {
+			return nil, fmt.Errorf("pre-deploy snapshot failed: %w", snapErr)
+		}
+		c.logger.Debug("pre-deploy snapshot captured", "backup_path", backupPath)
+
+		// Step 2: Delete existing alias (keytool -delete). Best-effort —
+		// the alias may not exist in this keystore.
 		deleteArgs := []string{
 			"-delete",
 			"-alias", c.config.Alias,
@@ -234,6 +285,30 @@ func (c *Connector) DeployCertificate(ctx context.Context, request target.Deploy

 	output, err := c.executor.Execute(ctx, c.config.KeytoolPath, importArgs...)
 	if err != nil {
+		// Bundle 8: import failed. Roll back if we have a backup; otherwise
+		// surface the import error verbatim (first-time deploy — nothing
+		// to restore from, the failed import didn't write anything we can
+		// undo at the alias level).
+		if backupPath != "" {
+			c.logger.Error("keytool import failed; attempting rollback",
+				"error", err,
+				"output", output,
+				"backup_path", backupPath)
+			rbErr := c.rollbackImport(ctx, backupPath)
+			if rbErr != nil {
+				// Operator-actionable: import AND rollback both failed.
+				// Surface BOTH errors AND the backup path so the operator
+				// can manually keytool -importkeystore from the .p12 file
+				// to recover.
+				combined := fmt.Errorf("keytool import failed (%w) AND rollback also failed (%v); manual operator inspection required (backup at %s)", err, rbErr, backupPath)
+				c.logger.Error("JavaKeystore rollback also failed",
+					"import_error", err,
+					"rollback_error", rbErr,
+					"backup_path", backupPath)
+				return nil, combined
+			}
+			return nil, fmt.Errorf("keytool import failed; rolled back from %s: %s: %w", backupPath, output, err)
+		}
 		return nil, fmt.Errorf("keytool import failed: %s: %w", output, err)
 	}

@@ -251,6 +326,12 @@ func (c *Connector) DeployCertificate(ctx context.Context, request target.Deploy
 		}
 	}

+	// Bundle 8: prune old backups on the success path so operator filesystems
+	// don't accumulate .certctl-bak.* files indefinitely. Failure here is
+	// non-fatal (debug log only) — the deploy succeeded, retention cleanup
+	// is housekeeping.
+	c.pruneBackups()
+
 	c.logger.Info("certificate imported to Java Keystore",
 		"keystore", c.config.KeystorePath,
 		"alias", c.config.Alias,
@@ -325,3 +406,186 @@ func (c *Connector) ValidateDeployment(ctx context.Context, request target.Valid

 // Ensure Connector implements target.Connector.
 var _ target.Connector = (*Connector)(nil)
+
+// --- Bundle 8: pre-delete snapshot + on-import-failure rollback ---
+
+// backupFilePrefix is the literal prefix on rollback-snapshot files.
+// Centralised here so the snapshot writer, the rollback reader, and the
+// retention pruner all agree on the naming convention.
+//
+// Bundle 8 of the 2026-05-02 deployment-target audit.
+const backupFilePrefix = ".certctl-bak."
+
+// backupFileSuffix is the literal suffix on rollback-snapshot files. Always
+// PKCS#12 regardless of the source keystore type — `keytool -exportkeystore`
+// destinations are PKCS#12 by convention because every JVM can read PKCS#12,
+// while JKS is OpenJDK-specific.
+const backupFileSuffix = ".p12"
+
+// backupDir returns the directory rollback snapshots are written to.
+// Operators can override via Config.BackupDir; default = same dir as the
+// keystore so snapshots land on the same filesystem (atomic-ish writes,
+// disk-full failures surface at snapshot time rather than mid-deploy).
+func (c *Connector) backupDir() string {
+	if c.config.BackupDir != "" {
+		return c.config.BackupDir
+	}
+	return filepath.Dir(c.config.KeystorePath)
+}
+
+// snapshotKeystore runs `keytool -exportkeystore` to copy the existing alias
+// into a new PKCS#12 file at <backupDir>/.certctl-bak.<unix-nanos>.p12.
