open-nomad/nomad/structs/variables.go
Tim Gross 03312f3227
variables: restrict allowed paths for variables (#14547)
Restrict variable paths to RFC3986 URL-safe characters that don't conflict with
the use of characters "@" and "." in `template` blocks. This prevents users from
writing variables that will require tricky templating syntax or that they simply
won't be able to use.

Also restrict the length so that a user can't make queries in the state store
unusually expensive (as they are O(k) on the key length).
2022-09-12 16:37:33 -04:00

374 lines
10 KiB
Go

package structs
import (
"bytes"
"errors"
"fmt"
"reflect"
"regexp"
"strings"
)
const (
// VariablesApplyRPCMethod is the RPC method for upserting or deleting a
// variable by its namespace and path, with optional conflict detection.
//
// Args: VariablesApplyRequest
// Reply: VariablesApplyResponse
VariablesApplyRPCMethod = "Variables.Apply"
// VariablesListRPCMethod is the RPC method for listing variables within
// Nomad.
//
// Args: VariablesListRequest
// Reply: VariablesListResponse
VariablesListRPCMethod = "Variables.List"
// VariablesGetServiceRPCMethod is the RPC method for fetching a variable
// according to its namepace and path.
//
// Args: VariablesByNameRequest
// Reply: VariablesByNameResponse
VariablesReadRPCMethod = "Variables.Read"
// maxVariableSize is the maximum size of the unencrypted contents of a
// variable. This size is deliberately set low and is not configurable, to
// discourage DoS'ing the cluster
maxVariableSize = 16384
)
// VariableMetadata is the metadata envelope for a Variable, it is the list
// object and is shared data between an VariableEncrypted and a
// VariableDecrypted object.
type VariableMetadata struct {
Namespace string
Path string
CreateIndex uint64
CreateTime int64
ModifyIndex uint64
ModifyTime int64
}
// VariableEncrypted structs are returned from the Encrypter's encrypt
// method. They are the only form that should ever be persisted to storage.
type VariableEncrypted struct {
VariableMetadata
VariableData
}
// VariableData is the secret data for a Variable
type VariableData struct {
Data []byte // includes nonce
KeyID string // ID of root key used to encrypt this entry
}
// VariableDecrypted structs are returned from the Encrypter's decrypt
// method. Since they contains sensitive material, they should never be
// persisted to disk.
type VariableDecrypted struct {
VariableMetadata
Items VariableItems
}
// VariableItems are the actual secrets stored in a variable. They are always
// encrypted and decrypted as a single unit.
type VariableItems map[string]string
func (svi VariableItems) Size() uint64 {
var out uint64
for k, v := range svi {
out += uint64(len(k))
out += uint64(len(v))
}
return out
}
// Equals checks both the metadata and items in a VariableDecrypted struct
func (v1 VariableDecrypted) Equals(v2 VariableDecrypted) bool {
return v1.VariableMetadata.Equals(v2.VariableMetadata) &&
v1.Items.Equals(v2.Items)
}
// Equals is a convenience method to provide similar equality checking syntax
// for metadata and the VariablesData or VariableItems struct
func (sv VariableMetadata) Equals(sv2 VariableMetadata) bool {
return sv == sv2
}
// Equals performs deep equality checking on the cleartext items of a
// VariableDecrypted. Uses reflect.DeepEqual
func (i1 VariableItems) Equals(i2 VariableItems) bool {
return reflect.DeepEqual(i1, i2)
}
// Equals checks both the metadata and encrypted data for a VariableEncrypted
// struct
func (v1 VariableEncrypted) Equals(v2 VariableEncrypted) bool {
return v1.VariableMetadata.Equals(v2.VariableMetadata) &&
v1.VariableData.Equals(v2.VariableData)
}
// Equals performs deep equality checking on the encrypted data part of a
