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