2 * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
4 * Copyright (C) 2015 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation.
11 #include <asm/hwcap.h>
14 #include <asm/unaligned.h>
15 #include <crypto/cryptd.h>
16 #include <crypto/internal/hash.h>
17 #include <crypto/gf128mul.h>
18 #include <linux/cpufeature.h>
19 #include <linux/crypto.h>
20 #include <linux/module.h>
22 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
23 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
24 MODULE_LICENSE("GPL v2");
25 MODULE_ALIAS_CRYPTO("ghash");
27 #define GHASH_BLOCK_SIZE 16
28 #define GHASH_DIGEST_SIZE 16
37 struct ghash_desc_ctx {
38 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
39 u8 buf[GHASH_BLOCK_SIZE];
43 struct ghash_async_ctx {
44 struct cryptd_ahash *cryptd_tfm;
47 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
48 struct ghash_key const *k,
51 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
52 struct ghash_key const *k,
55 static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
56 struct ghash_key const *k,
59 static int ghash_init(struct shash_desc *desc)
61 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
63 *ctx = (struct ghash_desc_ctx){};
67 static int ghash_update(struct shash_desc *desc, const u8 *src,
70 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
71 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
75 if ((partial + len) >= GHASH_BLOCK_SIZE) {
76 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
80 int p = GHASH_BLOCK_SIZE - partial;
82 memcpy(ctx->buf + partial, src, p);
87 blocks = len / GHASH_BLOCK_SIZE;
88 len %= GHASH_BLOCK_SIZE;
91 pmull_ghash_update(blocks, ctx->digest, src, key,
92 partial ? ctx->buf : NULL);
94 src += blocks * GHASH_BLOCK_SIZE;
98 memcpy(ctx->buf + partial, src, len);
102 static int ghash_final(struct shash_desc *desc, u8 *dst)
104 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
105 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
108 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
110 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
112 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
115 put_unaligned_be64(ctx->digest[1], dst);
116 put_unaligned_be64(ctx->digest[0], dst + 8);
118 *ctx = (struct ghash_desc_ctx){};
122 static void ghash_reflect(u64 h[], const be128 *k)
124 u64 carry = be64_to_cpu(k->a) >> 63;
126 h[0] = (be64_to_cpu(k->b) << 1) | carry;
127 h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
130 h[1] ^= 0xc200000000000000UL;
133 static int ghash_setkey(struct crypto_shash *tfm,
134 const u8 *inkey, unsigned int keylen)
136 struct ghash_key *key = crypto_shash_ctx(tfm);
139 if (keylen != GHASH_BLOCK_SIZE) {
140 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
144 memcpy(&k, inkey, GHASH_BLOCK_SIZE);
145 ghash_reflect(key->h, &k);
148 gf128mul_lle(&h, &k);
149 ghash_reflect(key->h2, &h);
151 gf128mul_lle(&h, &k);
152 ghash_reflect(key->h3, &h);
154 gf128mul_lle(&h, &k);
155 ghash_reflect(key->h4, &h);
160 static struct shash_alg ghash_alg = {
161 .digestsize = GHASH_DIGEST_SIZE,
163 .update = ghash_update,
164 .final = ghash_final,
165 .setkey = ghash_setkey,
166 .descsize = sizeof(struct ghash_desc_ctx),
168 .cra_name = "__ghash",
169 .cra_driver_name = "__driver-ghash-ce",
171 .cra_flags = CRYPTO_ALG_INTERNAL,
172 .cra_blocksize = GHASH_BLOCK_SIZE,
173 .cra_ctxsize = sizeof(struct ghash_key),
174 .cra_module = THIS_MODULE,
178 static int ghash_async_init(struct ahash_request *req)
180 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
181 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
182 struct ahash_request *cryptd_req = ahash_request_ctx(req);
183 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
184 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
185 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
188 desc->flags = req->base.flags;
189 return crypto_shash_init(desc);
192 static int ghash_async_update(struct ahash_request *req)
194 struct ahash_request *cryptd_req = ahash_request_ctx(req);
195 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
196 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
197 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
199 if (!may_use_simd() ||
200 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
201 memcpy(cryptd_req, req, sizeof(*req));
202 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
203 return crypto_ahash_update(cryptd_req);
