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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 be128 *shash);
29
30void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
31 const be128 *shash);
32
33void clmul_ghash_setkey(be128 *shash, const u8 *key);
34
35struct ghash_async_ctx {
36 struct cryptd_ahash *cryptd_tfm;
37};
38
39struct ghash_ctx {
40 be128 shash;
41};
42
43struct ghash_desc_ctx {
44 u8 buffer[GHASH_BLOCK_SIZE];
45 u32 bytes;
46};
47
48static int ghash_init(struct shash_desc *desc)
49{
50 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
51
52 memset(dctx, 0, sizeof(*dctx));
53
54 return 0;
55}
56
57static int ghash_setkey(struct crypto_shash *tfm,
58 const u8 *key, unsigned int keylen)
59{
60 struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
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 clmul_ghash_setkey(&ctx->shash, key);
68
69 return 0;
70}
71
72static int ghash_update(struct shash_desc *desc,
73 const u8 *src, unsigned int srclen)
74{
75 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
76 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
77 u8 *dst = dctx->buffer;
78
79 kernel_fpu_begin();
80 if (dctx->bytes) {
81 int n = min(srclen, dctx->bytes);
82 u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
83
84 dctx->bytes -= n;
85 srclen -= n;
86
87 while (n--)
88 *pos++ ^= *src++;
89
90 if (!dctx->bytes)
91 clmul_ghash_mul(dst, &ctx->shash);
92 }
93
94 clmul_ghash_update(dst, src, srclen, &ctx->shash);
95 kernel_fpu_end();
96
97 if (srclen & 0xf) {
98 src += srclen - (srclen & 0xf);
99 srclen &= 0xf;
100 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
101 while (srclen--)
102 *dst++ ^= *src++;
103 }
104
105 return 0;
106}
107
108static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
109{
110 u8 *dst = dctx->buffer;
111
112 if (dctx->bytes) {
113 u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
114
115 while (dctx->bytes--)
116 *tmp++ ^= 0;
117
118 kernel_fpu_begin();
119 clmul_ghash_mul(dst, &ctx->shash);
120 kernel_fpu_end();
121 }
122
123 dctx->bytes = 0;
124}
125
126static int ghash_final(struct shash_desc *desc, u8 *dst)
127{
128 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
129 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
130 u8 *buf = dctx->buffer;
131
132 ghash_flush(ctx, dctx);
133 memcpy(dst, buf, GHASH_BLOCK_SIZE);
134
135 return 0;
136}
137
138static struct shash_alg ghash_alg = {
139 .digestsize = GHASH_DIGEST_SIZE,
140 .init = ghash_init,
141 .update = ghash_update,
142 .final = ghash_final,
143 .setkey = ghash_setkey,
144 .descsize = sizeof(struct ghash_desc_ctx),
145 .base = {
146 .cra_name = "__ghash",
147 .cra_driver_name = "__ghash-pclmulqdqni",
148 .cra_priority = 0,
149 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
150 .cra_blocksize = GHASH_BLOCK_SIZE,
151 .cra_ctxsize = sizeof(struct ghash_ctx),
152 .cra_module = THIS_MODULE,
153 },
154};
155
156static int ghash_async_init(struct ahash_request *req)
157{
158 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
159 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
160 struct ahash_request *cryptd_req = ahash_request_ctx(req);
161 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
162
163 if (!irq_fpu_usable()) {
164 memcpy(cryptd_req, req, sizeof(*req));
165 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
166 return crypto_ahash_init(cryptd_req);
167 } else {
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 desc->flags = req->base.flags;
173 return crypto_shash_init(desc);
174 }
175}
176
177static int ghash_async_update(struct ahash_request *req)
178{
179 struct ahash_request *cryptd_req = ahash_request_ctx(req);
180
181 if (!irq_fpu_usable()) {
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 memcpy(cryptd_req, req, sizeof(*req));
187 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
188 return crypto_ahash_update(cryptd_req);
189 } else {
190 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
191 return shash_ahash_update(req, desc);
192 }
193}
194
