1 /*
2 * QEMU Crypto af_alg-backend cipher support
3 *
4 * Copyright (c) 2017 HUAWEI TECHNOLOGIES CO., LTD.
5 *
6 * Authors:
7 * Longpeng(Mike) <longpeng2@huawei.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or
10 * (at your option) any later version. See the COPYING file in the
11 * top-level directory.
12 */
13 #include "qemu/osdep.h"
14 #include "qemu/sockets.h"
15 #include "qapi/error.h"
16 #include "crypto/cipher.h"
17 #include "cipherpriv.h"
18
19
20 static char *
qcrypto_afalg_cipher_format_name(QCryptoCipherAlgorithm alg,QCryptoCipherMode mode,Error ** errp)21 qcrypto_afalg_cipher_format_name(QCryptoCipherAlgorithm alg,
22 QCryptoCipherMode mode,
23 Error **errp)
24 {
25 char *name;
26 const char *alg_name;
27 const char *mode_name;
28
29 switch (alg) {
30 case QCRYPTO_CIPHER_ALG_AES_128:
31 case QCRYPTO_CIPHER_ALG_AES_192:
32 case QCRYPTO_CIPHER_ALG_AES_256:
33 alg_name = "aes";
34 break;
35 case QCRYPTO_CIPHER_ALG_CAST5_128:
36 alg_name = "cast5";
37 break;
38 case QCRYPTO_CIPHER_ALG_SERPENT_128:
39 case QCRYPTO_CIPHER_ALG_SERPENT_192:
40 case QCRYPTO_CIPHER_ALG_SERPENT_256:
41 alg_name = "serpent";
42 break;
43 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
44 case QCRYPTO_CIPHER_ALG_TWOFISH_192:
45 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
46 alg_name = "twofish";
47 break;
48
49 default:
50 error_setg(errp, "Unsupported cipher algorithm %d", alg);
51 return NULL;
52 }
53
54 mode_name = QCryptoCipherMode_str(mode);
55 name = g_strdup_printf("%s(%s)", mode_name, alg_name);
56
57 return name;
58 }
59
60 static const struct QCryptoCipherDriver qcrypto_cipher_afalg_driver;
61
62 QCryptoCipher *
qcrypto_afalg_cipher_ctx_new(QCryptoCipherAlgorithm alg,QCryptoCipherMode mode,const uint8_t * key,size_t nkey,Error ** errp)63 qcrypto_afalg_cipher_ctx_new(QCryptoCipherAlgorithm alg,
64 QCryptoCipherMode mode,
65 const uint8_t *key,
66 size_t nkey, Error **errp)
67 {
68 QCryptoAFAlg *afalg;
69 size_t expect_niv;
70 char *name;
71
72 name = qcrypto_afalg_cipher_format_name(alg, mode, errp);
73 if (!name) {
74 return NULL;
75 }
76
77 afalg = qcrypto_afalg_comm_alloc(AFALG_TYPE_CIPHER, name, errp);
78 if (!afalg) {
79 g_free(name);
80 return NULL;
81 }
82
83 g_free(name);
84
85 /* setkey */
86 if (setsockopt(afalg->tfmfd, SOL_ALG, ALG_SET_KEY, key,
87 nkey) != 0) {
88 error_setg_errno(errp, errno, "Set key failed");
89 qcrypto_afalg_comm_free(afalg);
90 return NULL;
91 }
92
93 /* prepare msg header */
94 afalg->msg = g_new0(struct msghdr, 1);
95 afalg->msg->msg_controllen += CMSG_SPACE(ALG_OPTYPE_LEN);
96 expect_niv = qcrypto_cipher_get_iv_len(alg, mode);
97 if (expect_niv) {
98 afalg->msg->msg_controllen += CMSG_SPACE(ALG_MSGIV_LEN(expect_niv));
99 }
100 afalg->msg->msg_control = g_new0(uint8_t, afalg->msg->msg_controllen);
101
102 /* We use 1st msghdr for crypto-info and 2nd msghdr for IV-info */
103 afalg->cmsg = CMSG_FIRSTHDR(afalg->msg);
104 afalg->cmsg->cmsg_type = ALG_SET_OP;
105 afalg->cmsg->cmsg_len = CMSG_SPACE(ALG_OPTYPE_LEN);
106 if (expect_niv) {
107 afalg->cmsg = CMSG_NXTHDR(afalg->msg, afalg->cmsg);
108 afalg->cmsg->cmsg_type = ALG_SET_IV;
109 afalg->cmsg->cmsg_len = CMSG_SPACE(ALG_MSGIV_LEN(expect_niv));
110 }
111 afalg->cmsg = CMSG_FIRSTHDR(afalg->msg);
112
113 afalg->base.driver = &qcrypto_cipher_afalg_driver;
114 return &afalg->base;
115 }
116
117 static int
qcrypto_afalg_cipher_setiv(QCryptoCipher * cipher,const uint8_t * iv,size_t niv,Error ** errp)118 qcrypto_afalg_cipher_setiv(QCryptoCipher *cipher,
119 const uint8_t *iv,
