[Fuzzing] Update the fuzzing suite to native Go-Fuzz

Makefile

@@ -19,6 +19,10 @@ fmt: ## Run go fmt against code
 tests: ## Run all tests and requires a running rabbitmq-server. Use GO_TEST_FLAGS to add extra flags to go test
 	go test -race -v -tags integration $(GO_TEST_FLAGS)
 
+.PHONY: fuzzing
+fuzzing: ## Run fuzzing tests
+	go test -fuzz=FuzzReadFrame .
+
 .PHONY: tests-docker
 tests-docker: rabbitmq-server
 	RABBITMQ_RABBITMQCTL_PATH="DOCKER:$(CONTAINER_NAME)" go test -race -v -tags integration $(GO_TEST_FLAGS)

read.go

@@ -114,6 +114,12 @@ func readLongstr(r io.Reader) (v string, err error) {
 		return
 	}
 
+	// LRB TODO obviously this is not realistic
+	if length > 65536 {
+		err = ErrMsgSize
+		return
+	}
+
 	bytes := make([]byte, length)
 	if _, err = io.ReadFull(r, bytes); err != nil {
 		return

read_test.go

@@ -6,6 +6,7 @@
 package amqp091
 
 import (
+	"bytes"
 	"strings"
 	"testing"
 )
@@ -29,3 +30,15 @@ func TestGoFuzzCrashers(t *testing.T) {
 		}
 	}
 }
+
+func FuzzReadFrame(f *testing.F) {
+
+	f.Add([]byte("\b000000"))
+	f.Add([]byte("\x02\x16\x10�[��\t\xbdui�" + "\x10\x01\x00\xff\xbf\xef\xbfｻn\x99\x00\x10r"))
+	f.Add([]byte("\x0300\x00\x00\x00\x040000"))
+
+	f.Fuzz(func(t *testing.T, input_data []byte) {
+		r := reader{bytes.NewReader(input_data)}
+		_, _ = r.ReadFrame()
+	})
+}

types.go

@@ -63,6 +63,9 @@ var (
 
 	// ErrFieldType is returned when writing a message containing a Go type unsupported by AMQP.
 	ErrFieldType = &Error{Code: SyntaxError, Reason: "unsupported table field type"}
+
+	// ErrMsgSize is returned when the length specifier for a frame or its data exceeds 128 MiB
+	ErrMsgSize = &Error{Code: FrameError, Reason: "frame or message is too large"}
 )
 
 // internal errors used inside the library