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
24
25struct ccp_aes_xts_def {
26 const char *name;
27 const char *drv_name;
28};
29
30static struct ccp_aes_xts_def aes_xts_algs[] = {
31 {
32 .name = "xts(aes)",
33 .drv_name = "xts-aes-ccp",
34 },
35};
36
37struct ccp_unit_size_map {
38 unsigned int size;
39 u32 value;
40};
41
42static struct ccp_unit_size_map unit_size_map[] = {
43 {
44 .size = 4096,
45 .value = CCP_XTS_AES_UNIT_SIZE_4096,
46 },
47 {
48 .size = 2048,
49 .value = CCP_XTS_AES_UNIT_SIZE_2048,
50 },
51 {
52 .size = 1024,
53 .value = CCP_XTS_AES_UNIT_SIZE_1024,
54 },
55 {
56 .size = 512,
57 .value = CCP_XTS_AES_UNIT_SIZE_512,
58 },
59 {
60 .size = 256,
61 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
62 },
63 {
64 .size = 128,
65 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
66 },
67 {
68 .size = 64,
69 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
70 },
71 {
72 .size = 32,
73 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
74 },
75 {
76 .size = 16,
77 .value = CCP_XTS_AES_UNIT_SIZE_16,
78 },
79 {
80 .size = 1,
81 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
82 },
83};
84
85static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
86{
87 struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
88 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
89
90 if (ret)
91 return ret;
92
93 memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
94
95 return 0;
96}
97
98static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
99 unsigned int key_len)
100{
101 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
102
103
104
105
106 switch (key_len) {
107 case AES_KEYSIZE_128 * 2:
108 memcpy(ctx->u.aes.key, key, key_len);
109 break;
110 }
111 ctx->u.aes.key_len = key_len / 2;
112 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
113
114 return crypto_ablkcipher_setkey(ctx->u.aes.tfm_ablkcipher, key,
115 key_len);
116}
117
118static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
119 unsigned int encrypt)
120{
121 struct crypto_tfm *tfm =
122 crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
123 struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
124 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
125 unsigned int unit;
126 int ret;
127
128 if (!ctx->u.aes.key_len)
129 return -EINVAL;
130
131 if (req->nbytes & (AES_BLOCK_SIZE - 1))
132 return -EINVAL;
133
134 if (!req->info)
135 return -EINVAL;
136
137 for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++)
138 if (!(req->nbytes & (unit_size_map[unit].size - 1)))
139 break;
140
141 if ((unit_size_map[unit].value == CCP_XTS_AES_UNIT_SIZE__LAST) ||
142 (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
143
144
145
146 ablkcipher_request_set_tfm(req, ctx->u.aes.tfm_ablkcipher);
147 ret = (encrypt) ? crypto_ablkcipher_encrypt(req) :
148 crypto_ablkcipher_decrypt(req);
149 ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
150
151 return ret;
152 }
153
154 memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
155 sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
156
157 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
158 INIT_LIST_HEAD(&rctx->cmd.entry);
159 rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
160 rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
161 : CCP_AES_ACTION_DECRYPT;
162 rctx->cmd.u.xts.unit_size = unit_size_map[unit].value;
163 rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
164 rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
165 rctx->cmd.u.xts.iv = &rctx->iv_sg;
166 rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
167 rctx->cmd.u.xts.src = req->src;
168 rctx->cmd.u.xts.src_len = req->nbytes;
169 rctx->cmd.u.xts.dst = req->dst;
170
171 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
172
173 return ret;
174}
175
176static int ccp_aes_xts_encrypt(struct ablkcipher_request *req)
177{
178 return ccp_aes_xts_crypt(req, 1);
179}
180
181static int ccp_aes_xts_decrypt(struct ablkcipher_request *req)
182{
183 return ccp_aes_xts_crypt(req, 0);
184}
185
186static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm)
187{
188 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
189 struct crypto_ablkcipher *fallback_tfm;
190
191 ctx->complete = ccp_aes_xts_complete;
192 ctx->u.aes.key_len = 0;
193
194 fallback_tfm = crypto_alloc_ablkcipher(tfm->__crt_alg->cra_name, 0,
195 CRYPTO_ALG_ASYNC |
196 CRYPTO_ALG_NEED_FALLBACK);
197 if (IS_ERR(fallback_tfm)) {
198 pr_warn("could not load fallback driver %s\n",
199 tfm->__crt_alg->cra_name);
200 return PTR_ERR(fallback_tfm);
201 }
202 ctx->u.aes.tfm_ablkcipher = fallback_tfm;
203
204 tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx) +
205 fallback_tfm->base.crt_ablkcipher.reqsize;
206
207 return 0;
208}
209
210static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm)
211{
212 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
213
214 if (ctx->u.aes.tfm_ablkcipher)
215 crypto_free_ablkcipher(ctx->u.aes.tfm_ablkcipher);
216 ctx->u.aes.tfm_ablkcipher = NULL;
217}
218
219
220static int ccp_register_aes_xts_alg(struct list_head *head,
221 const struct ccp_aes_xts_def *def)
222{
223 struct ccp_crypto_ablkcipher_alg *ccp_alg;
224 struct crypto_alg *alg;
225 int ret;
226
227 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
228 if (!ccp_alg)
229 return -ENOMEM;
230
231 INIT_LIST_HEAD(&ccp_alg->entry);
232
233 alg = &ccp_alg->alg;
234
235 snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
236 snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
237 def->drv_name);
238 alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
239 CRYPTO_ALG_KERN_DRIVER_ONLY |
240 CRYPTO_ALG_NEED_FALLBACK;
241 alg->cra_blocksize = AES_BLOCK_SIZE;
242 alg->cra_ctxsize = sizeof(struct ccp_ctx);
243 alg->cra_priority = CCP_CRA_PRIORITY;
244 alg->cra_type = &crypto_ablkcipher_type;
245 alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey;
246 alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt;
247 alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt;
248 alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2;
249 alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2;
250 alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE;
251 alg->cra_init = ccp_aes_xts_cra_init;
252 alg->cra_exit = ccp_aes_xts_cra_exit;
253 alg->cra_module = THIS_MODULE;
254
255 ret = crypto_register_alg(alg);
256 if (ret) {
257 pr_err("%s ablkcipher algorithm registration error (%d)\n",
258 alg->cra_name, ret);
259 kfree(ccp_alg);
260 return ret;
261 }
262
263 list_add(&ccp_alg->entry, head);
264
265 return 0;
266}
267
268int ccp_register_aes_xts_algs(struct list_head *head)
269{
270 int i, ret;
271
272 for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
273 ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);
274 if (ret)
275 return ret;
276 }
277
278 return 0;
279}
280
