package symm

import (
	"bytes"
	"testing"
)

// AES-XTS vectors from IEEE P1619/D16 Annex B (same set used by golang.org/x/crypto/xts tests).
var aesXTSStandardVectors = []struct {
	key           string
	dataUnitIndex uint64
	plaintext     string
	ciphertext    string
}{
	{
		key:           "0000000000000000000000000000000000000000000000000000000000000000",
		dataUnitIndex: 0,
		plaintext:     "0000000000000000000000000000000000000000000000000000000000000000",
		ciphertext:    "917cf69ebd68b2ec9b9fe9a3eadda692cd43d2f59598ed858c02c2652fbf922e",
	},
	{
		key:           "1111111111111111111111111111111122222222222222222222222222222222",
		dataUnitIndex: 0x3333333333,
		plaintext:     "4444444444444444444444444444444444444444444444444444444444444444",
		ciphertext:    "c454185e6a16936e39334038acef838bfb186fff7480adc4289382ecd6d394f0",
	},
	{
		key:           "fffefdfcfbfaf9f8f7f6f5f4f3f2f1f022222222222222222222222222222222",
		dataUnitIndex: 0x3333333333,
		plaintext:     "4444444444444444444444444444444444444444444444444444444444444444",
		ciphertext:    "af85336b597afc1a900b2eb21ec949d292df4c047e0b21532186a5971a227a89",
	},
}

func TestAesXTSStandardVectors(t *testing.T) {
	for i, tc := range aesXTSStandardVectors {
		master := mustHex(t, tc.key)
		key1, key2, err := SplitAesXTSMasterKey(master)
		if err != nil {
			t.Fatalf("#%d split key failed: %v", i, err)
		}

		plain := mustHex(t, tc.plaintext)
		wantCipher := mustHex(t, tc.ciphertext)
		dataUnitSize := len(plain)

		gotCipher, err := EncryptAesXTSAt(plain, key1, key2, dataUnitSize, tc.dataUnitIndex)
		if err != nil {
			t.Fatalf("#%d EncryptAesXTSAt failed: %v", i, err)
		}
		if !bytes.Equal(gotCipher, wantCipher) {
			t.Fatalf("#%d ciphertext mismatch", i)
		}

		gotPlain, err := DecryptAesXTSAt(wantCipher, key1, key2, dataUnitSize, tc.dataUnitIndex)
		if err != nil {
			t.Fatalf("#%d DecryptAesXTSAt failed: %v", i, err)
		}
		if !bytes.Equal(gotPlain, plain) {
			t.Fatalf("#%d plaintext mismatch", i)
		}

		encStream := &bytes.Buffer{}
		if err := EncryptAesXTSStreamAt(encStream, bytes.NewReader(plain), key1, key2, dataUnitSize, tc.dataUnitIndex); err != nil {
			t.Fatalf("#%d EncryptAesXTSStreamAt failed: %v", i, err)
		}
		if !bytes.Equal(encStream.Bytes(), wantCipher) {
			t.Fatalf("#%d stream ciphertext mismatch", i)
		}

		decStream := &bytes.Buffer{}
		if err := DecryptAesXTSStreamAt(decStream, bytes.NewReader(wantCipher), key1, key2, dataUnitSize, tc.dataUnitIndex); err != nil {
			t.Fatalf("#%d DecryptAesXTSStreamAt failed: %v", i, err)
		}
		if !bytes.Equal(decStream.Bytes(), plain) {
			t.Fatalf("#%d stream plaintext mismatch", i)
		}
	}
}