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
ghash_init(struct shash_desc * desc)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
ghash_setkey(struct crypto_shash * tfm,const u8 * key,unsigned int keylen)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
ghash_update(struct shash_desc * desc,const u8 * src,unsigned int srclen)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
ghash_flush(struct ghash_ctx * ctx,struct ghash_desc_ctx * dctx)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
ghash_final(struct shash_desc * desc,u8 * dst)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_INTERNAL,
158 .cra_blocksize = GHASH_BLOCK_SIZE,
159 .cra_ctxsize = sizeof(struct ghash_ctx),
160 .cra_module = THIS_MODULE,
161 },
162 };
163
ghash_async_init(struct ahash_request * req)164 static int ghash_async_init(struct ahash_request *req)
165 {
166 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
167 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
168 struct ahash_request *cryptd_req = ahash_request_ctx(req);
169 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
170 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
171 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
172
173 desc->tfm = child;
174 desc->flags = req->base.flags;
175 return crypto_shash_init(desc);
176 }
177
ghash_async_update(struct ahash_request * req)178 static int ghash_async_update(struct ahash_request *req)
179 {
180 struct ahash_request *cryptd_req = ahash_request_ctx(req);
181 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
182 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
183 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
184
185 if (!irq_fpu_usable() ||
186 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
187 memcpy(cryptd_req, req, sizeof(*req));
188 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
189 return crypto_ahash_update(cryptd_req);
190 } else {
191 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
192 return shash_ahash_update(req, desc);
193 }
194 }
195
ghash_async_final(struct ahash_request * req)196 static int ghash_async_final(struct ahash_request *req)
197 {
198 struct ahash_request *cryptd_req = ahash_request_ctx(req);
199 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
200 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
201 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
202
203 if (!irq_fpu_usable() ||
204 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
205 memcpy(cryptd_req, req, sizeof(*req));
206 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
207 return crypto_ahash_final(cryptd_req);
208 } else {
209 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
210 return crypto_shash_final(desc, req->result);
211 }
212 }
213
ghash_async_import(struct ahash_request * req,const void * in)214 static int ghash_async_import(struct ahash_request *req, const void *in)
215 {
216 struct ahash_request *cryptd_req = ahash_request_ctx(req);
217 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
218 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
219
220 ghash_async_init(req);
221 memcpy(dctx, in, sizeof(*dctx));
222 return 0;
223
224 }
225
ghash_async_export(struct ahash_request * req,void * out)226 static int ghash_async_export(struct ahash_request *req, void *out)
227 {
228 struct ahash_request *cryptd_req = ahash_request_ctx(req);
229 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
230 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
231
232 memcpy(out, dctx, sizeof(*dctx));
233 return 0;
234
235 }
236
ghash_async_digest(struct ahash_request * req)237 static int ghash_async_digest(struct ahash_request *req)
238 {
239 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
240 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
241 struct ahash_request *cryptd_req = ahash_request_ctx(req);
242 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
243
244 if (!irq_fpu_usable() ||
245 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
246 memcpy(cryptd_req, req, sizeof(*req));
247 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
248 return crypto_ahash_digest(cryptd_req);
249 } else {
250 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
251 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
252
253 desc->tfm = child;
254 desc->flags = req->base.flags;
255 return shash_ahash_digest(req, desc);
256 }
257 }
258
ghash_async_setkey(struct crypto_ahash * tfm,const u8 * key,unsigned int keylen)259 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
260 unsigned int keylen)
261 {
262 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
263 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
264 int err;
265
266 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
267 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
268 & CRYPTO_TFM_REQ_MASK);
269 err = crypto_ahash_setkey(child, key, keylen);
270 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
271 & CRYPTO_TFM_RES_MASK);
272
273 return err;
274 }
275
ghash_async_init_tfm(struct crypto_tfm * tfm)276 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
277 {
278 struct cryptd_ahash *cryptd_tfm;
279 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
280
281 cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni",
282 CRYPTO_ALG_INTERNAL,
283 CRYPTO_ALG_INTERNAL);
284 if (IS_ERR(cryptd_tfm))
285 return PTR_ERR(cryptd_tfm);
286 ctx->cryptd_tfm = cryptd_tfm;
287 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
288 sizeof(struct ahash_request) +
289 crypto_ahash_reqsize(&cryptd_tfm->base));
290
291 return 0;
292 }
293
ghash_async_exit_tfm(struct crypto_tfm * tfm)294 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
295 {
296 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
297
298 cryptd_free_ahash(ctx->cryptd_tfm);
299 }
300
301 static struct ahash_alg ghash_async_alg = {
302 .init = ghash_async_init,
303 .update = ghash_async_update,
304 .final = ghash_async_final,
305 .setkey = ghash_async_setkey,
306 .digest = ghash_async_digest,
307 .export = ghash_async_export,
308 .import = ghash_async_import,
309 .halg = {
310 .digestsize = GHASH_DIGEST_SIZE,
311 .statesize = sizeof(struct ghash_desc_ctx),
312 .base = {
313 .cra_name = "ghash",
314 .cra_driver_name = "ghash-clmulni",
315 .cra_priority = 400,
316 .cra_ctxsize = sizeof(struct ghash_async_ctx),
317 .cra_flags = CRYPTO_ALG_ASYNC,
318 .cra_blocksize = GHASH_BLOCK_SIZE,
319 .cra_module = THIS_MODULE,
320 .cra_init = ghash_async_init_tfm,
321 .cra_exit = ghash_async_exit_tfm,
322 },
323 },
324 };
325
326 static const struct x86_cpu_id pcmul_cpu_id[] = {
327 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */
328 {}
329 };
330 MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
331
ghash_pclmulqdqni_mod_init(void)332 static int __init ghash_pclmulqdqni_mod_init(void)
333 {
334 int err;
335
336 if (!x86_match_cpu(pcmul_cpu_id))
337 return -ENODEV;
338
339 err = crypto_register_shash(&ghash_alg);
340 if (err)
341 goto err_out;
342 err = crypto_register_ahash(&ghash_async_alg);
343 if (err)
344 goto err_shash;
345
346 return 0;
347
348 err_shash:
349 crypto_unregister_shash(&ghash_alg);
350 err_out:
351 return err;
352 }
353
ghash_pclmulqdqni_mod_exit(void)354 static void __exit ghash_pclmulqdqni_mod_exit(void)
355 {
356 crypto_unregister_ahash(&ghash_async_alg);
357 crypto_unregister_shash(&ghash_alg);
358 }
359
360 module_init(ghash_pclmulqdqni_mod_init);
361 module_exit(ghash_pclmulqdqni_mod_exit);
362
363 MODULE_LICENSE("GPL");
364 MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
365 "accelerated by PCLMULQDQ-NI");
366 MODULE_ALIAS_CRYPTO("ghash");
367