// VariableEncrypted
func (d1 VariableData) Equals(d2 VariableData) bool {
return d1.KeyID == d2.KeyID &&
bytes.Equal(d1.Data, d2.Data)
}
func (sv VariableDecrypted) Copy() VariableDecrypted {
return VariableDecrypted{
VariableMetadata: sv.VariableMetadata,
Items: sv.Items.Copy(),
}
}
func (sv VariableItems) Copy() VariableItems {
out := make(VariableItems, len(sv))
for k, v := range sv {
out[k] = v
}
return out
}
func (sv VariableEncrypted) Copy() VariableEncrypted {
return VariableEncrypted{
VariableMetadata: sv.VariableMetadata,
VariableData: sv.VariableData.Copy(),
}
}
func (sv VariableData) Copy() VariableData {
out := make([]byte, len(sv.Data))
copy(out, sv.Data)
return VariableData{
Data: out,
KeyID: sv.KeyID,
}
}
var (
// validVariablePath is used to validate a variable path. We restrict to
// RFC3986 URL-safe characters that don't conflict with the use of
// characters "@" and "." in template blocks. We also restrict the length so
// that a user can't make queries in the state store unusually expensive (as
// they are O(k) on the key length)
validVariablePath = regexp.MustCompile("^[a-zA-Z0-9-_~/]{1,128}$")
)
func (v VariableDecrypted) Validate() error {
if len(v.Path) == 0 {
return fmt.Errorf("variable requires path")
}
if !validVariablePath.MatchString(v.Path) {
return fmt.Errorf("invalid path %q", v.Path)
}
parts := strings.Split(v.Path, "/")
switch {
case len(parts) == 1 && parts[0] == "nomad":
return fmt.Errorf("\"nomad\" is a reserved top-level directory path, but you may write variables to \"nomad/jobs\" or below")
case len(parts) >= 2 && parts[0] == "nomad" && parts[1] != "jobs":
return fmt.Errorf("only paths at \"nomad/jobs\" or below are valid paths under the top-level \"nomad\" directory")
}
if len(v.Items) == 0 {
return errors.New("empty variables are invalid")
}
if v.Items.Size() > maxVariableSize {
return errors.New("variables are limited to 16KiB in total size")
}
if v.Namespace == AllNamespacesSentinel {
return errors.New("can not target wildcard (\"*\")namespace")
}
return nil
}
func (sv *VariableDecrypted) Canonicalize() {
if sv.Namespace == "" {
sv.Namespace = DefaultNamespace
}
}
// GetNamespace returns the variable's namespace. Used for pagination.
func (sv *VariableMetadata) Copy() *VariableMetadata {
var out VariableMetadata = *sv
return &out
}
// GetNamespace returns the variable's namespace. Used for pagination.
func (sv VariableMetadata) GetNamespace() string {
return sv.Namespace
}
// GetID returns the variable's path. Used for pagination.
func (sv VariableMetadata) GetID() string {
return sv.Path
}
// GetCreateIndex returns the variable's create index. Used for pagination.
func (sv VariableMetadata) GetCreateIndex() uint64 {
return sv.CreateIndex
}
// VariablesQuota is used to track the total size of variables entries per
// namespace. The total length of Variable.EncryptedData in bytes will be added
// to the VariablesQuota table in the same transaction as a write, update, or
// delete. This tracking effectively caps the maximum size of variables in a
// given namespace to MaxInt64 bytes.
type VariablesQuota struct {
Namespace string
Size int64
CreateIndex uint64
ModifyIndex uint64
}
func (svq *VariablesQuota) Copy() *VariablesQuota {
if svq == nil {
return nil
}
nq := new(VariablesQuota)
*nq = *svq
return nq
}
// ---------------------------------------
// RPC and FSM request/response objects
// VarOp constants give possible operations available in a transaction.
type VarOp string
const (
VarOpSet VarOp = "set"
VarOpDelete VarOp = "delete"
VarOpDeleteCAS VarOp = "delete-cas"
VarOpCAS VarOp = "cas"
)
// VarOpResult constants give possible operations results from a transaction.
