projects/linux·blob v3.13 · refs

187 lines · 4.9 KiB

1/*
2 * ECB: Electronic CodeBook mode
3 *
4 * Copyright (c) 2006 Herbert Xu <[email protected]>
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 <crypto/algapi.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/scatterlist.h>
19#include <linux/slab.h>
20
21struct crypto_ecb_ctx {
22 struct crypto_cipher *child;
23};
24
25static int crypto_ecb_setkey(struct crypto_tfm *parent, const u8 *key,
26 unsigned int keylen)
27{
28 struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(parent);
29 struct crypto_cipher *child = ctx->child;
30 int err;
31
32 crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
33 crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
34 CRYPTO_TFM_REQ_MASK);
35 err = crypto_cipher_setkey(child, key, keylen);
36 crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
37 CRYPTO_TFM_RES_MASK);
38 return err;
39}
40
41static int crypto_ecb_crypt(struct blkcipher_desc *desc,
42 struct blkcipher_walk *walk,
43 struct crypto_cipher *tfm,
44 void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
45{
46 int bsize = crypto_cipher_blocksize(tfm);
47 unsigned int nbytes;
48 int err;
49
50 err = blkcipher_walk_virt(desc, walk);
51
52 while ((nbytes = walk->nbytes)) {
53 u8 *wsrc = walk->src.virt.addr;
54 u8 *wdst = walk->dst.virt.addr;
55
56 do {
57 fn(crypto_cipher_tfm(tfm), wdst, wsrc);
58
59 wsrc += bsize;
60 wdst += bsize;
61 } while ((nbytes -= bsize) >= bsize);
62
63 err = blkcipher_walk_done(desc, walk, nbytes);
64 }
65
66 return err;
67}
68
69static int crypto_ecb_encrypt(struct blkcipher_desc *desc,
70 struct scatterlist *dst, struct scatterlist *src,
71 unsigned int nbytes)
72{
73 struct blkcipher_walk walk;
74 struct crypto_blkcipher *tfm = desc->tfm;
75 struct crypto_ecb_ctx *ctx = crypto_blkcipher_ctx(tfm);
76 struct crypto_cipher *child = ctx->child;
77
78 blkcipher_walk_init(&walk, dst, src, nbytes);
79 return crypto_ecb_crypt(desc, &walk, child,
80 crypto_cipher_alg(child)->cia_encrypt);
81}
82
83static int crypto_ecb_decrypt(struct blkcipher_desc *desc,
84 struct scatterlist *dst, struct scatterlist *src,
85 unsigned int nbytes)
86{
87 struct blkcipher_walk walk;
88 struct crypto_blkcipher *tfm = desc->tfm;
89 struct crypto_ecb_ctx *ctx = crypto_blkcipher_ctx(tfm);
90 struct crypto_cipher *child = ctx->child;
91
92 blkcipher_walk_init(&walk, dst, src, nbytes);
93 return crypto_ecb_crypt(desc, &walk, child,
94 crypto_cipher_alg(child)->cia_decrypt);
95}
96
97static int crypto_ecb_init_tfm(struct crypto_tfm *tfm)
98{
99 struct crypto_instance *inst = (void *)tfm->__crt_alg;
100 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
101 struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(tfm);
102 struct crypto_cipher *cipher;
103
104 cipher = crypto_spawn_cipher(spawn);
105 if (IS_ERR(cipher))
106 return PTR_ERR(cipher);
107
108 ctx->child = cipher;
109 return 0;
110}
111
112static void crypto_ecb_exit_tfm(struct crypto_tfm *tfm)
113{
114 struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(tfm);
115 crypto_free_cipher(ctx->child);
116}
117
118static struct crypto_instance *crypto_ecb_alloc(struct rtattr **tb)
119{
120 struct crypto_instance *inst;
121 struct crypto_alg *alg;
122 int err;
123
124 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
125 if (err)
126 return ERR_PTR(err);
127
128 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
129 CRYPTO_ALG_TYPE_MASK);
130 if (IS_ERR(alg))
131 return ERR_CAST(alg);
132
133 inst = crypto_alloc_instance("ecb", alg);
134 if (IS_ERR(inst))
135 goto out_put_alg;
136
137 inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
138 inst->alg.cra_priority = alg->cra_priority;
139 inst->alg.cra_blocksize = alg->cra_blocksize;
140 inst->alg.cra_alignmask = alg->cra_alignmask;
141 inst->alg.cra_type = &crypto_blkcipher_type;
142
143 inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
144 inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
145
146 inst->alg.cra_ctxsize = sizeof(struct crypto_ecb_ctx);
147
148 inst->alg.cra_init = crypto_ecb_init_tfm;
149 inst->alg.cra_exit = crypto_ecb_exit_tfm;
150
151 inst->alg.cra_blkcipher.setkey = crypto_ecb_setkey;
152 inst->alg.cra_blkcipher.encrypt = crypto_ecb_encrypt;
153 inst->alg.cra_blkcipher.decrypt = crypto_ecb_decrypt;
154
155out_put_alg:
156 crypto_mod_put(alg);
157 return inst;
158}
159
160static void crypto_ecb_free(struct crypto_instance *inst)
161{
162 crypto_drop_spawn(crypto_instance_ctx(inst));
163 kfree(inst);
164}
165
166static struct crypto_template crypto_ecb_tmpl = {
167 .name = "ecb",
168 .alloc = crypto_ecb_alloc,
169 .free = crypto_ecb_free,
170 .module = THIS_MODULE,
171};
172
173static int __init crypto_ecb_module_init(void)
174{
175 return crypto_register_template(&crypto_ecb_tmpl);
176}
177
178static void __exit crypto_ecb_module_exit(void)
179{
180 crypto_unregister_template(&crypto_ecb_tmpl);
181}
182
183module_init(crypto_ecb_module_init);
184module_exit(crypto_ecb_module_exit);
185
186MODULE_LICENSE("GPL");
187MODULE_DESCRIPTION("ECB block cipher algorithm");