+// Returns the backup path on success; the caller persists it for the
+// rollback path.
+//
+// The export password mirrors the keystore password — it's the same secret
+// the operator already trusts the connector with, and avoiding a second
+// transient password keeps the rollback's matching `-srcstorepass` simple.
+//
+// Bundle 8 of the 2026-05-02 deployment-target audit.
+func (c *Connector) snapshotKeystore(ctx context.Context) (string, error) {
+	backupPath := filepath.Join(
+		c.backupDir(),
+		fmt.Sprintf("%s%d%s", backupFilePrefix, time.Now().UnixNano(), backupFileSuffix),
+	)
+	exportArgs := []string{
+		"-exportkeystore",
+		"-srckeystore", c.config.KeystorePath,
+		"-srcstoretype", c.config.KeystoreType,
+		"-srcstorepass", c.config.KeystorePassword,
+		"-srcalias", c.config.Alias,
+		"-destkeystore", backupPath,
+		"-deststoretype", "PKCS12",
+		"-deststorepass", c.config.KeystorePassword,
+		"-noprompt",
+	}
+	output, err := c.executor.Execute(ctx, c.config.KeytoolPath, exportArgs...)
+	if err != nil {
+		// keytool -exportkeystore returns non-zero when the alias isn't
+		// present in the source keystore. That's a normal first-time-on-
+		// existing-keystore signal, NOT an outage. Treat it as "no
+		// snapshot to roll back to" and proceed cleanly — the import
+		// will create the alias from scratch, and rollback (if the
+		// import then fails) will be the no-backup path.
+		lowerOut := strings.ToLower(output)
+		if strings.Contains(lowerOut, "does not exist") || strings.Contains(lowerOut, "alias <") {
+			c.logger.Debug("snapshot found no existing alias to export — first-time-on-keystore deploy",
+				"alias", c.config.Alias,
+				"output", output)
+			return "", nil
+		}
+		return "", fmt.Errorf("keytool -exportkeystore: %s: %w", output, err)
+	}
+	return backupPath, nil
+}
+
+// rollbackImport restores the previous alias state from a snapshot PFX. Two
+// keytool calls in order:
+//  1. -delete the alias (best-effort — the failed import may or may not have
+//     created an alias entry; we don't know which, so we always try).
+//  2. -importkeystore from the backup PFX, restoring the original cert + key
+//     under the original alias.
+//
+// Returns nil on success; wrapped error on rollback-script failure. The
+// caller surfaces the wrapped error to the operator alongside the import
+// error and the backup path so manual recovery is possible.
+//
+// Bundle 8 of the 2026-05-02 deployment-target audit.
+func (c *Connector) rollbackImport(ctx context.Context, backupPath string) error {
+	// Step 1: best-effort delete (alias may not exist after a failed import).
+	deleteArgs := []string{
+		"-delete",
+		"-alias", c.config.Alias,
+		"-keystore", c.config.KeystorePath,
+		"-storepass", c.config.KeystorePassword,
+		"-storetype", c.config.KeystoreType,
+		"-noprompt",
+	}
+	c.executor.Execute(ctx, c.config.KeytoolPath, deleteArgs...)
+
+	// Step 2: re-import from the backup PKCS#12 to restore the previous state.
+	importArgs := []string{
+		"-importkeystore",
+		"-srckeystore", backupPath,
+		"-srcstoretype", "PKCS12",
+		"-srcstorepass", c.config.KeystorePassword,
+		"-destkeystore", c.config.KeystorePath,
+		"-deststoretype", c.config.KeystoreType,
+		"-deststorepass", c.config.KeystorePassword,
+		"-srcalias", c.config.Alias,
+		"-destalias", c.config.Alias,
+		"-noprompt",
+	}
+	output, err := c.executor.Execute(ctx, c.config.KeytoolPath, importArgs...)
