GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / crypto / ghash-clmulni-intel_glue.c
1 /*
2  * Accelerated GHASH implementation with Intel PCLMULQDQ-NI
3  * instructions. This file contains glue code.
4  *
5  * Copyright (c) 2009 Intel Corp.
6  *   Author: Huang Ying <ying.huang@intel.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published
10  * by the Free Software Foundation.
11  */
12
13 #include <linux/err.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/crypto.h>
18 #include <crypto/algapi.h>
19 #include <crypto/cryptd.h>
20 #include <crypto/gf128mul.h>
21 #include <crypto/internal/hash.h>
22 #include <asm/fpu/api.h>
23 #include <asm/cpu_device_id.h>
24
25 #define GHASH_BLOCK_SIZE        16
26 #define GHASH_DIGEST_SIZE       16
27
28 void clmul_ghash_mul(char *dst, const u128 *shash);
29
30 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
31                         const u128 *shash);
32
33 struct ghash_async_ctx {
34         struct cryptd_ahash *cryptd_tfm;
35 };
36
37 struct ghash_ctx {
38         u128 shash;
39 };
40
41 struct ghash_desc_ctx {
42         u8 buffer[GHASH_BLOCK_SIZE];
43         u32 bytes;
44 };
45
46 static int ghash_init(struct shash_desc *desc)
47 {
48         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
49
50         memset(dctx, 0, sizeof(*dctx));
51
52         return 0;
53 }
54
55 static int ghash_setkey(struct crypto_shash *tfm,
56                         const u8 *key, unsigned int keylen)
57 {
58         struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
59         be128 *x = (be128 *)key;
60         u64 a, b;
61
62         if (keylen != GHASH_BLOCK_SIZE) {
63                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
64                 return -EINVAL;
65         }
66
67         /* perform multiplication by 'x' in GF(2^128) */
68         a = be64_to_cpu(x->a);
69         b = be64_to_cpu(x->b);
70
71         ctx->shash.a = (b << 1) | (a >> 63);
72         ctx->shash.b = (a << 1) | (b >> 63);
73
74         if (a >> 63)
75                 ctx->shash.b ^= ((u64)0xc2) << 56;
76
77         return 0;
78 }
79
80 static int ghash_update(struct shash_desc *desc,
81                          const u8 *src, unsigned int srclen)
82 {
83         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
84         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
85         u8 *dst = dctx->buffer;
86
87         kernel_fpu_begin();
88         if (dctx->bytes) {
89                 int n = min(srclen, dctx->bytes);
90                 u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
91
92                 dctx->bytes -= n;
93                 srclen -= n;
94
95                 while (n--)
96                         *pos++ ^= *src++;
97
98                 if (!dctx->bytes)
99                         clmul_ghash_mul(dst, &ctx->shash);
100         }
101
102         clmul_ghash_update(dst, src, srclen, &ctx->shash);
103         kernel_fpu_end();
104
105         if (srclen & 0xf) {
106                 src += srclen - (srclen & 0xf);
107                 srclen &= 0xf;
108                 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
109                 while (srclen--)
110                         *dst++ ^= *src++;
111         }
112
113         return 0;
114 }
115
116 static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
117 {
118         u8 *dst = dctx->buffer;
119
120         if (dctx->bytes) {
121                 u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
122
123                 while (dctx->bytes--)
124                         *tmp++ ^= 0;
125
126                 kernel_fpu_begin();
127                 clmul_ghash_mul(dst, &ctx->shash);
128                 kernel_fpu_end();
129         }
130
131         dctx->bytes = 0;
132 }
133
134 static int ghash_final(struct shash_desc *desc, u8 *dst)
135 {
136         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
137         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
138         u8 *buf = dctx->buffer;
139
140         ghash_flush(ctx, dctx);
141         memcpy(dst, buf, GHASH_BLOCK_SIZE);
142
143         return 0;
144 }
145
146 static struct shash_alg ghash_alg = {
147         .digestsize     = GHASH_DIGEST_SIZE,
148         .init           = ghash_init,
149         .update         = ghash_update,
150         .final          = ghash_final,
151         .setkey         = ghash_setkey,
152         .descsize       = sizeof(struct ghash_desc_ctx),
153         .base           = {
154                 .cra_name               = "__ghash",
155                 .cra_driver_name        = "__ghash-pclmulqdqni",
156                 .cra_priority           = 0,
157                 .cra_flags              = CRYPTO_ALG_TYPE_SHASH |
158                                           CRYPTO_ALG_INTERNAL,
159                 .cra_blocksize          = GHASH_BLOCK_SIZE,
160                 .cra_ctxsize            = sizeof(struct ghash_ctx),
161                 .cra_module             = THIS_MODULE,
162         },
163 };
164
165 static int ghash_async_init(struct ahash_request *req)
166 {
167         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
168         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
169         struct ahash_request *cryptd_req = ahash_request_ctx(req);
170         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
171         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
172         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
173
174         desc->tfm = child;
175         desc->flags = req->base.flags;
176         return crypto_shash_init(desc);
177 }
178
179 static int ghash_async_update(struct ahash_request *req)
180 {
181         struct ahash_request *cryptd_req = ahash_request_ctx(req);
182         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
183         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
184         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
185
186         if (!irq_fpu_usable() ||
187             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
188                 memcpy(cryptd_req, req, sizeof(*req));
189                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
190                 return crypto_ahash_update(cryptd_req);
191         } else {
192                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
193                 return shash_ahash_update(req, desc);
194         }
195 }
196
197 static int ghash_async_final(struct ahash_request *req)
198 {
199         struct ahash_request *cryptd_req = ahash_request_ctx(req);
