ACPI: thinkpad-acpi: update information on T43 thermal sensor 0xc1
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / crypto / api.c
blob005d874462a612d3d1bb76467923c8e3165ff2bd
1 /*
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)
14 * any later version.
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>
27 #include "internal.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);
40 return alg;
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)
51 struct module *module = alg->cra_module;
53 crypto_alg_put(alg);
54 module_put(module);
56 EXPORT_SYMBOL_GPL(crypto_mod_put);
58 struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, u32 mask)
60 struct crypto_alg *q, *alg = NULL;
61 int best = -2;
63 list_for_each_entry(q, &crypto_alg_list, cra_list) {
64 int exact, fuzzy;
66 if (crypto_is_moribund(q))
67 continue;
69 if ((q->cra_flags ^ type) & mask)
70 continue;
72 if (crypto_is_larval(q) &&
73 ((struct crypto_larval *)q)->mask != mask)
74 continue;
76 exact = !strcmp(q->cra_driver_name, name);
77 fuzzy = !strcmp(q->cra_name, name);
78 if (!exact && !(fuzzy && q->cra_priority > best))
79 continue;
81 if (unlikely(!crypto_mod_get(q)))
82 continue;
84 best = q->cra_priority;
85 if (alg)
86 crypto_mod_put(alg);
87 alg = q;
89 if (exact)
90 break;
93 return alg;
95 EXPORT_SYMBOL_GPL(__crypto_alg_lookup);
97 static void crypto_larval_destroy(struct crypto_alg *alg)
99 struct crypto_larval *larval = (void *)alg;
101 BUG_ON(!crypto_is_larval(alg));
102 if (larval->adult)
103 crypto_mod_put(larval->adult);
104 kfree(larval);
107 static struct crypto_alg *crypto_larval_alloc(const char *name, u32 type,
108 u32 mask)
110 struct crypto_alg *alg;
111 struct crypto_larval *larval;
113 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
114 if (!larval)
115 return ERR_PTR(-ENOMEM);
117 larval->mask = mask;
118 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
119 larval->alg.cra_priority = -1;
120 larval->alg.cra_destroy = crypto_larval_destroy;
122 atomic_set(&larval->alg.cra_refcnt, 2);
123 strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
124 init_completion(&larval->completion);
126 down_write(&crypto_alg_sem);
127 alg = __crypto_alg_lookup(name, type, mask);
128 if (!alg) {
129 alg = &larval->alg;
130 list_add(&alg->cra_list, &crypto_alg_list);
132 up_write(&crypto_alg_sem);
134 if (alg != &larval->alg)
135 kfree(larval);
137 return alg;
140 static void crypto_larval_kill(struct crypto_alg *alg)
142 struct crypto_larval *larval = (void *)alg;
144 down_write(&crypto_alg_sem);
145 list_del(&alg->cra_list);
146 up_write(&crypto_alg_sem);
147 complete(&larval->completion);
148 crypto_alg_put(alg);
151 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
153 struct crypto_larval *larval = (void *)alg;
155 wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
156 alg = larval->adult;
157 if (alg) {
158 if (!crypto_mod_get(alg))
159 alg = ERR_PTR(-EAGAIN);
160 } else
161 alg = ERR_PTR(-ENOENT);
162 crypto_mod_put(&larval->alg);
164 return alg;
167 static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
168 u32 mask)
170 struct crypto_alg *alg;
172 down_read(&crypto_alg_sem);
173 alg = __crypto_alg_lookup(name, type, mask);
174 up_read(&crypto_alg_sem);
176 return alg;
179 struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
181 struct crypto_alg *alg;
182 struct crypto_alg *larval;
183 int ok;
185 if (!name)
186 return ERR_PTR(-ENOENT);
188 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
189 type &= mask;
191 alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
192 name);
193 if (alg)
194 return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
196 larval = crypto_larval_alloc(name, type, mask);
197 if (IS_ERR(larval) || !crypto_is_larval(larval))
198 return larval;
200 ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
201 if (ok == NOTIFY_DONE) {
202 request_module("cryptomgr");
203 ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
206 if (ok == NOTIFY_STOP)
207 alg = crypto_larval_wait(larval);
208 else {
209 crypto_mod_put(larval);
210 alg = ERR_PTR(-ENOENT);
212 crypto_larval_kill(larval);
213 return alg;
215 EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
217 static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
219 tfm->crt_flags = flags & CRYPTO_TFM_REQ_MASK;
220 flags &= ~CRYPTO_TFM_REQ_MASK;
222 switch (crypto_tfm_alg_type(tfm)) {
223 case CRYPTO_ALG_TYPE_CIPHER:
224 return crypto_init_cipher_flags(tfm, flags);
226 case CRYPTO_ALG_TYPE_DIGEST:
227 return crypto_init_digest_flags(tfm, flags);
229 case CRYPTO_ALG_TYPE_COMPRESS:
230 return crypto_init_compress_flags(tfm, flags);
233 return 0;
236 static int crypto_init_ops(struct crypto_tfm *tfm)
238 const struct crypto_type *type = tfm->__crt_alg->cra_type;
240 if (type)
241 return type->init(tfm);
243 switch (crypto_tfm_alg_type(tfm)) {
244 case CRYPTO_ALG_TYPE_CIPHER:
245 return crypto_init_cipher_ops(tfm);
247 case CRYPTO_ALG_TYPE_DIGEST:
248 return crypto_init_digest_ops(tfm);
