Add label validation for non printable chars (#1650)

* Add label validation for non printable chars

* Fix printable chars check

Author: pinosu

x/wasm/types/tx_test.go

@@ -116,6 +116,42 @@ func TestInstantiateContractValidation(t *testing.T) {
 			},
 			valid: false,
 		},
+		"white space ending label": {
+			msg: MsgInstantiateContract{
+				Sender: goodAddress,
+				CodeID: firstCodeID,
+				Label:  "foo ",
+				Msg:    []byte("{}"),
+			},
+			valid: false,
+		},
+		"non printable chars ending label": {
+			msg: MsgInstantiateContract{
+				Sender: goodAddress,
+				CodeID: firstCodeID,
+				Label:  "foo\v",
+				Msg:    []byte("{}"),
+			},
+			valid: false,
+		},
+		"non printable chars in label": {
+			msg: MsgInstantiateContract{
+				Sender: goodAddress,
+				CodeID: firstCodeID,
+				Label:  "f\voo",
+				Msg:    []byte("{}"),
+			},
+			valid: false,
+		},
+		"non printable chars beginning label": {
+			msg: MsgInstantiateContract{
+				Sender: goodAddress,
+				CodeID: firstCodeID,
+				Label:  "\vfoo",
+				Msg:    []byte("{}"),
+			},
+			valid: false,
+		},
 		"label too long": {
 			msg: MsgInstantiateContract{
 				Sender: goodAddress,

x/wasm/types/validation.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net/url"
 	"strings"
+	"unicode"
 
 	"github.com/distribution/reference"
 
@@ -45,6 +46,15 @@ func ValidateLabel(label string) error {
 	if label != strings.TrimSpace(label) {
 		return ErrInvalid.Wrap("label must not start/end with whitespaces")
 	}
+	labelWithPrintableCharsOnly := strings.Map(func(r rune) rune {
+		if unicode.IsPrint(r) {
+			return r
+		}
+		return -1
+	}, label)
+	if label != labelWithPrintableCharsOnly {
+		return ErrInvalid.Wrap("label must have printable characters only")
+	}
 	return nil
 }