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13#include <linux/module.h>
14#include <linux/sched.h>
15#include <linux/delay.h>
16#include <linux/scatterlist.h>
17#include <crypto/aes.h>
18#include <crypto/internal/skcipher.h>
19#include <crypto/scatterwalk.h>
20
21#include "ccp-crypto.h"
22
23struct ccp_aes_xts_def {
24 const char *name;
25 const char *drv_name;
26};
27
28static struct ccp_aes_xts_def aes_xts_algs[] = {
29 {
30 .name = "xts(aes)",
31 .drv_name = "xts-aes-ccp",
32 },
33};
34
35struct ccp_unit_size_map {
36 unsigned int size;
37 u32 value;
38};
39
40static struct ccp_unit_size_map unit_size_map[] = {
41 {
42 .size = 4096,
43 .value = CCP_XTS_AES_UNIT_SIZE_4096,
44 },
45 {
46 .size = 2048,
47 .value = CCP_XTS_AES_UNIT_SIZE_2048,
48 },
49 {
50 .size = 1024,
51 .value = CCP_XTS_AES_UNIT_SIZE_1024,
52 },
53 {
54 .size = 512,
55 .value = CCP_XTS_AES_UNIT_SIZE_512,
56 },
57 {
58 .size = 256,
59 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
60 },
61 {
62 .size = 128,
63 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
64 },
65 {
66 .size = 64,
67 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
68 },
69 {
70 .size = 32,
71 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
72 },
73 {
74 .size = 16,
75 .value = CCP_XTS_AES_UNIT_SIZE_16,
76 },
77 {
78 .size = 1,
79 .value = CCP_XTS_AES_UNIT_SIZE__LAST,
80 },
81};
82
83static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
84{
85 struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
86 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
87
88 if (ret)
89 return ret;
90
91 memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
92
93 return 0;
94}
95
96static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
97 unsigned int key_len)
98{
99 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
100
101
102
103
104 switch (key_len) {
105 case AES_KEYSIZE_128 * 2:
106 memcpy(ctx->u.aes.key, key, key_len);
107 break;
108 }
109 ctx->u.aes.key_len = key_len / 2;
110 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
111
112 return crypto_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len);
113}
114
115static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
116 unsigned int encrypt)
117{
118 struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
119 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
120 unsigned int unit;
121 u32 unit_size;
122 int ret;
123
124 if (!ctx->u.aes.key_len)
125 return -EINVAL;
126
127 if (req->nbytes & (AES_BLOCK_SIZE - 1))
128 return -EINVAL;
129
130 if (!req->info)
131 return -EINVAL;
132
133 unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
134 if (req->nbytes <= unit_size_map[0].size) {
135 for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++) {
136 if (!(req->nbytes & (unit_size_map[unit].size - 1))) {
137 unit_size = unit_size_map[unit].value;
138 break;
139 }
140 }
141 }
142
143 if ((unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) ||
144 (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
145 SKCIPHER_REQUEST_ON_STACK(subreq, ctx->u.aes.tfm_skcipher);
146
147
148
149
150 skcipher_request_set_tfm(subreq, ctx->u.aes.tfm_skcipher);
151 skcipher_request_set_callback(subreq, req->base.flags,
152 NULL, NULL);
153 skcipher_request_set_crypt(subreq, req->src, req->dst,
154 req->nbytes, req->info);
155 ret = encrypt ? crypto_skcipher_encrypt(subreq) :
156 crypto_skcipher_decrypt(subreq);
157 skcipher_request_zero(subreq);
158 return ret;
159 }
160
161 memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
162 sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
163
164 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
165 INIT_LIST_HEAD(&rctx->cmd.entry);
166 rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
167 rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
168 : CCP_AES_ACTION_DECRYPT;
169 rctx->cmd.u.xts.unit_size = unit_size;
170 rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
171 rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
172 rctx->cmd.u.xts.iv = &rctx->iv_sg;
173 rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
174 rctx->cmd.u.xts.src = req->src;
175 rctx->cmd.u.xts.src_len = req->nbytes;
176 rctx->cmd.u.xts.dst = req->dst;
177
178 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
179
180 return ret;
181}
182
183static int ccp_aes_xts_encrypt(struct ablkcipher_request *req)
184{
185 return ccp_aes_xts_crypt(req, 1);
186}
187
188static int ccp_aes_xts_decrypt(struct ablkcipher_request *req)
189{
190 return ccp_aes_xts_crypt(req, 0);
191}
192
193static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm)
194{
195 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
196 struct crypto_skcipher *fallback_tfm;
197
198 ctx->complete = ccp_aes_xts_complete;
199 ctx->u.aes.key_len = 0;
200
201 fallback_tfm = crypto_alloc_skcipher("xts(aes)", 0,
202 CRYPTO_ALG_ASYNC |
203 CRYPTO_ALG_NEED_FALLBACK);
204 if (IS_ERR(fallback_tfm)) {
205 pr_warn("could not load fallback driver xts(aes)\n");
206 return PTR_ERR(fallback_tfm);
207 }
208 ctx->u.aes.tfm_skcipher = fallback_tfm;
209
210 tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
211
212 return 0;
213}
214
215static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm)
216{
217 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
218
219 crypto_free_skcipher(ctx->u.aes.tfm_skcipher);
220}
221
222static int ccp_register_aes_xts_alg(struct list_head *head,
223 const struct ccp_aes_xts_def *def)
224{
225 struct ccp_crypto_ablkcipher_alg *ccp_alg;
226 struct crypto_alg *alg;
227 int ret;
228
229 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
230 if (!ccp_alg)
231 return -ENOMEM;
232
233 INIT_LIST_HEAD(&ccp_alg->entry);
234
235 alg = &ccp_alg->alg;
236
237 snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
238 snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
239 def->drv_name);
240 alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
241 CRYPTO_ALG_KERN_DRIVER_ONLY |
242 CRYPTO_ALG_NEED_FALLBACK;
243 alg->cra_blocksize = AES_BLOCK_SIZE;
244 alg->cra_ctxsize = sizeof(struct ccp_ctx);
245 alg->cra_priority = CCP_CRA_PRIORITY;
246 alg->cra_type = &crypto_ablkcipher_type;
247 alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey;
248 alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt;
249 alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt;
250 alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2;
251 alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2;
252 alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE;
253 alg->cra_init = ccp_aes_xts_cra_init;
254 alg->cra_exit = ccp_aes_xts_cra_exit;
255 alg->cra_module = THIS_MODULE;
256
257 ret = crypto_register_alg(alg);
258 if (ret) {
259 pr_err("%s ablkcipher algorithm registration error (%d)\n",
260 alg->cra_name, ret);
261 kfree(ccp_alg);
262 return ret;
263 }
264
265 list_add(&ccp_alg->entry, head);
266
267 return 0;
268}
269
270int ccp_register_aes_xts_algs(struct list_head *head)
271{
272 int i, ret;
273
274 for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
275 ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);
276 if (ret)
277 return ret;
278 }
279
280 return 0;
281}
282
