1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21#include "qemu/osdep.h"
22#include "qapi/error.h"
23#include "crypto/cipher.h"
24
25
26static size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = {
27 [QCRYPTO_CIPHER_ALG_AES_128] = 16,
28 [QCRYPTO_CIPHER_ALG_AES_192] = 24,
29 [QCRYPTO_CIPHER_ALG_AES_256] = 32,
30 [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
31 [QCRYPTO_CIPHER_ALG_CAST5_128] = 16,
32 [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
33 [QCRYPTO_CIPHER_ALG_SERPENT_192] = 24,
34 [QCRYPTO_CIPHER_ALG_SERPENT_256] = 32,
35 [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
36 [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 24,
37 [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 32,
38};
39
40static size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = {
41 [QCRYPTO_CIPHER_ALG_AES_128] = 16,
42 [QCRYPTO_CIPHER_ALG_AES_192] = 16,
43 [QCRYPTO_CIPHER_ALG_AES_256] = 16,
44 [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,
45 [QCRYPTO_CIPHER_ALG_CAST5_128] = 8,
46 [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
47 [QCRYPTO_CIPHER_ALG_SERPENT_192] = 16,
48 [QCRYPTO_CIPHER_ALG_SERPENT_256] = 16,
49 [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
50 [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 16,
51 [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 16,
52};
53
54static bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
55 [QCRYPTO_CIPHER_MODE_ECB] = false,
56 [QCRYPTO_CIPHER_MODE_CBC] = true,
57 [QCRYPTO_CIPHER_MODE_XTS] = true,
58};
59
60
61size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg)
62{
63 if (alg >= G_N_ELEMENTS(alg_key_len)) {
64 return 0;
65 }
66 return alg_block_len[alg];
67}
68
69
70size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg)
71{
72 if (alg >= G_N_ELEMENTS(alg_key_len)) {
73 return 0;
74 }
75 return alg_key_len[alg];
76}
77
78
79size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg,
80 QCryptoCipherMode mode)
81{
82 if (alg >= G_N_ELEMENTS(alg_block_len)) {
83 return 0;
84 }
85 if (mode >= G_N_ELEMENTS(mode_need_iv)) {
86 return 0;
87 }
88
89 if (mode_need_iv[mode]) {
90 return alg_block_len[alg];
91 }
92 return 0;
93}
94
95
96static bool
97qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg,
98 QCryptoCipherMode mode,
99 size_t nkey,
100 Error **errp)
101{
102 if ((unsigned)alg >= QCRYPTO_CIPHER_ALG__MAX) {
103 error_setg(errp, "Cipher algorithm %d out of range",
104 alg);
105 return false;
106 }
107
108 if (mode == QCRYPTO_CIPHER_MODE_XTS) {
109 if (alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
110 error_setg(errp, "XTS mode not compatible with DES-RFB");
111 return false;
112 }
113 if (nkey % 2) {
114 error_setg(errp, "XTS cipher key length should be a multiple of 2");
115 return false;
116 }
117
118 if (alg_key_len[alg] != (nkey / 2)) {
119 error_setg(errp, "Cipher key length %zu should be %zu",
120 nkey, alg_key_len[alg] * 2);
121 return false;
122 }
123 } else {
124 if (alg_key_len[alg] != nkey) {
125 error_setg(errp, "Cipher key length %zu should be %zu",
126 nkey, alg_key_len[alg]);
127 return false;
128 }
129 }
130 return true;
131}
132
133#if defined(CONFIG_GCRYPT) || defined(CONFIG_NETTLE)
134static uint8_t *
135qcrypto_cipher_munge_des_rfb_key(const uint8_t *key,
136 size_t nkey)
137{
138 uint8_t *ret = g_new0(uint8_t, nkey);
139 size_t i;
140 for (i = 0; i < nkey; i++) {
141 uint8_t r = key[i];
142 r = (r & 0xf0) >> 4 | (r & 0x0f) << 4;
143 r = (r & 0xcc) >> 2 | (r & 0x33) << 2;
144 r = (r & 0xaa) >> 1 | (r & 0x55) << 1;
145 ret[i] = r;
146 }
147 return ret;
148}
149#endif
150
151#ifdef CONFIG_GCRYPT
152#include "crypto/cipher-gcrypt.c"
153#elif defined CONFIG_NETTLE
154#include "crypto/cipher-nettle.c"
155#else
156#include "crypto/cipher-builtin.c"
157#endif
158