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