open-vault/vault/barrier_view.go

123 lines
2.8 KiB
Go

package vault
import (
"errors"
"strings"
"github.com/hashicorp/vault/logical"
)
// BarrierView wraps a SecurityBarrier and ensures all access is automatically
// prefixed. This is used to prevent anyone with access to the view to access
// any data in the durable storage outside of their prefix. Conceptually this
// is like a "chroot" into the barrier.
//
// BarrierView implements logical.Storage so it can be passed in as the
// durable storage mechanism for logical views.
type BarrierView struct {
barrier BarrierStorage
prefix string
readonly bool
}
var (
ErrRelativePath = errors.New("relative paths not supported")
)
// NewBarrierView takes an underlying security barrier and returns
// a view of it that can only operate with the given prefix.
func NewBarrierView(barrier BarrierStorage, prefix string) *BarrierView {
return &BarrierView{
barrier: barrier,
prefix: prefix,
}
}
// sanityCheck is used to perform a sanity check on a key
func (v *BarrierView) sanityCheck(key string) error {
if strings.Contains(key, "..") {
return ErrRelativePath
}
return nil
}
// logical.Storage impl.
func (v *BarrierView) List(prefix string) ([]string, error) {
if err := v.sanityCheck(prefix); err != nil {
return nil, err
}
return v.barrier.List(v.expandKey(prefix))
}
// logical.Storage impl.
func (v *BarrierView) Get(key string) (*logical.StorageEntry, error) {
if err := v.sanityCheck(key); err != nil {
return nil, err
}
entry, err := v.barrier.Get(v.expandKey(key))
if err != nil {
return nil, err
}
if entry == nil {
return nil, nil
}
if entry != nil {
entry.Key = v.truncateKey(entry.Key)
}
return &logical.StorageEntry{
Key: entry.Key,
Value: entry.Value,
}, nil
}
// logical.Storage impl.
func (v *BarrierView) Put(entry *logical.StorageEntry) error {
if err := v.sanityCheck(entry.Key); err != nil {
return err
}
expandedKey := v.expandKey(entry.Key)
if v.readonly {
return logical.ErrReadOnly
}
nested := &Entry{
Key: expandedKey,
Value: entry.Value,
}
return v.barrier.Put(nested)
}
// logical.Storage impl.
func (v *BarrierView) Delete(key string) error {
if err := v.sanityCheck(key); err != nil {
return err
}
expandedKey := v.expandKey(key)
if v.readonly {
return logical.ErrReadOnly
}
return v.barrier.Delete(expandedKey)
}
// SubView constructs a nested sub-view using the given prefix
func (v *BarrierView) SubView(prefix string) *BarrierView {
sub := v.expandKey(prefix)
return &BarrierView{barrier: v.barrier, prefix: sub, readonly: v.readonly}
}
// expandKey is used to expand to the full key path with the prefix
func (v *BarrierView) expandKey(suffix string) string {
return v.prefix + suffix
}
// truncateKey is used to remove the prefix of the key
func (v *BarrierView) truncateKey(full string) string {
return strings.TrimPrefix(full, v.prefix)
}