1 //! Counter Mode with a 32-bit little endian counter
2
3 use cipher::{consts::U16, generic_array::GenericArray, NewCipher, StreamCipher};
4 use hex_literal::hex;
5
6 type Aes128Ctr = ctr::Ctr32LE<aes::Aes128>;
7
8 const KEY: &[u8; 16] = &hex!("000102030405060708090A0B0C0D0E0F");
9 const NONCE1: &[u8; 16] = &hex!("11111111111111111111111111111111");
10 const NONCE2: &[u8; 16] = &hex!("FEFFFFFF222222222222222222222222");
11
12 /// Compute nonce as used by AES-GCM-SIV
nonce(bytes: &[u8; 16]) -> GenericArray<u8, U16>13 fn nonce(bytes: &[u8; 16]) -> GenericArray<u8, U16> {
14 let mut n = *bytes;
15 n[15] |= 0x80;
16 n.into()
17 }
18
19 #[test]
counter_incr()20 fn counter_incr() {
21 let mut ctr = Aes128Ctr::new(KEY.into(), &nonce(NONCE1));
22 assert_eq!(ctr.current_block(), 0);
23
24 let mut buffer = [0u8; 64];
25 ctr.apply_keystream(&mut buffer);
26
27 // assert_eq!(ctr.current_ctr(), 4);
28 assert_eq!(
29 &buffer[..],
30 &hex!(
31 "2A0680B210CAD45E886D7EF6DAB357C9F18B39AFF6930FDB2D9FCE34261FF699
32 EB96774669D24B560C9AD028C5C39C4580775A82065256B4787DC91C6942B700"
33 )[..]
34 );
35 }
36
37 #[test]
counter_seek()38 fn counter_seek() {
39 let mut ctr = Aes128Ctr::new(KEY.into(), &nonce(NONCE1));
40 ctr.seek_block(1);
41 assert_eq!(ctr.current_block(), 1);
42
43 let mut buffer = [0u8; 64];
44 ctr.apply_keystream(&mut buffer);
45
46 assert_eq!(ctr.current_block(), 5);
47 assert_eq!(
48 &buffer[..],
49 &hex!(
50 "F18B39AFF6930FDB2D9FCE34261FF699EB96774669D24B560C9AD028C5C39C45
51 80775A82065256B4787DC91C6942B7001564DDA1B07DCED9201AB71BAF06905B"
52 )[..]
53 );
54 }
55
56 #[test]
keystream_xor()57 fn keystream_xor() {
58 let mut ctr = Aes128Ctr::new(KEY.into(), &nonce(NONCE1));
59 let mut buffer = [1u8; 64];
60
61 ctr.apply_keystream(&mut buffer);
62 assert_eq!(
63 &buffer[..],
64 &hex!(
65 "2B0781B311CBD55F896C7FF7DBB256C8F08A38AEF7920EDA2C9ECF35271EF798
66 EA97764768D34A570D9BD129C4C29D4481765B83075357B5797CC81D6843B601"
67 )[..]
68 );
69 }
70
71 #[test]
counter_wrap()72 fn counter_wrap() {
73 let mut ctr = Aes128Ctr::new(KEY.into(), &nonce(NONCE2));
74 assert_eq!(ctr.current_block(), 0);
75
76 let mut buffer = [0u8; 64];
77 ctr.apply_keystream(&mut buffer);
78
79 assert_eq!(ctr.current_block(), 4);
80 assert_eq!(
81 &buffer[..],
82 &hex!(
83 "A1E649D8B382293DC28375C42443BB6A226BAADC9E9CCA8214F56E07A4024E06
84 6355A0DA2E08FB00112FFA38C26189EE55DD5B0B130ED87096FE01B59A665A60"
85 )[..]
86 );
87 }
88