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 26 #define GHASH_BLOCK_SIZE 16 27 #define GHASH_DIGEST_SIZE 16 28 29 struct ghash_key { 30 u64 a; 31 u64 b; 32 }; 33 34 struct ghash_desc_ctx { 35 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)]; 36 u8 buf[GHASH_BLOCK_SIZE]; 37 u32 count; 38 }; 39 40 struct ghash_async_ctx { 41 struct cryptd_ahash *cryptd_tfm; 42 }; 43 44 asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src, 45 struct ghash_key const *k, const char *head); 46 47 static int ghash_init(struct shash_desc *desc) 48 { 49 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 50 51 *ctx = (struct ghash_desc_ctx){}; 52 return 0; 53 } 54 55 static int ghash_update(struct shash_desc *desc, const u8 *src, 56 unsigned int len) 57 { 58 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 59 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 60 61 ctx->count += len; 62 63 if ((partial + len) >= GHASH_BLOCK_SIZE) { 64 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 65 int blocks; 66 67 if (partial) { 68 int p = GHASH_BLOCK_SIZE - partial; 69 70 memcpy(ctx->buf + partial, src, p); 71 src += p; 72 len -= p; 73 } 74 75 blocks = len / GHASH_BLOCK_SIZE; 76 len %= GHASH_BLOCK_SIZE; 77 78 kernel_neon_begin(); 79 pmull_ghash_update(blocks, ctx->digest, src, key, 80 partial ? ctx->buf : NULL); 81 kernel_neon_end(); 82 src += blocks * GHASH_BLOCK_SIZE; 83 partial = 0; 84 } 85 if (len) 86 memcpy(ctx->buf + partial, src, len); 87 return 0; 88 } 89 90 static int ghash_final(struct shash_desc *desc, u8 *dst) 91 { 92 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 93 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 94 95 if (partial) { 96 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 97 98 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 99 kernel_neon_begin(); 100 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL); 101 kernel_neon_end(); 102 } 103 put_unaligned_be64(ctx->digest[1], dst); 104 put_unaligned_be64(ctx->digest[0], dst + 8); 105 106 *ctx = (struct ghash_desc_ctx){}; 107 return 0; 108 } 109 110 static int ghash_setkey(struct crypto_shash *tfm, 111 const u8 *inkey, unsigned int keylen) 112 { 113 struct ghash_key *key = crypto_shash_ctx(tfm); 114 u64 a, b; 115 116 if (keylen != GHASH_BLOCK_SIZE) { 117 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 118 return -EINVAL; 119 } 120 121 /* perform multiplication by 'x' in GF(2^128) */ 122 b = get_unaligned_be64(inkey); 123 a = get_unaligned_be64(inkey + 8); 124 125 key->a = (a << 1) | (b >> 63); 126 key->b = (b << 1) | (a >> 63); 127 128 if (b >> 63) 129 key->b ^= 0xc200000000000000UL; 130 131 return 0; 132 } 133 134 static struct shash_alg ghash_alg = { 135 .digestsize = GHASH_DIGEST_SIZE, 136 .init = ghash_init, 137 .update = ghash_update, 138 .final = ghash_final, 139 .setkey = ghash_setkey, 140 .descsize = sizeof(struct ghash_desc_ctx), 141 .base = { 142 .cra_name = "__ghash", 143 .cra_driver_name = "__driver-ghash-ce", 144 .cra_priority = 0, 145 .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_INTERNAL, 146 .cra_blocksize = GHASH_BLOCK_SIZE, 147 .cra_ctxsize = sizeof(struct ghash_key), 148 .cra_module = THIS_MODULE, 149 }, 150 }; 151 152 static int ghash_async_init(struct ahash_request *req) 153 { 154 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 155 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 156 struct ahash_request *cryptd_req = ahash_request_ctx(req); 157 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 158 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 159 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm); 160 161 desc->tfm = child; 162 desc->flags = req->base.flags; 163 return crypto_shash_init(desc); 164 } 165 166 static int ghash_async_update(struct ahash_request *req) 167 { 168 struct ahash_request *cryptd_req = ahash_request_ctx(req); 169 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 170 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 171 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 172 173 if (!may_use_simd() || 174 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) { 175 memcpy(cryptd_req, req, sizeof(*req)); 176 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 177 return crypto_ahash_update(cryptd_req); 178 } else { 179 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 180 return shash_ahash_update(req, desc); 181 } 182 } 183 184 static int ghash_async_final(struct ahash_request *req) 185 { 186 struct ahash_request *cryptd_req = ahash_request_ctx(req); 187 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 188 