1// Copyright 2010 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package cipher_test
6
7import (
8	"bytes"
9	"crypto/aes"
10	"crypto/cipher"
11	"crypto/rand"
12	"encoding/hex"
13	"testing"
14)
15
16// cfbTests contains the test vectors from
17// https://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf, section
18// F.3.13.
19var cfbTests = []struct {
20	key, iv, plaintext, ciphertext string
21}{
22	{
23		"2b7e151628aed2a6abf7158809cf4f3c",
24		"000102030405060708090a0b0c0d0e0f",
25		"6bc1bee22e409f96e93d7e117393172a",
26		"3b3fd92eb72dad20333449f8e83cfb4a",
27	},
28	{
29		"2b7e151628aed2a6abf7158809cf4f3c",
30		"3B3FD92EB72DAD20333449F8E83CFB4A",
31		"ae2d8a571e03ac9c9eb76fac45af8e51",
32		"c8a64537a0b3a93fcde3cdad9f1ce58b",
33	},
34	{
35		"2b7e151628aed2a6abf7158809cf4f3c",
36		"C8A64537A0B3A93FCDE3CDAD9F1CE58B",
37		"30c81c46a35ce411e5fbc1191a0a52ef",
38		"26751f67a3cbb140b1808cf187a4f4df",
39	},
40	{
41		"2b7e151628aed2a6abf7158809cf4f3c",
42		"26751F67A3CBB140B1808CF187A4F4DF",
43		"f69f2445df4f9b17ad2b417be66c3710",
44		"c04b05357c5d1c0eeac4c66f9ff7f2e6",
45	},
46}
47
48func TestCFBVectors(t *testing.T) {
49	for i, test := range cfbTests {
50		key, err := hex.DecodeString(test.key)
51		if err != nil {
52			t.Fatal(err)
53		}
54		iv, err := hex.DecodeString(test.iv)
55		if err != nil {
56			t.Fatal(err)
57		}
58		plaintext, err := hex.DecodeString(test.plaintext)
59		if err != nil {
60			t.Fatal(err)
61		}
62		expected, err := hex.DecodeString(test.ciphertext)
63		if err != nil {
64			t.Fatal(err)
65		}
66
67		block, err := aes.NewCipher(key)
68		if err != nil {
69			t.Fatal(err)
70		}
71
72		ciphertext := make([]byte, len(plaintext))
73		cfb := cipher.NewCFBEncrypter(block, iv)
74		cfb.XORKeyStream(ciphertext, plaintext)
75
76		if !bytes.Equal(ciphertext, expected) {
77			t.Errorf("#%d: wrong output: got %x, expected %x", i, ciphertext, expected)
78		}
79
80		cfbdec := cipher.NewCFBDecrypter(block, iv)
81		plaintextCopy := make([]byte, len(ciphertext))
82		cfbdec.XORKeyStream(plaintextCopy, ciphertext)
83
84		if !bytes.Equal(plaintextCopy, plaintext) {
85			t.Errorf("#%d: wrong plaintext: got %x, expected %x", i, plaintextCopy, plaintext)
86		}
87	}
88}
89
90func TestCFBInverse(t *testing.T) {
91	block, err := aes.NewCipher(commonKey128)
92	if err != nil {
93		t.Error(err)
94		return
95	}
96
97	plaintext := []byte("this is the plaintext. this is the plaintext.")
98	iv := make([]byte, block.BlockSize())
99	rand.Reader.Read(iv)
100	cfb := cipher.NewCFBEncrypter(block, iv)
101	ciphertext := make([]byte, len(plaintext))
102	copy(ciphertext, plaintext)
103	cfb.XORKeyStream(ciphertext, ciphertext)
104
105	cfbdec := cipher.NewCFBDecrypter(block, iv)
106	plaintextCopy := make([]byte, len(plaintext))
107	copy(plaintextCopy, ciphertext)
108	cfbdec.XORKeyStream(plaintextCopy, plaintextCopy)
109
110	if !bytes.Equal(plaintextCopy, plaintext) {
111		t.Errorf("got: %x, want: %x", plaintextCopy, plaintext)
112	}
113}
114