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Add web UI for SSH CA, Transit, and User engines; full security audit and remediation

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Web UI: Added browser-based management for all three remaining engines
(SSH CA, Transit, User E2E). Includes gRPC client wiring, handler files,
7 HTML templates, dashboard mount forms, and conditional navigation links.
Fixed REST API routes to match design specs (SSH CA cert singular paths,
Transit PATCH for update-key-config).

Security audit: Conducted full-system audit covering crypto core, all
engine implementations, API servers, policy engine, auth, deployment,
and documentation. Identified 42 new findings (#39-#80) across all
severity levels.

Remediation of all 8 High findings:
- #68: Replaced 14 JSON-injection-vulnerable error responses with safe
  json.Encoder via writeJSONError helper
- #48: Added two-layer path traversal defense (barrier validatePath
  rejects ".." segments; engine ValidateName enforces safe name pattern)
- #39: Extended RLock through entire crypto operations in barrier
  Get/Put/Delete/List to eliminate TOCTOU race with Seal
- #40: Unified ReWrapKeys and seal_config UPDATE into single SQLite
  transaction to prevent irrecoverable data loss on crash during MEK
  rotation
- #49: Added resolveTTL to CA engine enforcing issuer MaxTTL ceiling
  on handleIssue and handleSignCSR
- #61: Store raw ECDH private key bytes in userState for effective
  zeroization on Seal
- #62: Fixed user engine policy resource path from mountPath to
  mountName() so policy rules match correctly
- #69: Added newPolicyChecker helper and passed service-level policy
  evaluation to all 25 typed REST handler engine.Request structs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
Kyle Isom
2026-03-16 22:02:06 -07:00
parent 128f5abc4d
commit a80323e320
29 changed files with 5061 additions and 647 deletions
Download Patch File Download Diff File Expand all files Collapse all files

