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11#include <asm/hwcap.h>
12#include <asm/neon.h>
13#include <asm/simd.h>
14#include <asm/unaligned.h>
15#include <crypto/cryptd.h>
16#include <crypto/internal/hash.h>
17#include <crypto/gf128mul.h>
18#include <linux/crypto.h>
19#include <linux/module.h>
20
21MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
22MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
23MODULE_LICENSE("GPL v2");
24
25#define GHASH_BLOCK_SIZE 16
26#define GHASH_DIGEST_SIZE 16
27
28struct ghash_key {
29 u64 a;
30 u64 b;
31};
32
33struct ghash_desc_ctx {
34 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
35 u8 buf[GHASH_BLOCK_SIZE];
36 u32 count;
37};
38
39struct ghash_async_ctx {
40 struct cryptd_ahash *cryptd_tfm;
41};
42
43asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src,
44 struct ghash_key const *k, const char *head);
45
46static int ghash_init(struct shash_desc *desc)
47{
48 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
49
50 *ctx = (struct ghash_desc_ctx){};
51 return 0;
52}
53
54static int ghash_update(struct shash_desc *desc, const u8 *src,
55 unsigned int len)
56{
57 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
58 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
59
60 ctx->count += len;
61
62 if ((partial + len) >= GHASH_BLOCK_SIZE) {
63 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
64 int blocks;
65
66 if (partial) {
67 int p = GHASH_BLOCK_SIZE - partial;
68
69 memcpy(ctx->buf + partial, src, p);
70 src += p;
71 len -= p;
72 }
73
74 blocks = len / GHASH_BLOCK_SIZE;
75 len %= GHASH_BLOCK_SIZE;
76
77 kernel_neon_begin();
78 pmull_ghash_update(blocks, ctx->digest, src, key,
79 partial ? ctx->buf : NULL);
80 kernel_neon_end();
81 src += blocks * GHASH_BLOCK_SIZE;
82 partial = 0;
83 }
84 if (len)
85 memcpy(ctx->buf + partial, src, len);
86 return 0;
87}
88
89static int ghash_final(struct shash_desc *desc, u8 *dst)
90{
91 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
92 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
93
94 if (partial) {
95 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
96
97 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
98 kernel_neon_begin();
99 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
100 kernel_neon_end();
101 }
102 put_unaligned_be64(ctx->digest[1], dst);
103 put_unaligned_be64(ctx->digest[0], dst + 8);
104
105 *ctx = (struct ghash_desc_ctx){};
106 return 0;
107}
108
109static int ghash_setkey(struct crypto_shash *tfm,
110 const u8 *inkey, unsigned int keylen)
111{
112 struct ghash_key *key = crypto_shash_ctx(tfm);
113 u64 a, b;
114
115 if (keylen != GHASH_BLOCK_SIZE) {
116 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
117 return -EINVAL;
118 }
119
120
121 b = get_unaligned_be64(inkey);
122 a = get_unaligned_be64(inkey + 8);
123
124 key->a = (a << 1) | (b >> 63);
125 key->b = (b << 1) | (a >> 63);
126
127 if (b >> 63)
128 key->b ^= 0xc200000000000000UL;
129
130 return 0;
131}
132
133static struct shash_alg ghash_alg = {
134 .digestsize = GHASH_DIGEST_SIZE,
135 .init = ghash_init,
136 .update = ghash_update,
137 .final = ghash_final,
138 .setkey = ghash_setkey,
139 .descsize = sizeof(struct ghash_desc_ctx),
140 .base = {
141 .cra_name = "ghash",
142 .cra_driver_name = "__driver-ghash-ce",
143 .cra_priority = 0,
144 .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_INTERNAL,
145 .cra_blocksize = GHASH_BLOCK_SIZE,
146 .cra_ctxsize = sizeof(struct ghash_key),
147 .cra_module = THIS_MODULE,
148 },
149};
150
151static int ghash_async_init(struct ahash_request *req)
152{
153 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
154 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
155 struct ahash_request *cryptd_req = ahash_request_ctx(req);
156 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
157
158 if (!may_use_simd()) {
159 memcpy(cryptd_req, req, sizeof(*req));
160 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
161 return crypto_ahash_init(cryptd_req);
162 } else {
163 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
164 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
165
166 desc->tfm = child;
167 desc->flags = req->base.flags;
168 return crypto_shash_init(desc);
169 }
170}
171
172static int ghash_async_update(struct ahash_request *req)
173{
174 struct ahash_request *cryptd_req = ahash_request_ctx(req);
