Solve emersion#23: header with extra black line generated in in some …

…rare cases
ludusrusso · Mar 10, 2020 · 978f565 · 978f565
1 parent 322c864
commit 978f565
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/dkim/header.go b/dkim/header.go
@@ -49,7 +49,7 @@ func writeHeader(w io.Writer, h header) error {
 }
 
 func foldHeaderField(kv string) string {
-	buf := bytes.NewBufferString(kv + crlf)
+	buf := bytes.NewBufferString(kv)
 
 	line := make([]byte, 75) // 78 - len("\r\n\s")
 	first := true
@@ -63,7 +63,7 @@ func foldHeaderField(kv string) string {
 		fold.Write(line[:len])
 	}
 
-	return fold.String()
+	return fold.String() + crlf
 }
 
 func parseHeaderField(s string) (k string, v string) {

diff --git a/dkim/header_test.go b/dkim/header_test.go
@@ -102,3 +102,11 @@ func TestHeaderPicker_Pick(t *testing.T) {
 
 	})
 }
+
+func TestFoldHeaderField(t *testing.T) {
+	header := `DKIM-Signature: a=rsa-sha256; bh=bvW0aiEWdP0ie2rawBb+IiTxlHI9KgEIYjEYTGzMRa0=; c=simple/simple; d=test.xxxxxxxxxx.xxxxx; h=Return-Path:From:To:Subject:Message-ID:Date; s=brisbane; t=1583859773; v=1; b=IIlaZ79pLDdypX2YzJuy9EvxsbrqF360CLhkQqMqVC/GIa1K/X8p8POny7WuVuFTMHLvA1zH9YcXgEgIH+X0GgGsqqzq8ETL+QGZ9g1EKCmIg+ZEYV5JnH25Ar6bJpGra3jg6sIxKi6CthpK50kd8T0Q3K/oZGot4BkLaPqogpo=;`
+	folded := foldHeaderField(header)
+	if strings.HasSuffix(folded, "\r\n \n") {
+		t.Errorf("Extra black line added in header:\n ---Start--- %v ---End---", folded)
+	}
+}