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8#include <asm/neon.h>
9#include <asm/simd.h>
10#include <asm/unaligned.h>
11#include <crypto/aes.h>
12#include <crypto/scatterwalk.h>
13#include <crypto/internal/aead.h>
14#include <crypto/internal/simd.h>
15#include <crypto/internal/skcipher.h>
16#include <linux/module.h>
17
18#include "aes-ce-setkey.h"
19
20static int num_rounds(struct crypto_aes_ctx *ctx)
21{
22
23
24
25
26
27
28
29 return 6 + ctx->key_length / 4;
30}
31
32asmlinkage void ce_aes_ccm_auth_data(u8 mac[], u8 const in[], u32 abytes,
33 u32 *macp, u32 const rk[], u32 rounds);
34
35asmlinkage void ce_aes_ccm_encrypt(u8 out[], u8 const in[], u32 cbytes,
36 u32 const rk[], u32 rounds, u8 mac[],
37 u8 ctr[]);
38
39asmlinkage void ce_aes_ccm_decrypt(u8 out[], u8 const in[], u32 cbytes,
40 u32 const rk[], u32 rounds, u8 mac[],
41 u8 ctr[]);
42
43asmlinkage void ce_aes_ccm_final(u8 mac[], u8 const ctr[], u32 const rk[],
44 u32 rounds);
45
46static int ccm_setkey(struct crypto_aead *tfm, const u8 *in_key,
47 unsigned int key_len)
48{
49 struct crypto_aes_ctx *ctx = crypto_aead_ctx(tfm);
50 int ret;
51
52 ret = ce_aes_expandkey(ctx, in_key, key_len);
53 if (!ret)
54 return 0;
55
56 tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
57 return -EINVAL;
58}
59
60static int ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
61{
62 if ((authsize & 1) || authsize < 4)
63 return -EINVAL;
64 return 0;
65}
66
67static int ccm_init_mac(struct aead_request *req, u8 maciv[], u32 msglen)
68{
69 struct crypto_aead *aead = crypto_aead_reqtfm(req);
70 __be32 *n = (__be32 *)&maciv[AES_BLOCK_SIZE - 8];
71 u32 l = req->iv[0] + 1;
72
73
74 if (l < 2 || l > 8)
75 return -EINVAL;
76
77
78 if (l < 4 && msglen >> (8 * l))
79 return -EOVERFLOW;
80
81
82
83
84
85 n[0] = 0;
86 n[1] = cpu_to_be32(msglen);
87
88 memcpy(maciv, req->iv, AES_BLOCK_SIZE - l);
89
90
91
92
93
94
95
96
97 maciv[0] |= (crypto_aead_authsize(aead) - 2) << 2;
98 if (req->assoclen)
99 maciv[0] |= 0x40;
100
101 memset(&req->iv[AES_BLOCK_SIZE - l], 0, l);
102 return 0;
103}
104
105static void ccm_update_mac(struct crypto_aes_ctx *key, u8 mac[], u8 const in[],
106 u32 abytes, u32 *macp)
107{
108 if (crypto_simd_usable()) {
109 kernel_neon_begin();
110 ce_aes_ccm_auth_data(mac, in, abytes, macp, key->key_enc,
111 num_rounds(key));
112 kernel_neon_end();
113 } else {
114 if (*macp > 0 && *macp < AES_BLOCK_SIZE) {
115 int added = min(abytes, AES_BLOCK_SIZE - *macp);
116
117 crypto_xor(&mac[*macp], in, added);
118
119 *macp += added;
120 in += added;
121 abytes -= added;
122 }
123
124 while (abytes >= AES_BLOCK_SIZE) {
125 aes_encrypt(key, mac, mac);
126 crypto_xor(mac, in, AES_BLOCK_SIZE);
127
128 in += AES_BLOCK_SIZE;
129 abytes -= AES_BLOCK_SIZE;
130 }
131
132 if (abytes > 0) {
133 aes_encrypt(key, mac, mac);
134 crypto_xor(mac, in, abytes);
135 *macp = abytes;
136 }
137 }
138}
139
140static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
141{
