xref: /linux/crypto/ecb.c (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ECB: Electronic CodeBook mode
4  *
5  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
6  */
7 
8 #include <crypto/internal/cipher.h>
9 #include <crypto/internal/skcipher.h>
10 #include <linux/err.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 
16 static int crypto_ecb_crypt(struct crypto_cipher *cipher, const u8 *src,
17 			    u8 *dst, unsigned nbytes, bool final,
18 			    void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
19 {
20 	const unsigned int bsize = crypto_cipher_blocksize(cipher);
21 
22 	while (nbytes >= bsize) {
23 		fn(crypto_cipher_tfm(cipher), dst, src);
24 
25 		src += bsize;
26 		dst += bsize;
27 
28 		nbytes -= bsize;
29 	}
30 
31 	return nbytes && final ? -EINVAL : nbytes;
32 }
33 
34 static int crypto_ecb_encrypt2(struct crypto_lskcipher *tfm, const u8 *src,
35 			       u8 *dst, unsigned len, u8 *iv, bool final)
36 {
37 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
38 	struct crypto_cipher *cipher = *ctx;
39 
40 	return crypto_ecb_crypt(cipher, src, dst, len, final,
41 				crypto_cipher_alg(cipher)->cia_encrypt);
42 }
43 
44 static int crypto_ecb_decrypt2(struct crypto_lskcipher *tfm, const u8 *src,
45 			       u8 *dst, unsigned len, u8 *iv, bool final)
46 {
47 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
48 	struct crypto_cipher *cipher = *ctx;
49 
50 	return crypto_ecb_crypt(cipher, src, dst, len, final,
51 				crypto_cipher_alg(cipher)->cia_decrypt);
52 }
53 
54 static int lskcipher_setkey_simple2(struct crypto_lskcipher *tfm,
55 				    const u8 *key, unsigned int keylen)
56 {
57 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
58 	struct crypto_cipher *cipher = *ctx;
59 
60 	crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
61 	crypto_cipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &
62 				CRYPTO_TFM_REQ_MASK);
63 	return crypto_cipher_setkey(cipher, key, keylen);
64 }
65 
66 static int lskcipher_init_tfm_simple2(struct crypto_lskcipher *tfm)
67 {
68 	struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);
69 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
70 	struct crypto_cipher_spawn *spawn;
71 	struct crypto_cipher *cipher;
72 
73 	spawn = lskcipher_instance_ctx(inst);
74 	cipher = crypto_spawn_cipher(spawn);
75 	if (IS_ERR(cipher))
76 		return PTR_ERR(cipher);
77 
78 	*ctx = cipher;
79 	return 0;
80 }
81 
82 static void lskcipher_exit_tfm_simple2(struct crypto_lskcipher *tfm)
83 {
84 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
85 
86 	crypto_free_cipher(*ctx);
87 }
88 
89 static void lskcipher_free_instance_simple2(struct lskcipher_instance *inst)
90 {
91 	crypto_drop_cipher(lskcipher_instance_ctx(inst));
92 	kfree(inst);
93 }
94 
95 static struct lskcipher_instance *lskcipher_alloc_instance_simple2(
96 	struct crypto_template *tmpl, struct rtattr **tb)
97 {
98 	struct crypto_cipher_spawn *spawn;
99 	struct lskcipher_instance *inst;
100 	struct crypto_alg *cipher_alg;
101 	u32 mask;
102 	int err;
103 
104 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);
105 	if (err)
106 		return ERR_PTR(err);
107 
108 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
109 	if (!inst)
110 		return ERR_PTR(-ENOMEM);
111 	spawn = lskcipher_instance_ctx(inst);
112 
113 	err = crypto_grab_cipher(spawn, lskcipher_crypto_instance(inst),
114 				 crypto_attr_alg_name(tb[1]), 0, mask);
