From: Jeff Halter <redacted>
Date: Tue, 24 May 2022 23:05:19 +0000 (-0700)
Subject: Fix file corruption bug for commented files
X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/commitdiff_plain/bb7fe19f7e331f0e8c79f4da61543981acd36422

Fix file corruption bug for commented files

This fixes a bug that happens when an uploaded file contains a file comment.  The bug happens because the comment byte length was not included when calculating the length of the information header, causing the comment bytes to be appendedto the file.
---

diff --git a/hotline/flattened_file_object.go b/hotline/flattened_file_object.go
index 02804f6..ee8a69b 100644
--- a/hotline/flattened_file_object.go
+++ b/hotline/flattened_file_object.go
@@ -67,18 +67,18 @@ func NewFlatFileInformationFork(fileName string) FlatFileInformationFork {
 		ModifyDate:       []byte{0x07, 0x70, 0x00, 0x00, 0xba, 0x74, 0x24, 0x73}, // TODO: implement
 		NameScript:       make([]byte, 2),                                        // TODO: What is this?
 		Name:             []byte(fileName),
+		CommentSize:      []byte{0, 4},
 		Comment:          []byte("TODO"), // TODO: implement (maybe?)
 	}
 }
 
-// Size of the flat file information fork, which is the fixed size of 72 bytes
-// plus the number of bytes in the FileName
-// TODO: plus the size of the Comment!
+// DataSize calculates the size of the flat file information fork, which is
+// 72 bytes for the fixed length fields plus the length of the Name + Comment
 func (ffif FlatFileInformationFork) DataSize() []byte {
 	size := make([]byte, 4)
-	nameLen := len(ffif.Name)
+
 	//TODO: Can I do math directly on two byte slices?
-	dataSize := nameLen + 74
+	dataSize := len(ffif.Name) + len(ffif.Comment) + 74
 
 	binary.BigEndian.PutUint32(size, uint32(dataSize))
 
@@ -184,9 +184,8 @@ func (f flattenedFileObject) BinaryMarshal() []byte {
 	out = append(out, f.FlatFileInformationFork.NameScript...)
 	out = append(out, f.FlatFileInformationFork.ReadNameSize()...)
 	out = append(out, f.FlatFileInformationFork.Name...)
-
-	// TODO: Implement commentlen and comment field
-	out = append(out, []byte{0, 0}...)
+	out = append(out, f.FlatFileInformationFork.CommentSize...)
+	out = append(out, f.FlatFileInformationFork.Comment...)
 
 	out = append(out, f.FlatFileDataForkHeader.ForkType...)
 	out = append(out, f.FlatFileDataForkHeader.CompressionType...)
diff --git a/hotline/flattened_file_object_test.go b/hotline/flattened_file_object_test.go
index df05c09..5bbaf1d 100644
--- a/hotline/flattened_file_object_test.go
+++ b/hotline/flattened_file_object_test.go
@@ -74,3 +74,67 @@ func TestNewFlattenedFileObject(t *testing.T) {
 		})
 	}
 }
+
+func Test_flattenedFileObject_BinaryMarshal(t *testing.T) {
+
+	testData, _ := hex.DecodeString("46494c500001000000000000000000000000000000000002494e464f000000000000000000000052414d414354455854747478740000000000000100000000000000000000000000000000000000000000000000000000000000000007700000ba74247307700000ba74247300000008746573742e74787400004441544100000000000000000000000474657374")
+	testFile := ReadFlattenedFileObject(testData)
+	testFile.FlatFileInformationFork.Comment = []byte("test!")
+	testFile.FlatFileInformationFork.CommentSize = []byte{0x00, 0x05}
+
+	type fields struct {
+		FlatFileHeader                FlatFileHeader
+		FlatFileInformationForkHeader FlatFileInformationForkHeader
+		FlatFileInformationFork       FlatFileInformationFork
+		FlatFileDataForkHeader        FlatFileDataForkHeader
+		FileData                      []byte
+	}
+	tests := []struct {
+		name   string
+		fields fields
+		want   []byte
+	}{
+		{
+			name: "with a valid file",
+			fields: fields{
+				FlatFileHeader:                testFile.FlatFileHeader,
+				FlatFileInformationForkHeader: testFile.FlatFileInformationForkHeader,
+				FlatFileInformationFork:       testFile.FlatFileInformationFork,
+				FlatFileDataForkHeader:        testFile.FlatFileDataForkHeader,
+				FileData:                      testFile.FileData,
+			},
+			want: []byte{
+				0x46, 0x49, 0x4c, 0x50, 0x00, 0x01, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,
+				0x49, 0x4e, 0x46, 0x4f, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x57,
+				0x41, 0x4d, 0x41, 0x43, 0x54, 0x45, 0x58, 0x54,
+				0x74, 0x74, 0x78, 0x74, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x07, 0x70, 0x00, 0x00,
+				0xba, 0x74, 0x24, 0x73, 0x07, 0x70, 0x00, 0x00,
+				0xba, 0x74, 0x24, 0x73, 0x00, 0x00, 0x00, 0x08,
+				0x74, 0x65, 0x73, 0x74, 0x2e, 0x74, 0x78, 0x74,
+				0x00, 0x05, 0x74, 0x65, 0x73, 0x74, 0x21, 0x44,
+				0x41, 0x54, 0x41, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			f := flattenedFileObject{
+				FlatFileHeader:                tt.fields.FlatFileHeader,
+				FlatFileInformationForkHeader: tt.fields.FlatFileInformationForkHeader,
+				FlatFileInformationFork:       tt.fields.FlatFileInformationFork,
+				FlatFileDataForkHeader:        tt.fields.FlatFileDataForkHeader,
+				FileData:                      tt.fields.FileData,
+			}
+			assert.Equalf(t, tt.want, f.BinaryMarshal(), "BinaryMarshal()")
+		})
+	}
+}