crypto/algapi.c

   1 /*
   2  * Cryptographic API for algorithms (i.e., low-level API).
   3  *
   4  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/init.h>
  15 #include <linux/kernel.h>
  16 #include <linux/list.h>
  17 #include <linux/module.h>
  18 #include <linux/string.h>
  19
  20 #include "internal.h"
  21
  22 static LIST_HEAD(crypto_template_list);
  23
  24 void crypto_larval_error(const char *name, u32 type, u32 mask)
  25 {
  26         struct crypto_alg *alg;
  27
  28         down_read(&crypto_alg_sem);
  29         alg = __crypto_alg_lookup(name, type, mask);
  30         up_read(&crypto_alg_sem);
  31
  32         if (alg) {
  33                 if (crypto_is_larval(alg)) {
  34                         struct crypto_larval *larval = (void *)alg;
  35                         complete(&larval->completion);
  36                 }
  37                 crypto_mod_put(alg);
  38         }
  39 }
  40 EXPORT_SYMBOL_GPL(crypto_larval_error);
  41
  42 static inline int crypto_set_driver_name(struct crypto_alg *alg)
  43 {
  44         static const char suffix[] = "-generic";
  45         char *driver_name = alg->cra_driver_name;
  46         int len;
  47
  48         if (*driver_name)
  49                 return 0;
  50
  51         len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
  52         if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
  53                 return -ENAMETOOLONG;
  54
  55         memcpy(driver_name + len, suffix, sizeof(suffix));
  56         return 0;
  57 }
  58
  59 static int crypto_check_alg(struct crypto_alg *alg)
  60 {
  61         if (alg->cra_alignmask & (alg->cra_alignmask + 1))
  62                 return -EINVAL;
  63
  64         if (alg->cra_alignmask & alg->cra_blocksize)
  65                 return -EINVAL;
  66
  67         if (alg->cra_blocksize > PAGE_SIZE / 8)
  68                 return -EINVAL;
  69
  70         if (alg->cra_priority < 0)
  71                 return -EINVAL;
  72
  73         return crypto_set_driver_name(alg);
  74 }
  75
  76 static int __crypto_register_alg(struct crypto_alg *alg)
  77 {
  78         struct crypto_alg *q;
  79         int ret = -EEXIST;
  80
  81         atomic_set(&alg->cra_refcnt, 1);
  82         list_for_each_entry(q, &crypto_alg_list, cra_list) {
  83                 if (q == alg)
  84                         goto out;
  85                 if (crypto_is_larval(q) &&
  86                     (!strcmp(alg->cra_name, q->cra_name) ||
  87                      !strcmp(alg->cra_driver_name, q->cra_name))) {
  88                         struct crypto_larval *larval = (void *)q;
  89
  90                         if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
  91                                 continue;
  92                         if (!crypto_mod_get(alg))
  93                                 continue;
  94                         larval->adult = alg;
  95                         complete(&larval->completion);
  96                 }
  97         }
  98
  99         list_add(&alg->cra_list, &crypto_alg_list);
 100
 101         crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
 102         ret = 0;
 103
 104 out:
 105         return ret;
 106 }
 107
 108 int crypto_register_alg(struct crypto_alg *alg)
 109 {
 110         int err;
 111
 112         err = crypto_check_alg(alg);
 113         if (err)
 114                 return err;
 115
 116         down_write(&crypto_alg_sem);
 117         err = __crypto_register_alg(alg);
 118         up_write(&crypto_alg_sem);
 119
 120         return err;
 121 }
 122 EXPORT_SYMBOL_GPL(crypto_register_alg);
 123
 124 int crypto_unregister_alg(struct crypto_alg *alg)
 125 {
 126         int ret = -ENOENT;
 127
 128         down_write(&crypto_alg_sem);
 129         if (likely(!list_empty(&alg->cra_list))) {
 130                 list_del_init(&alg->cra_list);
 131                 ret = 0;
 132         }
 133         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
 134         up_write(&crypto_alg_sem);
 135
 136         if (ret)
 137                 return ret;
 138
 139         BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
 140         if (alg->cra_destroy)
 141                 alg->cra_destroy(alg);
