2 * Scatterlist Cryptographic API.
4 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
5 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
7 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
8 * and Nettle, by Niels Möller.
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the Free
12 * Software Foundation; either version 2 of the License, or (at your option)
16 #include <linux/init.h>
17 #include <linux/crypto.h>
18 #include <linux/errno.h>
19 #include <linux/kmod.h>
20 #include <linux/rwsem.h>
21 #include <linux/slab.h>
24 LIST_HEAD(crypto_alg_list);
25 DECLARE_RWSEM(crypto_alg_sem);
27 static inline int crypto_alg_get(struct crypto_alg *alg)
29 return try_module_get(alg->cra_module);
32 static inline void crypto_alg_put(struct crypto_alg *alg)
34 module_put(alg->cra_module);
37 static struct crypto_alg *crypto_alg_lookup(const char *name)
39 struct crypto_alg *q, *alg = NULL;
44 down_read(&crypto_alg_sem);
46 list_for_each_entry(q, &crypto_alg_list, cra_list) {
47 if (!(strcmp(q->cra_name, name))) {
48 if (crypto_alg_get(q))
54 up_read(&crypto_alg_sem);
58 /* A far more intelligent version of this is planned. For now, just
59 * try an exact match on the name of the algorithm. */
60 static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name)
62 return try_then_request_module(crypto_alg_lookup(name), name);
65 static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
69 switch (crypto_tfm_alg_type(tfm)) {
70 case CRYPTO_ALG_TYPE_CIPHER:
71 return crypto_init_cipher_flags(tfm, flags);
73 case CRYPTO_ALG_TYPE_DIGEST:
74 return crypto_init_digest_flags(tfm, flags);
76 case CRYPTO_ALG_TYPE_COMPRESS:
77 return crypto_init_compress_flags(tfm, flags);
87 static int crypto_init_ops(struct crypto_tfm *tfm)
89 switch (crypto_tfm_alg_type(tfm)) {
90 case CRYPTO_ALG_TYPE_CIPHER:
91 return crypto_init_cipher_ops(tfm);
93 case CRYPTO_ALG_TYPE_DIGEST:
94 return crypto_init_digest_ops(tfm);
96 case CRYPTO_ALG_TYPE_COMPRESS:
97 return crypto_init_compress_ops(tfm);
107 static void crypto_exit_ops(struct crypto_tfm *tfm)
109 switch (crypto_tfm_alg_type(tfm)) {
110 case CRYPTO_ALG_TYPE_CIPHER:
111 crypto_exit_cipher_ops(tfm);
114 case CRYPTO_ALG_TYPE_DIGEST:
115 crypto_exit_digest_ops(tfm);
118 case CRYPTO_ALG_TYPE_COMPRESS:
119 crypto_exit_compress_ops(tfm);
128 static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
132 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
136 case CRYPTO_ALG_TYPE_CIPHER:
137 len = crypto_cipher_ctxsize(alg, flags);
140 case CRYPTO_ALG_TYPE_DIGEST:
141 len = crypto_digest_ctxsize(alg, flags);
144 case CRYPTO_ALG_TYPE_COMPRESS:
145 len = crypto_compress_ctxsize(alg, flags);
149 return len + alg->cra_alignmask;
152 struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
154 struct crypto_tfm *tfm = NULL;
155 struct crypto_alg *alg;
156 unsigned int tfm_size;
158 alg = crypto_alg_mod_lookup(name);
162 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
163 tfm = kmalloc(tfm_size, GFP_KERNEL);
167 memset(tfm, 0, tfm_size);
169 tfm->__crt_alg = alg;
171 if (crypto_init_flags(tfm, flags))
174 if (crypto_init_ops(tfm)) {
175 crypto_exit_ops(tfm);
190 void crypto_free_tfm(struct crypto_tfm *tfm)
192 struct crypto_alg *alg = tfm->__crt_alg;
193 int size = sizeof(*tfm) + alg->cra_ctxsize;
195 crypto_exit_ops(tfm);
197 memset(tfm, 0, size);
201 int crypto_register_alg(struct crypto_alg *alg)
204 struct crypto_alg *q;
206 if (alg->cra_alignmask & (alg->cra_alignmask + 1))
209 if (alg->cra_alignmask > PAGE_SIZE)
212 down_write(&crypto_alg_sem);
214 list_for_each_entry(q, &crypto_alg_list, cra_list) {
215 if (!(strcmp(q->cra_name, alg->cra_name))) {
221 list_add_tail(&alg->cra_list, &crypto_alg_list);
223 up_write(&crypto_alg_sem);
227 int crypto_unregister_alg(struct crypto_alg *alg)
230 struct crypto_alg *q;
232 BUG_ON(!alg->cra_module);
234 down_write(&crypto_alg_sem);
235 list_for_each_entry(q, &crypto_alg_list, cra_list) {
237 list_del(&alg->cra_list);
243 up_write(&crypto_alg_sem);
247 int crypto_alg_available(const char *name, u32 flags)
250 struct crypto_alg *alg = crypto_alg_mod_lookup(name);
260 static int __init init_crypto(void)
262 printk(KERN_INFO "Initializing Cryptographic API\n");
267 __initcall(init_crypto);
269 EXPORT_SYMBOL_GPL(crypto_register_alg);
270 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
271 EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
272 EXPORT_SYMBOL_GPL(crypto_free_tfm);
273 EXPORT_SYMBOL_GPL(crypto_alg_available);