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/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/kmod.h>
21 #include <linux/param.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
26 LIST_HEAD(crypto_alg_list);
27 EXPORT_SYMBOL_GPL(crypto_alg_list);
28 DECLARE_RWSEM(crypto_alg_sem);
29 EXPORT_SYMBOL_GPL(crypto_alg_sem);
31 BLOCKING_NOTIFIER_HEAD(crypto_chain);
32 EXPORT_SYMBOL_GPL(crypto_chain);
34 static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
36 atomic_inc(&alg->cra_refcnt);
40 static inline void crypto_alg_put(struct crypto_alg *alg)
42 if (atomic_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)
43 alg->cra_destroy(alg);
46 struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
48 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
50 EXPORT_SYMBOL_GPL(crypto_mod_get);
52 void crypto_mod_put(struct crypto_alg *alg)
55 module_put(alg->cra_module);
57 EXPORT_SYMBOL_GPL(crypto_mod_put);
59 struct crypto_alg *__crypto_alg_lookup(const char *name)
61 struct crypto_alg *q, *alg = NULL;
64 list_for_each_entry(q, &crypto_alg_list, cra_list) {
67 exact = !strcmp(q->cra_driver_name, name);
68 fuzzy = !strcmp(q->cra_name, name);
69 if (!exact && !(fuzzy && q->cra_priority > best))
72 if (unlikely(!crypto_mod_get(q)))
75 best = q->cra_priority;
86 EXPORT_SYMBOL_GPL(__crypto_alg_lookup);
88 static void crypto_larval_destroy(struct crypto_alg *alg)
90 struct crypto_larval *larval = (void *)alg;
92 BUG_ON(!crypto_is_larval(alg));
94 crypto_mod_put(larval->adult);
98 static struct crypto_alg *crypto_larval_alloc(const char *name)
100 struct crypto_alg *alg;
101 struct crypto_larval *larval;
103 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
107 larval->alg.cra_flags = CRYPTO_ALG_LARVAL;
108 larval->alg.cra_priority = -1;
109 larval->alg.cra_destroy = crypto_larval_destroy;
111 atomic_set(&larval->alg.cra_refcnt, 2);
112 strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
113 init_completion(&larval->completion);
115 down_write(&crypto_alg_sem);
116 alg = __crypto_alg_lookup(name);
119 list_add(&alg->cra_list, &crypto_alg_list);
121 up_write(&crypto_alg_sem);
123 if (alg != &larval->alg)
129 static void crypto_larval_kill(struct crypto_alg *alg)
131 struct crypto_larval *larval = (void *)alg;
133 down_write(&crypto_alg_sem);
134 list_del(&alg->cra_list);
135 up_write(&crypto_alg_sem);
136 complete(&larval->completion);
140 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
142 struct crypto_larval *larval = (void *)alg;
144 wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
146 if (alg && !crypto_mod_get(alg))
148 crypto_mod_put(&larval->alg);
153 static struct crypto_alg *crypto_alg_lookup(const char *name)
155 struct crypto_alg *alg;
160 down_read(&crypto_alg_sem);
161 alg = __crypto_alg_lookup(name);
162 up_read(&crypto_alg_sem);
167 /* A far more intelligent version of this is planned. For now, just
168 * try an exact match on the name of the algorithm. */
169 static struct crypto_alg *crypto_alg_mod_lookup(const char *name)
171 struct crypto_alg *alg;
172 struct crypto_alg *larval;
174 alg = try_then_request_module(crypto_alg_lookup(name), name);
176 return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
178 larval = crypto_larval_alloc(name);
179 if (!larval || !crypto_is_larval(larval))
182 if (crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval) == NOTIFY_STOP)
183 alg = crypto_larval_wait(larval);
185 crypto_mod_put(larval);
188 crypto_larval_kill(larval);
192 static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
194 tfm->crt_flags = flags & CRYPTO_TFM_REQ_MASK;
195 flags &= ~CRYPTO_TFM_REQ_MASK;
197 switch (crypto_tfm_alg_type(tfm)) {
198 case CRYPTO_ALG_TYPE_CIPHER:
199 return crypto_init_cipher_flags(tfm, flags);
201 case CRYPTO_ALG_TYPE_DIGEST:
202 return crypto_init_digest_flags(tfm, flags);
204 case CRYPTO_ALG_TYPE_COMPRESS:
205 return crypto_init_compress_flags(tfm, flags);
215 static int crypto_init_ops(struct crypto_tfm *tfm)
217 switch (crypto_tfm_alg_type(tfm)) {
218 case CRYPTO_ALG_TYPE_CIPHER:
219 return crypto_init_cipher_ops(tfm);
221 case CRYPTO_ALG_TYPE_DIGEST:
222 return crypto_init_digest_ops(tfm);
224 case CRYPTO_ALG_TYPE_COMPRESS:
225 return crypto_init_compress_ops(tfm);
235 static void crypto_exit_ops(struct crypto_tfm *tfm)
237 switch (crypto_tfm_alg_type(tfm)) {
238 case CRYPTO_ALG_TYPE_CIPHER:
239 crypto_exit_cipher_ops(tfm);
242 case CRYPTO_ALG_TYPE_DIGEST:
243 crypto_exit_digest_ops(tfm);
246 case CRYPTO_ALG_TYPE_COMPRESS:
247 crypto_exit_compress_ops(tfm);
256 static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
260 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
264 case CRYPTO_ALG_TYPE_CIPHER:
265 len = crypto_cipher_ctxsize(alg, flags);
268 case CRYPTO_ALG_TYPE_DIGEST:
269 len = crypto_digest_ctxsize(alg, flags);
272 case CRYPTO_ALG_TYPE_COMPRESS:
273 len = crypto_compress_ctxsize(alg, flags);
277 return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
280 struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
282 struct crypto_tfm *tfm = NULL;
283 struct crypto_alg *alg;
284 unsigned int tfm_size;
286 alg = crypto_alg_mod_lookup(name);
290 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
291 tfm = kzalloc(tfm_size, GFP_KERNEL);
295 tfm->__crt_alg = alg;
297 if (crypto_init_flags(tfm, flags))
300 if (crypto_init_ops(tfm))
303 if (alg->cra_init && alg->cra_init(tfm))
304 goto cra_init_failed;
309 crypto_exit_ops(tfm);
319 void crypto_free_tfm(struct crypto_tfm *tfm)
321 struct crypto_alg *alg;
327 alg = tfm->__crt_alg;
328 size = sizeof(*tfm) + alg->cra_ctxsize;
332 crypto_exit_ops(tfm);
334 memset(tfm, 0, size);
338 int crypto_alg_available(const char *name, u32 flags)
341 struct crypto_alg *alg = crypto_alg_mod_lookup(name);
351 EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
352 EXPORT_SYMBOL_GPL(crypto_free_tfm);
353 EXPORT_SYMBOL_GPL(crypto_alg_available);