cmd/clef, signer: support removing stored keys (delpw + rules)

cmd/clef/main.go

@@ -93,7 +93,7 @@ var (
 	chainIdFlag = cli.Int64Flag{
 		Name:  "chainid",
 		Value: params.MainnetChainConfig.ChainID.Int64(),
-		Usage: "Chain id to use for signing (1=mainnet, 3=ropsten, 4=rinkeby, 5=Goerli)",
+		Usage: "Chain id to use for signing (1=mainnet, 3=Ropsten, 4=Rinkeby, 5=Goerli)",
 	}
 	rpcPortFlag = cli.IntFlag{
 		Name:  "rpcport",
@@ -116,8 +116,7 @@ var (
 	}
 	ruleFlag = cli.StringFlag{
 		Name:  "rules",
-		Usage: "Enable rule-engine",
-		Value: "",
+		Usage: "Path to the rule file to auto-authorize requests with",
 	}
 	stdiouiFlag = cli.BoolFlag{
 		Name: "stdio-ui",
@@ -160,7 +159,6 @@ incoming requests.
 Whenever you make an edit to the rule file, you need to use attestation to tell
 Clef that the file is 'safe' to execute.`,
 	}
-
 	setCredentialCommand = cli.Command{
 		Action:    utils.MigrateFlags(setCredential),
 		Name:      "setpw",
@@ -173,6 +171,19 @@ Clef that the file is 'safe' to execute.`,
 		},
 		Description: `
 The setpw command stores a password for a given address (keyfile).
+`}
+	delCredentialCommand = cli.Command{
+		Action:    utils.MigrateFlags(removeCredential),
+		Name:      "delpw",
+		Usage:     "Remove a credential for a keystore file",
+		ArgsUsage: "<address>",
+		Flags: []cli.Flag{
+			logLevelFlag,
+			configdirFlag,
+			signerSecretFlag,
+		},
+		Description: `
+The delpw command removes a password for a given address (keyfile).
 `}
 	gendocCommand = cli.Command{
 		Action: GenDoc,
@@ -209,9 +220,9 @@ func init() {
 		advancedMode,
 	}
 	app.Action = signer
-	app.Commands = []cli.Command{initCommand, attestCommand, setCredentialCommand, gendocCommand}
-
+	app.Commands = []cli.Command{initCommand, attestCommand, setCredentialCommand, delCredentialCommand, gendocCommand}
 }
+
 func main() {
 	if err := app.Run(os.Args); err != nil {
 		fmt.Fprintln(os.Stderr, err)
@@ -317,7 +328,6 @@ func setCredential(ctx *cli.Context) error {
 	if err := initialize(ctx); err != nil {
 		return err
 	}
-
 	addr := ctx.Args().First()
 	if !common.IsHexAddress(addr) {
 		utils.Fatalf("Invalid address specified: %s", addr)
@@ -334,10 +344,38 @@ func setCredential(ctx *cli.Context) error {
 	vaultLocation := filepath.Join(configDir, common.Bytes2Hex(crypto.Keccak256([]byte("vault"), stretchedKey)[:10]))
 	pwkey := crypto.Keccak256([]byte("credentials"), stretchedKey)
 
-	// Initialize the encrypted storages
 	pwStorage := storage.NewAESEncryptedStorage(filepath.Join(vaultLocation, "credentials.json"), pwkey)
 	pwStorage.Put(address.Hex(), password)
-	log.Info("Credential store updated", "key", address)
+
+	log.Info("Credential store updated", "set", address)
+	return nil
+}
+
+func removeCredential(ctx *cli.Context) error {
+	if len(ctx.Args()) < 1 {
+		utils.Fatalf("This command requires an address to be passed as an argument")
+	}
+	if err := initialize(ctx); err != nil {
+		return err
+	}
+	addr := ctx.Args().First()
+	if !common.IsHexAddress(addr) {
+		utils.Fatalf("Invalid address specified: %s", addr)
+	}
+	address := common.HexToAddress(addr)
+
+	stretchedKey, err := readMasterKey(ctx, nil)
+	if err != nil {
+		utils.Fatalf(err.Error())
+	}
+	configDir := ctx.GlobalString(configdirFlag.Name)
+	vaultLocation := filepath.Join(configDir, common.Bytes2Hex(crypto.Keccak256([]byte("vault"), stretchedKey)[:10]))
+	pwkey := crypto.Keccak256([]byte("credentials"), stretchedKey)
+
+	pwStorage := storage.NewAESEncryptedStorage(filepath.Join(vaultLocation, "credentials.json"), pwkey)
+	pwStorage.Del(address.Hex())
+
+	log.Info("Credential store updated", "unset", address)
 	return nil
 }
 