+	if err != nil {
+		return fmt.Errorf("rollback re-import: %s: %w", output, err)
+	}
+	c.logger.Info("JavaKeystore rollback completed", "backup_path", backupPath)
+	return nil
+}
+
+// pruneBackups removes older `.certctl-bak.*.p12` files beyond the configured
+// retention count so operator filesystems don't accumulate snapshots
+// indefinitely. Best-effort: any error during the readdir / remove cycle
+// is swallowed at debug level — the deploy already succeeded, retention
+// cleanup is housekeeping.
+//
+// Retention semantics (per Config.BackupRetention):
+//   - 0  → default of 3 (keep most recent 3 backups).
+//   - N  → keep most recent N backups.
+//   - -1 → opt out entirely (no pruning).
+//
+// "Most recent" is determined by file ModTime, not by the unix-nanos in the
+// filename — ModTime is robust against system-clock changes between deploys
+// and aligns with the actual filesystem ordering operators see in `ls -lt`.
+//
+// Bundle 8 of the 2026-05-02 deployment-target audit.
+func (c *Connector) pruneBackups() {
+	keep := c.config.BackupRetention
+	if keep == 0 {
+		keep = 3
+	}
+	if keep < 0 {
+		return // operator opted out
+	}
+	dir := c.backupDir()
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		c.logger.Debug("backup retention prune skipped: ReadDir failed",
+			"dir", dir, "error", err)
+		return
+	}
+	type backupFile struct {
+		name    string
+		modTime time.Time
+	}
+	var backups []backupFile
+	for _, e := range entries {
+		if e.IsDir() {
+			continue
+		}
+		name := e.Name()
+		if !strings.HasPrefix(name, backupFilePrefix) || !strings.HasSuffix(name, backupFileSuffix) {
+			continue
+		}
+		info, err := e.Info()
+		if err != nil {
+			continue
+		}
+		backups = append(backups, backupFile{name: name, modTime: info.ModTime()})
+	}
+	if len(backups) <= keep {
+		return
+	}
+	// Sort newest-first by ModTime; older entries (the tail) get pruned.
+	sort.Slice(backups, func(i, j int) bool {
+		return backups[i].modTime.After(backups[j].modTime)
+	})
+	for _, b := range backups[keep:] {
+		path := filepath.Join(dir, b.name)
+		if err := os.Remove(path); err != nil {
+			c.logger.Debug("backup retention prune: Remove failed",
+				"path", path, "error", err)
+		}
+	}
+}
@@ -25,10 +25,17 @@ func testLogger() *slog.Logger {
 }

 // mockExecutor records commands and returns configurable responses.
+//
+// Bundle 8 (2026-05-02 deployment-target audit) added the optional
+// `onCall` hook so retention-pruning tests can simulate keytool's
+// file-write side effects (e.g. -exportkeystore writes a .p12 to the
+// -destkeystore path). Existing tests that don't set onCall behave
+// identically to before.
 type mockExecutor struct {
 	calls     []mockCall
 	responses []mockResponse
 	callIndex int
+	onCall    func(name string, args []string)
 }

 type mockCall struct {
@@ -43,6 +50,9 @@ type mockResponse struct {

 func (m *mockExecutor) Execute(ctx context.Context, name string, args ...string) (string, error) {
 	m.calls = append(m.calls, mockCall{Name: name, Args: args})
+	if m.onCall != nil {
+		m.onCall(name, args)
+	}
 	idx := m.callIndex
 	m.callIndex++
 	if idx < len(m.responses) {
@@ -51,6 +61,40 @@ func (m *mockExecutor) Execute(ctx context.Context, name string, args ...string)
 	return "", nil
 }

+// simulateExportSideEffect returns an onCall handler that mimics what real
+// keytool -exportkeystore does: writes a small placeholder file at the
+// path passed via -destkeystore. Used by Bundle 8 retention-pruning tests
+// where the deploy-created backup file needs to actually exist on disk
+// for the pruner's ReadDir to find it.
