1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * algif_hash: User-space interface for hash algorithms 4 * 5 * This file provides the user-space API for hash algorithms. 6 * 7 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> 8 */ 9 10 #include <crypto/hash.h> 11 #include <crypto/if_alg.h> 12 #include <linux/init.h> 13 #include <linux/kernel.h> 14 #include <linux/mm.h> 15 #include <linux/module.h> 16 #include <linux/net.h> 17 #include <net/sock.h> 18 19 struct hash_ctx { 20 struct af_alg_sgl sgl; 21 22 u8 *result; 23 24 struct crypto_wait wait; 25 26 unsigned int len; 27 bool more; 28 29 struct ahash_request req; 30 }; 31 32 static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx) 33 { 34 unsigned ds; 35 36 if (ctx->result) 37 return 0; 38 39 ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); 40 41 ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL); 42 if (!ctx->result) 43 return -ENOMEM; 44 45 memset(ctx->result, 0, ds); 46 47 return 0; 48 } 49 50 static void hash_free_result(struct sock *sk, struct hash_ctx *ctx) 51 { 52 unsigned ds; 53 54 if (!ctx->result) 55 return; 56 57 ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); 58 59 sock_kzfree_s(sk, ctx->result, ds); 60 ctx->result = NULL; 61 } 62 63 static int hash_sendmsg(struct socket *sock, struct msghdr *msg, 64 size_t ignored) 65 { 66 int limit = ALG_MAX_PAGES * PAGE_SIZE; 67 struct sock *sk = sock->sk; 68 struct alg_sock *ask = alg_sk(sk); 69 struct hash_ctx *ctx = ask->private; 70 long copied = 0; 71 int err; 72 73 if (limit > sk->sk_sndbuf) 74 limit = sk->sk_sndbuf; 75 76 lock_sock(sk); 77 if (!ctx->more) { 78 if ((msg->msg_flags & MSG_MORE)) 79 hash_free_result(sk, ctx); 80 81 err = crypto_wait_req(crypto_ahash_init(&ctx->req), &ctx->wait); 82 if (err) 83 goto unlock; 84 } 85 86 ctx->more = false; 87 88 while (msg_data_left(msg)) { 89 int len = msg_data_left(msg); 90 91 if (len > limit) 92 len = limit; 93 94 len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len); 95 if (len < 0) { 96 err = copied ? 0 : len; 97 goto unlock; 98 } 99 100 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len); 101 102 err = crypto_wait_req(crypto_ahash_update(&ctx->req), 103 &ctx->wait); 104 af_alg_free_sg(&ctx->sgl); 105 if (err) { 106 iov_iter_revert(&msg->msg_iter, len); 107 goto unlock; 108 } 109 110 copied += len; 111 } 112 113 err = 0; 114 115 ctx->more = msg->msg_flags & MSG_MORE; 116 if (!ctx->more) { 117 err = hash_alloc_result(sk, ctx); 118 if (err) 119 goto unlock; 120 121 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); 122 err = crypto_wait_req(crypto_ahash_final(&ctx->req), 123 &ctx->wait); 124 } 125 126 unlock: 127 release_sock(sk); 128 129 return err ?: copied; 130 } 131 132 static ssize_t hash_sendpage(struct socket *sock, struct page *page, 133 int offset, size_t size, int flags) 134 { 135 struct sock *sk = sock->sk; 136 struct alg_sock *ask = alg_sk(sk); 137 struct hash_ctx *ctx = ask->private; 138 int err; 139 140 if (flags & MSG_SENDPAGE_NOTLAST) 141 flags |= MSG_MORE; 142 143 lock_sock(sk); 144 sg_init_table(ctx->sgl.sg, 1); 145 sg_set_page(ctx->sgl.sg, page, size, offset); 146 147 if (!(flags & MSG_MORE)) { 148 err = hash_alloc_result(sk, ctx); 149 if (err) 150 goto unlock; 151 } else if (!ctx->more) 152 hash_free_result(sk, ctx); 153 154 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size); 155 156 if (!