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 = crypto_ahash_init(&ctx->req);
  55                 if (err)
  56                         goto unlock;
  57         }
  58
  59         ctx->more = 0;
  60
  61         for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
  62              iovlen--, iov++) {
  63                 unsigned long seglen = iov->iov_len;
  64                 char __user *from = iov->iov_base;
  65
  66                 while (seglen) {
  67                         int len = min_t(unsigned long, seglen, limit);
  68                         int newlen;
  69
  70                         newlen = af_alg_make_sg(&ctx->sgl, from, len, 0);
  71                         if (newlen < 0) {
  72                                 err = copied ? 0 : newlen;
  73                                 goto unlock;
  74                         }
  75
  76                         ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL,
  77                                                 newlen);
  78
  79                         err = af_alg_wait_for_completion(
  80                                 crypto_ahash_update(&ctx->req),
  81                                 &ctx->completion);
  82
  83                         af_alg_free_sg(&ctx->sgl);
  84
  85                         if (err)
  86                                 goto unlock;
  87
  88                         seglen -= newlen;
  89                         from += newlen;
  90                         copied += newlen;
  91                 }
  92         }
  93
  94         err = 0;
  95
  96         ctx->more = msg->msg_flags & MSG_MORE;
  97         if (!ctx->more) {
  98                 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
  99                 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
 100                                                  &ctx->completion);
 101         }
 102
 103 unlock:
 104         release_sock(sk);
 105
 106         return err ?: copied;
 107 }
 108
 109 static ssize_t hash_sendpage(struct socket *sock, struct page *page,
 110                              int offset, size_t size, int flags)
 111 {
 112         struct sock *sk = sock->sk;
 113         struct alg_sock *ask = alg_sk(sk);
 114         struct hash_ctx *ctx = ask->private;
 115         int err;
 116
 117         lock_sock(sk);
 118         sg_init_table(ctx->sgl.sg, 1);
 119         sg_set_page(ctx->sgl.sg, page, size, offset);
 120
 121         ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
 122
 123         if (!(flags & MSG_MORE)) {
 124                 if (ctx->more)
 125                         err = crypto_ahash_finup(&ctx->req);
 126                 else
 127                         err = crypto_ahash_digest(&ctx->req);
 128         } else {
 129                 if (!ctx->more) {
 130                         err = crypto_ahash_init(&ctx->req);
 131                         if (err)
 132                                 goto unlock;
 133                 }
 134
 135                 err = crypto_ahash_update(&ctx->req);
 136         }
 137
 138         err = af_alg_wait_for_completion(err, &ctx->completion);
 139         if (err)
 140                 goto unlock;
 141
 142         ctx->more = flags & MSG_MORE;
 143
 144 unlock:
 145         release_sock(sk);
 146
 147         return err ?: size;
 148 }
 149
 150 static int hash_recvmsg(struct kiocb *unused, struct socket *sock,
 151                         struct msghdr *msg, size_t len, int flags)
 152 {
 153         struct sock *sk = sock->sk;
 154         struct alg_sock *ask = alg_sk(sk);
 155         struct hash_ctx *ctx = ask->private;
 156         unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
 157         int err;
 158
 159         if (len > ds)
 160                 len = ds;
 161         else if (len < ds)
 162                 msg->msg_flags |= MSG_TRUNC;
 163
 164         msg->msg_namelen = 0;
 165
 166         lock_sock(sk);
 167         if (ctx->more) {
 168                 ctx->more = 0;
 169                 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
 170                 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
 171                                                  &ctx->completion);
 172                 if (err)
 173                         goto unlock;
 174         }
 175
 176         err = memcpy_toiovec(msg->msg_iov, ctx->result, len);
 177
 178 unlock:
 179         release_sock(sk);
 180
 181         return err ?: len;
 182 }
 183
 184 static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
 185 {
 186         struct sock *sk = sock->sk;