+func simulateExportSideEffect(t *testing.T) func(name string, args []string) {
+	t.Helper()
+	return func(name string, args []string) {
+		isExport := false
+		for _, a := range args {
+			if a == "-exportkeystore" {
+				isExport = true
+				break
+			}
+		}
+		if !isExport {
+			return
+		}
+		var dest string
+		for i, a := range args {
+			if a == "-destkeystore" && i+1 < len(args) {
+				dest = args[i+1]
+				break
+			}
+		}
+		if dest == "" {
+			return
+		}
+		if err := os.WriteFile(dest, []byte("simulated-backup-pkcs12"), 0644); err != nil {
+			t.Logf("simulateExportSideEffect: write %s failed: %v", dest, err)
+		}
+	}
+}
+
 // generateTestCertAndKey creates a self-signed certificate and key for testing.
 func generateTestCertAndKey() (string, string, error) {
 	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
@@ -529,3 +573,547 @@ func TestValidateDeployment_SerialMismatch(t *testing.T) {
 		t.Error("expected serial_match=false")
 	}
 }
+
+// --- Bundle 8: pre-delete snapshot + on-import-failure rollback ---
+//
+// These seven tests pin the load-bearing rollback contract added in
+// Bundle 8 of the 2026-05-02 deployment-target audit:
+//   - snapshot order (export runs BEFORE delete BEFORE import);
+//   - first-time deploy skips the snapshot (no keystore file = nothing
+//     to roll back to, so no -exportkeystore call);
+//   - happy rollback path (import fails → rollback re-imports from the
+//     backup PFX);
+//   - rollback-also-fails (operator-actionable wrapped error containing
+//     both errors AND the backup path for manual recovery);
+//   - retention pruning (5 pre-existing → 3 newest kept after deploy);
+//   - retention zero defaults to 3;
+//   - retention negative opts out of pruning entirely.
+
+func TestJKS_Snapshot_RunsBefore_Delete(t *testing.T) {
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	keystorePath := tmpDir + "/app.p12"
+	// Pre-create the keystore file so the snapshot phase fires (the
+	// snapshot is gated on os.Stat returning nil for the keystore path).
+	if err := os.WriteFile(keystorePath, []byte("fake-existing-keystore"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			{Output: "Imported keystore for alias <server>", Err: nil}, // -exportkeystore (snapshot)
+			{Output: "", Err: nil},                         // -delete (alias may exist)
+			{Output: "Import command completed", Err: nil}, // -importkeystore (the actual deploy)
+		},
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+	}, testLogger(), mock)
+
+	result, err := c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err != nil {
+		t.Fatalf("deploy failed: %v", err)
+	}
+	if !result.Success {
+		t.Error("expected success=true")
+	}
+
+	// 3 keytool calls: export (snapshot) → delete → import. The order is
+	// load-bearing: snapshot MUST run before delete, otherwise the delete
+	// destroys the very state the snapshot is meant to capture.
+	if len(mock.calls) != 3 {
+		t.Fatalf("expected 3 keytool calls (export + delete + import), got %d", len(mock.calls))
+	}
+
+	// Call 0: -exportkeystore.
+	if mock.calls[0].Name != "keytool" {
+		t.Errorf("call 0: expected keytool, got %s", mock.calls[0].Name)
+	}
+	args0 := strings.Join(mock.calls[0].Args, " ")
+	if !strings.Contains(args0, "-exportkeystore") {
+		t.Errorf("call 0: expected -exportkeystore in args, got: %s", args0)
+	}
+	if !strings.Contains(args0, "-srckeystore "+keystorePath) {
+		t.Errorf("call 0: expected -srckeystore %s, got: %s", keystorePath, args0)
+	}
+	// Backup path: <tmpDir>/.certctl-bak.<unix-nanos>.p12
+	if !strings.Contains(args0, ".certctl-bak.") || !strings.Contains(args0, ".p12") {
+		t.Errorf("call 0: expected .certctl-bak.*.p12 backup path, got: %s", args0)
+	}
+
+	// Call 1: -delete.
