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/internal/simd.h>
18 #include <crypto/gf128mul.h>
19 #include <linux/cpufeature.h>
20 #include <linux/crypto.h>
21 #include <linux/module.h>
23 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
24 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
25 MODULE_LICENSE("GPL v2");
26 MODULE_ALIAS_CRYPTO("ghash");
28 #define GHASH_BLOCK_SIZE 16
29 #define GHASH_DIGEST_SIZE 16
38 struct ghash_desc_ctx {
39 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
40 u8 buf[GHASH_BLOCK_SIZE];
44 struct ghash_async_ctx {
45 struct cryptd_ahash *cryptd_tfm;
48 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
49 struct ghash_key const *k,
52 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
53 struct ghash_key const *k,
56 static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
57 struct ghash_key const *k,
60 static int ghash_init(struct shash_desc *desc)
62 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
64 *ctx = (struct ghash_desc_ctx){};
68 static int ghash_update(struct shash_desc *desc, const u8 *src,
71 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
72 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
76 if ((partial + len) >= GHASH_BLOCK_SIZE) {
77 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
81 int p = GHASH_BLOCK_SIZE - partial;
83 memcpy(ctx->buf + partial, src, p);
88 blocks = len / GHASH_BLOCK_SIZE;
89 len %= GHASH_BLOCK_SIZE;
92 pmull_ghash_update(blocks, ctx->digest, src, key,
93 partial ? ctx->buf : NULL);
95 src += blocks * GHASH_BLOCK_SIZE;
99 memcpy(ctx->buf + partial, src, len);
103 static int ghash_final(struct shash_desc *desc, u8 *dst)
105 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
106 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
109 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
111 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
113 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
116 put_unaligned_be64(ctx->digest[1], dst);
117 put_unaligned_be64(ctx->digest[0], dst + 8);
119 *ctx = (struct ghash_desc_ctx){};
123 static void ghash_reflect(u64 h[], const be128 *k)
125 u64 carry = be64_to_cpu(k->a) >> 63;
127 h[0] = (be64_to_cpu(k->b) << 1) | carry;
128 h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
131 h[1] ^= 0xc200000000000000UL;
134 static int ghash_setkey(struct crypto_shash *tfm,
135 const u8 *inkey, unsigned int keylen)
137 struct ghash_key *key = crypto_shash_ctx(tfm);
140 if (keylen != GHASH_BLOCK_SIZE) {
141 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
145 memcpy(&k, inkey, GHASH_BLOCK_SIZE);
146 ghash_reflect(key->h, &k);
149 gf128mul_lle(&h, &k);
150 ghash_reflect(key->h2, &h);
152 gf128mul_lle(&h, &k);
153 ghash_reflect(key->h3, &h);
155 gf128mul_lle(&h, &k);
156 ghash_reflect(key->h4, &h);
161 static struct shash_alg ghash_alg = {
162 .digestsize = GHASH_DIGEST_SIZE,
164 .update = ghash_update,
165 .final = ghash_final,
166 .setkey = ghash_setkey,
167 .descsize = sizeof(struct ghash_desc_ctx),
169 .cra_name = "__ghash",
170 .cra_driver_name = "__driver-ghash-ce",
172 .cra_flags = CRYPTO_ALG_INTERNAL,
173 .cra_blocksize = GHASH_BLOCK_SIZE,
174 .cra_ctxsize = sizeof(struct ghash_key),
175 .cra_module = THIS_MODULE,
179 static int ghash_async_init(struct ahash_request *req)
181 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
182 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
183 struct ahash_request *cryptd_req = ahash_request_ctx(req);
184 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
185 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
186 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
189 desc->flags = req->base.flags;
190 return crypto_shash_init(desc);
193 static int ghash_async_update(struct ahash_request *req)
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;
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_update(cryptd_req);
206 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
207 return shash_ahash_update(req, desc);
211 static int ghash_async_final(struct ahash_request *req)
213 struct ahash_request *cryptd_req = ahash_request_ctx(req);
214 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
215 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
216 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
218 if (!crypto_simd_usable() ||
219 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
220 memcpy(cryptd_req, req, sizeof(*req));
221 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
222 return crypto_ahash_final(cryptd_req);
224 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
225 return crypto_shash_final(desc, req->result);
229 static int ghash_async_digest(struct ahash_request *req)
231 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
232 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
233 struct ahash_request *cryptd_req = ahash_request_ctx(req);
234 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
236 if (!crypto_simd_usable() ||
237 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
238 memcpy(cryptd_req, req, sizeof(*req));
239 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
240 return crypto_ahash_digest(cryptd_req);
242 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
243 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
246 desc->flags = req->base.flags;
247 return shash_ahash_digest(req, desc);
251 static int ghash_async_import(struct ahash_request *req, const void *in)
253 struct ahash_request *cryptd_req = ahash_request_ctx(req);
254 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
255 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
256 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
258 desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
259 desc->flags = req->base.flags;
261 return crypto_shash_import(desc, in);
264 static int ghash_async_export(struct ahash_request *req, void *out)
266 struct ahash_request *cryptd_req = ahash_request_ctx(req);
267 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
269 return crypto_shash_export(desc, out);
272 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
275 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
276 struct crypto_ahash *child = &ctx->cryptd_tfm->base;
279 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
280 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
281 & CRYPTO_TFM_REQ_MASK);
282 err = crypto_ahash_setkey(child, key, keylen);
283 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
284 & CRYPTO_TFM_RES_MASK);
289 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
291 struct cryptd_ahash *cryptd_tfm;
292 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
294 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
296 CRYPTO_ALG_INTERNAL);
297 if (IS_ERR(cryptd_tfm))
298 return PTR_ERR(cryptd_tfm);
299 ctx->cryptd_tfm = cryptd_tfm;
300 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
301 sizeof(struct ahash_request) +
302 crypto_ahash_reqsize(&cryptd_tfm->base));
307 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
309 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
311 cryptd_free_ahash(ctx->cryptd_tfm);
314 static struct ahash_alg ghash_async_alg = {
315 .init = ghash_async_init,
316 .update = ghash_async_update,
317 .final = ghash_async_final,
318 .setkey = ghash_async_setkey,
319 .digest = ghash_async_digest,
320 .import = ghash_async_import,
321 .export = ghash_async_export,
322 .halg.digestsize = GHASH_DIGEST_SIZE,
323 .halg.statesize = sizeof(struct ghash_desc_ctx),
326 .cra_driver_name = "ghash-ce",
328 .cra_flags = CRYPTO_ALG_ASYNC,
329 .cra_blocksize = GHASH_BLOCK_SIZE,
330 .cra_ctxsize = sizeof(struct ghash_async_ctx),
331 .cra_module = THIS_MODULE,
332 .cra_init = ghash_async_init_tfm,
333 .cra_exit = ghash_async_exit_tfm,
337 static int __init ghash_ce_mod_init(void)
341 if (!(elf_hwcap & HWCAP_NEON))
344 if (elf_hwcap2 & HWCAP2_PMULL)
345 pmull_ghash_update = pmull_ghash_update_p64;
347 pmull_ghash_update = pmull_ghash_update_p8;
349 err = crypto_register_shash(&ghash_alg);
352 err = crypto_register_ahash(&ghash_async_alg);
359 crypto_unregister_shash(&ghash_alg);
363 static void __exit ghash_ce_mod_exit(void)
365 crypto_unregister_ahash(&ghash_async_alg);
366 crypto_unregister_shash(&ghash_alg);
369 module_init(ghash_ce_mod_init);
370 module_exit(ghash_ce_mod_exit);