type VarOpResult string
const (
VarOpResultOk VarOpResult = "ok"
VarOpResultConflict VarOpResult = "conflict"
VarOpResultRedacted VarOpResult = "conflict-redacted"
VarOpResultError VarOpResult = "error"
)
// VariablesApplyRequest is used by users to operate on the variable store
type VariablesApplyRequest struct {
Op VarOp // Operation to be performed during apply
Var *VariableDecrypted // Variable-shaped request data
WriteRequest
}
// VariablesApplyResponse is sent back to the user to inform them of success or failure
type VariablesApplyResponse struct {
Op VarOp // Operation performed
Input *VariableDecrypted // Input supplied
Result VarOpResult // Return status from operation
Error error // Error if any
Conflict *VariableDecrypted // Conflicting value if applicable
Output *VariableDecrypted // Operation Result if successful; nil for successful deletes
WriteMeta
}
func (r *VariablesApplyResponse) IsOk() bool {
return r.Result == VarOpResultOk
}
func (r *VariablesApplyResponse) IsConflict() bool {
return r.Result == VarOpResultConflict || r.Result == VarOpResultRedacted
}
func (r *VariablesApplyResponse) IsError() bool {
return r.Result == VarOpResultError
}
func (r *VariablesApplyResponse) IsRedacted() bool {
return r.Result == VarOpResultRedacted
}
// VarApplyStateRequest is used by the FSM to modify the variable store
type VarApplyStateRequest struct {
Op VarOp // Which operation are we performing
Var *VariableEncrypted // Which directory entry
WriteRequest
}
// VarApplyStateResponse is used by the FSM to inform the RPC layer of success or failure
type VarApplyStateResponse struct {
Op VarOp // Which operation were we performing
Result VarOpResult // What happened (ok, conflict, error)
Error error // error if any
Conflict *VariableEncrypted // conflicting variable if applies
WrittenSVMeta *VariableMetadata // for making the VariablesApplyResponse
WriteMeta
}
func (r *VarApplyStateRequest) ErrorResponse(raftIndex uint64, err error) *VarApplyStateResponse {
return &VarApplyStateResponse{
Op: r.Op,
Result: VarOpResultError,
Error: err,
WriteMeta: WriteMeta{Index: raftIndex},
}
}
func (r *VarApplyStateRequest) SuccessResponse(raftIndex uint64, meta *VariableMetadata) *VarApplyStateResponse {
return &VarApplyStateResponse{
Op: r.Op,
Result: VarOpResultOk,
WrittenSVMeta: meta,
WriteMeta: WriteMeta{Index: raftIndex},
}
}
func (r *VarApplyStateRequest) ConflictResponse(raftIndex uint64, cv *VariableEncrypted) *VarApplyStateResponse {
var cvCopy VariableEncrypted
if cv != nil {
// make a copy so that we aren't sending
// the live state store version
cvCopy = cv.Copy()
}
return &VarApplyStateResponse{
Op: r.Op,
Result: VarOpResultConflict,
Conflict: &cvCopy,
WriteMeta: WriteMeta{Index: raftIndex},
}
}
func (r *VarApplyStateResponse) IsOk() bool {
return r.Result == VarOpResultOk
}
func (r *VarApplyStateResponse) IsConflict() bool {
return r.Result == VarOpResultConflict
}
func (r *VarApplyStateResponse) IsError() bool {
// FIXME: This is brittle and requires immense faith that
// the response is properly managed.
return r.Result == VarOpResultError
}
type VariablesListRequest struct {
QueryOptions
}
type VariablesListResponse struct {
Data []*VariableMetadata
QueryMeta
}
type VariablesReadRequest struct {
Path string
QueryOptions
}
type VariablesReadResponse struct {
Data *VariableDecrypted
QueryMeta
}