1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Accelerated GHASH implementation with Intel PCLMULQDQ-NI
4 * instructions. This file contains glue code.
5 *
6 * Copyright (c) 2009 Intel Corp.
7 * Author: Huang Ying <ying.huang@intel.com>
8 */
9
10 #include <linux/err.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/crypto.h>
15 #include <crypto/algapi.h>
16 #include <crypto/cryptd.h>
17 #include <crypto/gf128mul.h>
18 #include <crypto/internal/hash.h>
19 #include <crypto/internal/simd.h>
20 #include <asm/cpu_device_id.h>
21 #include <asm/simd.h>
22 #include <asm/unaligned.h>
23
24 #define GHASH_BLOCK_SIZE 16
25 #define GHASH_DIGEST_SIZE 16
26
27 void clmul_ghash_mul(char *dst, const u128 *shash);
28
29 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
30 const u128 *shash);
31
32 struct ghash_async_ctx {
33 struct cryptd_ahash *cryptd_tfm;
34 };
35
36 struct ghash_ctx {
37 u128 shash;
38 };
39
40 struct ghash_desc_ctx {
41 u8 buffer[GHASH_BLOCK_SIZE];
42 u32 bytes;
43 };
44
ghash_init(struct shash_desc * desc)45 static int ghash_init(struct shash_desc *desc)
46 {
47 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
48
49 memset(dctx, 0, sizeof(*dctx));
50
51 return 0;
52 }
53
ghash_setkey(struct crypto_shash * tfm,const u8 * key,unsigned int keylen)54 static int ghash_setkey(struct crypto_shash *tfm,
55 const u8 *key, unsigned int keylen)
56 {
57 struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
58 u64 a, b;
59
60 if (keylen != GHASH_BLOCK_SIZE) {
61 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
62 return -EINVAL;
63 }
64
65 /* perform multiplication by 'x' in GF(2^128) */
66 a = get_unaligned_be64(key);
67 b = get_unaligned_be64(key + 8);
68
69 ctx->shash.a = (b << 1) | (a >> 63);
70 ctx->shash.b = (a << 1) | (b >> 63);
71
72 if (a >> 63)
73 ctx->shash.b ^= ((u64)0xc2) << 56;
74
75 return 0;
76 }
77
ghash_update(struct shash_desc * desc,const u8 * src,unsigned int srclen)78 static int ghash_update(struct shash_desc *desc,
79 const u8 *src, unsigned int srclen)
80 {
81 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
82 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
83 u8 *dst = dctx->buffer;
84
85 kernel_fpu_begin();
86 if (dctx->bytes) {
87 int n = min(srclen, dctx->bytes);
88 u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
89
90 dctx->bytes -= n;
91 srclen -= n;
92
93 while (n--)
94 *pos++ ^= *src++;
95
96 if (!dctx->bytes)
97 clmul_ghash_mul(dst, &ctx->shash);
98 }
99
100 clmul_ghash_update(dst, src, srclen, &ctx->shash);
101 kernel_fpu_end();
102
103 if (srclen & 0xf) {
104 src += srclen - (srclen & 0xf);
105 srclen &= 0xf;
106 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
107 while (srclen--)
108 *dst++ ^= *src++;
109 }
110
111 return 0;
112 }
113
ghash_flush(struct ghash_ctx * ctx,struct ghash_desc_ctx * dctx)114 static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
115 {
116 u8 *dst = dctx->buffer;
117
118 if (dctx->bytes) {
119 u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
120
121 while (dctx->bytes--)
122 *tmp++ ^= 0;
123
124 kernel_fpu_begin();
125 clmul_ghash_mul(dst, &ctx->shash);
126 kernel_fpu_end();
127 }
128
129 dctx->bytes = 0;
130 }
131
ghash_final(struct shash_desc * desc,u8 * dst)132 static int ghash_final(struct shash_desc *desc, u8 *dst)
133 {
134 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
135 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
136 u8 *buf = dctx->buffer;
137
138 ghash_flush(ctx, dctx);
139 memcpy(dst, buf, GHASH_BLOCK_SIZE);
140
141 return 0;
142 }
143
144 static struct shash_alg ghash_alg = {
145 .digestsize = GHASH_DIGEST_SIZE,
146 .init = ghash_init,
147 .update = ghash_update,
148 .final = ghash_final,
149 .setkey = ghash_setkey,
150 .descsize = sizeof(struct ghash_desc_ctx),
151 .base = {
152 .cra_name = "__ghash",
153 .cra_driver_name = "__ghash-pclmulqdqni",
154 .cra_priority = 0,
155 .cra_flags = CRYPTO_ALG_INTERNAL,
156 .cra_blocksize = GHASH_BLOCK_SIZE,
157 .cra_ctxsize = sizeof(struct ghash_ctx),
158 .cra_module = THIS_MODULE,
159 },
160 };
161
ghash_async_init(struct ahash_request * req)162 static int ghash_async_init(struct ahash_request *req)
163 {
164 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
165 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
166 struct ahash_request *cryptd_req = ahash_request_ctx(req);
167 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
168 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
169 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
170
171 desc->tfm = child;
172 return crypto_shash_init(desc);
173 }
174
ghash_async_update(struct ahash_request * req)175 static int ghash_async_update(struct ahash_request *req)
176 {
177 struct ahash_request *cryptd_req = ahash_request_ctx(req);
178 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
179 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
180 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
181
182 if (!crypto_simd_usable() ||
183 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
184 memcpy(cryptd_req, req, sizeof(*req));
185 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
186 return crypto_ahash_update(cryptd_req);
187 } else {
188 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
189 return shash_ahash_update(req, desc);
190 }
191 }
192
ghash_async_final(struct ahash_request * req)193 static int ghash_async_final(struct ahash_request *req)
194 {
