Blame view

crypto/cbc.c 5.09 KB
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
1
2
3
  /*
   * CBC: Cipher Block Chaining mode
   *
cc868d82a   Herbert Xu   crypto: cbc - Exp...
4
   * Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
5
6
7
8
9
10
11
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; either version 2 of the License, or (at your option)
   * any later version.
   *
   */
e6c2e65c7   Marcelo Cerri   crypto: cbc - Pro...
12
  #include <crypto/algapi.h>
cc868d82a   Herbert Xu   crypto: cbc - Exp...
13
  #include <crypto/cbc.h>
79c65d179   Herbert Xu   crypto: cbc - Con...
14
  #include <crypto/internal/skcipher.h>
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
15
16
17
  #include <linux/err.h>
  #include <linux/init.h>
  #include <linux/kernel.h>
50b6544e1   Herbert Xu   [CRYPTO] cbc: Req...
18
  #include <linux/log2.h>
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
19
  #include <linux/module.h>
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
20
21
22
23
  #include <linux/slab.h>
  
  struct crypto_cbc_ctx {
  	struct crypto_cipher *child;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
24
  };
79c65d179   Herbert Xu   crypto: cbc - Con...
25
  static int crypto_cbc_setkey(struct crypto_skcipher *parent, const u8 *key,
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
26
27
  			     unsigned int keylen)
  {
79c65d179   Herbert Xu   crypto: cbc - Con...
28
  	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(parent);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
29
30
31
32
  	struct crypto_cipher *child = ctx->child;
  	int err;
  
  	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
79c65d179   Herbert Xu   crypto: cbc - Con...
33
  	crypto_cipher_set_flags(child, crypto_skcipher_get_flags(parent) &
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
34
35
  				       CRYPTO_TFM_REQ_MASK);
  	err = crypto_cipher_setkey(child, key, keylen);
79c65d179   Herbert Xu   crypto: cbc - Con...
36
37
  	crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(child) &
  					  CRYPTO_TFM_RES_MASK);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
38
39
  	return err;
  }
79c65d179   Herbert Xu   crypto: cbc - Con...
40
41
42
43
44
45
46
47
48
  static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
  					  const u8 *src, u8 *dst)
  {
  	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
  
  	crypto_cipher_encrypt_one(ctx->child, dst, src);
  }
  
  static int crypto_cbc_encrypt(struct skcipher_request *req)
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
49
  {
79c65d179   Herbert Xu   crypto: cbc - Con...
50
51
  	return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
  }
79c65d179   Herbert Xu   crypto: cbc - Con...
52
53
54
55
56
57
58
59
60
61
62
63
  static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
  					  const u8 *src, u8 *dst)
  {
  	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
  
  	crypto_cipher_decrypt_one(ctx->child, dst, src);
  }
  
  static int crypto_cbc_decrypt(struct skcipher_request *req)
  {
  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  	struct skcipher_walk walk;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
64
  	int err;
79c65d179   Herbert Xu   crypto: cbc - Con...
65
  	err = skcipher_walk_virt(&walk, req, false);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
66

79c65d179   Herbert Xu   crypto: cbc - Con...
67
68
69
70
  	while (walk.nbytes) {
  		err = crypto_cbc_decrypt_blocks(&walk, tfm,
  						crypto_cbc_decrypt_one);
  		err = skcipher_walk_done(&walk, err);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
71
72
73
74
  	}
  
  	return err;
  }
79c65d179   Herbert Xu   crypto: cbc - Con...
75
  static int crypto_cbc_init_tfm(struct crypto_skcipher *tfm)
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
76
  {
79c65d179   Herbert Xu   crypto: cbc - Con...
77
78
79
  	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
  	struct crypto_spawn *spawn = skcipher_instance_ctx(inst);
  	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
2e306ee01   Herbert Xu   [CRYPTO] api: Add...
80
  	struct crypto_cipher *cipher;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
81

2e306ee01   Herbert Xu   [CRYPTO] api: Add...
82
83
84
  	cipher = crypto_spawn_cipher(spawn);
  	if (IS_ERR(cipher))
  		return PTR_ERR(cipher);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
85

2e306ee01   Herbert Xu   [CRYPTO] api: Add...
86
  	ctx->child = cipher;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
87
88
  	return 0;
  }
79c65d179   Herbert Xu   crypto: cbc - Con...
89
  static void crypto_cbc_exit_tfm(struct crypto_skcipher *tfm)
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
90
  {
79c65d179   Herbert Xu   crypto: cbc - Con...
91
  	struct crypto_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
92
93
  	crypto_free_cipher(ctx->child);
  }
79c65d179   Herbert Xu   crypto: cbc - Con...
94
  static void crypto_cbc_free(struct skcipher_instance *inst)
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
95
  {
79c65d179   Herbert Xu   crypto: cbc - Con...
96
97
98
99
100
101
102
  	crypto_drop_skcipher(skcipher_instance_ctx(inst));
  	kfree(inst);
  }
  
