add To func

tea.go

@@ -2,4 +2,35 @@
 // from https://github.com/Mrs4s/MiraiGo/blob/master/binary/tea.go
 package tea
 
+import (
+	"encoding/binary"
+	_ "unsafe" // required by go:linkname
+)
+
 type TEA [4]uint32
+
+// randuint32 returns a lock free uint32 value.
+//go:linkname randuint32 runtime.fastrand
+func randuint32() uint32
+
+//go:nosplit
+func NewTeaCipher(key []byte) (t TEA) {
+	if len(key) == 16 {
+		t[3] = binary.BigEndian.Uint32(key[12:])
+		t[2] = binary.BigEndian.Uint32(key[8:])
+		t[1] = binary.BigEndian.Uint32(key[4:])
+		t[0] = binary.BigEndian.Uint32(key[0:])
+	}
+	return
+}
+
+//go:nosplit
+func NewTeaCipherLittleEndian(key []byte) (t TEA) {
+	if len(key) == 16 {
+		t[3] = binary.LittleEndian.Uint32(key[12:])
+		t[2] = binary.LittleEndian.Uint32(key[8:])
+		t[1] = binary.LittleEndian.Uint32(key[4:])
+		t[0] = binary.LittleEndian.Uint32(key[0:])
+	}
+	return
+}