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8#include <asm/hwcap.h>
9#include <asm/neon.h>
10#include <asm/simd.h>
11#include <asm/unaligned.h>
12#include <crypto/b128ops.h>
13#include <crypto/cryptd.h>
14#include <crypto/internal/hash.h>
15#include <crypto/internal/simd.h>
16#include <crypto/gf128mul.h>
17#include <linux/cpufeature.h>
18#include <linux/crypto.h>
19#include <linux/module.h>
20
21MODULE_DESCRIPTION("GHASH hash function using ARMv8 Crypto Extensions");
22MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
23MODULE_LICENSE("GPL v2");
24MODULE_ALIAS_CRYPTO("ghash");
25
26#define GHASH_BLOCK_SIZE 16
27#define GHASH_DIGEST_SIZE 16
28
29struct ghash_key {
30 u64 h[2];
31 u64 h2[2];
32 u64 h3[2];
33 u64 h4[2];
34
35 be128 k;
36};
37
38struct ghash_desc_ctx {
39 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
40 u8 buf[GHASH_BLOCK_SIZE];
41 u32 count;
42};
43
44struct ghash_async_ctx {
45 struct cryptd_ahash *cryptd_tfm;
46};
47
48asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
49 struct ghash_key const *k,
50 const char *head);
51
52asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
53 struct ghash_key const *k,
54 const char *head);
55
56static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
57 struct ghash_key const *k,
58 const char *head);
59
60static int ghash_init(struct shash_desc *desc)
61{
62 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
63
64 *ctx = (struct ghash_desc_ctx){};
65 return 0;
66}
67
68static void ghash_do_update(int blocks, u64 dg[], const char *src,
69 struct ghash_key *key, const char *head)
70{
71 if (likely(crypto_simd_usable())) {
72 kernel_neon_begin();
73 pmull_ghash_update(blocks, dg, src, key, head);
74 kernel_neon_end();
75 } else {
76 be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) };
77
78 do {
79 const u8 *in = src;
80
81 if (head) {
82 in = head;
83 blocks++;
84 head = NULL;
85 } else {
86 src += GHASH_BLOCK_SIZE;
87 }
88
89 crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE);
90 gf128mul_lle(&dst, &key->k);
91 } while (--blocks);
92
93 dg[0] = be64_to_cpu(dst.b);
94 dg[1] = be64_to_cpu(dst.a);
95 }
96}
97
98static int ghash_update(struct shash_desc *desc, const u8 *src,
99 unsigned int len)
100{
101 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
102 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
103
104 ctx->count += len;
105
106 if ((partial + len) >= GHASH_BLOCK_SIZE) {
107 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
108 int blocks;
109
110 if (partial) {
111 int p = GHASH_BLOCK_SIZE - partial;
112
113 memcpy(ctx->buf + partial, src, p);
114 src += p;
115 len -= p;
116 }
117
118 blocks = len / GHASH_BLOCK_SIZE;
119 len %= GHASH_BLOCK_SIZE;
120
121 ghash_do_update(blocks, ctx->digest, src, key,
122 partial ? ctx->buf : NULL);
123 src += blocks * GHASH_BLOCK_SIZE;
124 partial = 0;
125 }
126 if (len)
127 memcpy(ctx->buf + partial, src, len);
128 return 0;
129}
130
131static int ghash_final(struct shash_desc *desc, u8 *dst)
132{
133 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
134 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
135
136 if (partial) {
137 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
138
139 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
140 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL);
141 }
142 put_unaligned_be64(ctx->digest[1], dst);
143 put_unaligned_be64(ctx->digest[0], dst + 8);
144
145 *ctx = (struct ghash_desc_ctx){};
146 return 0;
147}
148
149static void ghash_reflect(u64 h[], const be128 *k)
150{
151 u64 carry = be64_to_cpu(k->a) >> 63;
152
153 h[0] = (be64_to_cpu(k->b) << 1) | carry;
154 h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
155
156 if (carry)
157 h[1] ^= 0xc200000000000000UL;
158}
159
160static int ghash_setkey(struct crypto_shash *tfm,
161 const u8 *inkey, unsigned int keylen)
162{
163 struct ghash_key *key = crypto_shash_ctx(tfm);
164 be128 h;
165
166 if (keylen != GHASH_BLOCK_SIZE) {
167 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
168 return -EINVAL;
169 }
170
171
172 memcpy(&key->k, inkey, GHASH_BLOCK_SIZE);
173 ghash_reflect(key->h, &key->k);
174
175 h = key->k;
176 gf128mul_lle(&h, &key->k);
177 ghash_reflect(key->h2, &h);
178
179 gf128mul_lle(&h, &key->k);
180 ghash_reflect(key->h3, &h);
181
182 gf128mul_lle(&h, &key->k);
183 ghash_reflect(key->h4, &h);
184
185 return 0;
186}
187
188static struct shash_alg ghash_alg = {
189 .digestsize = GHASH_DIGEST_SIZE,
190 .init = ghash_init,
191 .update = ghash_update,
192 .final = ghash_final,
193 .setkey = ghash_setkey,
194 .descsize = sizeof(struct ghash_desc_ctx),
195
196 .base.cra_name = "ghash",
197 .base.cra_driver_name = "ghash-ce-sync",
198 .base.cra_priority = 300 - 1,
199 .base.cra_blocksize = GHASH_BLOCK_SIZE,
200 .base.cra_ctxsize = sizeof(struct ghash_key),
201 .base.cra_module = THIS_MODULE,
202};
203
204static int ghash_async_init(struct ahash_request *req)
205{
206 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
207 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
208 struct ahash_request *cryptd_req = ahash_request_ctx(req);
209 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
210 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
211 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
212
213 desc->tfm = child;
214 return crypto_shash_init(desc);
215}
216
217static int ghash_async_update(struct ahash_request *req)
