Add checks for indentation value

Signed-off-by: Bastien <bastien.wermeille@gmail.com>

stores/json/store.go

@@ -250,8 +250,10 @@ func (store Store) treeBranchFromJSON(in []byte) (sops.TreeBranch, error) {
 func (store Store) reindentJSON(in []byte) ([]byte, error) {
 	var out bytes.Buffer
 	indent := "\t"
-	if store.config.Indent != -1 {
+	if store.config.Indent > -1 {
 		indent = strings.Repeat(" ", store.config.Indent)
+	} else if store.config.Indent < -1 {
+		return nil, errors.New("JSON Indentation parameter smaller than -1 is not accepted")
 	}
 	err := json.Indent(&out, in, "", indent)
 	return out.Bytes(), err

stores/yaml/store.go

@@ -2,6 +2,7 @@ package yaml //import "github.com/getsops/sops/v3/stores/yaml"
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"strings"
@@ -326,19 +327,25 @@ func (store *Store) LoadPlainFile(in []byte) (sops.TreeBranches, error) {
 	return branches, nil
 }
 
-func (store *Store) getIndentation() int {
-	if store.config.Indent != 0 {
-		return store.config.Indent
+func (store *Store) getIndentation() (int, error) {
+	if store.config.Indent > 0 {
+		return store.config.Indent, nil
+	} else if store.config.Indent < 0 {
+		return 0, errors.New("YAML Negative indentation not accepted")
 	}
-	return IndentDefault
+	return IndentDefault, nil
 }
 
 // EmitEncryptedFile returns the encrypted bytes of the yaml file corresponding to a
 // sops.Tree runtime object
 func (store *Store) EmitEncryptedFile(in sops.Tree) ([]byte, error) {
 	var b bytes.Buffer
 	e := yaml.NewEncoder(io.Writer(&b))
-	e.SetIndent(store.getIndentation())
+	indent, err := store.getIndentation()
+	if err != nil {
+		return nil, err
+	}
+	e.SetIndent(indent)
 	for _, branch := range in.Branches {
 		// Document root
 		var doc = yaml.Node{}
@@ -370,7 +377,11 @@ func (store *Store) EmitEncryptedFile(in sops.Tree) ([]byte, error) {
 func (store *Store) EmitPlainFile(branches sops.TreeBranches) ([]byte, error) {
 	var b bytes.Buffer
 	e := yaml.NewEncoder(io.Writer(&b))
-	e.SetIndent(store.getIndentation())
+	indent, err := store.getIndentation()
+	if err != nil {
+		return nil, err
+	}
+	e.SetIndent(indent)
 	for _, branch := range branches {
 		// Document root
 		var doc = yaml.Node{}