Harden scan robustness and tests

plugins/services/rabbitmq_test.go

@@ -1,7 +1,11 @@
+//go:build plugin_rabbitmq || !plugin_selective
+
 package services
 
 import (
+	"bytes"
 	"context"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -18,3 +22,41 @@ func TestRabbitMQManagementRejectsGenericHTTP(t *testing.T) {
 		t.Fatalf("testManagementInterface reported generic HTTP as RabbitMQ: %#v", result)
 	}
 }
+
+func TestReadRabbitMQAMQPResponseHandlesChunkedReads(t *testing.T) {
+	ok, err := readRabbitMQAMQPResponse(&chunkedByteReader{data: []byte("AMQP"), chunkSize: 1})
+	if err != nil || !ok {
+		t.Fatalf("readRabbitMQAMQPResponse(AMQP) = %v, %v", ok, err)
+	}
+
+	ok, err = readRabbitMQAMQPResponse(&chunkedByteReader{data: []byte{0x01, 0, 0, 0, 0, 0, 0, 0}, chunkSize: 2})
+	if err != nil || !ok {
+		t.Fatalf("readRabbitMQAMQPResponse(frame) = %v, %v", ok, err)
+	}
+
+	ok, err = readRabbitMQAMQPResponse(bytes.NewReader([]byte{0x01, 0, 0}))
+	if err == nil || ok {
+		t.Fatalf("readRabbitMQAMQPResponse(short) = %v, %v; want short read error", ok, err)
+	}
+}
+
+type chunkedByteReader struct {
+	data      []byte
+	chunkSize int
+}
+
+func (r *chunkedByteReader) Read(p []byte) (int, error) {
+	if len(r.data) == 0 {
+		return 0, io.EOF
+	}
+	n := len(r.data)
+	if r.chunkSize > 0 && n > r.chunkSize {
+		n = r.chunkSize
+	}
+	if n > len(p) {
+		n = len(p)
+	}
+	copy(p, r.data[:n])
+	r.data = r.data[n:]
+	return n, nil
+}