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; 157 158 if (!may_use_simd()) { 159 memcpy(cryptd_req, req, sizeof(*req)); 160 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 161 return crypto_ahash_init(cryptd_req); 162 } else { 163 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 164 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm); 165 166 desc->tfm = child; 167 desc->flags = req->base.flags; 168 return crypto_shash_init(desc); 169 } 170 } 171 172 static int ghash_async_update(struct ahash_request *req) 173 { 174 struct ahash_request *cryptd_req = ahash_request_ctx(req); 175 176 if (!may_use_simd()) { 177 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 178 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 179 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 180 181 memcpy(cryptd_req, req, sizeof(*req)); 182 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 183 return crypto_ahash_update(cryptd_req); 184 } else { 185 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 186 return shash_ahash_update(req, desc); 187 } 188 } 189 190 static int ghash_async_final(struct ahash_request *req) 191 { 192 struct ahash_request *cryptd_req = ahash_request_ctx(req); 193 194 if (!may_use_simd()) { 195 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 196 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 197 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 198 199 memcpy(cryptd_req, req, sizeof(*req)); 200 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 201 return crypto_ahash_final(cryptd_req); 202 } else { 203 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 204 return crypto_shash_final(desc, req->result); 205 } 206 } 207 208 static int ghash_async_digest(struct ahash_request *req) 209 { 210 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 211 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 212 struct ahash_request *cryptd_req = ahash_request_ctx(req); 213 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm; 214 215 if (!may_use_simd()) { 216 memcpy(cryptd_req, req, sizeof(*req)); 217 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base); 218 return crypto_ahash_digest(cryptd_req); 219 } else { 220 struct shash_desc *desc = cryptd_shash_desc(cryptd_req); 221 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm); 222 223 desc->tfm = child; 224 desc->flags = req->base.flags; 225 return shash_ahash_digest(req, desc); 226 } 227 } 228 229 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key, 230 unsigned int keylen) 231 { 232 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm); 233 struct crypto_ahash *child = &ctx->cryptd_tfm->base; 234 int err; 235 236 crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK); 237 crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm) 238 & CRYPTO_TFM_REQ_MASK); 239 err = crypto_ahash_setkey(child, key, keylen); 240 crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child) 241 & CRYPTO_TFM_RES_MASK); 242 243 return err; 244 } 245 246 static int ghash_async_init_tfm(struct crypto_tfm *tfm) 247 { 248 struct cryptd_ahash *cryptd_tfm; 249 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 250 251 cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce", 252 CRYPTO_ALG_INTERNAL, 253 CRYPTO_ALG_INTERNAL); 254 if (IS_ERR(cryptd_tfm)) 255 return PTR_ERR(cryptd_tfm); 256 ctx->cryptd_tfm = cryptd_tfm; 257 crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm), 258 sizeof(struct ahash_request) + 259 crypto_ahash_reqsize(&cryptd_tfm->base)); 260 261 return 0; 262 } 263 264 static void ghash_async_exit_tfm(struct crypto_tfm *tfm) 265 { 266 struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm); 267 268 cryptd_free_ahash(ctx->cryptd_tfm); 269 } 270 271 static struct ahash_alg ghash_async_alg = { 272 .init = ghash_async_init, 273 .update = ghash_async_update, 274 .final = ghash_async_final, 275 .setkey = ghash_async_setkey, 276 .digest = ghash_async_digest, 277 .halg.digestsize = GHASH_DIGEST_SIZE, 278 .halg.base = { 279 .cra_name = "ghash", 280 .cra_driver_name = "ghash-ce", 281 .cra_priority = 300, 282 .cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC, 283 .cra_blocksize = GHASH_BLOCK_SIZE, 284 .cra_type = &crypto_ahash_type, 285 .cra_ctxsize = sizeof(struct ghash_async_ctx), 286 .cra_module = THIS_MODULE, 287 .cra_init = ghash_async_init_tfm, 288 .cra_exit = ghash_async_exit_tfm, 289 }, 290 }; 291 292 static int __init ghash_ce_mod_init(void) 293 { 294 int err; 295 296 if (!(elf_hwcap2 & HWCAP2_PMULL)) 297 return -ENODEV; 298 299 err = crypto_register_shash(&ghash_alg); 300 if (err) 301 return err; 302 err = crypto_register_ahash(&ghash_async_alg); 303 if (err) 304 goto err_shash; 305 306 return 0; 307 308 err_shash: 309 crypto_unregister_shash(&ghash_alg); 310 return err; 311 } 312 313 static void __exit ghash_ce_mod_exit(void) 314 { 315 crypto_unregister_ahash(&ghash_async_alg); 316 crypto_unregister_shash(&ghash_alg); 317 } 318 319 module_init(ghash_ce_mod_init); 320 module_exit(ghash_ce_mod_exit); 321