195static int ghash_async_final(struct ahash_request *req)
196{
197 struct ahash_request *cryptd_req = ahash_request_ctx(req);
198
199 if (!irq_fpu_usable()) {
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 memcpy(cryptd_req, req, sizeof(*req));
205 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
206 return crypto_ahash_final(cryptd_req);
207 } else {
208 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
209 return crypto_shash_final(desc, req->result);
210 }
211}
212
213static int ghash_async_digest(struct ahash_request *req)
214{
215 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
216 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
217 struct ahash_request *cryptd_req = ahash_request_ctx(req);
218 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
219
220 if (!irq_fpu_usable()) {
221 memcpy(cryptd_req, req, sizeof(*req));
222 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
223 return crypto_ahash_digest(cryptd_req);
224 } else {
225 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
226 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
227
228 desc->tfm = child;
229 desc->flags = req->base.flags;
230 return shash_ahash_digest(req, desc);
231 }
232}
233
234static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
235 unsigned int keylen)
236{
237 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
238 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
239 int err;
240
241 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
242 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
243 & CRYPTO_TFM_REQ_MASK);
244 err = crypto_ahash_setkey(child, key, keylen);
245 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
246 & CRYPTO_TFM_RES_MASK);
247
248 return err;
249}
250
251static int ghash_async_init_tfm(struct crypto_tfm *tfm)
252{
253 struct cryptd_ahash *cryptd_tfm;
254 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
255
256 cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni", 0, 0);
257 if (IS_ERR(cryptd_tfm))
258 return PTR_ERR(cryptd_tfm);
259 ctx->cryptd_tfm = cryptd_tfm;
260 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
261 sizeof(struct ahash_request) +
262 crypto_ahash_reqsize(&cryptd_tfm->base));
263
264 return 0;
265}
266
267static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
268{
269 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
270
271 cryptd_free_ahash(ctx->cryptd_tfm);
272}
273
274static struct ahash_alg ghash_async_alg = {
275 .init = ghash_async_init,
276 .update = ghash_async_update,
277 .final = ghash_async_final,
278 .setkey = ghash_async_setkey,
279 .digest = ghash_async_digest,
280 .halg = {
281 .digestsize = GHASH_DIGEST_SIZE,
282 .base = {
283 .cra_name = "ghash",
284 .cra_driver_name = "ghash-clmulni",
285 .cra_priority = 400,
286 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
287 .cra_blocksize = GHASH_BLOCK_SIZE,
288 .cra_type = &crypto_ahash_type,
289 .cra_module = THIS_MODULE,
290 .cra_init = ghash_async_init_tfm,
291 .cra_exit = ghash_async_exit_tfm,
292 },
293 },
294};
295
296static const struct x86_cpu_id pcmul_cpu_id[] = {
297 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
298 {}
299};
300MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
301
302static int __init ghash_pclmulqdqni_mod_init(void)
303{
304 int err;
305
306 if (!x86_match_cpu(pcmul_cpu_id))
307 return -ENODEV;
308
309 err = crypto_register_shash(&ghash_alg);
310 if (err)
311 goto err_out;
312 err = crypto_register_ahash(&ghash_async_alg);
313 if (err)
314 goto err_shash;
315
316 return 0;
317
318err_shash:
319 crypto_unregister_shash(&ghash_alg);
320err_out:
321 return err;
322}
323
324static void __exit ghash_pclmulqdqni_mod_exit(void)
325{
326 crypto_unregister_ahash(&ghash_async_alg);
327 crypto_unregister_shash(&ghash_alg);
328}
329
330module_init(ghash_pclmulqdqni_mod_init);
331module_exit(ghash_pclmulqdqni_mod_exit);
332
333MODULE_LICENSE("GPL");
334MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
335 "acclerated by PCLMULQDQ-NI");
336MODULE_ALIAS("ghash");
337