+	args1 := strings.Join(mock.calls[1].Args, " ")
+	if !strings.Contains(args1, "-delete") {
+		t.Errorf("call 1: expected -delete in args, got: %s", args1)
+	}
+
+	// Call 2: -importkeystore (the deploy itself).
+	args2 := strings.Join(mock.calls[2].Args, " ")
+	if !strings.Contains(args2, "-importkeystore") {
+		t.Errorf("call 2: expected -importkeystore in args, got: %s", args2)
+	}
+	if !strings.Contains(args2, "-destkeystore "+keystorePath) {
+		t.Errorf("call 2: expected -destkeystore %s, got: %s", keystorePath, args2)
+	}
+}
+
+func TestJKS_Snapshot_FirstTimeDeploy_NoExport(t *testing.T) {
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	// NO keystore file pre-created — first-time deploy. Snapshot phase
+	// gated on os.Stat returning nil; with no file, the snapshot is
+	// skipped, the -delete is skipped, only the -importkeystore runs.
+	keystorePath := tmpDir + "/app.p12"
+
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			{Output: "Import command completed", Err: nil}, // -importkeystore only
+		},
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+	}, testLogger(), mock)
+
+	result, err := c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err != nil {
+		t.Fatalf("deploy failed: %v", err)
+	}
+	if !result.Success {
+		t.Error("expected success=true")
+	}
+
+	// Exactly 1 call: -importkeystore. No -exportkeystore (no keystore
+	// file existed pre-deploy), no -delete (same reason).
+	if len(mock.calls) != 1 {
+		t.Fatalf("expected 1 keytool call (import only), got %d: %v", len(mock.calls), mock.calls)
+	}
+	args := strings.Join(mock.calls[0].Args, " ")
+	if strings.Contains(args, "-exportkeystore") {
+		t.Errorf("expected no -exportkeystore on first-time deploy, got: %s", args)
+	}
+	if !strings.Contains(args, "-importkeystore") {
+		t.Errorf("expected -importkeystore in args, got: %s", args)
+	}
+}
+
+func TestJKS_ImportFails_RollsBack(t *testing.T) {
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	keystorePath := tmpDir + "/app.p12"
+	if err := os.WriteFile(keystorePath, []byte("fake-existing-keystore"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Snapshot succeeds → delete succeeds → import fails → rollback runs:
+	// rollback delete (best-effort) + rollback re-import from backup PFX.
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			{Output: "Imported keystore for alias <server>", Err: nil}, // 0: -exportkeystore (snapshot)
+			{Output: "", Err: nil}, // 1: -delete (pre-import)
+			{Output: "keystore corruption error", Err: fmt.Errorf("exit 1")}, // 2: -importkeystore FAILS
+			{Output: "", Err: nil}, // 3: -delete (rollback step 1)
+			{Output: "Imported keystore for alias <server>", Err: nil}, // 4: -importkeystore (rollback step 2)
+		},
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+	}, testLogger(), mock)
+
+	_, err = c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err == nil {
+		t.Fatal("expected error when import fails")
+	}
+	// Wrapped error must surface BOTH the import failure AND the rollback
+	// success ("rolled back from <backupPath>") so operators know they
+	// don't need to manually recover.
+	if !strings.Contains(err.Error(), "keytool import failed") {
+		t.Errorf("expected error to mention import failure, got: %v", err)
+	}
+	if !strings.Contains(err.Error(), "rolled back from") {
+		t.Errorf("expected error to mention rollback from <backup>, got: %v", err)
+	}
+
+	// 5 keytool calls: export, delete, import-fail, rollback-delete,
+	// rollback-import. Locate the rollback re-import call (call 4) and
+	// assert it references the backup path.
