crypto/algif_hash.c

   1 /*
   2  * algif_hash: User-space interface for hash algorithms
   3  *
   4  * This file provides the user-space API for hash algorithms.
   5  *
   6  * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
   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 as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14
  15 #include <crypto/hash.h>
  16 #include <crypto/if_alg.h>
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/mm.h>
  20 #include <linux/module.h>
  21 #include <linux/net.h>
  22 #include <net/sock.h>
  23
  24 struct hash_ctx {
  25         struct af_alg_sgl sgl;
  26
  27         u8 *result;
  28
  29         struct af_alg_completion completion;
  30
  31         unsigned int len;
  32         bool more;
  33
  34         struct ahash_request req;
  35 };
  36
  37 static int hash_sendmsg(struct kiocb *unused, struct socket *sock,
  38                         struct msghdr *msg, size_t ignored)
  39 {
  40         int limit = ALG_MAX_PAGES * PAGE_SIZE;
  41         struct sock *sk = sock->sk;
  42         struct alg_sock *ask = alg_sk(sk);
  43         struct hash_ctx *ctx = ask->private;
  44         unsigned long iovlen;
  45         struct iovec *iov;
  46         long copied = 0;
  47         int err;
  48
  49         if (limit > sk->sk_sndbuf)
  50                 limit = sk->sk_sndbuf;
  51
  52         lock_sock(sk);
  53         if (!ctx->more) {
  54                 err = af_alg_wait_for_completion(crypto_ahash_init(&ctx->req),
  55                                                 &ctx->completion);
  56                 if (err)
  57                         goto unlock;
  58         }
  59
  60         ctx->more = 0;
  61
  62         for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
  63              iovlen--, iov++) {
  64                 unsigned long seglen = iov->iov_len;
  65                 char __user *from = iov->iov_base;
  66
  67                 while (seglen) {
  68                         int len = min_t(unsigned long, seglen, limit);
  69                         int newlen;
  70
  71                         newlen = af_alg_make_sg(&ctx->sgl, from, len, 0);
  72                         if (newlen < 0) {
  73                                 err = copied ? 0 : newlen;
  74                                 goto unlock;
  75                         }
  76
  77                         ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL,
  78                                                 newlen);
  79
  80                         err = af_alg_wait_for_completion(
  81                                 crypto_ahash_update(&ctx->req),
  82                                 &ctx->completion);
  83
  84                         af_alg_free_sg(&ctx->sgl);
  85
  86                         if (err)
  87                                 goto unlock;
  88
  89                         seglen -= newlen;
  90                         from += newlen;
  91                         copied += newlen;
  92                 }
  93         }
  94
  95         err = 0;
  96
  97         ctx->more = msg->msg_flags & MSG_MORE;
  98         if (!ctx->more) {
  99                 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
 100                 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
 101                                                  &ctx->completion);
 102         }
 103
 104 unlock:
 105         release_sock(sk);
 106
 107         return err ?: copied;
 108 }
 109
 110 static ssize_t hash_sendpage(struct socket *sock, struct page *page,
 111                              int offset, size_t size, int flags)
 112 {
 113         struct sock *sk = sock->sk;
 114         struct alg_sock *ask = alg_sk(sk);
 115         struct hash_ctx *ctx = ask->private;
 116         int err;
 117
 118         if (flags & MSG_SENDPAGE_NOTLAST)
 119                 flags |= MSG_MORE;
 120
 121         lock_sock(sk);
 122         sg_init_table(ctx->sgl.sg, 1);
 123         sg_set_page(ctx->sgl.sg, page, size, offset);
 124
 125         ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
 126
 127         if (!(flags & MSG_MORE)) {
 128                 if (ctx->more)
 129                         err = crypto_ahash_finup(&ctx->req);
 130                 else
 131                         err = crypto_ahash_digest(&ctx->req);
 132         } else {
 133                 if (!ctx->more) {
 134                         err = crypto_ahash_init(&ctx->req);
 135                         err = af_alg_wait_for_completion(err, &ctx->completion);
 136                         if (err)
 137                                 goto unlock;
 138                 }
 139
 140                 err = crypto_ahash_update(&ctx->req);
 141         }
 142
 143         err = af_alg_wait_for_completion(err, &ctx->completion);
 144         if (err)
 145                 goto unlock;
 146
 147         ctx->more = flags & MSG_MORE;
 148
 149 unlock:
 150         release_sock(sk);
 151
 152         return err ?: size;
 153 }
 154
 155 static int hash_recvmsg(struct kiocb *unused, struct socket *sock,
 156                         struct msghdr *msg, size_t len, int flags)
 157 {
 158         struct sock *sk = sock->sk;
 159         struct alg_sock *ask = alg_sk(sk);
 160         struct hash_ctx *ctx = ask->private;
 161         unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
 162         int err;
 163
 164         if (len > ds)
 165                 len = ds;
 166         else if (len < ds)
