1
2
3
4
5
6
7
8
9
10
11
12
13#include <linux/module.h>
14#include <linux/sched.h>
15#include <linux/delay.h>
16#include <linux/scatterlist.h>
17#include <linux/crypto.h>
18#include <crypto/algapi.h>
19#include <crypto/aes.h>
20#include <crypto/scatterwalk.h>
21
22#include "ccp-crypto.h"
23
24struct ccp_aes_xts_def {
25 const char *name;
26 const char *drv_name;
27};
28
29static struct ccp_aes_xts_def aes_xts_algs[] = {
30 {
31 .name = "xts(aes)",
32 .drv_name = "xts-aes-ccp",
33 },
34};
35
36struct ccp_unit_size_map {
37 unsigned int size;
38 u32 value;
39};
40
41static struct ccp_unit_size_map unit_size_map[] = {
42 {
43 .size = 4096,
44 .value = CCP_XTS_AES_UNIT_SIZE_4096,
45 },
46 {
47 .size = 2048,
48 .value = CCP_XTS_AES_UNIT_SIZE_2048,
49 },
50 {
51 .size = 1024,
52 .value = CCP_XTS_AES_UNIT_SIZE_1024,
53 },
54 {
55 .size = 512,
56 .value = CCP_XTS_AES_UNIT_SIZE_512,
57 },
58 {
59 .size = 256,
60 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
61 },
62 {
63 .size = 128,
64 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
65 },
66 {
67 .size = 64,
68 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
69 },
70 {
71 .size = 32,
72 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
73 },
74 {
75 .size = 16,
76 .value = CCP_XTS_AES_UNIT_SIZE_16,
77 },
78 {
79 .size = 1,
80 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
81 },
82};
83
84static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
85{
86 struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
87 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
88
89 if (ret)
90 return ret;
91
92 memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
93
94 return 0;
95}
96
97static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
98 unsigned int key_len)
99{
100 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
101
102
103
104
105 switch (key_len) {
106 case AES_KEYSIZE_128 * 2:
107 memcpy(ctx->u.aes.key, key, key_len);
108 break;
109 }
110 ctx->u.aes.key_len = key_len / 2;
111 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
112
113 return crypto_ablkcipher_setkey(ctx->u.aes.tfm_ablkcipher, key,
114 key_len);
115}
116
117static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
118 unsigned int encrypt)
119{
120 struct crypto_tfm *tfm =
121 crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
122 struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
123 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
124 unsigned int unit;
125 int ret;
126
127 if (!ctx->u.aes.key_len)
128 return -EINVAL;
129
130 if (req->nbytes & (AES_BLOCK_SIZE - 1))
131 return -EINVAL;
132
133 if (!req->info)
134 return -EINVAL;
135
136 for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++)
137 if (!(req->nbytes & (unit_size_map[unit].size - 1)))
138 break;
139
140 if ((unit_size_map[unit].value == CCP_XTS_AES_UNIT_SIZE__LAST) ||
141 (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
142
143
144
145 ablkcipher_request_set_tfm(req, ctx->u.aes.tfm_ablkcipher);
146 ret = (encrypt) ? crypto_ablkcipher_encrypt(req) :
147 crypto_ablkcipher_decrypt(req);
148 ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
149
150 return ret;
151 }
152
153 memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
154 sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
155
156 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
157 INIT_LIST_HEAD(&rctx->cmd.entry);
158 rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
159 rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
160 : CCP_AES_ACTION_DECRYPT;
161 rctx->cmd.u.xts.unit_size = unit_size_map[unit].value;
162 rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
163 rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
164 rctx->cmd.u.xts.iv = &rctx->iv_sg;
165 rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
166 rctx->cmd.u.xts.src = req->src;
167 rctx->cmd.u.xts.src_len = req->nbytes;
168 rctx->cmd.u.xts.dst = req->dst;
169
170 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
171
172 return ret;
173}
174
175static int ccp_aes_xts_encrypt(struct ablkcipher_request *req)
176{
177 return ccp_aes_xts_crypt(req, 1);
178}
179
180static int ccp_aes_xts_decrypt(struct ablkcipher_request *req)
181{
182 return ccp_aes_xts_crypt(req, 0);
183}
184
185static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm)
186{
187 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
188 struct crypto_ablkcipher *fallback_tfm;
189
190 ctx->complete = ccp_aes_xts_complete;
191 ctx->u.aes.key_len = 0;
192
193 fallback_tfm = crypto_alloc_ablkcipher(crypto_tfm_alg_name(tfm), 0,
194 CRYPTO_ALG_ASYNC |
195 CRYPTO_ALG_NEED_FALLBACK);
196 if (IS_ERR(fallback_tfm)) {
197 pr_warn("could not load fallback driver %s\n",
198 crypto_tfm_alg_name(tfm));
199 return PTR_ERR(fallback_tfm);
200 }
201 ctx->u.aes.tfm_ablkcipher = fallback_tfm;
202
203 tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx) +
204 fallback_tfm->base.crt_ablkcipher.reqsize;
205
206 return 0;
207}
208
209static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm)
210{
211 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
212
213 if (ctx->u.aes.tfm_ablkcipher)
214 crypto_free_ablkcipher(ctx->u.aes.tfm_ablkcipher);
215 ctx->u.aes.tfm_ablkcipher = NULL;
216}
217
218static int ccp_register_aes_xts_alg(struct list_head *head,
219 const struct ccp_aes_xts_def *def)
220{
221 struct ccp_crypto_ablkcipher_alg *ccp_alg;
222 struct crypto_alg *alg;
223 int ret;
224
225 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
226 if (!ccp_alg)
227 return -ENOMEM;
228
229 INIT_LIST_HEAD(&ccp_alg->entry);
230
231 alg = &ccp_alg->alg;
232
233 snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
234 snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
235 def->drv_name);
236 alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
237 CRYPTO_ALG_KERN_DRIVER_ONLY |
238 CRYPTO_ALG_NEED_FALLBACK;
239 alg->cra_blocksize = AES_BLOCK_SIZE;
240 alg->cra_ctxsize = sizeof(struct ccp_ctx);
241 alg->cra_priority = CCP_CRA_PRIORITY;
242 alg->cra_type = &crypto_ablkcipher_type;
243 alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey;
244 alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt;
245 alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt;
246 alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2;
247 alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2;
248 alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE;
249 alg->cra_init = ccp_aes_xts_cra_init;
250 alg->cra_exit = ccp_aes_xts_cra_exit;
251 alg->cra_module = THIS_MODULE;
252
253 ret = crypto_register_alg(alg);
254 if (ret) {
255 pr_err("%s ablkcipher algorithm registration error (%d)\n",
256 alg->cra_name, ret);
257 kfree(ccp_alg);
258 return ret;
259 }
260
261 list_add(&ccp_alg->entry, head);
262
263 return 0;
264}
265
266int ccp_register_aes_xts_algs(struct list_head *head)
267{
268 int i, ret;
269
270 for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
271 ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);
272 if (ret)
273 return ret;
274 }
275
276 return 0;
277}
278