205 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
206 return shash_ahash_update(req, desc);
210 static int ghash_async_final(struct ahash_request *req)
212 struct ahash_request *cryptd_req = ahash_request_ctx(req);
213 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
214 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
215 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
217 if (!may_use_simd() ||
218 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
219 memcpy(cryptd_req, req, sizeof(*req));
220 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
221 return crypto_ahash_final(cryptd_req);
223 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
224 return crypto_shash_final(desc, req->result);
228 static int ghash_async_digest(struct ahash_request *req)
230 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
231 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
232 struct ahash_request *cryptd_req = ahash_request_ctx(req);
233 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
235 if (!may_use_simd() ||
236 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
237 memcpy(cryptd_req, req, sizeof(*req));
238 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
239 return crypto_ahash_digest(cryptd_req);
241 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
242 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
245 desc->flags = req->base.flags;
246 return shash_ahash_digest(req, desc);
250 static int ghash_async_import(struct ahash_request *req, const void *in)
252 struct ahash_request *cryptd_req = ahash_request_ctx(req);
253 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
254 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
255 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
257 desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
258 desc->flags = req->base.flags;
260 return crypto_shash_import(desc, in);
263 static int ghash_async_export(struct ahash_request *req, void *out)
265 struct ahash_request *cryptd_req = ahash_request_ctx(req);
266 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
268 return crypto_shash_export(desc, out);
271 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
274 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
275 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
278 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
279 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
280 & CRYPTO_TFM_REQ_MASK);
281 err = crypto_ahash_setkey(child, key, keylen);
282 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
283 & CRYPTO_TFM_RES_MASK);
288 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
290 struct cryptd_ahash *cryptd_tfm;
291 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
293 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
295 CRYPTO_ALG_INTERNAL);
296 if (IS_ERR(cryptd_tfm))
297 return PTR_ERR(cryptd_tfm);
298 ctx->cryptd_tfm = cryptd_tfm;
299 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
300 sizeof(struct ahash_request) +
301 crypto_ahash_reqsize(&cryptd_tfm->base));
306 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
308 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
310 cryptd_free_ahash(ctx->cryptd_tfm);
313 static struct ahash_alg ghash_async_alg = {
314 .init = ghash_async_init,
315 .update = ghash_async_update,
316 .final = ghash_async_final,
317 .setkey = ghash_async_setkey,
318 .digest = ghash_async_digest,
319 .import = ghash_async_import,
320 .export = ghash_async_export,
321 .halg.digestsize = GHASH_DIGEST_SIZE,
322 .halg.statesize = sizeof(struct ghash_desc_ctx),
325 .cra_driver_name = "ghash-ce",
327 .cra_flags = CRYPTO_ALG_ASYNC,
328 .cra_blocksize = GHASH_BLOCK_SIZE,
329 .cra_ctxsize = sizeof(struct ghash_async_ctx),
330 .cra_module = THIS_MODULE,
331 .cra_init = ghash_async_init_tfm,
332 .cra_exit = ghash_async_exit_tfm,
336 static int __init ghash_ce_mod_init(void)
340 if (!(elf_hwcap & HWCAP_NEON))
343 if (elf_hwcap2 & HWCAP2_PMULL)
344 pmull_ghash_update = pmull_ghash_update_p64;
346 pmull_ghash_update = pmull_ghash_update_p8;
348 err = crypto_register_shash(&ghash_alg);
351 err = crypto_register_ahash(&ghash_async_alg);
358 crypto_unregister_shash(&ghash_alg);
362 static void __exit ghash_ce_mod_exit(void)
364 crypto_unregister_ahash(&ghash_async_alg);
365 crypto_unregister_shash(&ghash_alg);
368 module_init(ghash_ce_mod_init);
369 module_exit(ghash_ce_mod_exit);