(flags & MSG_MORE)) { 157 if (ctx->more) 158 err = crypto_ahash_finup(&ctx->req); 159 else 160 err = crypto_ahash_digest(&ctx->req); 161 } else { 162 if (!ctx->more) { 163 err = crypto_ahash_init(&ctx->req); 164 err = crypto_wait_req(err, &ctx->wait); 165 if (err) 166 goto unlock; 167 } 168 169 err = crypto_ahash_update(&ctx->req); 170 } 171 172 err = crypto_wait_req(err, &ctx->wait); 173 if (err) 174 goto unlock; 175 176 ctx->more = flags & MSG_MORE; 177 178 unlock: 179 release_sock(sk); 180 181 return err ?: size; 182 } 183 184 static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 185 int flags) 186 { 187 struct sock *sk = sock->sk; 188 struct alg_sock *ask = alg_sk(sk); 189 struct hash_ctx *ctx = ask->private; 190 unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); 191 bool result; 192 int err; 193 194 if (len > ds) 195 len = ds; 196 else if (len < ds) 197 msg->msg_flags |= MSG_TRUNC; 198 199 lock_sock(sk); 200 result = ctx->result; 201 err = hash_alloc_result(sk, ctx); 202 if (err) 203 goto unlock; 204 205 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); 206 207 if (!result && !ctx->more) { 208 err = crypto_wait_req(crypto_ahash_init(&ctx->req), 209 &ctx->wait); 210 if (err) 211 goto unlock; 212 } 213 214 if (!result || ctx->more) { 215 ctx->more = false; 216 err = crypto_wait_req(crypto_ahash_final(&ctx->req), 217 &ctx->wait); 218 if (err) 219 goto unlock; 220 } 221 222 err = memcpy_to_msg(msg, ctx->result, len); 223 224 unlock: 225 hash_free_result(sk, ctx); 226 release_sock(sk); 227 228 return err ?: len; 229 } 230 231 static int hash_accept(struct socket *sock, struct socket *newsock, int flags, 232 bool kern) 233 { 234 struct sock *sk = sock->sk; 235 struct alg_sock *ask = alg_sk(sk); 236 struct hash_ctx *ctx = ask->private; 237 struct ahash_request *req = &ctx->req; 238 char state[HASH_MAX_STATESIZE]; 239 struct sock *sk2; 240 struct alg_sock *ask2; 241 struct hash_ctx *ctx2; 242 bool more; 243 int err; 244 245 lock_sock(sk); 246 more = ctx->more; 247 err = more ? crypto_ahash_export(req, state) : 0; 248 release_sock(sk); 249 250 if (err) 251 return err; 252 253 err = af_alg_accept(ask->parent, newsock, kern); 254 if (err) 255 return err; 256 257 sk2 = newsock->sk; 258 ask2 = alg_sk(sk2); 259 ctx2 = ask2->private; 260 ctx2->more = more; 261 262 if (!more) 263 return err; 264 265 err = crypto_ahash_import(&ctx2->req, state); 266 if (err) { 267 sock_orphan(sk2); 268 sock_put(sk2); 269 } 270 271 return err; 272 } 273 274 static struct proto_ops algif_hash_ops = { 275 .family = PF_ALG, 276 277 .connect = sock_no_connect, 278 .socketpair = sock_no_socketpair, 279 .getname = sock_no_getname, 280 .ioctl = sock_no_ioctl, 281 .listen = sock_no_listen, 282 .shutdown = sock_no_shutdown, 283 .mmap = sock_no_mmap, 284 .bind = sock_no_bind, 285 286 .release = af_alg_release, 287 .sendmsg = hash_sendmsg, 288 .sendpage = hash_sendpage, 289 .recvmsg = hash_recvmsg, 290 .accept = hash_accept, 291 }; 292 293 static int hash_check_key(struct socket *sock) 294 { 295 int err = 0; 296 struct sock *psk; 297 struct alg_sock *pask; 298 struct crypto_ahash *tfm; 299 struct sock *sk = sock->sk; 300 struct alg_sock *ask = alg_sk(sk); 301 302 lock_sock(sk); 303 if (!atomic_read(&ask->nokey_refcnt)) 304 goto unlock_child; 305 306 psk = ask->parent; 307 pask = alg_sk(ask->parent); 308 tfm = pask->private; 309 310 err = -ENOKEY; 311 lock_sock_nested(psk, SINGLE_DEPTH_NESTING); 312 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 313 goto unlock; 314 315 atomic_dec(&pask->nokey_refcnt); 316 atomic_set(&ask->nokey_refcnt, 0); 317 318 err = 0; 319 320 unlock: 321 release_sock(psk); 322 unlock_child: 323 release_sock(sk); 324 325 return err; 326 } 327 328 static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg, 329 size_t size) 330 { 331 int err; 332 333 err = hash_check_key(sock); 