195 struct ahash_request *cryptd_req = ahash_request_ctx(req);
196 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
197 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
198 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
199
200 if (!crypto_simd_usable() ||
201 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
202 memcpy(cryptd_req, req, sizeof(*req));
203 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
204 return crypto_ahash_final(cryptd_req);
205 } else {
206 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
207 return crypto_shash_final(desc, req->result);
208 }
209 }
210
ghash_async_import(struct ahash_request * req,const void * in)211 static int ghash_async_import(struct ahash_request *req, const void *in)
212 {
213 struct ahash_request *cryptd_req = ahash_request_ctx(req);
214 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
215 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
216
217 ghash_async_init(req);
218 memcpy(dctx, in, sizeof(*dctx));
219 return 0;
220
221 }
222
ghash_async_export(struct ahash_request * req,void * out)223 static int ghash_async_export(struct ahash_request *req, void *out)
224 {
225 struct ahash_request *cryptd_req = ahash_request_ctx(req);
226 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
227 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
228
229 memcpy(out, dctx, sizeof(*dctx));
230 return 0;
231
232 }
233
ghash_async_digest(struct ahash_request * req)234 static int ghash_async_digest(struct ahash_request *req)
235 {
236 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
237 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
238 struct ahash_request *cryptd_req = ahash_request_ctx(req);
239 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
240
241 if (!crypto_simd_usable() ||
242 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
243 memcpy(cryptd_req, req, sizeof(*req));
244 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
245 return crypto_ahash_digest(cryptd_req);
246 } else {
247 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
248 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
249
250 desc->tfm = child;
251 return shash_ahash_digest(req, desc);
252 }
253 }
254
ghash_async_setkey(struct crypto_ahash * tfm,const u8 * key,unsigned int keylen)255 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
256 unsigned int keylen)
257 {
258 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
259 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
260 int err;
261
262 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
263 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
264 & CRYPTO_TFM_REQ_MASK);
265 err = crypto_ahash_setkey(child, key, keylen);
266 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
267 & CRYPTO_TFM_RES_MASK);
268
269 return err;
270 }
271
ghash_async_init_tfm(struct crypto_tfm * tfm)272 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
273 {
274 struct cryptd_ahash *cryptd_tfm;
275 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
276
277 cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni",
278 CRYPTO_ALG_INTERNAL,
279 CRYPTO_ALG_INTERNAL);
280 if (IS_ERR(cryptd_tfm))
281 return PTR_ERR(cryptd_tfm);
282 ctx->cryptd_tfm = cryptd_tfm;
283 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
284 sizeof(struct ahash_request) +
285 crypto_ahash_reqsize(&cryptd_tfm->base));
286
287 return 0;
288 }
289
ghash_async_exit_tfm(struct crypto_tfm * tfm)290 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
291 {
292 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
293
294 cryptd_free_ahash(ctx->cryptd_tfm);
295 }
296
297 static struct ahash_alg ghash_async_alg = {
298 .init = ghash_async_init,
299 .update = ghash_async_update,
300 .final = ghash_async_final,
301 .setkey = ghash_async_setkey,
302 .digest = ghash_async_digest,
303 .export = ghash_async_export,
304 .import = ghash_async_import,
305 .halg = {
306 .digestsize = GHASH_DIGEST_SIZE,
307 .statesize = sizeof(struct ghash_desc_ctx),
308 .base = {
309 .cra_name = "ghash",
310 .cra_driver_name = "ghash-clmulni",
311 .cra_priority = 400,
312 .cra_ctxsize = sizeof(struct ghash_async_ctx),
313 .cra_flags = CRYPTO_ALG_ASYNC,
314 .cra_blocksize = GHASH_BLOCK_SIZE,
315 .cra_module = THIS_MODULE,
316 .cra_init = ghash_async_init_tfm,
317 .cra_exit = ghash_async_exit_tfm,
318 },
319 },
320 };
321
322 static const struct x86_cpu_id pcmul_cpu_id[] = {
323 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */
324 {}
325 };
326 MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
327
ghash_pclmulqdqni_mod_init(void)328 static int __init ghash_pclmulqdqni_mod_init(void)
329 {
330 int err;
331
332 if (!x86_match_cpu(pcmul_cpu_id))
333 return -ENODEV;
334
335 err = crypto_register_shash(&ghash_alg);
336 if (err)
337 goto err_out;
338 err = crypto_register_ahash(&ghash_async_alg);
339 if (err)
340 goto err_shash;
341
342 return 0;
343
344 err_shash:
345 crypto_unregister_shash(&ghash_alg);
346 err_out:
347 return err;
348 }
349
ghash_pclmulqdqni_mod_exit(void)350 static void __exit ghash_pclmulqdqni_mod_exit(void)
351 {
352 crypto_unregister_ahash(&ghash_async_alg);
353 crypto_unregister_shash(&ghash_alg);
354 }
355
356 module_init(ghash_pclmulqdqni_mod_init);
357 module_exit(ghash_pclmulqdqni_mod_exit);
358
359 MODULE_LICENSE("GPL");
360 MODULE_DESCRIPTION("GHASH hash function, accelerated by PCLMULQDQ-NI");
361 MODULE_ALIAS_CRYPTO("ghash");
362