120 size_t niv, Error **errp)
121 {
122 QCryptoAFAlg *afalg = container_of(cipher, QCryptoAFAlg, base);
123 struct af_alg_iv *alg_iv;
124 size_t expect_niv;
125
126 expect_niv = qcrypto_cipher_get_iv_len(cipher->alg, cipher->mode);
127 if (niv != expect_niv) {
128 error_setg(errp, "Set IV len(%zu) not match expected(%zu)",
129 niv, expect_niv);
130 return -1;
131 }
132
133 /* move ->cmsg to next msghdr, for IV-info */
134 afalg->cmsg = CMSG_NXTHDR(afalg->msg, afalg->cmsg);
135
136 /* build setiv msg */
137 afalg->cmsg->cmsg_level = SOL_ALG;
138 alg_iv = (struct af_alg_iv *)CMSG_DATA(afalg->cmsg);
139 alg_iv->ivlen = niv;
140 memcpy(alg_iv->iv, iv, niv);
141
142 return 0;
143 }
144
145 static int
qcrypto_afalg_cipher_op(QCryptoAFAlg * afalg,const void * in,void * out,size_t len,bool do_encrypt,Error ** errp)146 qcrypto_afalg_cipher_op(QCryptoAFAlg *afalg,
147 const void *in, void *out,
148 size_t len, bool do_encrypt,
149 Error **errp)
150 {
151 uint32_t *type = NULL;
152 struct iovec iov;
153 size_t ret, rlen, done = 0;
154 uint32_t origin_controllen;
155
156 origin_controllen = afalg->msg->msg_controllen;
157 /* movev ->cmsg to first header, for crypto-info */
158 afalg->cmsg = CMSG_FIRSTHDR(afalg->msg);
159
160 /* build encrypt msg */
161 afalg->cmsg->cmsg_level = SOL_ALG;
162 afalg->msg->msg_iov = &iov;
163 afalg->msg->msg_iovlen = 1;
164 type = (uint32_t *)CMSG_DATA(afalg->cmsg);
165 if (do_encrypt) {
166 *type = ALG_OP_ENCRYPT;
167 } else {
168 *type = ALG_OP_DECRYPT;
169 }
170
171 do {
172 iov.iov_base = (void *)in + done;
173 iov.iov_len = len - done;
174
175 /* send info to AF_ALG core */
176 ret = sendmsg(afalg->opfd, afalg->msg, 0);
177 if (ret == -1) {
178 error_setg_errno(errp, errno, "Send data to AF_ALG core failed");
179 return -1;
180 }
181
182 /* encrypto && get result */
183 rlen = read(afalg->opfd, out, ret);
184 if (rlen == -1) {
185 error_setg_errno(errp, errno, "Get result from AF_ALG core failed");
186 return -1;
187 }
188 assert(rlen == ret);
189
190 /* do not update IV for following chunks */
191 afalg->msg->msg_controllen = 0;
192 done += ret;
193 } while (done < len);
194
195 afalg->msg->msg_controllen = origin_controllen;
196
197 return 0;
198 }
199
200 static int
qcrypto_afalg_cipher_encrypt(QCryptoCipher * cipher,const void * in,void * out,size_t len,Error ** errp)201 qcrypto_afalg_cipher_encrypt(QCryptoCipher *cipher,
202 const void *in, void *out,
203 size_t len, Error **errp)
204 {
205 QCryptoAFAlg *afalg = container_of(cipher, QCryptoAFAlg, base);
206
207 return qcrypto_afalg_cipher_op(afalg, in, out, len, true, errp);
208 }
209
210 static int
qcrypto_afalg_cipher_decrypt(QCryptoCipher * cipher,const void * in,void * out,size_t len,Error ** errp)211 qcrypto_afalg_cipher_decrypt(QCryptoCipher *cipher,
212 const void *in, void *out,
213 size_t len, Error **errp)
214 {
215 QCryptoAFAlg *afalg = container_of(cipher, QCryptoAFAlg, base);
216
217 return qcrypto_afalg_cipher_op(afalg, in, out, len, false, errp);
218 }
219
qcrypto_afalg_comm_ctx_free(QCryptoCipher * cipher)220 static void qcrypto_afalg_comm_ctx_free(QCryptoCipher *cipher)
221 {
222 QCryptoAFAlg *afalg = container_of(cipher, QCryptoAFAlg, base);
223
224 qcrypto_afalg_comm_free(afalg);
225 }
226
227 static const struct QCryptoCipherDriver qcrypto_cipher_afalg_driver = {
228 .cipher_encrypt = qcrypto_afalg_cipher_encrypt,
229 .cipher_decrypt = qcrypto_afalg_cipher_decrypt,
230 .cipher_setiv = qcrypto_afalg_cipher_setiv,
231 .cipher_free = qcrypto_afalg_comm_ctx_free,
232 };
233