open-vault/vault/audit.go
Jeff Mitchell 27c960d8df
Split SubView functionality into logical.StorageView (#6141)
This lets other parts of Vault that can't depend on the vault package
take advantage of the subview functionality.

This also allows getting rid of BarrierStorage and vault.Entry, two
totally redundant abstractions.
2019-01-31 09:25:18 -05:00

503 lines
13 KiB
Go

package vault
import (
"context"
"crypto/sha256"
"errors"
"fmt"
"strings"
uuid "github.com/hashicorp/go-uuid"
"github.com/hashicorp/vault/audit"
"github.com/hashicorp/vault/helper/jsonutil"
"github.com/hashicorp/vault/helper/namespace"
"github.com/hashicorp/vault/helper/salt"
"github.com/hashicorp/vault/logical"
)
const (
// coreAuditConfigPath is used to store the audit configuration.
// Audit configuration is protected within the Vault itself, which means it
// can only be viewed or modified after an unseal.
coreAuditConfigPath = "core/audit"
// coreLocalAuditConfigPath is used to store audit information for local
// (non-replicated) mounts
coreLocalAuditConfigPath = "core/local-audit"
// auditBarrierPrefix is the prefix to the UUID used in the
// barrier view for the audit backends.
auditBarrierPrefix = "audit/"
// auditTableType is the value we expect to find for the audit table and
// corresponding entries
auditTableType = "audit"
)
var (
// loadAuditFailed if loading audit tables encounters an error
errLoadAuditFailed = errors.New("failed to setup audit table")
)
// enableAudit is used to enable a new audit backend
func (c *Core) enableAudit(ctx context.Context, entry *MountEntry, updateStorage bool) error {
// Ensure we end the path in a slash
if !strings.HasSuffix(entry.Path, "/") {
entry.Path += "/"
}
// Ensure there is a name
if entry.Path == "/" {
return fmt.Errorf("backend path must be specified")
}
// Update the audit table
c.auditLock.Lock()
defer c.auditLock.Unlock()
// Look for matching name
for _, ent := range c.audit.Entries {
switch {
// Existing is sql/mysql/ new is sql/ or
// existing is sql/ and new is sql/mysql/
case strings.HasPrefix(ent.Path, entry.Path):
fallthrough
case strings.HasPrefix(entry.Path, ent.Path):
return fmt.Errorf("path already in use")
}
}
// Generate a new UUID and view
if entry.UUID == "" {
entryUUID, err := uuid.GenerateUUID()
if err != nil {
return err
}
entry.UUID = entryUUID
}
if entry.Accessor == "" {
accessor, err := c.generateMountAccessor("audit_" + entry.Type)
if err != nil {
return err
}
entry.Accessor = accessor
}
viewPath := entry.ViewPath()
view := NewBarrierView(c.barrier, viewPath)
addAuditPathChecker(c, entry, view, viewPath)
origViewReadOnlyErr := view.getReadOnlyErr()
// Mark the view as read-only until the mounting is complete and
// ensure that it is reset after. This ensures that there will be no
// writes during the construction of the backend.
view.setReadOnlyErr(logical.ErrSetupReadOnly)
defer view.setReadOnlyErr(origViewReadOnlyErr)
// Lookup the new backend
backend, err := c.newAuditBackend(ctx, entry, view, entry.Options)
if err != nil {
return err
}
if backend == nil {
return fmt.Errorf("nil audit backend of type %q returned from factory", entry.Type)
}
newTable := c.audit.shallowClone()
newTable.Entries = append(newTable.Entries, entry)
ns, err := namespace.FromContext(ctx)
if err != nil {
return err
}
entry.NamespaceID = ns.ID
entry.namespace = ns
if updateStorage {
if err := c.persistAudit(ctx, newTable, entry.Local); err != nil {
return errors.New("failed to update audit table")
}
}
c.audit = newTable
// Register the backend
c.auditBroker.Register(entry.Path, backend, view, entry.Local)
if c.logger.IsInfo() {
c.logger.Info("enabled audit backend", "path", entry.Path, "type", entry.Type)
}
return nil
}
// disableAudit is used to disable an existing audit backend
func (c *Core) disableAudit(ctx context.Context, path string, updateStorage bool) (bool, error) {
// Ensure we end the path in a slash
if !strings.HasSuffix(path, "/") {
path += "/"
}
// Remove the entry from the mount table
c.auditLock.Lock()
defer c.auditLock.Unlock()
newTable := c.audit.shallowClone()
entry, err := newTable.remove(ctx, path)
if err != nil {
return false, err
}
// Ensure there was a match
if entry == nil {
return false, fmt.Errorf("no matching backend")
}
c.removeAuditReloadFunc(entry)
// When unmounting all entries the JSON code will load back up from storage
// as a nil slice, which kills tests...just set it nil explicitly
if len(newTable.Entries) == 0 {
newTable.Entries = nil
}
if updateStorage {
// Update the audit table
if err := c.persistAudit(ctx, newTable, entry.Local); err != nil {
return true, errors.New("failed to update audit table")
}
}
c.audit = newTable
// Unmount the backend
c.auditBroker.Deregister(path)
if c.logger.IsInfo() {
c.logger.Info("disabled audit backend", "path", path)