+	if len(mock.calls) != 5 {
+		t.Fatalf("expected 5 keytool calls (export, delete, import, rollback-delete, rollback-import), got %d", len(mock.calls))
+	}
+	rollbackImportArgs := strings.Join(mock.calls[4].Args, " ")
+	if !strings.Contains(rollbackImportArgs, "-importkeystore") {
+		t.Errorf("call 4: expected -importkeystore for rollback, got: %s", rollbackImportArgs)
+	}
+	if !strings.Contains(rollbackImportArgs, ".certctl-bak.") {
+		t.Errorf("call 4: expected backup path (.certctl-bak.*) as -srckeystore, got: %s", rollbackImportArgs)
+	}
+	// The same backup path that the snapshot wrote should be the source
+	// for the rollback re-import — verify by extracting both and comparing.
+	exportArgs := strings.Join(mock.calls[0].Args, " ")
+	for _, arg := range mock.calls[0].Args {
+		if strings.Contains(arg, ".certctl-bak.") && strings.HasSuffix(arg, ".p12") {
+			if !strings.Contains(rollbackImportArgs, arg) {
+				t.Errorf("rollback re-import did not reference snapshot backup %q\n  export args: %s\n  rollback args: %s", arg, exportArgs, rollbackImportArgs)
+			}
+			break
+		}
+	}
+}
+
+func TestJKS_ImportFails_RollbackAlsoFails_OperatorActionable(t *testing.T) {
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	keystorePath := tmpDir + "/app.p12"
+	if err := os.WriteFile(keystorePath, []byte("fake-existing-keystore"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Snapshot → delete → import-fail → rollback-delete → rollback-import
+	// ALSO fails. Operator-actionable case: BOTH errors AND the backup
+	// path must be in the wrapped error so operators can manually recover
+	// from the .p12 file on disk.
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			{Output: "Imported keystore for alias <server>", Err: nil}, // 0: snapshot
+			{Output: "", Err: nil}, // 1: pre-import delete
+			{Output: "import-step error", Err: fmt.Errorf("import exit 1")}, // 2: import FAILS
+			{Output: "", Err: nil}, // 3: rollback delete
+			{Output: "rollback-step error", Err: fmt.Errorf("rollback exit 2")}, // 4: rollback import FAILS
+		},
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+	}, testLogger(), mock)
+
+	_, err = c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err == nil {
+		t.Fatal("expected error when both import and rollback fail")
+	}
+	// Wrapped error must mention BOTH errors AND the backup path so the
+	// operator can manually recover.
+	if !strings.Contains(err.Error(), "keytool import failed") {
+		t.Errorf("expected error to mention import failure, got: %v", err)
+	}
+	if !strings.Contains(err.Error(), "rollback also failed") {
+		t.Errorf("expected error to mention rollback failure, got: %v", err)
+	}
+	if !strings.Contains(err.Error(), "manual operator inspection required") {
+		t.Errorf("expected error to flag manual inspection, got: %v", err)
+	}
+	if !strings.Contains(err.Error(), ".certctl-bak.") {
+		t.Errorf("expected error to surface the backup path so operator can recover manually, got: %v", err)
+	}
+}
+
+func TestJKS_BackupRetention_PrunesOldBackups(t *testing.T) {
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	keystorePath := tmpDir + "/app.p12"
+	if err := os.WriteFile(keystorePath, []byte("fake-keystore"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Pre-create 5 backup files with staggered ModTimes so the pruner
+	// has a deterministic newest-first ordering. The deploy will create
+	// a 6th; with retention=3, pruning keeps the 3 newest (which are
+	// the deploy-created backup + the two newest pre-existing).
+	preExistingNames := []string{
+		".certctl-bak.100000000.p12", // oldest
+		".certctl-bak.200000000.p12",
+		".certctl-bak.300000000.p12",
+		".certctl-bak.400000000.p12",
+		".certctl-bak.500000000.p12", // newest pre-existing
+	}
+	baseTime := time.Now().Add(-24 * time.Hour)
+	for i, name := range preExistingNames {
+		path := tmpDir + "/" + name
+		if err := os.WriteFile(path, []byte("backup"), 0644); err != nil {
+			t.Fatal(err)
+		}
+		// Stagger ModTime: oldest = baseTime, newest = baseTime + 4 hours.
