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"); 320