2 * Scatterlist Cryptographic API.
4 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
5 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
6 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
8 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
9 * and Nettle, by Niels Möller.
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the Free
13 * Software Foundation; either version 2 of the License, or (at your option)
18 #include <linux/err.h>
19 #include <linux/errno.h>
20 #include <linux/kernel.h>
21 #include <linux/kmod.h>
22 #include <linux/module.h>
23 #include <linux/param.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/string.h>
29 LIST_HEAD(crypto_alg_list
);
30 EXPORT_SYMBOL_GPL(crypto_alg_list
);
31 DECLARE_RWSEM(crypto_alg_sem
);
32 EXPORT_SYMBOL_GPL(crypto_alg_sem
);
34 BLOCKING_NOTIFIER_HEAD(crypto_chain
);
35 EXPORT_SYMBOL_GPL(crypto_chain
);
37 static inline struct crypto_alg
*crypto_alg_get(struct crypto_alg
*alg
)
39 atomic_inc(&alg
->cra_refcnt
);
43 struct crypto_alg
*crypto_mod_get(struct crypto_alg
*alg
)
45 return try_module_get(alg
->cra_module
) ? crypto_alg_get(alg
) : NULL
;
47 EXPORT_SYMBOL_GPL(crypto_mod_get
);
49 void crypto_mod_put(struct crypto_alg
*alg
)
52 module_put(alg
->cra_module
);
54 EXPORT_SYMBOL_GPL(crypto_mod_put
);
56 struct crypto_alg
*__crypto_alg_lookup(const char *name
, u32 type
, u32 mask
)
58 struct crypto_alg
*q
, *alg
= NULL
;
61 list_for_each_entry(q
, &crypto_alg_list
, cra_list
) {
64 if (crypto_is_moribund(q
))
67 if ((q
->cra_flags
^ type
) & mask
)
70 if (crypto_is_larval(q
) &&
71 ((struct crypto_larval
*)q
)->mask
!= mask
)
74 exact
= !strcmp(q
->cra_driver_name
, name
);
75 fuzzy
= !strcmp(q
->cra_name
, name
);
76 if (!exact
&& !(fuzzy
&& q
->cra_priority
> best
))
79 if (unlikely(!crypto_mod_get(q
)))
82 best
= q
->cra_priority
;
93 EXPORT_SYMBOL_GPL(__crypto_alg_lookup
);
95 static void crypto_larval_destroy(struct crypto_alg
*alg
)
97 struct crypto_larval
*larval
= (void *)alg
;
99 BUG_ON(!crypto_is_larval(alg
));
101 crypto_mod_put(larval
->adult
);
105 static struct crypto_alg
*crypto_larval_alloc(const char *name
, u32 type
,
108 struct crypto_alg
*alg
;
109 struct crypto_larval
*larval
;
111 larval
= kzalloc(sizeof(*larval
), GFP_KERNEL
);
113 return ERR_PTR(-ENOMEM
);
116 larval
->alg
.cra_flags
= CRYPTO_ALG_LARVAL
| type
;
117 larval
->alg
.cra_priority
= -1;
118 larval
->alg
.cra_destroy
= crypto_larval_destroy
;
120 atomic_set(&larval
->alg
.cra_refcnt
, 2);
121 strlcpy(larval
->alg
.cra_name
, name
, CRYPTO_MAX_ALG_NAME
);
122 init_completion(&larval
->completion
);
124 down_write(&crypto_alg_sem
);
125 alg
= __crypto_alg_lookup(name
, type
, mask
);
128 list_add(&alg
->cra_list
, &crypto_alg_list
);
130 up_write(&crypto_alg_sem
);
132 if (alg
!= &larval
->alg
)
138 static void crypto_larval_kill(struct crypto_alg
*alg
)
140 struct crypto_larval
*larval
= (void *)alg
;
142 down_write(&crypto_alg_sem
);
143 list_del(&alg
->cra_list
);
144 up_write(&crypto_alg_sem
);
145 complete(&larval
->completion
);
149 static struct crypto_alg
*crypto_larval_wait(struct crypto_alg
*alg
)
151 struct crypto_larval
*larval
= (void *)alg
;
153 wait_for_completion_interruptible_timeout(&larval
->completion
, 60 * HZ
);
156 if (!crypto_mod_get(alg
))
157 alg
= ERR_PTR(-EAGAIN
);
159 alg
= ERR_PTR(-ENOENT
);
160 crypto_mod_put(&larval
->alg
);
165 static struct crypto_alg
*crypto_alg_lookup(const char *name
, u32 type
,
168 struct crypto_alg
*alg
;
170 down_read(&crypto_alg_sem
);
171 alg
= __crypto_alg_lookup(name
, type
, mask
);
172 up_read(&crypto_alg_sem
);
177 struct crypto_alg
*crypto_alg_mod_lookup(const char *name
, u32 type
, u32 mask
)
179 struct crypto_alg
*alg
;
180 struct crypto_alg
*larval
;
184 return ERR_PTR(-ENOENT
);
186 mask
&= ~(CRYPTO_ALG_LARVAL
| CRYPTO_ALG_DEAD
);
189 alg
= try_then_request_module(crypto_alg_lookup(name
, type
, mask
),
192 return crypto_is_larval(alg
) ? crypto_larval_wait(alg
) : alg
;
194 larval
= crypto_larval_alloc(name
, type
, mask
);
195 if (IS_ERR(larval
) || !crypto_is_larval(larval
))
198 ok
= crypto_notify(CRYPTO_MSG_ALG_REQUEST
, larval
);
199 if (ok
== NOTIFY_DONE
) {
200 request_module("cryptomgr");
201 ok