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 189 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 190 191 if (!may_use_simd() || 192 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) { 193 memcpy(cryptd_req, req, sizeof(*req)); 194 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 195 return crypto_ahash_final(cryptd_req); 196 } else { 197 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 198 return crypto_shash_final(desc, req->result); 199 } 200 } 201 202 static int ghash_async_digest(struct ahash_request *req) 203 { 204 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 205 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 206 struct ahash_request *cryptd_req = ahash_request_ctx(req); 207 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 208 209 if (!may_use_simd() || 210 (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) { 211 memcpy(cryptd_req, req, sizeof(*req)); 212 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 213 return crypto_ahash_digest(cryptd_req); 214 } else { 215 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 216 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm); 217 218 desc->tfm = child; 219 desc->flags = req->base.flags; 220 return shash_ahash_digest(req, desc); 221 } 222 } 223 224 static int ghash_async_import(struct ahash_request *req, const void *in) 225 { 226 struct ahash_request *cryptd_req = ahash_request_ctx(req); 227 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 228 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 229 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 230 231 desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm); 232 desc->flags = req->base.flags; 233 234 return crypto_shash_import(desc, in); 235 } 236 237 static int ghash_async_export(struct ahash_request *req, void *out) 238 { 239 struct ahash_request *cryptd_req = ahash_request_ctx(req); 240 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 241 242 return crypto_shash_export(desc, out); 243 } 244 245 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key, 246 unsigned int keylen) 247 { 248 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 249 struct crypto_ahash *child = &ctx->cryptd_tfm->base; 250 int err; 251 252 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK); 253 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm) 254 & CRYPTO_TFM_REQ_MASK); 255 err = crypto_ahash_setkey(child, key, keylen); 256 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child) 257 & CRYPTO_TFM_RES_MASK); 258 259 return err; 260 } 261 262 static int ghash_async_init_tfm(struct crypto_tfm *tfm) 263 { 264 struct cryptd_ahash *cryptd_tfm; 265 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 266 267 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce", 268 CRYPTO_ALG_INTERNAL, 269 CRYPTO_ALG_INTERNAL); 270 if (IS_ERR(cryptd_tfm)) 271 return PTR_ERR(cryptd_tfm); 272 ctx->cryptd_tfm = cryptd_tfm; 273 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm), 274 sizeof(struct ahash_request) + 275 crypto_ahash_reqsize(&cryptd_tfm->base)); 276 277 return 0; 278 } 279 280 static void ghash_async_exit_tfm(struct crypto_tfm *tfm) 281 { 282 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 283 284 cryptd_free_ahash(ctx->cryptd_tfm); 285 } 286 287 static struct ahash_alg ghash_async_alg = { 288 .init = ghash_async_init, 289 .update = ghash_async_update, 290 .final = ghash_async_final, 291 .setkey = ghash_async_setkey, 292 .digest = ghash_async_digest, 293 .import = ghash_async_import, 294 .export = ghash_async_export, 295 .halg.digestsize = GHASH_DIGEST_SIZE, 296 .halg.statesize = sizeof(struct ghash_desc_ctx), 297 .halg.base = { 298 .cra_name = "ghash", 299 .cra_driver_name = "ghash-ce", 300 .cra_priority = 300, 301 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC, 302 .cra_blocksize = GHASH_BLOCK_SIZE, 303 .cra_type = &crypto_ahash_type, 304 .cra_ctxsize = sizeof(struct ghash_async_ctx), 305 .cra_module = THIS_MODULE, 306 .cra_init = ghash_async_init_tfm, 307 .cra_exit = ghash_async_exit_tfm, 308 }, 309 }; 310 311 static int __init ghash_ce_mod_init(void) 312 { 313 int err; 314 315 err = crypto_register_shash(&ghash_alg); 316 if (err) 317 return err; 318 err = crypto_register_ahash(&ghash_async_alg); 319 if (err) 320 goto err_shash; 321 322 return 0; 323 324 err_shash: 325 crypto_unregister_shash(&ghash_alg); 326 return err; 327 } 328 329 static void __exit ghash_ce_mod_exit(void) 330 { 331 crypto_unregister_ahash(&ghash_async_alg); 332 crypto_unregister_shash(&ghash_alg); 333 } 334 335 module_cpu_feature_match(PMULL, ghash_ce_mod_init); 336 module_exit(ghash_ce_mod_exit); 337