@@ -359,6 +397,10 @@ func initialize(c *cli.Context) error {
 }
 
 func signer(c *cli.Context) error {
+	// If we have some unrecognized command, bail out
+	if args := c.Args(); len(args) > 0 {
+		return fmt.Errorf("invalid command: %q", args[0])
+	}
 	if err := initialize(c); err != nil {
 		return err
 	}

signer/rules/rules.go

@@ -83,7 +83,12 @@ func (r *rulesetUI) execute(jsfunc string, jsarg interface{}) (otto.Value, error
 	vm.Set("storage", struct{}{})
 	storageObj, _ := vm.Get("storage")
 	storageObj.Object().Set("put", func(call otto.FunctionCall) otto.Value {
-		r.storage.Put(call.Argument(0).String(), call.Argument(1).String())
+		key, val := call.Argument(0).String(), call.Argument(1).String()
+		if val == "" {
+			r.storage.Del(key)
+		} else {
+			r.storage.Put(key, val)
+		}
 		return otto.NullValue()
 	})
 	storageObj.Object().Set("get", func(call otto.FunctionCall) otto.Value {

signer/storage/aes_gcm_storage.go

@@ -53,7 +53,7 @@ func NewAESEncryptedStorage(filename string, key []byte) *AESEncryptedStorage {
 	}
 }
 
-// Put stores a value by key. 0-length keys results in no-op
+// Put stores a value by key. 0-length keys results in noop.
 func (s *AESEncryptedStorage) Put(key, value string) {
 	if len(key) == 0 {
 		return
@@ -99,6 +99,19 @@ func (s *AESEncryptedStorage) Get(key string) (string, error) {
 	return string(entry), nil
 }
 
+// Del removes a key-value pair. If the key doesn't exist, the method is a noop.
+func (s *AESEncryptedStorage) Del(key string) {
+	data, err := s.readEncryptedStorage()
+	if err != nil {
+		log.Warn("Failed to read encrypted storage", "err", err, "file", s.filename)
+		return
+	}
+	delete(data, key)
+	if err = s.writeEncryptedStorage(data); err != nil {
+		log.Warn("Failed to write entry", "err", err)
+	}
+}
+
 // readEncryptedStorage reads the file with encrypted creds
 func (s *AESEncryptedStorage) readEncryptedStorage() (map[string]storedCredential, error) {
 	creds := make(map[string]storedCredential)

signer/storage/storage.go

@@ -28,12 +28,15 @@ var (
 )
 
 type Storage interface {
-	// Put stores a value by key. 0-length keys results in no-op
+	// Put stores a value by key. 0-length keys results in noop.
 	Put(key, value string)
 
 	// Get returns the previously stored value, or an error if the key is 0-length
 	// or unknown.
 	Get(key string) (string, error)
+
+	// Del removes a key-value pair. If the key doesn't exist, the method is a noop.
+	Del(key string)
 }
 
 // EphemeralStorage is an in-memory storage that does
@@ -43,6 +46,7 @@ type EphemeralStorage struct {
 	namespace string
 }
 
+// Put stores a value by key. 0-length keys results in noop.
 func (s *EphemeralStorage) Put(key, value string) {
 	if len(key) == 0 {
 		return
@@ -62,6 +66,11 @@ func (s *EphemeralStorage) Get(key string) (string, error) {
 	return "", ErrNotFound
 }
 
+// Del removes a key-value pair. If the key doesn't exist, the method is a noop.
+func (s *EphemeralStorage) Del(key string) {
+	delete(s.data, key)
+}
+
 func NewEphemeralStorage() Storage {
 	s := &EphemeralStorage{
 		data: make(map[string]string),
@@ -73,6 +82,7 @@ func NewEphemeralStorage() Storage {
 type NoStorage struct{}
 
 func (s *NoStorage) Put(key, value string) {}
+func (s *NoStorage) Del(key string)        {}
 func (s *NoStorage) Get(key string) (string, error) {
 	return "", errors.New("I forgot")
 }