94
internal/barrier/barrier.go
View File

@@ -16,8 +16,19 @@ var (
ErrSealed = errors.New("barrier: sealed")
ErrNotFound = errors.New("barrier: entry not found")
ErrKeyNotFound = errors.New("barrier: key not found")
ErrInvalidPath = errors.New("barrier: invalid path")
)
// validatePath rejects paths containing ".." segments to prevent path traversal.
func validatePath(p string) error {
for _, seg := range strings.Split(p, "/") {
if seg == ".." {
return fmt.Errorf("%w: %q", ErrInvalidPath, p)
}
}
return nil
}
// Barrier is the encrypted storage barrier interface.
type Barrier interface {
// Unseal opens the barrier with the given master encryption key.
@@ -137,11 +148,12 @@ func resolveKeyID(path string) string {
}
func (b *AESGCMBarrier) Get(ctx context.Context, path string) ([]byte, error) {
if err := validatePath(path); err != nil {
return nil, err
}
b.mu.RLock()
mek := b.mek
keys := b.keys
b.mu.RUnlock()
if mek == nil {
defer b.mu.RUnlock()
if b.mek == nil {
return nil, ErrSealed
}
@@ -161,7 +173,7 @@ func (b *AESGCMBarrier) Get(ctx context.Context, path string) ([]byte, error) {
if err != nil {
return nil, fmt.Errorf("barrier: extract key ID %q: %w", path, err)
}
dek, ok := keys[keyID]
dek, ok := b.keys[keyID]
if !ok {
return nil, fmt.Errorf("barrier: %w: %q for path %q", ErrKeyNotFound, keyID, path)
}
@@ -173,7 +185,7 @@ func (b *AESGCMBarrier) Get(ctx context.Context, path string) ([]byte, error) {
}
// v1 ciphertext — use MEK directly (backward compat).
pt, err := crypto.Decrypt(mek, encrypted, []byte(path))
pt, err := crypto.Decrypt(b.mek, encrypted, []byte(path))
if err != nil {
return nil, fmt.Errorf("barrier: decrypt %q: %w", path, err)
}
@@ -181,11 +193,12 @@ func (b *AESGCMBarrier) Get(ctx context.Context, path string) ([]byte, error) {
}
func (b *AESGCMBarrier) Put(ctx context.Context, path string, value []byte) error {
if err := validatePath(path); err != nil {
return err
}
b.mu.RLock()
mek := b.mek
keys := b.keys
b.mu.RUnlock()
if mek == nil {
defer b.mu.RUnlock()
if b.mek == nil {
return ErrSealed
}
@@ -194,12 +207,12 @@ func (b *AESGCMBarrier) Put(ctx context.Context, path string, value []byte) erro
var encrypted []byte
var err error
if dek, ok := keys[keyID]; ok {
if dek, ok := b.keys[keyID]; ok {
// Use v2 format with the appropriate DEK.
encrypted, err = crypto.EncryptV2(dek, keyID, value, []byte(path))
} else {
// No DEK registered for this key ID — fall back to MEK with v1 format.
encrypted, err = crypto.Encrypt(mek, value, []byte(path))
encrypted, err = crypto.Encrypt(b.mek, value, []byte(path))
}
if err != nil {
return fmt.Errorf("barrier: encrypt %q: %w", path, err)
@@ -216,10 +229,12 @@ func (b *AESGCMBarrier) Put(ctx context.Context, path string, value []byte) erro
}
func (b *AESGCMBarrier) Delete(ctx context.Context, path string) error {
if err := validatePath(path); err != nil {
return err
}
b.mu.RLock()
mek := b.mek
b.mu.RUnlock()
if mek == nil {
defer b.mu.RUnlock()
if b.mek == nil {
return ErrSealed
}
@@ -232,10 +247,12 @@ func (b *AESGCMBarrier) Delete(ctx context.Context, path string) error {
}
func (b *AESGCMBarrier) List(ctx context.Context, prefix string) ([]string, error) {
if err := validatePath(prefix); err != nil {
return nil, err
}
b.mu.RLock()
mek := b.mek
b.mu.RUnlock()
if mek == nil {
defer b.mu.RUnlock()
if b.mek == nil {
return nil, ErrSealed
}
@@ -605,7 +622,8 @@ func (b *AESGCMBarrier) createKeyLockedTx(ctx context.Context, tx *sql.Tx, keyID
}
// ReWrapKeys re-encrypts all DEKs with a new MEK. Called during MEK rotation.
// The new MEK is already set in b.mek by the caller.
// This method manages its own transaction. For atomic MEK rotation where
// the seal_config update must be in the same transaction, use ReWrapKeysTx.
func (b *AESGCMBarrier) ReWrapKeys(ctx context.Context, newMEK []byte) error {
b.mu.Lock()
defer b.mu.Unlock()
@@ -620,6 +638,30 @@ func (b *AESGCMBarrier) ReWrapKeys(ctx context.Context, newMEK []byte) error {
}
defer func() { _ = tx.Rollback() }()
if err := b.reWrapKeysLocked(ctx, tx, newMEK); err != nil {
return err
}
if err := tx.Commit(); err != nil {
return fmt.Errorf("barrier: commit re-wrap: %w", err)
}
b.swapMEKLocked(newMEK)
return nil
}
// ReWrapKeysTx re-encrypts all DEKs with a new MEK within the given
// transaction. The caller is responsible for committing the transaction
// and then calling SwapMEK to update the in-memory state.
// The barrier mutex must be held by the caller.
func (b *AESGCMBarrier) ReWrapKeysTx(ctx context.Context, tx *sql.Tx, newMEK []byte) error {
if b.mek == nil {
return ErrSealed
}
return b.reWrapKeysLocked(ctx, tx, newMEK)
}
func (b *AESGCMBarrier) reWrapKeysLocked(ctx context.Context, tx *sql.Tx, newMEK []byte) error {
for keyID, dek := range b.keys {
encDEK, err := crypto.Encrypt(newMEK, dek, []byte(keyID))
if err != nil {
@@ -632,15 +674,19 @@ func (b *AESGCMBarrier) ReWrapKeys(ctx context.Context, newMEK []byte) error {
return fmt.Errorf("barrier: update key %q: %w", keyID, err)
}
}
return nil
}
if err := tx.Commit(); err != nil {
return fmt.Errorf("barrier: commit re-wrap: %w", err)
}
// SwapMEK updates the in-memory MEK after a committed transaction.
func (b *AESGCMBarrier) SwapMEK(newMEK []byte) {
b.mu.Lock()
defer b.mu.Unlock()
b.swapMEKLocked(newMEK)
}
// Update the MEK in memory.
func (b *AESGCMBarrier) swapMEKLocked(newMEK []byte) {
crypto.Zeroize(b.mek)
k := make([]byte, len(newMEK))
copy(k, newMEK)
b.mek = k
return nil
}