 167                 msg->msg_flags |= MSG_TRUNC;
 168
 169         lock_sock(sk);
 170         if (ctx->more) {
 171                 ctx->more = 0;
 172                 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
 173                 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
 174                                                  &ctx->completion);
 175                 if (err)
 176                         goto unlock;
 177         }
 178
 179         err = memcpy_toiovec(msg->msg_iov, ctx->result, len);
 180
 181 unlock:
 182         release_sock(sk);
 183
 184         return err ?: len;
 185 }
 186
 187 static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
 188 {
 189         struct sock *sk = sock->sk;
 190         struct alg_sock *ask = alg_sk(sk);
 191         struct hash_ctx *ctx = ask->private;
 192         struct ahash_request *req = &ctx->req;
 193         char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))];
 194         struct sock *sk2;
 195         struct alg_sock *ask2;
 196         struct hash_ctx *ctx2;
 197         bool more;
 198         int err;
 199
 200         lock_sock(sk);
 201         more = ctx->more;
 202         err = more ? crypto_ahash_export(req, state) : 0;
 203         release_sock(sk);
 204
 205         if (err)
 206                 return err;
 207
 208         err = af_alg_accept(ask->parent, newsock);
 209         if (err)
 210                 return err;
 211
 212         sk2 = newsock->sk;
 213         ask2 = alg_sk(sk2);
 214         ctx2 = ask2->private;
 215         ctx2->more = more;
 216
 217         if (!more)
 218                 return err;
 219
 220         err = crypto_ahash_import(&ctx2->req, state);
 221         if (err) {
 222                 sock_orphan(sk2);
 223                 sock_put(sk2);
 224         }
 225
 226         return err;
 227 }
 228
 229 static struct proto_ops algif_hash_ops = {
 230         .family         =       PF_ALG,
 231
 232         .connect        =       sock_no_connect,
 233         .socketpair     =       sock_no_socketpair,
 234         .getname        =       sock_no_getname,
 235         .ioctl          =       sock_no_ioctl,
 236         .listen         =       sock_no_listen,
 237         .shutdown       =       sock_no_shutdown,
 238         .getsockopt     =       sock_no_getsockopt,
 239         .mmap           =       sock_no_mmap,
 240         .bind           =       sock_no_bind,
 241         .setsockopt     =       sock_no_setsockopt,
 242         .poll           =       sock_no_poll,
 243
 244         .release        =       af_alg_release,
 245         .sendmsg        =       hash_sendmsg,
 246         .sendpage       =       hash_sendpage,
 247         .recvmsg        =       hash_recvmsg,
 248         .accept         =       hash_accept,
 249 };
 250
 251 static void *hash_bind(const char *name, u32 type, u32 mask)
 252 {
 253         return crypto_alloc_ahash(name, type, mask);
 254 }
 255
 256 static void hash_release(void *private)
 257 {
 258         crypto_free_ahash(private);
 259 }
 260
 261 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
 262 {
 263         return crypto_ahash_setkey(private, key, keylen);
 264 }
 265
 266 static void hash_sock_destruct(struct sock *sk)
 267 {
 268         struct alg_sock *ask = alg_sk(sk);
 269         struct hash_ctx *ctx = ask->private;
 270
 271         sock_kfree_s(sk, ctx->result,
 272                      crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
 273         sock_kfree_s(sk, ctx, ctx->len);
 274         af_alg_release_parent(sk);
 275 }
 276
 277 static int hash_accept_parent(void *private, struct sock *sk)
 278 {
 279         struct hash_ctx *ctx;
 280         struct alg_sock *ask = alg_sk(sk);
 281         unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private);
 282         unsigned ds = crypto_ahash_digestsize(private);
 283
 284         ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 285         if (!ctx)
 286                 return -ENOMEM;
 287
 288         ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
 289         if (!ctx->result) {
 290                 sock_kfree_s(sk, ctx, len);
 291                 return -ENOMEM;
 292         }
 293
 294         memset(ctx->result, 0, ds);
 295
 296         ctx->len = len;
 297         ctx->more = 0;
 298         af_alg_init_completion(&ctx->completion);
 299
 300         ask->private = ctx;
 301
 302         ahash_request_set_tfm(&ctx->req, private);
 303         ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 304                                    af_alg_complete, &ctx->completion);
 305
 306         sk->sk_destruct = hash_sock_destruct;
 307
 308         return 0;
 309 }
 310
 311 static const struct af_alg_type algif_type_hash = {
 312         .bind           =       hash_bind,
 313         .release        =       hash_release,
 314         .setkey         =       hash_setkey,
 315         .accept         =       hash_accept_parent,
 316         .ops            =       &algif_hash_ops,
 317         .name           =       "hash",
 318         .owner          =       THIS_MODULE
 319 };
 320
 321 static int __init algif_hash_init(void)
 322 {
 323         return af_alg_register_type(&algif_type_hash);
 324 }
 325
 326 static void __exit algif_hash_exit(void)
 327 {
 328         int err = af_alg_unregister_type(&algif_type_hash);
 329         BUG_ON(err);
 330 }
 331
 332 module_init(algif_hash_init);
 333 module_exit(algif_hash_exit);
 334 MODULE_LICENSE("GPL");