142 struct crypto_aead *aead = crypto_aead_reqtfm(req);
143 struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead);
144 struct __packed { __be16 l; __be32 h; u16 len; } ltag;
145 struct scatter_walk walk;
146 u32 len = req->assoclen;
147 u32 macp = 0;
148
149
150 if (len < 0xff00) {
151 ltag.l = cpu_to_be16(len);
152 ltag.len = 2;
153 } else {
154 ltag.l = cpu_to_be16(0xfffe);
155 put_unaligned_be32(len, <ag.h);
156 ltag.len = 6;
157 }
158
159 ccm_update_mac(ctx, mac, (u8 *)<ag, ltag.len, &macp);
160 scatterwalk_start(&walk, req->src);
161
162 do {
163 u32 n = scatterwalk_clamp(&walk, len);
164 u8 *p;
165
166 if (!n) {
167 scatterwalk_start(&walk, sg_next(walk.sg));
168 n = scatterwalk_clamp(&walk, len);
169 }
170 p = scatterwalk_map(&walk);
171 ccm_update_mac(ctx, mac, p, n, &macp);
172 len -= n;
173
174 scatterwalk_unmap(p);
175 scatterwalk_advance(&walk, n);
176 scatterwalk_done(&walk, 0, len);
177 } while (len);
178}
179
180static int ccm_crypt_fallback(struct skcipher_walk *walk, u8 mac[], u8 iv0[],
181 struct crypto_aes_ctx *ctx, bool enc)
182{
183 u8 buf[AES_BLOCK_SIZE];
184 int err = 0;
185
186 while (walk->nbytes) {
187 int blocks = walk->nbytes / AES_BLOCK_SIZE;
188 u32 tail = walk->nbytes % AES_BLOCK_SIZE;
189 u8 *dst = walk->dst.virt.addr;
190 u8 *src = walk->src.virt.addr;
191 u32 nbytes = walk->nbytes;
192
193 if (nbytes == walk->total && tail > 0) {
194 blocks++;
195 tail = 0;
196 }
197
198 do {
199 u32 bsize = AES_BLOCK_SIZE;
200
201 if (nbytes < AES_BLOCK_SIZE)
202 bsize = nbytes;
203
204 crypto_inc(walk->iv, AES_BLOCK_SIZE);
205 aes_encrypt(ctx, buf, walk->iv);
206 aes_encrypt(ctx, mac, mac);
207 if (enc)
208 crypto_xor(mac, src, bsize);
209 crypto_xor_cpy(dst, src, buf, bsize);
210 if (!enc)
211 crypto_xor(mac, dst, bsize);
212 dst += bsize;
213 src += bsize;
214 nbytes -= bsize;
215 } while (--blocks);
216
217 err = skcipher_walk_done(walk, tail);
218 }
219
220 if (!err) {
221 aes_encrypt(ctx, buf, iv0);
222 aes_encrypt(ctx, mac, mac);
223 crypto_xor(mac, buf, AES_BLOCK_SIZE);
224 }
225 return err;
226}
227
228static int ccm_encrypt(struct aead_request *req)
229{
230 struct crypto_aead *aead = crypto_aead_reqtfm(req);
231 struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead);
232 struct skcipher_walk walk;
233 u8 __aligned(8) mac[AES_BLOCK_SIZE];
234 u8 buf[AES_BLOCK_SIZE];
235 u32 len = req->cryptlen;
236 int err;
237
238 err = ccm_init_mac(req, mac, len);
239 if (err)
240 return err;
241
242 if (req->assoclen)
243 ccm_calculate_auth_mac(req, mac);
244
245
246 memcpy(buf, req->iv, AES_BLOCK_SIZE);
247
248 err = skcipher_walk_aead_encrypt(&walk, req, false);
249
250 if (crypto_simd_usable()) {
251 while (walk.nbytes) {
252 u32 tail = walk.nbytes % AES_BLOCK_SIZE;
253
254 if (walk.nbytes == walk.total)
255 tail = 0;
256
257 kernel_neon_begin();
258 ce_aes_ccm_encrypt(walk.dst.virt.addr,
259 walk.src.virt.addr,
260 walk.nbytes - tail, ctx->key_enc,
261 num_rounds(ctx), mac, walk.iv);
