1 /* 2 * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions. 3 * 4 * Copyright (C) 2015 Linaro Ltd. <ard.biesheuvel@linaro.org> 5 * 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. 9 */ 10 11 #include <asm/hwcap.h> 12 #include <asm/neon.h> 13 #include <asm/simd.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> 21 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"); 26 27 #define GHASH_BLOCK_SIZE 16 28 #define GHASH_DIGEST_SIZE 16 29 30 struct ghash_key { 31 u64 a; 32 u64 b; 33 }; 34 35 struct ghash_desc_ctx { 36 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)]; 37 u8 buf[GHASH_BLOCK_SIZE]; 38 u32 count; 39 }; 40 41 struct ghash_async_ctx { 42 struct cryptd_ahash *cryptd_tfm; 43 }; 44 45 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src, 46 struct ghash_key const *k, 47 const char *head); 48 49 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src, 50 struct ghash_key const *k, 51 const char *head); 52 53 static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src, 54 struct ghash_key const *k, 55 const char *head); 56 57 static int ghash_init(struct shash_desc *desc) 58 { 59 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 60 61 *ctx = (struct ghash_desc_ctx){}; 62 return 0; 63 } 64 65 static int ghash_update(struct shash_desc *desc, const u8 *src, 66 unsigned int len) 67 { 68 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 69 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 70 71 ctx->count += len; 72 73 if ((partial + len) >= GHASH_BLOCK_SIZE) { 74 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 75 int blocks; 76 77 if (partial) { 78 int p = GHASH_BLOCK_SIZE - partial; 79 80 memcpy(ctx->buf + partial, src, p); 81 src += p; 82 len -= p; 83 } 84 85 blocks = len / GHASH_BLOCK_SIZE; 86 len %= GHASH_BLOCK_SIZE; 87 88 kernel_neon_begin(); 89 pmull_ghash_update(blocks, ctx->digest, src, key, 90 partial ? ctx->buf : NULL); 91 kernel_neon_end(); 92 src += blocks * GHASH_BLOCK_SIZE; 93 partial = 0; 94 } 95 if (len) 96 memcpy(ctx->buf + partial, src, len); 97 return 0; 98 } 99 100 static int ghash_final(struct shash_desc *desc, u8 *dst) 101 { 102 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 103 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 104 105 if (partial) { 106 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 107 108 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 109 kernel_neon_begin(); 110 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL); 111 kernel_neon_end(); 112 } 113 put_unaligned_be64(ctx->digest[1], dst); 114 put_unaligned_be64(ctx->digest[0], dst + 8); 115 116 *ctx = (struct ghash_desc_ctx){}; 117 return 0; 118 } 119 120 static int ghash_setkey(struct crypto_shash *tfm, 121 const u8 *inkey, unsigned int keylen) 122 { 123 struct ghash_key *key = crypto_shash_ctx(tfm); 124 u64 a, b; 125 126 if (keylen != GHASH_BLOCK_SIZE) { 127 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 128 return -EINVAL; 129 } 130 131 /* perform multiplication by 'x' in GF(2^128) */ 132 b = get_unaligned_be64(inkey); 133 a = get_unaligned_be64(inkey + 8); 134 135 key->a = (a << 1) | (b >> 63); 136 key->b = (b << 1) | (a >> 63); 137 138 if (b >> 63) 139 key->b ^= 0xc200000000000000UL; 140 141 return 0; 142 } 143 144 static struct shash_alg ghash_alg = { 145 .digestsize = GHASH_DIGEST_SIZE, 146 .init = ghash_init, 147 .update = ghash_update, 148 .final = ghash_final, 149 .setkey = ghash_setkey, 150 .descsize = sizeof(struct ghash_desc_ctx), 151 .base = { 152 .cra_name = "__ghash", 153 .cra_driver_name = "__driver-ghash-ce", 154 .cra_priority = 0, 155 .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_INTERNAL, 156 .cra_blocksize = GHASH_BLOCK_SIZE, 157 .cra_ctxsize = sizeof(struct ghash_key), 158 .cra_module = THIS_MODULE, 159 }, 160 }; 161 162 static int ghash_async_init(struct ahash_request *req) 163 { 164 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 165 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 166 struct ahash_request *cryptd_req = ahash_request_ctx(req); 167 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 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 static int ghash_async_update(struct ahash_request *req) 177 { 178 struct ahash_request *cryptd_req = ahash_request_ctx(req); 179 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 180 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 181 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 182 183 if (!may_use_simd() || 184 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) { 185 memcpy(cryptd_req, req, sizeof(*req)); 186 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 187 return crypto_ahash_update(cryptd_req); 188 } else { 189 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 