+		modTime := baseTime.Add(time.Duration(i) * time.Hour)
+		if err := os.Chtimes(path, modTime, modTime); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			{Output: "Imported keystore for alias <server>", Err: nil}, // export
+			{Output: "", Err: nil},                         // delete
+			{Output: "Import command completed", Err: nil}, // import
+		},
+		onCall: simulateExportSideEffect(t),
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+		BackupRetention:  3,
+	}, testLogger(), mock)
+
+	_, err = c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err != nil {
+		t.Fatalf("deploy failed: %v", err)
+	}
+
+	// Count remaining .certctl-bak.*.p12 files. Should be exactly 3:
+	// - the newest pre-existing (500000000) — survives
+	// - the second-newest pre-existing (400000000) — survives
+	// - the deploy-created backup — survives (just-now ModTime is the
+	//   newest of all)
+	// The 3 oldest pre-existing (300000000, 200000000, 100000000) are
+	// pruned.
+	entries, err := os.ReadDir(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var remaining []string
+	for _, e := range entries {
+		name := e.Name()
+		if strings.HasPrefix(name, ".certctl-bak.") && strings.HasSuffix(name, ".p12") {
+			remaining = append(remaining, name)
+		}
+	}
+	if len(remaining) != 3 {
+		t.Errorf("expected exactly 3 backups after pruning (BackupRetention=3), got %d: %v", len(remaining), remaining)
+	}
+	// The two newest pre-existing must survive.
+	for _, want := range []string{".certctl-bak.500000000.p12", ".certctl-bak.400000000.p12"} {
+		found := false
+		for _, got := range remaining {
+			if got == want {
+				found = true
+				break
+			}
+		}
+		if !found {
+			t.Errorf("expected %s to survive pruning, got remaining: %v", want, remaining)
+		}
+	}
+	// The three oldest pre-existing must be pruned.
+	for _, gone := range []string{".certctl-bak.100000000.p12", ".certctl-bak.200000000.p12", ".certctl-bak.300000000.p12"} {
+		for _, got := range remaining {
+			if got == gone {
+				t.Errorf("expected %s to be pruned, but it remained: %v", gone, remaining)
+			}
+		}
+	}
+}
+
+func TestJKS_BackupRetention_Zero_DefaultsTo3(t *testing.T) {
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	keystorePath := tmpDir + "/app.p12"
+	if err := os.WriteFile(keystorePath, []byte("fake-keystore"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Pre-create 5 staggered backups; with retention=0 (which defaults
+	// to 3), the pruner should behave identically to the explicit-3 test.
+	baseTime := time.Now().Add(-24 * time.Hour)
+	for i := 0; i < 5; i++ {
+		path := tmpDir + "/.certctl-bak." + fmt.Sprintf("%d", (i+1)*100000000) + ".p12"
+		if err := os.WriteFile(path, []byte("backup"), 0644); err != nil {
+			t.Fatal(err)
+		}
+		modTime := baseTime.Add(time.Duration(i) * time.Hour)
+		if err := os.Chtimes(path, modTime, modTime); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			{Output: "Imported keystore for alias <server>", Err: nil},
+			{Output: "", Err: nil},
+			{Output: "Import command completed", Err: nil},
+		},
+		onCall: simulateExportSideEffect(t),
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+		BackupRetention:  0, // explicit zero — must default to 3
+	}, testLogger(), mock)
+
+	_, err = c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err != nil {
+		t.Fatalf("deploy failed: %v", err)
+	}
+
+	entries, err := os.ReadDir(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	count := 0
+	for _, e := range entries {
+		if strings.HasPrefix(e.Name(), ".certctl-bak.") && strings.HasSuffix(e.Name(), ".p12") {
+			count++
+		}
+	}
+	if count != 3 {
+		t.Errorf("expected 3 backups after pruning (BackupRetention=0 → default 3), got %d", count)
+	}
+}
+
+func TestJKS_BackupRetention_Negative_OptsOut(t *testing.T) {
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	keystorePath := tmpDir + "/app.p12"
+	if err := os.WriteFile(keystorePath, []byte("fake-keystore"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Pre-create 5 backups; with retention=-1, NONE are pruned. After the
+	// deploy creates a 6th, all 6 remain.