250 case CRYPTO_ALG_TYPE_COMPRESS:
251 return crypto_init_compress_ops(tfm);
253 default:
254 break;
257 BUG();
258 return -EINVAL;
261 static void crypto_exit_ops(struct crypto_tfm *tfm)
263 const struct crypto_type *type = tfm->__crt_alg->cra_type;
265 if (type) {
266 if (type->exit)
267 type->exit(tfm);
268 return;
271 switch (crypto_tfm_alg_type(tfm)) {
272 case CRYPTO_ALG_TYPE_CIPHER:
273 crypto_exit_cipher_ops(tfm);
274 break;
276 case CRYPTO_ALG_TYPE_DIGEST:
277 crypto_exit_digest_ops(tfm);
278 break;
280 case CRYPTO_ALG_TYPE_COMPRESS:
281 crypto_exit_compress_ops(tfm);
282 break;
284 default:
285 BUG();
290 static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
292 const struct crypto_type *type = alg->cra_type;
293 unsigned int len;
295 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
296 if (type)
297 return len + type->ctxsize(alg);
299 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
300 default:
301 BUG();
303 case CRYPTO_ALG_TYPE_CIPHER:
304 len += crypto_cipher_ctxsize(alg, flags);
305 break;
307 case CRYPTO_ALG_TYPE_DIGEST:
308 len += crypto_digest_ctxsize(alg, flags);
309 break;
311 case CRYPTO_ALG_TYPE_COMPRESS:
312 len += crypto_compress_ctxsize(alg, flags);
313 break;
316 return len;
319 void crypto_shoot_alg(struct crypto_alg *alg)
321 down_write(&crypto_alg_sem);
322 alg->cra_flags |= CRYPTO_ALG_DYING;
323 up_write(&crypto_alg_sem);
325 EXPORT_SYMBOL_GPL(crypto_shoot_alg);
327 struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 flags)
329 struct crypto_tfm *tfm = NULL;
330 unsigned int tfm_size;
331 int err = -ENOMEM;
333 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
334 tfm = kzalloc(tfm_size, GFP_KERNEL);
335 if (tfm == NULL)
336 goto out_err;
338 tfm->__crt_alg = alg;
340 err = crypto_init_flags(tfm, flags);
341 if (err)
342 goto out_free_tfm;
344 err = crypto_init_ops(tfm);
345 if (err)
346 goto out_free_tfm;
348 if (alg->cra_init && (err = alg->cra_init(tfm))) {
349 if (err == -EAGAIN)
350 crypto_shoot_alg(alg);
351 goto cra_init_failed;
354 goto out;
356 cra_init_failed:
357 crypto_exit_ops(tfm);
358 out_free_tfm:
359 kfree(tfm);
360 out_err:
361 tfm = ERR_PTR(err);
362 out:
363 return tfm;
365 EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
367 struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
369 struct crypto_tfm *tfm = NULL;
370 int err;
372 do {
373 struct crypto_alg *alg;
375 alg = crypto_alg_mod_lookup(name, 0, CRYPTO_ALG_ASYNC);
376 err = PTR_ERR(alg);
377 if (IS_ERR(alg))
378 continue;
380 tfm = __crypto_alloc_tfm(alg, flags);
381 err = 0;
382 if (IS_ERR(tfm)) {
383 crypto_mod_put(alg);
384 err = PTR_ERR(tfm);
385 tfm = NULL;
387 } while (err == -EAGAIN && !signal_pending(current));
389 return tfm;
393 * crypto_alloc_base - Locate algorithm and allocate transform
394 * @alg_name: Name of algorithm
395 * @type: Type of algorithm
396 * @mask: Mask for type comparison
398 * crypto_alloc_base() will first attempt to locate an already loaded
399 * algorithm. If that fails and the kernel supports dynamically loadable
400 * modules, it will then attempt to load a module of the same name or
401 * alias. If that fails it will send a query to any loaded crypto manager
402 * to construct an algorithm on the fly. A refcount is grabbed on the
403 * algorithm which is then associated with the new transform.
405 * The returned transform is of a non-determinate type. Most people
406 * should use one of the more specific allocation functions such as
407 * crypto_alloc_blkcipher.
409 * In case of error the return value is an error pointer.
411 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
413 struct crypto_tfm *tfm;
414 int err;
416 for (;;) {
417 struct crypto_alg *alg;
419 alg = crypto_alg_mod_lookup(alg_name, type, mask);
420 if (IS_ERR(alg)) {
421 err = PTR_ERR(alg);
422 goto err;
425 tfm = __crypto_alloc_tfm(alg, 0);
426 if (!IS_ERR(tfm))
427 return tfm;
429 crypto_mod_put(alg);
430 err = PTR_ERR(tfm);
432 err:
433 if (err != -EAGAIN)
434 break;
435 if (signal_pending(current)) {
436 err = -EINTR;
437 break;
441 return ERR_PTR(err);
443 EXPORT_SYMBOL_GPL(crypto_alloc_base);
446 * crypto_free_tfm - Free crypto transform
447 * @tfm: Transform to free
449 * crypto_free_tfm() frees up the transform and any associated resources,
450 * then drops the refcount on the associated algorithm.
452 void crypto_free_tfm(struct crypto_tfm *tfm)
454 struct crypto_alg *alg;
455 int size;
457 if (unlikely(!tfm))
458 return;
460 alg = tfm->__crt_alg;
461 size = sizeof(*tfm) + alg->cra_ctxsize;
463 if (alg->cra_exit)
464 alg->cra_exit(tfm);
465 crypto_exit_ops(tfm);
466 crypto_mod_put(alg);
467 memset(tfm, 0, size);
468 kfree(tfm);
471 EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
472 EXPORT_SYMBOL_GPL(crypto_free_tfm);
474 int crypto_has_alg(const char *name, u32 type, u32 mask)
476 int ret = 0;
477 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
479 if (!IS_ERR(alg)) {
480 crypto_mod_put(alg);
481 ret = 1;
484 return ret;
486 EXPORT_SYMBOL_GPL(crypto_has_alg);