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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/i387.h>
23#include <asm/cpu_device_id.h>
24
25#define GHASH_BLOCK_SIZE 16
26#define GHASH_DIGEST_SIZE 16
27
28void clmul_ghash_mul(char *dst, const u128 *shash);
29
30void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
31 const u128 *shash);
32
33struct ghash_async_ctx {
34 struct cryptd_ahash *cryptd_tfm;
35};
36
37struct ghash_ctx {
38 u128 shash;
39};
40
41struct ghash_desc_ctx {
42 u8 buffer[GHASH_BLOCK_SIZE];
43 u32 bytes;
44};
45
46static 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
55static 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
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
80static 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
116static 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
134static 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
146static 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
165static 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
172 if (!irq_fpu_usable()) {
173 memcpy(cryptd_req, req, sizeof(*req));
174 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
175 return crypto_ahash_init(cryptd_req);
176 } else {
177 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
178 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
179
180 desc->tfm = child;
181 desc->flags = req->base.flags;
182 return crypto_shash_init(desc);
183 }
184}
185
186static int ghash_async_update(struct ahash_request *req)
187{
188 struct ahash_request *cryptd_req = ahash_request_ctx(req);
189
190 if (!irq_fpu_usable()) {
191 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
192 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
193 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
194
195 memcpy(cryptd_req, req, sizeof(*req));
196 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
197 return crypto_ahash_update(cryptd_req);
198 } else {
199 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
200 return shash_ahash_update(req, desc);
201 }
202}
203
204static int ghash_async_final(struct ahash_request *req)
205{
206 struct ahash_request *cryptd_req = ahash_request_ctx(req);
207
208 if (!irq_fpu_usable()) {
209 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
210 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
211 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
212
213 memcpy(cryptd_req, req, sizeof(*req));
214 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
215 return crypto_ahash_final(cryptd_req);
216 } else {
217 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
218 return crypto_shash_final(desc, req->result);
219 }
220}
221
222static int ghash_async_digest(struct ahash_request *req)
223{
224 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
225 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
226 struct ahash_request *cryptd_req = ahash_request_ctx(req);
227 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
228
229 if (!irq_fpu_usable()) {
230 memcpy(cryptd_req, req, sizeof(*req));
231 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
232 return crypto_ahash_digest(cryptd_req);
233 } else {
234 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
235 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
236
237 desc->tfm = child;
238 desc->flags = req->base.flags;
239 return shash_ahash_digest(req, desc);
240 }
241}
242
243static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
244 unsigned int keylen)
245{
246 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
247 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
248 int err;
249
250 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
251 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
252 & CRYPTO_TFM_REQ_MASK);
253 err = crypto_ahash_setkey(child, key, keylen);
254 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
255 & CRYPTO_TFM_RES_MASK);
256
257 return err;
258}
259
260static int ghash_async_init_tfm(struct crypto_tfm *tfm)
261{
262 struct cryptd_ahash *cryptd_tfm;
263 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
264
265 cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni",
266 CRYPTO_ALG_INTERNAL,
267 CRYPTO_ALG_INTERNAL);
268 if (IS_ERR(cryptd_tfm))
269 return PTR_ERR(cryptd_tfm);
270 ctx->cryptd_tfm = cryptd_tfm;
271 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
272 sizeof(struct ahash_request) +
273 crypto_ahash_reqsize(&cryptd_tfm->base));
274
275 return 0;
276}
277
278static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
279{
280 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
281
282 cryptd_free_ahash(ctx->cryptd_tfm);
283}
284
285static struct ahash_alg ghash_async_alg = {
286 .init = ghash_async_init,
287 .update = ghash_async_update,
288 .final = ghash_async_final,
289 .setkey = ghash_async_setkey,
290 .digest = ghash_async_digest,
291 .halg = {
292 .digestsize = GHASH_DIGEST_SIZE,
293 .base = {
294 .cra_name = "ghash",
295 .cra_driver_name = "ghash-clmulni",
296 .cra_priority = 400,
297 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
298 .cra_blocksize = GHASH_BLOCK_SIZE,
299 .cra_type = &crypto_ahash_type,
300 .cra_module = THIS_MODULE,
301 .cra_init = ghash_async_init_tfm,
302 .cra_exit = ghash_async_exit_tfm,
303 },
304 },
305};
306
307static const struct x86_cpu_id pcmul_cpu_id[] = {
308 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
309 {}
310};
311MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
312
313static int __init ghash_pclmulqdqni_mod_init(void)
314{
315 int err;
316
317 if (!x86_match_cpu(pcmul_cpu_id))
318 return -ENODEV;
319
320 err = crypto_register_shash(&ghash_alg);
321 if (err)
322 goto err_out;
323 err = crypto_register_ahash(&ghash_async_alg);
324 if (err)
325 goto err_shash;
326
327 return 0;
328
329err_shash:
330 crypto_unregister_shash(&ghash_alg);
331err_out:
332 return err;
333}
334
335static void __exit ghash_pclmulqdqni_mod_exit(void)
336{
337 crypto_unregister_ahash(&ghash_async_alg);
338 crypto_unregister_shash(&ghash_alg);
339}
340
341module_init(ghash_pclmulqdqni_mod_init);
342module_exit(ghash_pclmulqdqni_mod_exit);
343
344MODULE_LICENSE("GPL");
345MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
346 "acclerated by PCLMULQDQ-NI");
347MODULE_ALIAS_CRYPTO("ghash");
348