200         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
201         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
202         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
203
204         if (!irq_fpu_usable() ||
205             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
206                 memcpy(cryptd_req, req, sizeof(*req));
207                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
208                 return crypto_ahash_final(cryptd_req);
209         } else {
210                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
211                 return crypto_shash_final(desc, req->result);
212         }
213 }
214
215 static int ghash_async_import(struct ahash_request *req, const void *in)
216 {
217         struct ahash_request *cryptd_req = ahash_request_ctx(req);
218         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
219         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
220
221         ghash_async_init(req);
222         memcpy(dctx, in, sizeof(*dctx));
223         return 0;
224
225 }
226
227 static int ghash_async_export(struct ahash_request *req, void *out)
228 {
229         struct ahash_request *cryptd_req = ahash_request_ctx(req);
230         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
231         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
232
233         memcpy(out, dctx, sizeof(*dctx));
234         return 0;
235
236 }
237
238 static int ghash_async_digest(struct ahash_request *req)
239 {
240         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
241         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
242         struct ahash_request *cryptd_req = ahash_request_ctx(req);
243         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
244
245         if (!irq_fpu_usable() ||
246             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
247                 memcpy(cryptd_req, req, sizeof(*req));
248                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
249                 return crypto_ahash_digest(cryptd_req);
250         } else {
251                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
252                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
253
254                 desc->tfm = child;
255                 desc->flags = req->base.flags;
256                 return shash_ahash_digest(req, desc);
257         }
258 }
259
260 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
261                               unsigned int keylen)
262 {
263         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
264         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
265         int err;
266
267         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
268         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
269                                & CRYPTO_TFM_REQ_MASK);
270         err = crypto_ahash_setkey(child, key, keylen);
271         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
272                                & CRYPTO_TFM_RES_MASK);
273
274         return err;
275 }
276
277 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
278 {
279         struct cryptd_ahash *cryptd_tfm;
280         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
281
282         cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni",
283                                         CRYPTO_ALG_INTERNAL,
284                                         CRYPTO_ALG_INTERNAL);
285         if (IS_ERR(cryptd_tfm))
286                 return PTR_ERR(cryptd_tfm);
287         ctx->cryptd_tfm = cryptd_tfm;
288         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
289                                  sizeof(struct ahash_request) +
290                                  crypto_ahash_reqsize(&cryptd_tfm->base));
291
292         return 0;
293 }
294
295 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
296 {
297         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
298
299         cryptd_free_ahash(ctx->cryptd_tfm);
300 }
301
302 static struct ahash_alg ghash_async_alg = {
303         .init           = ghash_async_init,
304         .update         = ghash_async_update,
305         .final          = ghash_async_final,
306         .setkey         = ghash_async_setkey,
307         .digest         = ghash_async_digest,
308         .export         = ghash_async_export,
309         .import         = ghash_async_import,
310         .halg = {
311                 .digestsize     = GHASH_DIGEST_SIZE,
312                 .statesize = sizeof(struct ghash_desc_ctx),
313                 .base = {
314                         .cra_name               = "ghash",
315                         .cra_driver_name        = "ghash-clmulni",
316                         .cra_priority           = 400,
317                         .cra_ctxsize            = sizeof(struct ghash_async_ctx),
318                         .cra_flags              = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
319                         .cra_blocksize          = GHASH_BLOCK_SIZE,
320                         .cra_type               = &crypto_ahash_type,
321                         .cra_module             = THIS_MODULE,
322                         .cra_init               = ghash_async_init_tfm,
323                         .cra_exit               = ghash_async_exit_tfm,
324                 },
325         },
326 };
327
328 static const struct x86_cpu_id pcmul_cpu_id[] = {
329         X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */
330         {}
331 };
332 MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
333
334 static int __init ghash_pclmulqdqni_mod_init(void)
335 {
336         int err;
337
338         if (!x86_match_cpu(pcmul_cpu_id))
339                 return -ENODEV;
340
341         err = crypto_register_shash(&ghash_alg);
342         if (err)
343                 goto err_out;
344         err = crypto_register_ahash(&ghash_async_alg);
345         if (err)
346                 goto err_shash;
347
348         return 0;
349
350 err_shash:
351         crypto_unregister_shash(&ghash_alg);
352 err_out:
353         return err;
354 }
355
356 static void __exit ghash_pclmulqdqni_mod_exit(void)
357 {
358         crypto_unregister_ahash(&ghash_async_alg);
359         crypto_unregister_shash(&ghash_alg);
360 }
361
362 module_init(ghash_pclmulqdqni_mod_init);
363 module_exit(ghash_pclmulqdqni_mod_exit);
364
365 MODULE_LICENSE("GPL");
366 MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
367                    "acclerated by PCLMULQDQ-NI");
368 MODULE_ALIAS_CRYPTO("ghash");