Initial commit

pkg/syscallobf/encode.go

@@ -0,0 +1,44 @@
+package syscallobf
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"sync"
+)
+
+var (
+	dispatchKey  uint64
+	dispatchOnce sync.Once
+)
+
+func initDispatchKey() {
+	dispatchOnce.Do(func() {
+		var buf [8]byte
+		rand.Read(buf[:])
+		dispatchKey = binary.LittleEndian.Uint64(buf[:])
+		if dispatchKey == 0 {
+			dispatchKey = 0xDEADBEEFCAFEBABE
+		}
+	})
+}
+
+func EncodeTrap(num uintptr) uintptr {
+	initDispatchKey()
+	return uintptr(uint64(num) ^ dispatchKey)
+}
+
+func DecodeTrap(encoded uintptr) uintptr {
+	return uintptr(uint64(encoded) ^ dispatchKey)
+}
+
+type encodedSyscall struct {
+	encoded uintptr
+}
+
+func NewEncodedSyscall(num uintptr) encodedSyscall {
+	return encodedSyscall{encoded: EncodeTrap(num)}
+}
+
+func (e encodedSyscall) Trap() uintptr {
+	return DecodeTrap(e.encoded)
+}