 142
 143         return 0;
 144 }
 145 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 146
 147 int crypto_register_template(struct crypto_template *tmpl)
 148 {
 149         struct crypto_template *q;
 150         int err = -EEXIST;
 151
 152         down_write(&crypto_alg_sem);
 153
 154         list_for_each_entry(q, &crypto_template_list, list) {
 155                 if (q == tmpl)
 156                         goto out;
 157         }
 158
 159         list_add(&tmpl->list, &crypto_template_list);
 160         crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
 161         err = 0;
 162 out:
 163         up_write(&crypto_alg_sem);
 164         return err;
 165 }
 166 EXPORT_SYMBOL_GPL(crypto_register_template);
 167
 168 void crypto_unregister_template(struct crypto_template *tmpl)
 169 {
 170         struct crypto_instance *inst;
 171         struct hlist_node *p, *n;
 172         struct hlist_head *list;
 173
 174         down_write(&crypto_alg_sem);
 175
 176         BUG_ON(list_empty(&tmpl->list));
 177         list_del_init(&tmpl->list);
 178
 179         list = &tmpl->instances;
 180         hlist_for_each_entry(inst, p, list, list) {
 181                 BUG_ON(list_empty(&inst->alg.cra_list));
 182                 list_del_init(&inst->alg.cra_list);
 183                 crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
 184         }
 185
 186         crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
 187
 188         up_write(&crypto_alg_sem);
 189
 190         hlist_for_each_entry_safe(inst, p, n, list, list) {
 191                 BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
 192                 tmpl->free(inst);
 193         }
 194 }
 195 EXPORT_SYMBOL_GPL(crypto_unregister_template);
 196
 197 static struct crypto_template *__crypto_lookup_template(const char *name)
 198 {
 199         struct crypto_template *q, *tmpl = NULL;
 200
 201         down_read(&crypto_alg_sem);
 202         list_for_each_entry(q, &crypto_template_list, list) {
 203                 if (strcmp(q->name, name))
 204                         continue;
 205                 if (unlikely(!crypto_tmpl_get(q)))
 206                         continue;
 207
 208                 tmpl = q;
 209                 break;
 210         }
 211         up_read(&crypto_alg_sem);
 212
 213         return tmpl;
 214 }
 215
 216 struct crypto_template *crypto_lookup_template(const char *name)
 217 {
 218         return try_then_request_module(__crypto_lookup_template(name), name);
 219 }
 220 EXPORT_SYMBOL_GPL(crypto_lookup_template);
 221
 222 int crypto_register_instance(struct crypto_template *tmpl,
 223                              struct crypto_instance *inst)
 224 {
 225         int err = -EINVAL;
 226
 227         if (inst->alg.cra_destroy)
 228                 goto err;
 229
 230         err = crypto_check_alg(&inst->alg);
 231         if (err)
 232                 goto err;
 233
 234         inst->alg.cra_module = tmpl->module;
 235
 236         down_write(&crypto_alg_sem);
 237
 238         err = __crypto_register_alg(&inst->alg);
 239         if (err)
 240                 goto unlock;
 241
 242         hlist_add_head(&inst->list, &tmpl->instances);
 243         inst->tmpl = tmpl;
 244
 245 unlock:
 246         up_write(&crypto_alg_sem);
 247
 248 err:
 249         return err;
 250 }
 251 EXPORT_SYMBOL_GPL(crypto_register_instance);
 252
 253 int crypto_register_notifier(struct notifier_block *nb)
 254 {
 255         return blocking_notifier_chain_register(&crypto_chain, nb);
 256 }
 257 EXPORT_SYMBOL_GPL(crypto_register_notifier);
 258
 259 int crypto_unregister_notifier(struct notifier_block *nb)
 260 {
 261         return blocking_notifier_chain_unregister(&crypto_chain, nb);
 262 }
 263 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
 264
 265 static int __init crypto_algapi_init(void)
 266 {
 267         crypto_init_proc();
 268         return 0;
 269 }
 270
 271 static void __exit crypto_algapi_exit(void)
 272 {
 273         crypto_exit_proc();
 274 }
 275
 276 module_init(crypto_algapi_init);
 277 module_exit(crypto_algapi_exit);
 278
 279 MODULE_LICENSE("GPL");
 280 MODULE_DESCRIPTION("Cryptographic algorithms API");