}
removeAuditPathChecker(c, entry)
return true, nil
}
// loadAudits is invoked as part of postUnseal to load the audit table
func (c *Core) loadAudits(ctx context.Context) error {
auditTable := &MountTable{}
localAuditTable := &MountTable{}
// Load the existing audit table
raw, err := c.barrier.Get(ctx, coreAuditConfigPath)
if err != nil {
c.logger.Error("failed to read audit table", "error", err)
return errLoadAuditFailed
}
rawLocal, err := c.barrier.Get(ctx, coreLocalAuditConfigPath)
if err != nil {
c.logger.Error("failed to read local audit table", "error", err)
return errLoadAuditFailed
}
c.auditLock.Lock()
defer c.auditLock.Unlock()
if raw != nil {
if err := jsonutil.DecodeJSON(raw.Value, auditTable); err != nil {
c.logger.Error("failed to decode audit table", "error", err)
return errLoadAuditFailed
}
c.audit = auditTable
}
var needPersist bool
if c.audit == nil {
c.audit = defaultAuditTable()
needPersist = true
}
if rawLocal != nil {
if err := jsonutil.DecodeJSON(rawLocal.Value, localAuditTable); err != nil {
c.logger.Error("failed to decode local audit table", "error", err)
return errLoadAuditFailed
}
if localAuditTable != nil && len(localAuditTable.Entries) > 0 {
c.audit.Entries = append(c.audit.Entries, localAuditTable.Entries...)
}
}
// Upgrade to typed auth table
if c.audit.Type == "" {
c.audit.Type = auditTableType
needPersist = true
}
// Upgrade to table-scoped entries
for _, entry := range c.audit.Entries {
if entry.Table == "" {
entry.Table = c.audit.Type
needPersist = true
}
if entry.Accessor == "" {
accessor, err := c.generateMountAccessor("audit_" + entry.Type)
if err != nil {
return err
}
entry.Accessor = accessor
needPersist = true
}
if entry.NamespaceID == "" {
entry.NamespaceID = namespace.RootNamespaceID
needPersist = true
}
// Get the namespace from the namespace ID and load it in memory
ns, err := NamespaceByID(ctx, entry.NamespaceID, c)
if err != nil {
return err
}
if ns == nil {
return namespace.ErrNoNamespace
}
entry.namespace = ns
}
if !needPersist || c.perfStandby {
return nil
}
if err := c.persistAudit(ctx, c.audit, false); err != nil {
return errLoadAuditFailed
}
return nil
}
// persistAudit is used to persist the audit table after modification
func (c *Core) persistAudit(ctx context.Context, table *MountTable, localOnly bool) error {
if table.Type != auditTableType {
c.logger.Error("given table to persist has wrong type", "actual_type", table.Type, "expected_type", auditTableType)
return fmt.Errorf("invalid table type given, not persisting")
}
for _, entry := range table.Entries {
if entry.Table != table.Type {
c.logger.Error("given entry to persist in audit table has wrong table value", "path", entry.Path, "entry_table_type", entry.Table, "actual_type", table.Type)
return fmt.Errorf("invalid audit entry found, not persisting")
}
}
nonLocalAudit := &MountTable{
Type: auditTableType,
}
localAudit := &MountTable{
Type: auditTableType,
}
for _, entry := range table.Entries {
if entry.Local {
localAudit.Entries = append(localAudit.Entries, entry)
} else {
nonLocalAudit.Entries = append(nonLocalAudit.Entries, entry)
}
}
if !localOnly {
// Marshal the table
compressedBytes, err := jsonutil.EncodeJSONAndCompress(nonLocalAudit, nil)
if err != nil {
c.logger.Error("failed to encode and/or compress audit table", "error", err)
return err
}
// Create an entry
entry := &logical.StorageEntry{
Key: coreAuditConfigPath,
Value: compressedBytes,
}
// Write to the physical backend
if err := c.barrier.Put(ctx, entry); err != nil {
c.logger.Error("failed to persist audit table", "error", err)
return err
}
}
// Repeat with local audit
compressedBytes, err := jsonutil.EncodeJSONAndCompress(localAudit, nil)
if err != nil {
c.logger.Error("failed to encode and/or compress local audit table", "error", err)
return err
}
entry := &logical.StorageEntry{
Key: coreLocalAuditConfigPath,
Value: compressedBytes,
}
if err := c.barrier.Put(ctx, entry); err != nil {
c.logger.Error("failed to persist local audit table", "error", err)
return err
}
return nil
}
// setupAudit is invoked after we've loaded the audit able to
// initialize the audit backends
func (c *Core) setupAudits(ctx context.Context) error {
brokerLogger := c.baseLogger.Named("audit")
c.AddLogger(brokerLogger)
broker := NewAuditBroker(brokerLogger)
c.auditLock.Lock()
defer c.auditLock.Unlock()
var successCount int
for _, entry := range c.audit.Entries {
// Create a barrier view using the UUID
viewPath := entry.ViewPath()
view := NewBarrierView(c.barrier, viewPath)
addAuditPathChecker(c, entry, view, viewPath)
origViewReadOnlyErr := view.getReadOnlyErr()
// Mark the view as read-only until the mounting is complete and
// ensure that it is reset after. This ensures that there will be no
// writes during the construction of the backend.
