2 * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
4 * Copyright (C) 2015 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/crypto.h>
19 #include <linux/module.h>
21 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
22 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
23 MODULE_LICENSE("GPL v2");
25 #define GHASH_BLOCK_SIZE 16
26 #define GHASH_DIGEST_SIZE 16
33 struct ghash_desc_ctx {
34 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
35 u8 buf[GHASH_BLOCK_SIZE];
39 struct ghash_async_ctx {
40 struct cryptd_ahash *cryptd_tfm;
43 asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src,
44 struct ghash_key const *k, const char *head);
46 static int ghash_init(struct shash_desc *desc)
48 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
50 *ctx = (struct ghash_desc_ctx){};
54 static int ghash_update(struct shash_desc *desc, const u8 *src,
57 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
58 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
62 if ((partial + len) >= GHASH_BLOCK_SIZE) {
63 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
67 int p = GHASH_BLOCK_SIZE - partial;
69 memcpy(ctx->buf + partial, src, p);
74 blocks = len / GHASH_BLOCK_SIZE;
75 len %= GHASH_BLOCK_SIZE;
78 pmull_ghash_update(blocks, ctx->digest, src, key,
79 partial ? ctx->buf : NULL);
81 src += blocks * GHASH_BLOCK_SIZE;
85 memcpy(ctx->buf + partial, src, len);
89 static int ghash_final(struct shash_desc *desc, u8 *dst)
91 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
92 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
95 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
97 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
99 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
102 put_unaligned_be64(ctx->digest[1], dst);
103 put_unaligned_be64(ctx->digest[0], dst + 8);
105 *ctx = (struct ghash_desc_ctx){};
109 static int ghash_setkey(struct crypto_shash *tfm,
110 const u8 *inkey, unsigned int keylen)
112 struct ghash_key *key = crypto_shash_ctx(tfm);
115 if (keylen != GHASH_BLOCK_SIZE) {
116 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
120 /* perform multiplication by 'x' in GF(2^128) */
121 b = get_unaligned_be64(inkey);
122 a = get_unaligned_be64(inkey + 8);
124 key->a = (a << 1) | (b >> 63);
125 key->b = (b << 1) | (a >> 63);
128 key->b ^= 0xc200000000000000UL;
133 static struct shash_alg ghash_alg = {
134 .digestsize = GHASH_DIGEST_SIZE,
136 .update = ghash_update,
137 .final = ghash_final,
138 .setkey = ghash_setkey,
139 .descsize = sizeof(struct ghash_desc_ctx),
141 .cra_name = "__ghash",
142 .cra_driver_name = "__driver-ghash-ce",
144 .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_INTERNAL,
145 .cra_blocksize = GHASH_BLOCK_SIZE,
146 .cra_ctxsize = sizeof(struct ghash_key),
147 .cra_module = THIS_MODULE,
151 static int ghash_async_init(struct ahash_request *req)
153 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
154 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
155 struct ahash_request *cryptd_req = ahash_request_ctx(req);
156 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
157 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
158 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
161 desc->flags = req->base.flags;
162 return crypto_shash_init(desc);
165 static int ghash_async_update(struct ahash_request *req)
167 struct ahash_request *cryptd_req = ahash_request_ctx(req);
168 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
169 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
170 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
172 if (!may_use_simd() ||
173 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
174 memcpy(cryptd_req, req, sizeof(*req));
175 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
176 return crypto_ahash_update(cryptd_req);
178 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
179 return shash_ahash_update(req, desc);
183 static int ghash_async_final(struct ahash_request *req)
185 struct ahash_request *cryptd_req = ahash_request_ctx(req);
186 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
187 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
188 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
190 if (!may_use_simd() ||
191 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
192 memcpy(cryptd_req, req, sizeof(*req));
193 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
194 return crypto_ahash_final(cryptd_req);
196 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
197 return crypto_shash_final(desc, req->result);
201 static int ghash_async_digest(struct ahash_request *req)
203 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
204 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
205 struct ahash_request *cryptd_req = ahash_request_ctx(req);
206 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
208 if (!may_use_simd() ||
209 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
210 memcpy(cryptd_req, req, sizeof(*req));
211 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
212 return crypto_ahash_digest(cryptd_req);
214 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
215 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
218 desc->flags = req->base.flags;
219 return shash_ahash_digest(req, desc);
223 static int ghash_async_import(struct ahash_request *req, const void *in)
225 struct ahash_request *cryptd_req = ahash_request_ctx(req);
226 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
227 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
228 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
230 desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
231 desc->flags = req->base.flags;
233 return crypto_shash_import(desc, in);
236 static int ghash_async_export(struct ahash_request *req, void *out)
238 struct ahash_request *cryptd_req = ahash_request_ctx(req);
239 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
241 return crypto_shash_export(desc, out);
244 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
247 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
248 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
251 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
252 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
253 & CRYPTO_TFM_REQ_MASK);
254 err = crypto_ahash_setkey(child, key, keylen);
255 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
256 & CRYPTO_TFM_RES_MASK);
261 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
263 struct cryptd_ahash *cryptd_tfm;
264 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
266 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
268 CRYPTO_ALG_INTERNAL);
269 if (IS_ERR(cryptd_tfm))
270 return PTR_ERR(cryptd_tfm);
271 ctx->cryptd_tfm = cryptd_tfm;
272 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
273 sizeof(struct ahash_request) +
274 crypto_ahash_reqsize(&cryptd_tfm->base));
279 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
281 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
283 cryptd_free_ahash(ctx->cryptd_tfm);
286 static struct ahash_alg ghash_async_alg = {
287 .init = ghash_async_init,
288 .update = ghash_async_update,
289 .final = ghash_async_final,
290 .setkey = ghash_async_setkey,
291 .digest = ghash_async_digest,
292 .import = ghash_async_import,
293 .export = ghash_async_export,
294 .halg.digestsize = GHASH_DIGEST_SIZE,
295 .halg.statesize = sizeof(struct ghash_desc_ctx),
298 .cra_driver_name = "ghash-ce",
300 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
301 .cra_blocksize = GHASH_BLOCK_SIZE,
302 .cra_type = &crypto_ahash_type,
303 .cra_ctxsize = sizeof(struct ghash_async_ctx),
304 .cra_module = THIS_MODULE,
305 .cra_init = ghash_async_init_tfm,
306 .cra_exit = ghash_async_exit_tfm,
310 static int __init ghash_ce_mod_init(void)
314 if (!(elf_hwcap2 & HWCAP2_PMULL))
317 err = crypto_register_shash(&ghash_alg);
320 err = crypto_register_ahash(&ghash_async_alg);
327 crypto_unregister_shash(&ghash_alg);
331 static void __exit ghash_ce_mod_exit(void)
333 crypto_unregister_ahash(&ghash_async_alg);
334 crypto_unregister_shash(&ghash_alg);
337 module_init(ghash_ce_mod_init);
338 module_exit(ghash_ce_mod_exit);