115 	if (err)
116 		goto err_free_inst;
117 	cipher_alg = crypto_spawn_cipher_alg(spawn);
118 
119 	err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,
120 				  cipher_alg);
121 	if (err)
122 		goto err_free_inst;
123 
124 	inst->free = lskcipher_free_instance_simple2;
125 
126 	/* Default algorithm properties, can be overridden */
127 	inst->alg.co.base.cra_blocksize = cipher_alg->cra_blocksize;
128 	inst->alg.co.base.cra_alignmask = cipher_alg->cra_alignmask;
129 	inst->alg.co.base.cra_priority = cipher_alg->cra_priority;
130 	inst->alg.co.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
131 	inst->alg.co.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
132 	inst->alg.co.ivsize = cipher_alg->cra_blocksize;
133 
134 	/* Use struct crypto_cipher * by default, can be overridden */
135 	inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_cipher *);
136 	inst->alg.setkey = lskcipher_setkey_simple2;
137 	inst->alg.init = lskcipher_init_tfm_simple2;
138 	inst->alg.exit = lskcipher_exit_tfm_simple2;
139 
140 	return inst;
141 
142 err_free_inst:
143 	lskcipher_free_instance_simple2(inst);
144 	return ERR_PTR(err);
145 }
146 
147 static int crypto_ecb_create2(struct crypto_template *tmpl, struct rtattr **tb)
148 {
149 	struct lskcipher_instance *inst;
150 	int err;
151 
152 	inst = lskcipher_alloc_instance_simple2(tmpl, tb);
153 	if (IS_ERR(inst))
154 		return PTR_ERR(inst);
155 
156 	/* ECB mode doesn't take an IV */
157 	inst->alg.co.ivsize = 0;
158 
159 	inst->alg.encrypt = crypto_ecb_encrypt2;
160 	inst->alg.decrypt = crypto_ecb_decrypt2;
161 
162 	err = lskcipher_register_instance(tmpl, inst);
163 	if (err)
164 		inst->free(inst);
165 
166 	return err;
167 }
168 
169 static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
170 {
171 	struct crypto_lskcipher_spawn *spawn;
172 	struct lskcipher_alg *cipher_alg;
173 	struct lskcipher_instance *inst;
174 	int err;
175 
176 	inst = lskcipher_alloc_instance_simple(tmpl, tb);
177 	if (IS_ERR(inst)) {
178 		err = crypto_ecb_create2(tmpl, tb);
179 		return err;
180 	}
181 
182 	spawn = lskcipher_instance_ctx(inst);
183 	cipher_alg = crypto_lskcipher_spawn_alg(spawn);
184 
185 	/* ECB mode doesn't take an IV */
186 	inst->alg.co.ivsize = 0;
187 	if (cipher_alg->co.ivsize)
188 		return -EINVAL;
189 
190 	inst->alg.co.base.cra_ctxsize = cipher_alg->co.base.cra_ctxsize;
191 	inst->alg.setkey = cipher_alg->setkey;
192 	inst->alg.encrypt = cipher_alg->encrypt;
193 	inst->alg.decrypt = cipher_alg->decrypt;
194 	inst->alg.init = cipher_alg->init;
195 	inst->alg.exit = cipher_alg->exit;
196 
197 	err = lskcipher_register_instance(tmpl, inst);
198 	if (err)
199 		inst->free(inst);
200 
201 	return err;
202 }
203 
204 static struct crypto_template crypto_ecb_tmpl = {
205 	.name = "ecb",
206 	.create = crypto_ecb_create,
207 	.module = THIS_MODULE,
208 };
209 
210 static int __init crypto_ecb_module_init(void)
211 {
212 	return crypto_register_template(&crypto_ecb_tmpl);
213 }
214 
215 static void __exit crypto_ecb_module_exit(void)
216 {
217 	crypto_unregister_template(&crypto_ecb_tmpl);
218 }
219 
220 subsys_initcall(crypto_ecb_module_init);
221 module_exit(crypto_ecb_module_exit);
222 
223 MODULE_LICENSE("GPL");
224 MODULE_DESCRIPTION("ECB block cipher mode of operation");
225 MODULE_ALIAS_CRYPTO("ecb");
226 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
227