190 return shash_ahash_update(req, desc); 191 } 192 } 193 194 static int ghash_async_final(struct ahash_request *req) 195 { 196 struct ahash_request *cryptd_req = ahash_request_ctx(req); 197 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 198 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 199 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 200 201 if (!may_use_simd() || 202 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) { 203 memcpy(cryptd_req, req, sizeof(*req)); 204 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 205 return crypto_ahash_final(cryptd_req); 206 } else { 207 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 208 return crypto_shash_final(desc, req->result); 209 } 210 } 211 212 static int ghash_async_digest(struct ahash_request *req) 213 { 214 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 215 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 216 struct ahash_request *cryptd_req = ahash_request_ctx(req); 217 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 218 219 if (!may_use_simd() || 220 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) { 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 } 233 234 static int ghash_async_import(struct ahash_request *req, const void *in) 235 { 236 struct ahash_request *cryptd_req = ahash_request_ctx(req); 237 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 238 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 239 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 240 241 desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm); 242 desc->flags = req->base.flags; 243 244 return crypto_shash_import(desc, in); 245 } 246 247 static int ghash_async_export(struct ahash_request *req, void *out) 248 { 249 struct ahash_request *cryptd_req = ahash_request_ctx(req); 250 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 251 252 return crypto_shash_export(desc, out); 253 } 254 255 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key, 256 unsigned int keylen) 257 { 258 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 259 struct crypto_ahash *child = &ctx->cryptd_tfm->base; 260 int err; 261 262 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK); 263 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm) 264 & CRYPTO_TFM_REQ_MASK); 265 err = crypto_ahash_setkey(child, key, keylen); 266 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child) 267 & CRYPTO_TFM_RES_MASK); 268 269 return err; 270 } 271 272 static int ghash_async_init_tfm(struct crypto_tfm *tfm) 273 { 274 struct cryptd_ahash *cryptd_tfm; 275 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 276 277 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce", 278 CRYPTO_ALG_INTERNAL, 279 CRYPTO_ALG_INTERNAL); 280 if (IS_ERR(cryptd_tfm)) 281 return PTR_ERR(cryptd_tfm); 282 ctx->cryptd_tfm = cryptd_tfm; 283 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm), 284 sizeof(struct ahash_request) + 285 crypto_ahash_reqsize(&cryptd_tfm->base)); 286 287 return 0; 288 } 289 290 static void ghash_async_exit_tfm(struct crypto_tfm *tfm) 291 { 292 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 293 294 cryptd_free_ahash(ctx->cryptd_tfm); 295 } 296 297 static struct ahash_alg ghash_async_alg = { 298 .init = ghash_async_init, 299 .update = ghash_async_update, 300 .final = ghash_async_final, 301 .setkey = ghash_async_setkey, 302 .digest = ghash_async_digest, 303 .import = ghash_async_import, 304 .export = ghash_async_export, 305 .halg.digestsize = GHASH_DIGEST_SIZE, 306 .halg.statesize = sizeof(struct ghash_desc_ctx), 307 .halg.base = { 308 .cra_name = "ghash", 309 .cra_driver_name = "ghash-ce", 310 .cra_priority = 300, 311 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC, 312 .cra_blocksize = GHASH_BLOCK_SIZE, 313 .cra_type = &crypto_ahash_type, 314 .cra_ctxsize = sizeof(struct ghash_async_ctx), 315 .cra_module = THIS_MODULE, 316 .cra_init = ghash_async_init_tfm, 317 .cra_exit = ghash_async_exit_tfm, 318 }, 319 }; 320 321 static int __init ghash_ce_mod_init(void) 322 { 323 int err; 324 325 if (!(elf_hwcap & HWCAP_NEON)) 326 return -ENODEV; 327 328 if (elf_hwcap2 & HWCAP2_PMULL) 329 pmull_ghash_update = pmull_ghash_update_p64; 330 else 331 pmull_ghash_update = pmull_ghash_update_p8; 332 333 err = crypto_register_shash(&ghash_alg); 334 if (err) 335 return err; 336 err = crypto_register_ahash(&ghash_async_alg); 337 if (err) 338 goto err_shash; 339 340 return 0; 341 342 err_shash: 343 crypto_unregister_shash(&ghash_alg); 344 return err; 345 } 346 347 static void __exit ghash_ce_mod_exit(void) 348 { 349 crypto_unregister_ahash(&ghash_async_alg); 350 crypto_unregister_shash(&ghash_alg); 351 } 352 353 module_init(ghash_ce_mod_init); 354 module_exit(ghash_ce_mod_exit); 355