= crypto_notify(CRYPTO_MSG_ALG_REQUEST
, larval
);
204 if (ok
== NOTIFY_STOP
)
205 alg
= crypto_larval_wait(larval
);
207 crypto_mod_put(larval
);
208 alg
= ERR_PTR(-ENOENT
);
210 crypto_larval_kill(larval
);
213 EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup
);
215 static int crypto_init_ops(struct crypto_tfm
*tfm
, u32 type
, u32 mask
)
217 const struct crypto_type
*type_obj
= tfm
->__crt_alg
->cra_type
;
220 return type_obj
->init(tfm
, type
, mask
);
222 switch (crypto_tfm_alg_type(tfm
)) {
223 case CRYPTO_ALG_TYPE_CIPHER
:
224 return crypto_init_cipher_ops(tfm
);
226 case CRYPTO_ALG_TYPE_DIGEST
:
227 return crypto_init_digest_ops(tfm
);
229 case CRYPTO_ALG_TYPE_COMPRESS
:
230 return crypto_init_compress_ops(tfm
);
240 static void crypto_exit_ops(struct crypto_tfm
*tfm
)
242 const struct crypto_type
*type
= tfm
->__crt_alg
->cra_type
;
250 switch (crypto_tfm_alg_type(tfm
)) {
251 case CRYPTO_ALG_TYPE_CIPHER
:
252 crypto_exit_cipher_ops(tfm
);
255 case CRYPTO_ALG_TYPE_DIGEST
:
256 crypto_exit_digest_ops(tfm
);
259 case CRYPTO_ALG_TYPE_COMPRESS
:
260 crypto_exit_compress_ops(tfm
);
269 static unsigned int crypto_ctxsize(struct crypto_alg
*alg
, u32 type
, u32 mask
)
271 const struct crypto_type
*type_obj
= alg
->cra_type
;
274 len
= alg
->cra_alignmask
& ~(crypto_tfm_ctx_alignment() - 1);
276 return len
+ type_obj
->ctxsize(alg
, type
, mask
);
278 switch (alg
->cra_flags
& CRYPTO_ALG_TYPE_MASK
) {
282 case CRYPTO_ALG_TYPE_CIPHER
:
283 len
+= crypto_cipher_ctxsize(alg
);
286 case CRYPTO_ALG_TYPE_DIGEST
:
287 len
+= crypto_digest_ctxsize(alg
);
290 case CRYPTO_ALG_TYPE_COMPRESS
:
291 len
+= crypto_compress_ctxsize(alg
);
298 void crypto_shoot_alg(struct crypto_alg
*alg
)
300 down_write(&crypto_alg_sem
);
301 alg
->cra_flags
|= CRYPTO_ALG_DYING
;
302 up_write(&crypto_alg_sem
);
304 EXPORT_SYMBOL_GPL(crypto_shoot_alg
);
306 struct crypto_tfm
*__crypto_alloc_tfm(struct crypto_alg
*alg
, u32 type
,
309 struct crypto_tfm
*tfm
= NULL
;
310 unsigned int tfm_size
;
313 tfm_size
= sizeof(*tfm
) + crypto_ctxsize(alg
, type
, mask
);
314 tfm
= kzalloc(tfm_size
, GFP_KERNEL
);
318 tfm
->__crt_alg
= alg
;
320 err
= crypto_init_ops(tfm
, type
, mask
);
324 if (alg
->cra_init
&& (err
= alg
->cra_init(tfm
))) {
326 crypto_shoot_alg(alg
);
327 goto cra_init_failed
;
333 crypto_exit_ops(tfm
);
341 EXPORT_SYMBOL_GPL(__crypto_alloc_tfm
);
344 * crypto_alloc_base - Locate algorithm and allocate transform
345 * @alg_name: Name of algorithm
346 * @type: Type of algorithm
347 * @mask: Mask for type comparison
349 * crypto_alloc_base() will first attempt to locate an already loaded
350 * algorithm. If that fails and the kernel supports dynamically loadable
351 * modules, it will then attempt to load a module of the same name or
352 * alias. If that fails it will send a query to any loaded crypto manager
353 * to construct an algorithm on the fly. A refcount is grabbed on the
354 * algorithm which is then associated with the new transform.
356 * The returned transform is of a non-determinate type. Most people
357 * should use one of the more specific allocation functions such as
358 * crypto_alloc_blkcipher.
360 * In case of error the return value is an error pointer.
362 struct crypto_tfm
*crypto_alloc_base(const char *alg_name
, u32 type
, u32 mask
)
364 struct crypto_tfm
*tfm
;
368 struct crypto_alg
*alg
;
370 alg
= crypto_alg_mod_lookup(alg_name
, type
, mask
);
376 tfm
= __crypto_alloc_tfm(alg
, type
, mask
);
386 if (signal_pending(current
)) {
394 EXPORT_SYMBOL_GPL(crypto_alloc_base
);
397 * crypto_free_tfm - Free crypto transform
398 * @tfm: Transform to free
400 * crypto_free_tfm() frees up the transform and any associated resources,
401 * then drops the refcount on the associated algorithm.
403 void crypto_free_tfm(struct crypto_tfm
*tfm
)
405 struct crypto_alg
*alg
;
411 alg
= tfm
->__crt_alg
;
412 size
= sizeof(*tfm
) + alg
->cra_ctxsize
;
416 crypto_exit_ops(tfm
);
418 memset(tfm
, 0, size
);
422 EXPORT_SYMBOL_GPL(crypto_free_tfm
);
424 int crypto_has_alg(const char *name
, u32 type
, u32 mask
)
427 struct crypto_alg
*alg
= crypto_alg_mod_lookup(name
, type
, mask
);
436 EXPORT_SYMBOL_GPL(crypto_has_alg
);
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