Limit uncompressed content

x/wasm/internal/keeper/ioutil.go

@@ -15,12 +15,13 @@ var gzipIdent = []byte("\x1F\x8B\x08")
 // limit max bytes read to prevent gzip bombs
 const maxSize = 400 * 1024
 
+
 // uncompress returns gzip uncompressed content or given src when not gzip.
 func uncompress(src []byte) ([]byte, error) {
 	if len(src) < 3 {
 		return src, nil
 	}
-	in := io.LimitReader(bytes.NewReader(src), maxSize)
+	in := bytes.NewReader(src)
 	buf := make([]byte, 3)
 	if _, err := io.ReadAtLeast(in, buf, 3); err != nil {
 		return nil, err
@@ -34,5 +35,5 @@ func uncompress(src []byte) ([]byte, error) {
 	}
 	zr.Multistream(false)
 
-	return ioutil.ReadAll(zr)
+	return ioutil.ReadAll(io.LimitReader(zr, maxSize))
 }

x/wasm/internal/keeper/ioutil_test.go

@@ -1,6 +1,8 @@
 package keeper
 
 import (
+	"bytes"
+	"compress/gzip"
 	"errors"
 	"io"
 	"io/ioutil"
@@ -39,7 +41,7 @@ func TestUncompress(t *testing.T) {
 			src:       []byte{0x1, 0x2},
 			expResult: []byte{0x1, 0x2},
 		},
-		"handle big slice": {
+		"handle big input slice": {
 			src:       []byte(strings.Repeat("a", maxSize+1)),
 			expResult: []byte(strings.Repeat("a", maxSize+1)),
 		},
@@ -51,13 +53,32 @@ func TestUncompress(t *testing.T) {
 			src:      append(gzipIdent, byte(0x1)),
 			expError: io.ErrUnexpectedEOF,
 		},
+		"handle incomplete gzip": {
+			src:      wasmGzipped[:len(wasmGzipped)-5],
+			expError: io.ErrUnexpectedEOF,
+		},
+		"handle big gzip output": {
+			src:      asGzip(strings.Repeat("a", maxSize+1)),
+			expError: io.ErrUnexpectedEOF,
+		},
 	}
 	for msg, spec := range specs {
 		t.Run(msg, func(t *testing.T) {
 			r, err := uncompress(spec.src)
 			require.True(t, errors.Is(spec.expError, err), "exp %+v got %+v", spec.expError, err)
+			if spec.expError != nil {
+				return
+			}
 			assert.Equal(t, spec.expResult, r)
 		})
 	}
 
 }
+
+func asGzip(src string) []byte {
+	var buf bytes.Buffer
+	if _, err := io.Copy(gzip.NewWriter(&buf), strings.NewReader(src)); err != nil {
+		panic(err)
+	}
+	return buf.Bytes()
+}

x/wasm/internal/types/msg.go

@@ -9,9 +9,9 @@ const (
 )
 
 type MsgStoreCode struct {
-	Sender       sdk.AccAddress `json:"sender" yaml:"sender"`
+	Sender sdk.AccAddress `json:"sender" yaml:"sender"`
 	// WASMByteCode can be raw or gzip compressed
-	WASMByteCode []byte         `json:"wasm_byte_code" yaml:"wasm_byte_code"`
+	WASMByteCode []byte `json:"wasm_byte_code" yaml:"wasm_byte_code"`
 }
 
 func (msg MsgStoreCode) Route() string {