 187         struct alg_sock *ask = alg_sk(sk);
 188         struct hash_ctx *ctx = ask->private;
 189         struct ahash_request *req = &ctx->req;
 190         char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))];
 191         struct sock *sk2;
 192         struct alg_sock *ask2;
 193         struct hash_ctx *ctx2;
 194         int err;
 195
 196         err = crypto_ahash_export(req, state);
 197         if (err)
 198                 return err;
 199
 200         err = af_alg_accept(ask->parent, newsock);
 201         if (err)
 202                 return err;
 203
 204         sk2 = newsock->sk;
 205         ask2 = alg_sk(sk2);
 206         ctx2 = ask2->private;
 207         ctx2->more = 1;
 208
 209         err = crypto_ahash_import(&ctx2->req, state);
 210         if (err) {
 211                 sock_orphan(sk2);
 212                 sock_put(sk2);
 213         }
 214
 215         return err;
 216 }
 217
 218 static struct proto_ops algif_hash_ops = {
 219         .family         =       PF_ALG,
 220
 221         .connect        =       sock_no_connect,
 222         .socketpair     =       sock_no_socketpair,
 223         .getname        =       sock_no_getname,
 224         .ioctl          =       sock_no_ioctl,
 225         .listen         =       sock_no_listen,
 226         .shutdown       =       sock_no_shutdown,
 227         .getsockopt     =       sock_no_getsockopt,
 228         .mmap           =       sock_no_mmap,
 229         .bind           =       sock_no_bind,
 230         .setsockopt     =       sock_no_setsockopt,
 231         .poll           =       sock_no_poll,
 232
 233         .release        =       af_alg_release,
 234         .sendmsg        =       hash_sendmsg,
 235         .sendpage       =       hash_sendpage,
 236         .recvmsg        =       hash_recvmsg,
 237         .accept         =       hash_accept,
 238 };
 239
 240 static void *hash_bind(const char *name, u32 type, u32 mask)
 241 {
 242         return crypto_alloc_ahash(name, type, mask);
 243 }
 244
 245 static void hash_release(void *private)
 246 {
 247         crypto_free_ahash(private);
 248 }
 249
 250 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
 251 {
 252         return crypto_ahash_setkey(private, key, keylen);
 253 }
 254
 255 static void hash_sock_destruct(struct sock *sk)
 256 {
 257         struct alg_sock *ask = alg_sk(sk);
 258         struct hash_ctx *ctx = ask->private;
 259
 260         sock_kfree_s(sk, ctx->result,
 261                      crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
 262         sock_kfree_s(sk, ctx, ctx->len);
 263         af_alg_release_parent(sk);
 264 }
 265
 266 static int hash_accept_parent(void *private, struct sock *sk)
 267 {
 268         struct hash_ctx *ctx;
 269         struct alg_sock *ask = alg_sk(sk);
 270         unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private);
 271         unsigned ds = crypto_ahash_digestsize(private);
 272
 273         ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 274         if (!ctx)
 275                 return -ENOMEM;
 276
 277         ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
 278         if (!ctx->result) {
 279                 sock_kfree_s(sk, ctx, len);
 280                 return -ENOMEM;
 281         }
 282
 283         memset(ctx->result, 0, ds);
 284
 285         ctx->len = len;
 286         ctx->more = 0;
 287         af_alg_init_completion(&ctx->completion);
 288
 289         ask->private = ctx;
 290
 291         ahash_request_set_tfm(&ctx->req, private);
 292         ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 293                                    af_alg_complete, &ctx->completion);
 294
 295         sk->sk_destruct = hash_sock_destruct;
 296
 297         return 0;
 298 }
 299
 300 static const struct af_alg_type algif_type_hash = {
 301         .bind           =       hash_bind,
 302         .release        =       hash_release,
 303         .setkey         =       hash_setkey,
 304         .accept         =       hash_accept_parent,
 305         .ops            =       &algif_hash_ops,
 306         .name           =       "hash",
 307         .owner          =       THIS_MODULE
 308 };
 309
 310 static int __init algif_hash_init(void)
 311 {
 312         return af_alg_register_type(&algif_type_hash);
 313 }
 314
 315 static void __exit algif_hash_exit(void)
 316 {
 317         int err = af_alg_unregister_type(&algif_type_hash);
 318         BUG_ON(err);
 319 }
 320
 321 module_init(algif_hash_init);
 322 module_exit(algif_hash_exit);
 323 MODULE_LICENSE("GPL");