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/crypto.h> 19 #include <linux/module.h> 20 21 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions"); 22 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); 23 MODULE_LICENSE("GPL v2"); 24 25 #define GHASH_BLOCK_SIZE 16 26 #define GHASH_DIGEST_SIZE 16 27 28 struct ghash_key { 29 u64 a; 30 u64 b; 31 }; 32 33 struct ghash_desc_ctx { 34 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)]; 35 u8 buf[GHASH_BLOCK_SIZE]; 36 u32 count; 37 }; 38 39 struct ghash_async_ctx { 40 struct cryptd_ahash *cryptd_tfm; 41 }; 42 43 asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src, 44 struct ghash_key const *k, const char *head); 45 46 static int ghash_init(struct shash_desc *desc) 47 { 48 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 49 50 *ctx = (struct ghash_desc_ctx){}; 51 return 0; 52 } 53 54 static int ghash_update(struct shash_desc *desc, const u8 *src, 55 unsigned int len) 56 { 57 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 58 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 59 60 ctx->count += len; 61 62 if ((partial + len) >= GHASH_BLOCK_SIZE) { 63 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 64 int blocks; 65 66 if (partial) { 67 int p = GHASH_BLOCK_SIZE - partial; 68 69 memcpy(ctx->buf + partial, src, p); 70 src += p; 71 len -= p; 72 } 73 74 blocks = len / GHASH_BLOCK_SIZE; 75 len %= GHASH_BLOCK_SIZE; 76 77 kernel_neon_begin(); 78 pmull_ghash_update(blocks, ctx->digest, src, key, 79 partial ? ctx->buf : NULL); 80 kernel_neon_end(); 81 src += blocks * GHASH_BLOCK_SIZE; 82 partial = 0; 83 } 84 if (len) 85 memcpy(ctx->buf + partial, src, len); 86 return 0; 87 } 88 89 static int ghash_final(struct shash_desc *desc, u8 *dst) 90 { 91 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 92 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 93 94 if (partial) { 95 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 96 97 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 98 kernel_neon_begin(); 99 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL); 100 kernel_neon_end(); 101 } 102 put_unaligned_be64(ctx->digest[1], dst); 103 put_unaligned_be64(ctx->digest[0], dst + 8); 104 105 *ctx = (struct ghash_desc_ctx){}; 106 return 0; 107 } 108 109 static int ghash_setkey(struct crypto_shash *tfm, 110 const u8 *inkey, unsigned int keylen) 111 { 112 struct ghash_key *key = crypto_shash_ctx(tfm); 113 u64 a, b; 114 115 if (keylen != GHASH_BLOCK_SIZE) { 116 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 117 return -EINVAL; 118 } 119 120 /* perform multiplication by 'x' in GF(2^128) */ 121 b = get_unaligned_be64(inkey); 122 a = get_unaligned_be64(inkey + 8); 123 124 key->a = (a << 1) | (b >> 63); 125 key->b = (b << 1) | (a >> 63); 126 127 if (b >> 63) 128 key->b ^= 0xc200000000000000UL; 129 130 return 0; 131 } 132 133 static struct shash_alg ghash_alg = { 134 .digestsize = GHASH_DIGEST_SIZE, 135 .init = ghash_init, 136 .update = ghash_update, 137 .final = ghash_final, 138 .setkey = ghash_setkey, 139 .descsize = sizeof(struct ghash_desc_ctx), 140 .base = { 141 .cra_name = "__ghash", 142 .cra_driver_name = "__driver-ghash-ce", 143 .cra_priority = 0, 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, 148 }, 149 }; 150 151 static int ghash_async_init(struct ahash_request *req) 152 { 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); 159 160 desc->tfm = child; 161 desc->flags = req->base.flags; 162 return crypto_shash_init(desc); 163 } 164 165 static int ghash_async_update(struct ahash_request *req) 166 { 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; 171 172 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); 177 } else { 178 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 179 return shash_ahash_update(req, desc); 180 } 181 } 182 183 static int ghash_async_final(struct ahash_request *req) 184 { 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; 189 190 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); 195 } else { 196 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 197 return crypto_shash_final(desc, req->result); 198 } 199 } 200 201 static int ghash_async_digest(struct ahash_request *req) 202 { 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; 207 208 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); 213 } else { 214 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 215 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm); 216 217 desc->tfm = child; 218 desc->flags = req->base.flags; 219 return shash_ahash_digest(req, desc); 220 } 221 } 222 223 static int ghash_async_import(struct ahash_request *req, const void *in) 224 { 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); 229 230 desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm); 231 desc->flags = req->base.flags; 232 233 return crypto_shash_import(desc, in); 234 } 235 236 static int ghash_async_export(struct ahash_request *req, void *out) 237 { 238 struct ahash_request *cryptd_req = ahash_request_ctx(req); 239 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 240 241 return crypto_shash_export(desc, out); 242 } 243 244 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key, 245 unsigned int keylen) 246 { 247 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 248 struct crypto_ahash *child = &ctx->cryptd_tfm->base; 249 int err; 250 251 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); 257 258 return err; 259 } 260 261 static int ghash_async_init_tfm(struct crypto_tfm *tfm) 262 { 263 struct cryptd_ahash *cryptd_tfm; 264 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 265 266 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce", 267 CRYPTO_ALG_INTERNAL, 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)); 275 276 return 0; 277 } 278 279 static void ghash_async_exit_tfm(struct crypto_tfm *tfm) 280 { 281 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 282 283 cryptd_free_ahash(ctx->cryptd_tfm); 284 } 285 286 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), 296 .halg.base = { 297 .cra_name = "ghash", 298 .cra_driver_name = "ghash-ce", 299 .cra_priority = 300, 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, 307 }, 308 }; 309 310 static int __init ghash_ce_mod_init(void) 311 { 312 int err; 313 314 if (!(elf_hwcap2 & HWCAP2_PMULL)) 315 return -ENODEV; 316 317 err = crypto_register_shash(&ghash_alg); 318 if (err) 319 return err; 320 err = crypto_register_ahash(&ghash_async_alg); 321 if (err) 322 goto err_shash; 323 324 return 0; 325 326 err_shash: 327 crypto_unregister_shash(&ghash_alg); 328 return err; 329 } 330 331 static void __exit ghash_ce_mod_exit(void) 332 { 333 crypto_unregister_ahash(&ghash_async_alg); 334 crypto_unregister_shash(&ghash_alg); 335 } 336 337 module_init(ghash_ce_mod_init); 338 module_exit(ghash_ce_mod_exit); 339