Handle unprintable characters in kiss codes.

beevik · Oct 15, 2017 · 8ee33ea · 8ee33ea
1 parent 0201bad
commit 8ee33ea
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Showing 2 changed files with 11 additions and 0 deletions.
diff --git a/ntp.go b/ntp.go
@@ -548,11 +548,18 @@ func toInterval(t int8) time.Duration {
 }
 
 func kissCode(id uint32) string {
+	isPrintable := func(ch byte) bool { return ch >= 32 && ch <= 126 }
+
 	b := []byte{
 		byte(id >> 24),
 		byte(id >> 16),
 		byte(id >> 8),
 		byte(id),
 	}
+	for _, ch := range b {
+		if !isPrintable(ch) {
+			return ""
+		}
+	}
 	return string(b)
 }
diff --git a/ntp_test.go b/ntp_test.go
@@ -326,6 +326,10 @@ func TestKissCode(t *testing.T) {
 		{0x52415445, "RATE"},
 		{0x524d4f54, "RMOT"},
 		{0x53544550, "STEP"},
+		{0x01010101, ""},
+		{0xfefefefe, ""},
+		{0x01544450, ""},
+		{0x41544401, ""},
 	}
 	for _, c := range codes {
 		assert.Equal(t, kissCode(c.id), c.str)