Go1.17 encoding/gob fix

src/crypto/rsa/pkcs1v15_test.go

@@ -238,6 +238,10 @@ func TestHashVerifyPKCS1v15(t *testing.T) {
 }
 
 func TestOverlongMessagePKCS1v15(t *testing.T) {
+	// OpenSSL now returns a random string instead of an error
+	if boring.Enabled() {
+		t.Skip("Not relevant in boring mode")
+	}
 	ciphertext := decodeBase64("fjOVdirUzFoLlukv80dBllMLjXythIf22feqPrNo0YoIjzyzyoMFiLjAc/Y4krkeZ11XFThIrEvw\nkRiZcCq5ng==")
 	_, err := DecryptPKCS1v15(nil, rsaPrivateKey, ciphertext)
 	if err == nil {

src/encoding/gob/decode.go

@@ -874,8 +874,11 @@ func (dec *Decoder) decOpFor(wireId typeId, rt reflect.Type, name string, inProg
 var maxIgnoreNestingDepth = 10000
 
 // decIgnoreOpFor returns the decoding op for a field that has no destination.
-func (dec *Decoder) decIgnoreOpFor(wireId typeId, inProgress map[typeId]*decOp, depth int) *decOp {
-	if depth > maxIgnoreNestingDepth {
+func (dec *Decoder) decIgnoreOpFor(wireId typeId, inProgress map[typeId]*decOp) *decOp {
+	// Track how deep we've recursed trying to skip nested ignored fields.
+	dec.ignoreDepth++
+	defer func() { dec.ignoreDepth-- }()
+	if dec.ignoreDepth > maxIgnoreNestingDepth {
 		error_(errors.New("invalid nesting depth"))
 	}
 	// If this type is already in progress, it's a recursive type (e.g. map[string]*T).
@@ -901,23 +904,23 @@ func (dec *Decoder) decIgnoreOpFor(wireId typeId, inProgress map[typeId]*decOp,
 			errorf("bad data: undefined type %s", wireId.string())
 		case wire.ArrayT != nil:
 			elemId := wire.ArrayT.Elem
-			elemOp := dec.decIgnoreOpFor(elemId, inProgress, depth+1)
+			elemOp := dec.decIgnoreOpFor(elemId, inProgress)
 			op = func(i *decInstr, state *decoderState, value reflect.Value) {
 				state.dec.ignoreArray(state, *elemOp, wire.ArrayT.Len)
 			}
 
 		case wire.MapT != nil:
 			keyId := dec.wireType[wireId].MapT.Key
 			elemId := dec.wireType[wireId].MapT.Elem
-			keyOp := dec.decIgnoreOpFor(keyId, inProgress, depth+1)
-			elemOp := dec.decIgnoreOpFor(elemId, inProgress, depth+1)
+			keyOp := dec.decIgnoreOpFor(keyId, inProgress)
+			elemOp := dec.decIgnoreOpFor(elemId, inProgress)
 			op = func(i *decInstr, state *decoderState, value reflect.Value) {
 				state.dec.ignoreMap(state, *keyOp, *elemOp)
 			}
 
 		case wire.SliceT != nil:
 			elemId := wire.SliceT.Elem
-			elemOp := dec.decIgnoreOpFor(elemId, inProgress, depth+1)
+			elemOp := dec.decIgnoreOpFor(elemId, inProgress)
 			op = func(i *decInstr, state *decoderState, value reflect.Value) {
 				state.dec.ignoreSlice(state, *elemOp)
 			}
@@ -1078,7 +1081,7 @@ func (dec *Decoder) compileSingle(remoteId typeId, ut *userTypeInfo) (engine *de
 func (dec *Decoder) compileIgnoreSingle(remoteId typeId) *decEngine {
 	engine := new(decEngine)
 	engine.instr = make([]decInstr, 1) // one item
-	op := dec.decIgnoreOpFor(remoteId, make(map[typeId]*decOp), 0)
+	op := dec.decIgnoreOpFor(remoteId, make(map[typeId]*decOp))
 	ovfl := overflow(dec.typeString(remoteId))
 	engine.instr[0] = decInstr{*op, 0, nil, ovfl}
 	engine.numInstr = 1
@@ -1123,7 +1126,7 @@ func (dec *Decoder) compileDec(remoteId typeId, ut *userTypeInfo) (engine *decEn
 		localField, present := srt.FieldByName(wireField.Name)
 		// TODO(r): anonymous names
 		if !present || !isExported(wireField.Name) {
-			op := dec.decIgnoreOpFor(wireField.Id, make(map[typeId]*decOp), 0)
+			op := dec.decIgnoreOpFor(wireField.Id, make(map[typeId]*decOp))
 			engine.instr[fieldnum] = decInstr{*op, fieldnum, nil, ovfl}
 			continue
 		}

src/encoding/gob/decoder.go

@@ -34,6 +34,8 @@ type Decoder struct {
 	freeList     *decoderState                           // list of free decoderStates; avoids reallocation
 	countBuf     []byte                                  // used for decoding integers while parsing messages
 	err          error
+	// ignoreDepth tracks the depth of recursively parsed ignored fields
+	ignoreDepth int
 }
 
 // NewDecoder returns a new decoder that reads from the io.Reader.

src/encoding/gob/gobencdec_test.go

@@ -806,6 +806,8 @@ func TestIngoreDepthLimit(t *testing.T) {
 	defer func() { maxIgnoreNestingDepth = oldNestingDepth }()
 	b := new(bytes.Buffer)
 	enc := NewEncoder(b)
+
+	// Nested slice
 	typ := reflect.TypeOf(int(0))
 	nested := reflect.ArrayOf(1, typ)
 	for i := 0; i < 100; i++ {
@@ -819,4 +821,16 @@ func TestIngoreDepthLimit(t *testing.T) {
 	if err := dec.Decode(&output); err == nil || err.Error() != expectedErr {
 		t.Errorf("Decode didn't fail with depth limit of 100: want %q, got %q", expectedErr, err)
 	}
+
+	// Nested struct
+	nested = reflect.StructOf([]reflect.StructField{{Name: "F", Type: typ}})
+	for i := 0; i < 100; i++ {
+		nested = reflect.StructOf([]reflect.StructField{{Name: "F", Type: nested}})
+	}
+	badStruct = reflect.New(reflect.StructOf([]reflect.StructField{{Name: "F", Type: nested}}))
+	enc.Encode(badStruct.Interface())
+	dec = NewDecoder(b)
+	if err := dec.Decode(&output); err == nil || err.Error() != expectedErr {
+		t.Errorf("Decode didn't fail with depth limit of 100: want %q, got %q", expectedErr, err)
+	}
 }