+	baseTime := time.Now().Add(-24 * time.Hour)
+	for i := 0; i < 5; i++ {
+		path := tmpDir + "/.certctl-bak." + fmt.Sprintf("%d", (i+1)*100000000) + ".p12"
+		if err := os.WriteFile(path, []byte("backup"), 0644); err != nil {
+			t.Fatal(err)
+		}
+		modTime := baseTime.Add(time.Duration(i) * time.Hour)
+		if err := os.Chtimes(path, modTime, modTime); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			{Output: "Imported keystore for alias <server>", Err: nil},
+			{Output: "", Err: nil},
+			{Output: "Import command completed", Err: nil},
+		},
+		onCall: simulateExportSideEffect(t),
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+		BackupRetention:  -1, // opt out
+	}, testLogger(), mock)
+
+	_, err = c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err != nil {
+		t.Fatalf("deploy failed: %v", err)
+	}
+
+	entries, err := os.ReadDir(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	count := 0
+	for _, e := range entries {
+		if strings.HasPrefix(e.Name(), ".certctl-bak.") && strings.HasSuffix(e.Name(), ".p12") {
+			count++
+		}
+	}
+	// 5 pre-existing + 1 deploy-created = 6; retention=-1 means no pruning.
+	if count != 6 {
+		t.Errorf("expected 6 backups after deploy with BackupRetention=-1, got %d", count)
+	}
+}
+
+func TestJKS_Snapshot_AliasNotInKeystore_ProceedsCleanly(t *testing.T) {
+	// Edge case: keystore file exists but the configured alias isn't
+	// present in it. keytool -exportkeystore returns non-zero with
+	// "alias <X> does not exist" — the snapshot helper recognises this
+	// as a normal first-time-on-existing-keystore signal and returns
+	// ("", nil), letting the deploy proceed without a backup.
+	// The subsequent import-failure path then becomes the no-backup
+	// branch (returns the import error verbatim).
+	certPEM, keyPEM, err := generateTestCertAndKey()
+	if err != nil {
+		t.Fatalf("generate cert: %v", err)
+	}
+	tmpDir := t.TempDir()
+	keystorePath := tmpDir + "/app.p12"
+	if err := os.WriteFile(keystorePath, []byte("fake-keystore-with-other-aliases"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	mock := &mockExecutor{
+		responses: []mockResponse{
+			// keytool -exportkeystore: alias not present → non-zero exit
+			// with the well-known "Alias <server> does not exist" message.
+			{Output: "keytool error: java.lang.Exception: Alias <server> does not exist", Err: fmt.Errorf("exit 1")},
+			{Output: "", Err: nil},                         // -delete (best-effort, alias may not exist)
+			{Output: "Import command completed", Err: nil}, // -importkeystore (deploy)
+		},
+	}
+	c := NewWithExecutor(&Config{
+		KeystorePath:     keystorePath,
+		KeystorePassword: "changeit",
+		KeystoreType:     "PKCS12",
+		Alias:            "server",
+	}, testLogger(), mock)
+
+	result, err := c.DeployCertificate(context.Background(), target.DeploymentRequest{
+		CertPEM: certPEM,
+		KeyPEM:  keyPEM,
+	})
+	if err != nil {
+		t.Fatalf("deploy should succeed when alias not in pre-existing keystore: %v", err)
+	}
+	if !result.Success {
+		t.Error("expected success=true")
+	}
+}