view.setReadOnlyErr(logical.ErrSetupReadOnly)
c.postUnsealFuncs = append(c.postUnsealFuncs, func() {
view.setReadOnlyErr(origViewReadOnlyErr)
})
// Initialize the backend
backend, err := c.newAuditBackend(ctx, entry, view, entry.Options)
if err != nil {
c.logger.Error("failed to create audit entry", "path", entry.Path, "error", err)
continue
}
if backend == nil {
c.logger.Error("created audit entry was nil", "path", entry.Path, "type", entry.Type)
continue
}
// Mount the backend
broker.Register(entry.Path, backend, view, entry.Local)
successCount++
}
if len(c.audit.Entries) > 0 && successCount == 0 {
return errLoadAuditFailed
}
c.auditBroker = broker
return nil
}
// teardownAudit is used before we seal the vault to reset the audit
// backends to their unloaded state. This is reversed by loadAudits.
func (c *Core) teardownAudits() error {
c.auditLock.Lock()
defer c.auditLock.Unlock()
if c.audit != nil {
for _, entry := range c.audit.Entries {
c.removeAuditReloadFunc(entry)
removeAuditPathChecker(c, entry)
}
}
c.audit = nil
c.auditBroker = nil
return nil
}
// removeAuditReloadFunc removes the reload func from the working set. The
// audit lock needs to be held before calling this.
func (c *Core) removeAuditReloadFunc(entry *MountEntry) {
switch entry.Type {
case "file":
key := "audit_file|" + entry.Path
c.reloadFuncsLock.Lock()
if c.logger.IsDebug() {
c.baseLogger.Named("audit").Debug("removing reload function", "path", entry.Path)
}
delete(c.reloadFuncs, key)
c.reloadFuncsLock.Unlock()
}
}
// newAuditBackend is used to create and configure a new audit backend by name
func (c *Core) newAuditBackend(ctx context.Context, entry *MountEntry, view logical.Storage, conf map[string]string) (audit.Backend, error) {
f, ok := c.auditBackends[entry.Type]
if !ok {
return nil, fmt.Errorf("unknown backend type: %q", entry.Type)
}
saltConfig := &salt.Config{
HMAC: sha256.New,
HMACType: "hmac-sha256",
Location: salt.DefaultLocation,
}
be, err := f(ctx, &audit.BackendConfig{
SaltView: view,
SaltConfig: saltConfig,
Config: conf,
})
if err != nil {
return nil, err
}
if be == nil {
return nil, fmt.Errorf("nil backend returned from %q factory function", entry.Type)
}
auditLogger := c.baseLogger.Named("audit")
c.AddLogger(auditLogger)
switch entry.Type {
case "file":
key := "audit_file|" + entry.Path
c.reloadFuncsLock.Lock()
if auditLogger.IsDebug() {
auditLogger.Debug("adding reload function", "path", entry.Path)
if entry.Options != nil {
auditLogger.Debug("file backend options", "path", entry.Path, "file_path", entry.Options["file_path"])
}
}
c.reloadFuncs[key] = append(c.reloadFuncs[key], func(map[string]interface{}) error {
if auditLogger.IsInfo() {
auditLogger.Info("reloading file audit backend", "path", entry.Path)
}
return be.Reload(ctx)
})
c.reloadFuncsLock.Unlock()
case "socket":
if auditLogger.IsDebug() {
if entry.Options != nil {
auditLogger.Debug("socket backend options", "path", entry.Path, "address", entry.Options["address"], "socket type", entry.Options["socket_type"])
}
}
case "syslog":
if auditLogger.IsDebug() {
if entry.Options != nil {
auditLogger.Debug("syslog backend options", "path", entry.Path, "facility", entry.Options["facility"], "tag", entry.Options["tag"])
}
}
}
return be, err
}
// defaultAuditTable creates a default audit table
func defaultAuditTable() *MountTable {
table := &MountTable{
Type: auditTableType,
}
return table
}