open-vault/vault/barrier_view.go
2015-03-31 13:32:24 -07:00

146 lines
3.5 KiB
Go

package vault
import (
"fmt"
"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 SecurityBarrier
prefix string
}
// NewBarrierView takes an underlying security barrier and returns
// a view of it that can only operate with the given prefix.
func NewBarrierView(barrier SecurityBarrier, 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 fmt.Errorf("key cannot be relative path")
}
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
}
nested := &Entry{
Key: v.expandKey(entry.Key),
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
}
return v.barrier.Delete(v.expandKey(key))
}
// 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}
}
// 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)
}
// ScanView is used to scan all the keys in a view iteratively
func ScanView(view *BarrierView, cb func(path string)) error {
frontier := []string{""}
for len(frontier) > 0 {
n := len(frontier)
current := frontier[n-1]
frontier = frontier[:n-1]
// List the contents
contents, err := view.List(current)
if err != nil {
return fmt.Errorf("list failed at path '%s': %v", current, err)
}
// Handle the contents in the directory
for _, c := range contents {
fullPath := current + c
if strings.HasSuffix(c, "/") {
frontier = append(frontier, fullPath)
} else {
cb(fullPath)
}
}
}
return nil
}
// CollectKeys is used to collect all the keys in a view
func CollectKeys(view *BarrierView) ([]string, error) {
// Accumulate the keys
var existing []string
cb := func(path string) {
existing = append(existing, path)
}
// Scan for all the keys
if err := ScanView(view, cb); err != nil {
return nil, err
}
return existing, nil
}