334 if (err) 335 return err; 336 337 return hash_sendmsg(sock, msg, size); 338 } 339 340 static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page, 341 int offset, size_t size, int flags) 342 { 343 int err; 344 345 err = hash_check_key(sock); 346 if (err) 347 return err; 348 349 return hash_sendpage(sock, page, offset, size, flags); 350 } 351 352 static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg, 353 size_t ignored, int flags) 354 { 355 int err; 356 357 err = hash_check_key(sock); 358 if (err) 359 return err; 360 361 return hash_recvmsg(sock, msg, ignored, flags); 362 } 363 364 static int hash_accept_nokey(struct socket *sock, struct socket *newsock, 365 int flags, bool kern) 366 { 367 int err; 368 369 err = hash_check_key(sock); 370 if (err) 371 return err; 372 373 return hash_accept(sock, newsock, flags, kern); 374 } 375 376 static struct proto_ops algif_hash_ops_nokey = { 377 .family = PF_ALG, 378 379 .connect = sock_no_connect, 380 .socketpair = sock_no_socketpair, 381 .getname = sock_no_getname, 382 .ioctl = sock_no_ioctl, 383 .listen = sock_no_listen, 384 .shutdown = sock_no_shutdown, 385 .mmap = sock_no_mmap, 386 .bind = sock_no_bind, 387 388 .release = af_alg_release, 389 .sendmsg = hash_sendmsg_nokey, 390 .sendpage = hash_sendpage_nokey, 391 .recvmsg = hash_recvmsg_nokey, 392 .accept = hash_accept_nokey, 393 }; 394 395 static void *hash_bind(const char *name, u32 type, u32 mask) 396 { 397 return crypto_alloc_ahash(name, type, mask); 398 } 399 400 static void hash_release(void *private) 401 { 402 crypto_free_ahash(private); 403 } 404 405 static int hash_setkey(void *private, const u8 *key, unsigned int keylen) 406 { 407 return crypto_ahash_setkey(private, key, keylen); 408 } 409 410 static void hash_sock_destruct(struct sock *sk) 411 { 412 struct alg_sock *ask = alg_sk(sk); 413 struct hash_ctx *ctx = ask->private; 414 415 hash_free_result(sk, ctx); 416 sock_kfree_s(sk, ctx, ctx->len); 417 af_alg_release_parent(sk); 418 } 419 420 static int hash_accept_parent_nokey(void *private, struct sock *sk) 421 { 422 struct crypto_ahash *tfm = private; 423 struct alg_sock *ask = alg_sk(sk); 424 struct hash_ctx *ctx; 425 unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm); 426 427 ctx = sock_kmalloc(sk, len, GFP_KERNEL); 428 if (!ctx) 429 return -ENOMEM; 430 431 ctx->result = NULL; 432 ctx->len = len; 433 ctx->more = false; 434 crypto_init_wait(&ctx->wait); 435 436 ask->private = ctx; 437 438 ahash_request_set_tfm(&ctx->req, tfm); 439 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG, 440 crypto_req_done, &ctx->wait); 441 442 sk->sk_destruct = hash_sock_destruct; 443 444 return 0; 445 } 446 447 static int hash_accept_parent(void *private, struct sock *sk) 448 { 449 struct crypto_ahash *tfm = private; 450 451 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 452 return -ENOKEY; 453 454 return hash_accept_parent_nokey(private, sk); 455 } 456 457 static const struct af_alg_type algif_type_hash = { 458 .bind = hash_bind, 459 .release = hash_release, 460 .setkey = hash_setkey, 461 .accept = hash_accept_parent, 462 .accept_nokey = hash_accept_parent_nokey, 463 .ops = &algif_hash_ops, 464 .ops_nokey = &algif_hash_ops_nokey, 465 .name = "hash", 466 .owner = THIS_MODULE 467 }; 468 469 static int __init algif_hash_init(void) 470 { 471 return af_alg_register_type(&algif_type_hash); 472 } 473 474 static void __exit algif_hash_exit(void) 475 { 476 int err = af_alg_unregister_type(&algif_type_hash); 477 BUG_ON(err); 478 } 479 480 module_init(algif_hash_init); 481 module_exit(algif_hash_exit); 482 MODULE_LICENSE("GPL"); 483