262 kernel_neon_end();
263
264 err = skcipher_walk_done(&walk, tail);
265 }
266 if (!err) {
267 kernel_neon_begin();
268 ce_aes_ccm_final(mac, buf, ctx->key_enc,
269 num_rounds(ctx));
270 kernel_neon_end();
271 }
272 } else {
273 err = ccm_crypt_fallback(&walk, mac, buf, ctx, true);
274 }
275 if (err)
276 return err;
277
278
279 scatterwalk_map_and_copy(mac, req->dst, req->assoclen + req->cryptlen,
280 crypto_aead_authsize(aead), 1);
281
282 return 0;
283}
284
285static int ccm_decrypt(struct aead_request *req)
286{
287 struct crypto_aead *aead = crypto_aead_reqtfm(req);
288 struct crypto_aes_ctx *ctx = crypto_aead_ctx(aead);
289 unsigned int authsize = crypto_aead_authsize(aead);
290 struct skcipher_walk walk;
291 u8 __aligned(8) mac[AES_BLOCK_SIZE];
292 u8 buf[AES_BLOCK_SIZE];
293 u32 len = req->cryptlen - authsize;
294 int err;
295
296 err = ccm_init_mac(req, mac, len);
297 if (err)
298 return err;
299
300 if (req->assoclen)
301 ccm_calculate_auth_mac(req, mac);
302
303
304 memcpy(buf, req->iv, AES_BLOCK_SIZE);
305
306 err = skcipher_walk_aead_decrypt(&walk, req, false);
307
308 if (crypto_simd_usable()) {
309 while (walk.nbytes) {
310 u32 tail = walk.nbytes % AES_BLOCK_SIZE;
311
312 if (walk.nbytes == walk.total)
313 tail = 0;
314
315 kernel_neon_begin();
316 ce_aes_ccm_decrypt(walk.dst.virt.addr,
317 walk.src.virt.addr,
318 walk.nbytes - tail, ctx->key_enc,
319 num_rounds(ctx), mac, walk.iv);
320 kernel_neon_end();
321
322 err = skcipher_walk_done(&walk, tail);
323 }
324 if (!err) {
325 kernel_neon_begin();
326 ce_aes_ccm_final(mac, buf, ctx->key_enc,
327 num_rounds(ctx));
328 kernel_neon_end();
329 }
330 } else {
331 err = ccm_crypt_fallback(&walk, mac, buf, ctx, false);
332 }
333
334 if (err)
335 return err;
336
337
338 scatterwalk_map_and_copy(buf, req->src,
339 req->assoclen + req->cryptlen - authsize,
340 authsize, 0);
341
342 if (crypto_memneq(mac, buf, authsize))
343 return -EBADMSG;
344 return 0;
345}
346
347static struct aead_alg ccm_aes_alg = {
348 .base = {
349 .cra_name = "ccm(aes)",
350 .cra_driver_name = "ccm-aes-ce",
351 .cra_priority = 300,
352 .cra_blocksize = 1,
353 .cra_ctxsize = sizeof(struct crypto_aes_ctx),
354 .cra_module = THIS_MODULE,
355 },
356 .ivsize = AES_BLOCK_SIZE,
357 .chunksize = AES_BLOCK_SIZE,
358 .maxauthsize = AES_BLOCK_SIZE,
359 .setkey = ccm_setkey,
360 .setauthsize = ccm_setauthsize,
361 .encrypt = ccm_encrypt,
362 .decrypt = ccm_decrypt,
363};
364
365static int __init aes_mod_init(void)
366{
367 if (!cpu_have_named_feature(AES))
368 return -ENODEV;
369 return crypto_register_aead(&ccm_aes_alg);
370}
371
372static void __exit aes_mod_exit(void)
373{
374 crypto_unregister_aead(&ccm_aes_alg);
375}
376
377module_init(aes_mod_init);
378module_exit(aes_mod_exit);
379
380MODULE_DESCRIPTION("Synchronous AES in CCM mode using ARMv8 Crypto Extensions");
381MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
382MODULE_LICENSE("GPL v2");
383MODULE_ALIAS_CRYPTO("ccm(aes)");
384
