Add packing

packing.go

@@ -0,0 +1,77 @@
+package gopwn
+
+import (
+	"encoding/binary"
+)
+
+// P16L packs a uint16 into a byte slice in little endian format
+func P16L(i uint16) []byte {
+	b := make([]byte, 2)
+	binary.LittleEndian.PutUint16(b, i)
+	return b
+}
+
+// P16L packs a uint16 into a byte slice in big endian format
+func P16B(i uint16) []byte {
+	b := make([]byte, 2)
+	binary.BigEndian.PutUint16(b, i)
+	return b
+}
+
+// P32L packs a uint32 into a byte slice in little endian format
+func P32L(i uint32) []byte {
+	b := make([]byte, 4)
+	binary.LittleEndian.PutUint32(b, i)
+	return b
+}
+
+// P32L packs a uint32 into a byte slice in big endian format
+func P32B(i uint32) []byte {
+	b := make([]byte, 4)
+	binary.BigEndian.PutUint32(b, i)
+	return b
+}
+
+// P64L packs a uint64 into a byte slice in little endian format
+func P64L(i uint64) []byte {
+	b := make([]byte, 8)
+	binary.LittleEndian.PutUint64(b, i)
+	return b
+}
+
+// P32L packs a uint32 into a byte slice in big endian format
+func P64B(i uint64) []byte {
+	b := make([]byte, 8)
+	binary.BigEndian.PutUint64(b, i)
+	return b
+}
+
+// U16L unpacks a byte slice in little endian format into a uint16
+func U16L(b []byte) uint16 {
+	return binary.LittleEndian.Uint16(b)
+}
+
+// U16L unpacks a byte slice in big endian format into a uint16
+func U16B(b []byte) uint16 {
+	return binary.BigEndian.Uint16(b)
+}
+
+// U32L unpacks a byte slice in little endian format into a uint32
+func U32L(b []byte) uint32 {
+	return binary.LittleEndian.Uint32(b)
+}
+
+// U32L unpacks a byte slice in big endian format into a uint32
+func U32B(b []byte) uint32 {
+	return binary.BigEndian.Uint32(b)
+}
+
+// U64L unpacks a byte slice in little endian format into a uint64
+func U64L(b []byte) uint64 {
+	return binary.LittleEndian.Uint64(b)
+}
+
+// U64L unpacks a byte slice in big endian format into a uint64
+func U64B(b []byte) uint64 {
+	return binary.BigEndian.Uint64(b)
+}

packing_test.go

@@ -0,0 +1,71 @@
+package gopwn
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPack(t *testing.T) {
+	t.Run("16 LittleEndian", func(t *testing.T) {
+		b := P16L(0xdead)
+		assert.Equal(t, []byte("\xad\xde"), b)
+	})
+
+	t.Run("16 BigEndian", func(t *testing.T) {
+		b := P16B(0xdead)
+		assert.Equal(t, []byte("\xde\xad"), b)
+	})
+
+	t.Run("32 LittleEndian", func(t *testing.T) {
+		b := P32L(0xdeadbeef)
+		assert.Equal(t, []byte("\xef\xbe\xad\xde"), b)
+	})
+
+	t.Run("32 BigEndian", func(t *testing.T) {
+		b := P32B(0xdeadbeef)
+		assert.Equal(t, []byte("\xde\xad\xbe\xef"), b)
+	})
+
+	t.Run("64 LittleEndian", func(t *testing.T) {
+		b := P64L(0xdeadbeef)
+		assert.Equal(t, []byte("\xef\xbe\xad\xde\x00\x00\x00\x00"), b)
+	})
+
+	t.Run("64 BigEndian", func(t *testing.T) {
+		b := P64B(0xdeadbeef)
+		assert.Equal(t, []byte("\x00\x00\x00\x00\xde\xad\xbe\xef"), b)
+	})
+}
+
+func TestUnPack(t *testing.T) {
+	t.Run("16 LittleEndian", func(t *testing.T) {
+		i := U16L([]byte("\xad\xde"))
+		assert.Equal(t, uint16(0xdead), i)
+	})
+
+	t.Run("16 BigEndian", func(t *testing.T) {
+		i := U16B([]byte("\xde\xad"))
+		assert.Equal(t, uint16(0xdead), i)
+	})
+
+	t.Run("32 LittleEndian", func(t *testing.T) {
+		i := U32L([]byte("\xef\xbe\xad\xde"))
+		assert.Equal(t, uint32(0xdeadbeef), i)
+	})
+
+	t.Run("32 BigEndian", func(t *testing.T) {
+		i := U32B([]byte("\xde\xad\xbe\xef"))
+		assert.Equal(t, uint32(0xdeadbeef), i)
+	})
+
+	t.Run("64 LittleEndian", func(t *testing.T) {
+		i := U64L([]byte("\xef\xbe\xad\xde\x00\x00\x00\x00"))
+		assert.Equal(t, uint64(0xdeadbeef), i)
+	})
+
+	t.Run("64 BigEndian", func(t *testing.T) {
+		i := U64B([]byte("\x00\x00\x00\x00\xde\xad\xbe\xef"))
+		assert.Equal(t, uint64(0xdeadbeef), i)
+	})
+}