218{
219 struct ahash_request *cryptd_req = ahash_request_ctx(req);
220 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
221 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
222 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
223
224 if (!crypto_simd_usable() ||
225 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
226 memcpy(cryptd_req, req, sizeof(*req));
227 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
228 return crypto_ahash_update(cryptd_req);
229 } else {
230 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
231 return shash_ahash_update(req, desc);
232 }
233}
234
235static int ghash_async_final(struct ahash_request *req)
236{
237 struct ahash_request *cryptd_req = ahash_request_ctx(req);
238 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
239 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
240 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
241
242 if (!crypto_simd_usable() ||
243 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
244 memcpy(cryptd_req, req, sizeof(*req));
245 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
246 return crypto_ahash_final(cryptd_req);
247 } else {
248 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
249 return crypto_shash_final(desc, req->result);
250 }
251}
252
253static int ghash_async_digest(struct ahash_request *req)
254{
255 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
256 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
257 struct ahash_request *cryptd_req = ahash_request_ctx(req);
258 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
259
260 if (!crypto_simd_usable() ||
261 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
262 memcpy(cryptd_req, req, sizeof(*req));
263 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
264 return crypto_ahash_digest(cryptd_req);
265 } else {
266 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
267 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
268
269 desc->tfm = child;
270 return shash_ahash_digest(req, desc);
271 }
272}
273
274static int ghash_async_import(struct ahash_request *req, const void *in)
275{
276 struct ahash_request *cryptd_req = ahash_request_ctx(req);
277 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
278 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
279 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
280
281 desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
282
283 return crypto_shash_import(desc, in);
284}
285
286static int ghash_async_export(struct ahash_request *req, void *out)
287{
288 struct ahash_request *cryptd_req = ahash_request_ctx(req);
289 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
290
291 return crypto_shash_export(desc, out);
292}
293
294static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
295 unsigned int keylen)
296{
297 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
298 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
299 int err;
300
301 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
302 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
303 & CRYPTO_TFM_REQ_MASK);
304 err = crypto_ahash_setkey(child, key, keylen);
305 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
306 & CRYPTO_TFM_RES_MASK);
307
308 return err;
309}
310
311static int ghash_async_init_tfm(struct crypto_tfm *tfm)
312{
313 struct cryptd_ahash *cryptd_tfm;
314 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
315
316 cryptd_tfm = cryptd_alloc_ahash("ghash-ce-sync", 0, 0);
317 if (IS_ERR(cryptd_tfm))
318 return PTR_ERR(cryptd_tfm);
319 ctx->cryptd_tfm = cryptd_tfm;
320 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
321 sizeof(struct ahash_request) +
322 crypto_ahash_reqsize(&cryptd_tfm->base));
323
324 return 0;
325}
326
327static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
328{
329 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
330
331 cryptd_free_ahash(ctx->cryptd_tfm);
332}
333
334static struct ahash_alg ghash_async_alg = {
335 .init = ghash_async_init,
336 .update = ghash_async_update,
337 .final = ghash_async_final,
338 .setkey = ghash_async_setkey,
339 .digest = ghash_async_digest,
340 .import = ghash_async_import,
341 .export = ghash_async_export,
342 .halg.digestsize = GHASH_DIGEST_SIZE,
343 .halg.statesize = sizeof(struct ghash_desc_ctx),
344 .halg.base = {
345 .cra_name = "ghash",
346 .cra_driver_name = "ghash-ce",
347 .cra_priority = 300,
348 .cra_flags = CRYPTO_ALG_ASYNC,
349 .cra_blocksize = GHASH_BLOCK_SIZE,
350 .cra_ctxsize = sizeof(struct ghash_async_ctx),
351 .cra_module = THIS_MODULE,
352 .cra_init = ghash_async_init_tfm,
353 .cra_exit = ghash_async_exit_tfm,
354 },
355};
356
357static int __init ghash_ce_mod_init(void)
358{
359 int err;
360
361 if (!(elf_hwcap & HWCAP_NEON))
362 return -ENODEV;
363
364 if (elf_hwcap2 & HWCAP2_PMULL)
365 pmull_ghash_update = pmull_ghash_update_p64;
366 else
367 pmull_ghash_update = pmull_ghash_update_p8;
368
369 err = crypto_register_shash(&ghash_alg);
370 if (err)
371 return err;
372 err = crypto_register_ahash(&ghash_async_alg);
373 if (err)
374 goto err_shash;
375
376 return 0;
377
378err_shash:
379 crypto_unregister_shash(&ghash_alg);
380 return err;
381}
382
383static void __exit ghash_ce_mod_exit(void)
384{
385 crypto_unregister_ahash(&ghash_async_alg);
386 crypto_unregister_shash(&ghash_alg);
387}
388
389module_init(ghash_ce_mod_init);
390module_exit(ghash_ce_mod_exit);
391
