1 /* 2 * Accelerated GHASH implementation with Intel PCLMULQDQ-NI 3 * instructions. This file contains glue code. 4 * 5 * Copyright (c) 2009 Intel Corp. 6 * Author: Huang Ying <ying.huang@intel.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License version 2 as published 10 * by the Free Software Foundation. 11 */ 12 13 #include <linux/err.h> 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/kernel.h> 17 #include <linux/crypto.h> 18 #include <crypto/algapi.h> 19 #include <crypto/cryptd.h> 20 #include <crypto/gf128mul.h> 21 #include <crypto/internal/hash.h> 22 #include <asm/i387.h> 23 #include <asm/cpu_device_id.h> 24 25 #define GHASH_BLOCK_SIZE 16 26 #define GHASH_DIGEST_SIZE 16 27 28 void clmul_ghash_mul(char *dst, const u128 *shash); 29 30 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen, 31 const u128 *shash); 32 33 struct ghash_async_ctx { 34 struct cryptd_ahash *cryptd_tfm; 35 }; 36 37 struct ghash_ctx { 38 u128 shash; 39 }; 40 41 struct ghash_desc_ctx { 42 u8 buffer[GHASH_BLOCK_SIZE]; 43 u32 bytes; 44 }; 45 46 static int ghash_init(struct shash_desc *desc) 47 { 48 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc); 49 50 memset(dctx, 0, sizeof(*dctx)); 51 52 return 0; 53 } 54 55 static int ghash_setkey(struct crypto_shash *tfm, 56 const u8 *key, unsigned int keylen) 57 { 58 struct ghash_ctx *ctx = crypto_shash_ctx(tfm); 59 be128 *x = (be128 *)key; 60 u64 a, b; 61 62 if (keylen != GHASH_BLOCK_SIZE) { 63 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 64 return -EINVAL; 65 } 66 67 /* perform multiplication by 'x' in GF(2^128) */ 68 a = be64_to_cpu(x->a); 69 b = be64_to_cpu(x->b); 70 71 ctx->shash.a = (b << 1) | (a >> 63); 72 ctx->shash.b = (a << 1) | (b >> 63); 73 74 if (a >> 63) 75 ctx->shash.b ^= ((u64)0xc2) << 56; 76 77 return 0; 78 } 79 80 static int ghash_update(struct shash_desc *desc, 81 const u8 *src, unsigned int srclen) 82 { 83 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc); 84 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm); 85 u8 *dst = dctx->buffer; 86 87 kernel_fpu_begin(); 88 if (dctx->bytes) { 89 int n = min(srclen, dctx->bytes); 90 u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes); 91 92 dctx->bytes -= n; 93 srclen -= n; 94 95 while (n--) 96 *pos++ ^= *src++; 97 98 if (!dctx->bytes) 99 clmul_ghash_mul(dst, &ctx->shash); 100 } 101 102 clmul_ghash_update(dst, src, srclen, &ctx->shash); 103 kernel_fpu_end(); 104 105 if (srclen & 0xf) { 106 src += srclen - (srclen & 0xf); 107 srclen &= 0xf; 108 dctx->bytes = GHASH_BLOCK_SIZE - srclen; 109 while (srclen--) 110 *dst++ ^= *src++; 111 } 112 113 return 0; 114 } 115 116 static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx) 117 { 118 u8 *dst = dctx->buffer; 119 120 if (dctx->bytes) { 121 u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes); 122 123 while (dctx->bytes--) 124 *tmp++ ^= 0; 125 126 kernel_fpu_begin(); 127 clmul_ghash_mul(dst, &ctx->shash); 128 kernel_fpu_end(); 129 } 130 131 dctx->bytes = 0; 132 } 133 134 static int ghash_final(struct shash_desc *desc, u8 *dst) 135 { 136 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc); 137 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm); 138 u8 *buf = dctx->buffer; 139 140 ghash_flush(ctx, dctx); 141 memcpy(dst, buf, GHASH_BLOCK_SIZE); 142 143 return 0; 144 } 145 146 static struct shash_alg ghash_alg = { 147 .digestsize = GHASH_DIGEST_SIZE, 148 .init = ghash_init, 149 .update = ghash_update, 150 .final = ghash_final, 151 .setkey = ghash_setkey, 152 .descsize = sizeof(struct ghash_desc_ctx), 153 .base = { 154 .cra_name = "__ghash", 155 .cra_driver_name = "__ghash-pclmulqdqni", 156 .cra_priority = 0, 157 .cra_flags = CRYPTO_ALG_TYPE_SHASH, 158 .cra_blocksize = GHASH_BLOCK_SIZE, 159 .cra_ctxsize = sizeof(struct ghash_ctx), 160 .cra_module = THIS_MODULE, 161 }, 162 }; 163 164 static int ghash_async_init(struct ahash_request *req) 165 { 166 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 167 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 168 struct ahash_request *cryptd_req = ahash_request_ctx(req); 169 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 170 171 if (!irq_fpu_usable()) { 172 memcpy(cryptd_req, req, sizeof(*req)); 173 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 174 return crypto_ahash_init(cryptd_req); 175 } else { 176 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 177 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm); 178 179 desc->tfm = child; 180 desc->flags = req->base.flags; 181 return crypto_shash_init(desc); 182 } 183 } 184 185 static int ghash_async_update(struct ahash_request *req) 186 { 187 struct ahash_request *cryptd_req = ahash_request_ctx(req); 188 189 if (!irq_fpu_usable()) { 190 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 191 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 192 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 193 194 memcpy(cryptd_req, req, sizeof(*req)); 195 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 196 return crypto_ahash_update(cryptd_req); 197 } else { 198 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 199 return shash_ahash_update(req, desc); 200 } 201 } 202 203 static int ghash_async_final(struct ahash_request *req) 204 { 205 struct ahash_request *cryptd_req = ahash_request_ctx(req); 206 207 if (!irq_fpu_usable()) { 208 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 209 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 210 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 211 212 memcpy(cryptd_req, req, sizeof(*req)); 213 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 214 return crypto_ahash_final(cryptd_req); 215 } else { 216 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 217 return crypto_shash_final(desc, req->result); 218 } 219 } 220 221 static int ghash_async_digest(struct ahash_request *req) 222 { 223 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 224 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 225 struct ahash_request *cryptd_req = ahash_request_ctx(req); 226 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 227 228 if (!irq_fpu_usable()) { 229 memcpy(cryptd_req, req, sizeof(*req)); 230 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 231 return crypto_ahash_digest(cryptd_req); 232 } else { 233 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 234 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm); 235 236 desc->tfm = child; 237 desc->flags = req->base.flags; 238 return shash_ahash_digest(req, desc); 239 } 240 } 241 242 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key, 243 unsigned int keylen) 244 { 245 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 246 struct crypto_ahash *child = &ctx->cryptd_tfm->base; 247 int err; 248 249 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK); 250 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm) 251 & CRYPTO_TFM_REQ_MASK); 252 err = crypto_ahash_setkey(child, key, keylen); 253 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child) 254 & CRYPTO_TFM_RES_MASK); 255 256 return err; 257 } 258 259 static int ghash_async_init_tfm(struct crypto_tfm *tfm) 260 { 261 struct cryptd_ahash *cryptd_tfm; 262 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 263 264 cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni", 0, 0); 265 if (IS_ERR(cryptd_tfm)) 266 return PTR_ERR(cryptd_tfm); 267 ctx->cryptd_tfm = cryptd_tfm; 268 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm), 269 sizeof(struct ahash_request) + 270 crypto_ahash_reqsize(&cryptd_tfm->base)); 271 272 return 0; 273 } 274 275 static void ghash_async_exit_tfm(struct crypto_tfm *tfm) 276 { 277 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 278 279 cryptd_free_ahash(ctx->cryptd_tfm); 280 } 281 282 static struct ahash_alg ghash_async_alg = { 283 .init = ghash_async_init, 284 .update = ghash_async_update, 285 .final = ghash_async_final, 286 .setkey = ghash_async_setkey, 287 .digest = ghash_async_digest, 288 .halg = { 289 .digestsize = GHASH_DIGEST_SIZE, 290 .base = { 291 .cra_name = "ghash", 292 .cra_driver_name = "ghash-clmulni", 293 .cra_priority = 400, 294 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC, 295 .cra_blocksize = GHASH_BLOCK_SIZE, 296 .cra_type = &crypto_ahash_type, 297 .cra_module = THIS_MODULE, 298 .cra_init = ghash_async_init_tfm, 299 .cra_exit = ghash_async_exit_tfm, 300 }, 301 }, 302 }; 303 304 static const struct x86_cpu_id pcmul_cpu_id[] = { 305 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */ 306 {} 307 }; 308 MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id); 309 310 static int __init ghash_pclmulqdqni_mod_init(void) 311 { 312 int err; 313 314 if (!x86_match_cpu(pcmul_cpu_id)) 315 return -ENODEV; 316 317 err = crypto_register_shash(&ghash_alg); 318 if (err) 319 goto err_out; 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 err_out: 329 return err; 330 } 331 332 static void __exit ghash_pclmulqdqni_mod_exit(void) 333 { 334 crypto_unregister_ahash(&ghash_async_alg); 335 crypto_unregister_shash(&ghash_alg); 336 } 337 338 module_init(ghash_pclmulqdqni_mod_init); 339 module_exit(ghash_pclmulqdqni_mod_exit); 340 341 MODULE_LICENSE("GPL"); 342 MODULE_DESCRIPTION("GHASH Message Digest Algorithm, " 343 "acclerated by PCLMULQDQ-NI"); 344 MODULE_ALIAS("ghash"); 345