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 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); 175 176 unlock: 177 release_sock(sk); 178 179 return err ?: len; 180 } 181 182 static 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 } 215 216 static 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 }; 237 238 static void *hash_bind(const char *name, u32 type, u32 mask) 239 { 240 return crypto_alloc_ahash(name, type, mask); 241 } 242 243 static void hash_release(void *private) 244 { 245 crypto_free_ahash(private); 246 } 247 248 static int hash_setkey(void *private, const u8 *key, unsigned int keylen) 249 { 250 return crypto_ahash_setkey(private, key, keylen); 251 } 252 253 static 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 } 263 264 static 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 } 297 298 static 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 }; 307 308 static int __init algif_hash_init(void) 309 { 310 return af_alg_register_type(&algif_type_hash); 311 } 312 313 static void __exit algif_hash_exit(void) 314 { 315 int err = af_alg_unregister_type(&algif_type_hash); 316 BUG_ON(err); 317 } 318 319 module_init(algif_hash_init); 320 module_exit(algif_hash_exit); 321 MODULE_LICENSE("GPL"); 322