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 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; 143 144 unlock: 145 release_sock(sk); 146 147 return err ?: size; 148 } 149 150 static 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 msg->msg_namelen = 0; 165 166 lock_sock(sk); 167 if (ctx->more) { 168 ctx->more = 0; 169 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); 170 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req), 171 &ctx->completion); 172 if (err) 173 goto unlock; 174 } 175 176 err = memcpy_toiovec(msg->msg_iov, ctx->result, len); 177 178 unlock: 179 release_sock(sk); 180 181 return err ?: len; 182 } 183 184 static int hash_accept(struct socket *sock, struct socket *newsock, int flags) 185 { 186 struct sock *sk = sock->sk; 187 struct alg_sock *ask = alg_sk(sk); 188 struct hash_ctx *ctx = ask->private; 189 struct ahash_request *req = &ctx->req; 190 char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))]; 191 struct sock *sk2; 192 struct alg_sock *ask2; 193 struct hash_ctx *ctx2; 194 int err; 195 196 err = crypto_ahash_export(req, state); 197 if (err) 198 return err; 199 200 err = af_alg_accept(ask->parent, newsock); 201 if (err) 202 return err; 203 204 sk2 = newsock->sk; 205 ask2 = alg_sk(sk2); 206 ctx2 = ask2->private; 207 ctx2->more = 1; 208 209 err = crypto_ahash_import(&ctx2->req, state); 210 if (err) { 211 sock_orphan(sk2); 212 sock_put(sk2); 213 } 214 215 return err; 216 } 217 218 static struct proto_ops algif_hash_ops = { 219 .family = PF_ALG, 220 221 .connect = sock_no_connect, 222 .socketpair = sock_no_socketpair, 223 .getname = sock_no_getname, 224 .ioctl = sock_no_ioctl, 225 .listen = sock_no_listen, 226 .shutdown = sock_no_shutdown, 227 .getsockopt = sock_no_getsockopt, 228 .mmap = sock_no_mmap, 229 .bind = sock_no_bind, 230 .setsockopt = sock_no_setsockopt, 231 .poll = sock_no_poll, 232 233 .release = af_alg_release, 234 .sendmsg = hash_sendmsg, 235 .sendpage = hash_sendpage, 236 .recvmsg = hash_recvmsg, 237 .accept = hash_accept, 238 }; 239 240 static void *hash_bind(const char *name, u32 type, u32 mask) 241 { 242 return crypto_alloc_ahash(name, type, mask); 243 } 244 245 static void hash_release(void *private) 246 { 247 crypto_free_ahash(private); 248 } 249 250 static int hash_setkey(void *private, const u8 *key, unsigned int keylen) 251 { 252 return crypto_ahash_setkey(private, key, keylen); 253 } 254 255 static void hash_sock_destruct(struct sock *sk) 256 { 257 struct alg_sock *ask = alg_sk(sk); 258 struct hash_ctx *ctx = ask->private; 259 260 sock_kfree_s(sk, ctx->result, 261 crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req))); 262 sock_kfree_s(sk, ctx, ctx->len); 263 af_alg_release_parent(sk); 264 } 265 266 static int hash_accept_parent(void *private, struct sock *sk) 267 { 268 struct hash_ctx *ctx; 269 struct alg_sock *ask = alg_sk(sk); 270 unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private); 271 unsigned ds = crypto_ahash_digestsize(private); 272 273 ctx = sock_kmalloc(sk, len, GFP_KERNEL); 274 if (!ctx) 275 return -ENOMEM; 276 277 ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL); 278 if (!ctx->result) { 279 sock_kfree_s(sk, ctx, len); 280 return -ENOMEM; 281 } 282 283 memset(ctx->result, 0, ds); 284 285 ctx->len = len; 286 ctx->more = 0; 287 af_alg_init_completion(&ctx->completion); 288 289 ask->private = ctx; 290 291 ahash_request_set_tfm(&ctx->req, private); 292 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG, 293 af_alg_complete, &ctx->completion); 294 295 sk->sk_destruct = hash_sock_destruct; 296 297 return 0; 298 } 299 300 static const struct af_alg_type algif_type_hash = { 301 .bind = hash_bind, 302 .release = hash_release, 303 .setkey = hash_setkey, 304 .accept = hash_accept_parent, 305 .ops = &algif_hash_ops, 306 .name = "hash", 307 .owner = THIS_MODULE 308 }; 309 310 static int __init algif_hash_init(void) 311 { 312 return af_alg_register_type(&algif_type_hash); 313 } 314 315 static void __exit algif_hash_exit(void) 316 { 317 int err = af_alg_unregister_type(&algif_type_hash); 318 BUG_ON(err); 319 } 320 321 module_init(algif_hash_init); 322 module_exit(algif_hash_exit); 323 MODULE_LICENSE("GPL"); 324