  static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
  {
  	struct skcipher_instance *inst;
e6c2e65c7   Marcelo Cerri   crypto: cbc - Pro...
103
  	struct crypto_attr_type *algt;
79c65d179   Herbert Xu   crypto: cbc - Con...
104
  	struct crypto_spawn *spawn;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
105
  	struct crypto_alg *alg;
e6c2e65c7   Marcelo Cerri   crypto: cbc - Pro...
106
  	u32 mask;
ebc610e5b   Herbert Xu   [CRYPTO] template...
107
  	int err;
79c65d179   Herbert Xu   crypto: cbc - Con...
108
  	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER);
ebc610e5b   Herbert Xu   [CRYPTO] template...
109
  	if (err)
79c65d179   Herbert Xu   crypto: cbc - Con...
110
111
112
113
114
  		return err;
  
  	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
  	if (!inst)
  		return -ENOMEM;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
115

e6c2e65c7   Marcelo Cerri   crypto: cbc - Pro...
116
117
118
119
120
121
122
123
124
125
  	algt = crypto_get_attr_type(tb);
  	err = PTR_ERR(algt);
  	if (IS_ERR(algt))
  		goto err_free_inst;
  
  	mask = CRYPTO_ALG_TYPE_MASK |
  		crypto_requires_off(algt->type, algt->mask,
  				    CRYPTO_ALG_NEED_FALLBACK);
  
  	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask);
79c65d179   Herbert Xu   crypto: cbc - Con...
126
  	err = PTR_ERR(alg);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
127
  	if (IS_ERR(alg))
79c65d179   Herbert Xu   crypto: cbc - Con...
128
  		goto err_free_inst;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
129

79c65d179   Herbert Xu   crypto: cbc - Con...
130
131
132
133
134
135
136
137
138
139
  	spawn = skcipher_instance_ctx(inst);
  	err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),
  				CRYPTO_ALG_TYPE_MASK);
  	crypto_mod_put(alg);
  	if (err)
  		goto err_free_inst;
  
  	err = crypto_inst_setname(skcipher_crypto_instance(inst), "cbc", alg);
  	if (err)
  		goto err_drop_spawn;
50b6544e1   Herbert Xu   [CRYPTO] cbc: Req...
140

79c65d179   Herbert Xu   crypto: cbc - Con...
141
142
143
  	err = -EINVAL;
  	if (!is_power_of_2(alg->cra_blocksize))
  		goto err_drop_spawn;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
144

79c65d179   Herbert Xu   crypto: cbc - Con...
145
146
147
  	inst->alg.base.cra_priority = alg->cra_priority;
  	inst->alg.base.cra_blocksize = alg->cra_blocksize;
  	inst->alg.base.cra_alignmask = alg->cra_alignmask;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
148

79c65d179   Herbert Xu   crypto: cbc - Con...
149
150
151
  	inst->alg.ivsize = alg->cra_blocksize;
  	inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize;
  	inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
152

79c65d179   Herbert Xu   crypto: cbc - Con...
153
  	inst->alg.base.cra_ctxsize = sizeof(struct crypto_cbc_ctx);
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
154

79c65d179   Herbert Xu   crypto: cbc - Con...
155
156
  	inst->alg.init = crypto_cbc_init_tfm;
  	inst->alg.exit = crypto_cbc_exit_tfm;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
157

79c65d179   Herbert Xu   crypto: cbc - Con...
158
159
160
  	inst->alg.setkey = crypto_cbc_setkey;
  	inst->alg.encrypt = crypto_cbc_encrypt;
  	inst->alg.decrypt = crypto_cbc_decrypt;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
161

79c65d179   Herbert Xu   crypto: cbc - Con...
162
  	inst->free = crypto_cbc_free;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
163

79c65d179   Herbert Xu   crypto: cbc - Con...
164
165
166
167
168
169
170
171
172
173
  	err = skcipher_register_instance(tmpl, inst);
  	if (err)
  		goto err_drop_spawn;
  
  out:
  	return err;
  
  err_drop_spawn:
  	crypto_drop_spawn(spawn);
  err_free_inst:
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
174
  	kfree(inst);
79c65d179   Herbert Xu   crypto: cbc - Con...
175
  	goto out;
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
176
177
178
179
  }
  
  static struct crypto_template crypto_cbc_tmpl = {
  	.name = "cbc",
79c65d179   Herbert Xu   crypto: cbc - Con...
180
  	.create = crypto_cbc_create,
db131ef90   Herbert Xu   [CRYPTO] cipher: ...
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
  	.module = THIS_MODULE,
  };
  
  static int __init crypto_cbc_module_init(void)
  {
  	return crypto_register_template(&crypto_cbc_tmpl);
  }
  
  static void __exit crypto_cbc_module_exit(void)
  {
  	crypto_unregister_template(&crypto_cbc_tmpl);
  }
  
  module_init(crypto_cbc_module_init);
  module_exit(crypto_cbc_module_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("CBC block cipher algorithm");
4943ba16b   Kees Cook   crypto: include c...
199
  MODULE_ALIAS_CRYPTO("cbc");