175
176 if (!may_use_simd()) {
177 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
178 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
179 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
180
181 memcpy(cryptd_req, req, sizeof(*req));
182 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
183 return crypto_ahash_update(cryptd_req);
184 } else {
185 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
186 return shash_ahash_update(req, desc);
187 }
188}
189
190static int ghash_async_final(struct ahash_request *req)
191{
192 struct ahash_request *cryptd_req = ahash_request_ctx(req);
193
194 if (!may_use_simd()) {
195 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
196 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
197 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
198
199 memcpy(cryptd_req, req, sizeof(*req));
200 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
201 return crypto_ahash_final(cryptd_req);
202 } else {
203 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
204 return crypto_shash_final(desc, req->result);
205 }
206}
207
208static int ghash_async_digest(struct ahash_request *req)
209{
210 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
211 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
212 struct ahash_request *cryptd_req = ahash_request_ctx(req);
213 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
214
215 if (!may_use_simd()) {
216 memcpy(cryptd_req, req, sizeof(*req));
217 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
218 return crypto_ahash_digest(cryptd_req);
219 } else {
220 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
221 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
222
223 desc->tfm = child;
224 desc->flags = req->base.flags;
225 return shash_ahash_digest(req, desc);
226 }
227}
228
229static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
230 unsigned int keylen)
231{
232 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
233 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
234 int err;
235
236 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
237 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
238 & CRYPTO_TFM_REQ_MASK);
239 err = crypto_ahash_setkey(child, key, keylen);
240 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
241 & CRYPTO_TFM_RES_MASK);
242
243 return err;
244}
245
246static int ghash_async_init_tfm(struct crypto_tfm *tfm)
247{
248 struct cryptd_ahash *cryptd_tfm;
249 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
250
251 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
252 CRYPTO_ALG_INTERNAL,
253 CRYPTO_ALG_INTERNAL);
254 if (IS_ERR(cryptd_tfm))
255 return PTR_ERR(cryptd_tfm);
256 ctx->cryptd_tfm = cryptd_tfm;
257 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
258 sizeof(struct ahash_request) +
259 crypto_ahash_reqsize(&cryptd_tfm->base));
260
261 return 0;
262}
263
264static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
265{
266 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
267
268 cryptd_free_ahash(ctx->cryptd_tfm);
269}
270
271static struct ahash_alg ghash_async_alg = {
272 .init = ghash_async_init,
273 .update = ghash_async_update,
274 .final = ghash_async_final,
275 .setkey = ghash_async_setkey,
276 .digest = ghash_async_digest,
277 .halg.digestsize = GHASH_DIGEST_SIZE,
278 .halg.base = {
279 .cra_name = "ghash",
280 .cra_driver_name = "ghash-ce",
281 .cra_priority = 300,
282 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
283 .cra_blocksize = GHASH_BLOCK_SIZE,
284 .cra_type = &crypto_ahash_type,
285 .cra_ctxsize = sizeof(struct ghash_async_ctx),
286 .cra_module = THIS_MODULE,
287 .cra_init = ghash_async_init_tfm,
288 .cra_exit = ghash_async_exit_tfm,
289 },
290};
291
292static int __init ghash_ce_mod_init(void)
293{
294 int err;
295
296 if (!(elf_hwcap2 & HWCAP2_PMULL))
297 return -ENODEV;
298
299 err = crypto_register_shash(&ghash_alg);
300 if (err)
301 return err;
302 err = crypto_register_ahash(&ghash_async_alg);
303 if (err)
304 goto err_shash;
305
306 return 0;
307
308err_shash:
309 crypto_unregister_shash(&ghash_alg);
310 return err;
311}
312
313static void __exit ghash_ce_mod_exit(void)
314{
315 crypto_unregister_ahash(&ghash_async_alg);
316 crypto_unregister_shash(&ghash_alg);
317}
318
319module_init(ghash_ce_mod_init);
320module_exit(ghash_ce_mod_exit);
321
