linux/crypto/algif_hash.c
<<
>>
Prefs
   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
  24struct 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
  37static 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
 103unlock:
 104        release_sock(sk);
 105
 106        return err ?: copied;
 107}
 108
 109static 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
 144unlock:
 145        release_sock(sk);
 146
 147        return err ?: size;
 148}
 149
 150static 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        lock_sock(sk);
 165        if (ctx->more) {
 166                ctx->more = 0;
 167                ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
 168                err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
 169                                                 &ctx->completion);
 170                if (err)
 171                        goto unlock;
 172        }
 173
 174        err = memcpy_toiovec(msg->msg_iov, ctx->result, len);
 175
 176unlock:
 177        release_sock(sk);
 178
 179        return err ?: len;
 180}
 181
 182static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
 183{
 184        struct sock *sk = sock->sk;
 185        struct alg_sock *ask = alg_sk(sk);
 186        struct hash_ctx *ctx = ask->private;
 187        struct ahash_request *req = &ctx->req;
 188        char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))];
 189        struct sock *sk2;
 190        struct alg_sock *ask2;
 191        struct hash_ctx *ctx2;
 192        int err;
 193
 194        err = crypto_ahash_export(req, state);
 195        if (err)
 196                return err;
 197
 198        err = af_alg_accept(ask->parent, newsock);
 199        if (err)
 200                return err;
 201
 202        sk2 = newsock->sk;
 203        ask2 = alg_sk(sk2);
 204        ctx2 = ask2->private;
 205        ctx2->more = 1;
 206
 207        err = crypto_ahash_import(&ctx2->req, state);
 208        if (err) {
 209                sock_orphan(sk2);
 210                sock_put(sk2);
 211        }
 212
 213        return err;
 214}
 215
 216static struct proto_ops algif_hash_ops = {
 217        .family         =       PF_ALG,
 218
 219        .connect        =       sock_no_connect,
 220        .socketpair     =       sock_no_socketpair,
 221        .getname        =       sock_no_getname,
 222        .ioctl          =       sock_no_ioctl,
 223        .listen         =       sock_no_listen,
 224        .shutdown       =       sock_no_shutdown,
 225        .getsockopt     =       sock_no_getsockopt,
 226        .mmap           =       sock_no_mmap,
 227        .bind           =       sock_no_bind,
 228        .setsockopt     =       sock_no_setsockopt,
 229        .poll           =       sock_no_poll,
 230
 231        .release        =       af_alg_release,
 232        .sendmsg        =       hash_sendmsg,
 233        .sendpage       =       hash_sendpage,
 234        .recvmsg        =       hash_recvmsg,
 235        .accept         =       hash_accept,
 236};
 237
 238static void *hash_bind(const char *name, u32 type, u32 mask)
 239{
 240        return crypto_alloc_ahash(name, type, mask);
 241}
 242
 243static void hash_release(void *private)
 244{
 245        crypto_free_ahash(private);
 246}
 247
 248static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
 249{
 250        return crypto_ahash_setkey(private, key, keylen);
 251}
 252
 253static void hash_sock_destruct(struct sock *sk)
 254{
 255        struct alg_sock *ask = alg_sk(sk);
 256        struct hash_ctx *ctx = ask->private;
 257
 258        sock_kfree_s(sk, ctx->result,
 259                     crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
 260        sock_kfree_s(sk, ctx, ctx->len);
 261        af_alg_release_parent(sk);
 262}
 263
 264static int hash_accept_parent(void *private, struct sock *sk)
 265{
 266        struct hash_ctx *ctx;
 267        struct alg_sock *ask = alg_sk(sk);
 268        unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private);
 269        unsigned ds = crypto_ahash_digestsize(private);
 270
 271        ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 272        if (!ctx)
 273                return -ENOMEM;
 274
 275        ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
 276        if (!ctx->result) {
 277                sock_kfree_s(sk, ctx, len);
 278                return -ENOMEM;
 279        }
 280
 281        memset(ctx->result, 0, ds);
 282
 283        ctx->len = len;
 284        ctx->more = 0;
 285        af_alg_init_completion(&ctx->completion);
 286
 287        ask->private = ctx;
 288
 289        ahash_request_set_tfm(&ctx->req, private);
 290        ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 291                                   af_alg_complete, &ctx->completion);
 292
 293        sk->sk_destruct = hash_sock_destruct;
 294
 295        return 0;
 296}
 297
 298static const struct af_alg_type algif_type_hash = {
 299        .bind           =       hash_bind,
 300        .release        =       hash_release,
 301        .setkey         =       hash_setkey,
 302        .accept         =       hash_accept_parent,
 303        .ops            =       &algif_hash_ops,
 304        .name           =       "hash",
 305        .owner          =       THIS_MODULE
 306};
 307
 308static int __init algif_hash_init(void)
 309{
 310        return af_alg_register_type(&algif_type_hash);
 311}
 312
 313static void __exit algif_hash_exit(void)
 314{
 315        int err = af_alg_unregister_type(&algif_type_hash);
 316        BUG_ON(err);
 317}
 318
 319module_init(algif_hash_init);
 320module_exit(algif_hash_exit);
 321MODULE_LICENSE("GPL");
 322
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.