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"); 325