dkim: fix headerPicker.Pick with non-canonical header keys

Closes: #58
emersion · Nov 20, 2023 · a2108dd · a2108dd
1 parent bab2e0c
commit a2108dd
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/dkim/header.go b/dkim/header.go
@@ -149,6 +149,8 @@ func newHeaderPicker(h header) *headerPicker {
 }
 
 func (p *headerPicker) Pick(key string) string {
+	key = strings.ToLower(key)
+
 	at := p.picked[key]
 	for i := len(p.h) - 1; i >= 0; i-- {
 		kv := p.h[i]

diff --git a/dkim/header_test.go b/dkim/header_test.go
@@ -133,7 +133,18 @@ func TestHeaderPicker_Pick(t *testing.T) {
 				t.Errorf("Parameter %s not found in headers %s", k, headers)
 			}
 		}
-
+	})
+	t.Run("non-canonical header fields", func(t *testing.T) {
+		headers := header{
+			"Message-ID: asdf",
+		}
+		picker := newHeaderPicker(headers)
+		if v := picker.Pick("Message-Id"); v != headers[0] {
+			t.Errorf("Pick() = %q, want %q", v, headers[0])
+		}
+		if v := picker.Pick("Message-ID"); v != "" {
+			t.Errorf("Pick() = %q, want %q", v, "")
+		}
 	})
 }