xref: /linux/crypto/ecb.c (revision 63ba5b0fb4f54db256ec43b3062b2606b383055d)
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, u32 flags)
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,
41 				flags & CRYPTO_LSKCIPHER_FLAG_FINAL,
42 				crypto_cipher_alg(cipher)->cia_encrypt);
43 }
44 
45 static int crypto_ecb_decrypt2(struct crypto_lskcipher *tfm, const u8 *src,
46 			       u8 *dst, unsigned len, u8 *iv, u32 flags)
47 {
48 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
49 	struct crypto_cipher *cipher = *ctx;
50 
51 	return crypto_ecb_crypt(cipher, src, dst, len,
52 				flags & CRYPTO_LSKCIPHER_FLAG_FINAL,
53 				crypto_cipher_alg(cipher)->cia_decrypt);
54 }
55 
56 static int lskcipher_setkey_simple2(struct crypto_lskcipher *tfm,
57 				    const u8 *key, unsigned int keylen)
58 {
59 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
60 	struct crypto_cipher *cipher = *ctx;
61 
62 	crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
63 	crypto_cipher_set_flags(cipher, crypto_lskcipher_get_flags(tfm) &
64 				CRYPTO_TFM_REQ_MASK);
65 	return crypto_cipher_setkey(cipher, key, keylen);
66 }
67 
68 static int lskcipher_init_tfm_simple2(struct crypto_lskcipher *tfm)
69 {
70 	struct lskcipher_instance *inst = lskcipher_alg_instance(tfm);
71 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
72 	struct crypto_cipher_spawn *spawn;
73 	struct crypto_cipher *cipher;
74 
75 	spawn = lskcipher_instance_ctx(inst);
76 	cipher = crypto_spawn_cipher(spawn);
77 	if (IS_ERR(cipher))
78 		return PTR_ERR(cipher);
79 
80 	*ctx = cipher;
81 	return 0;
82 }
83 
84 static void lskcipher_exit_tfm_simple2(struct crypto_lskcipher *tfm)
85 {
86 	struct crypto_cipher **ctx = crypto_lskcipher_ctx(tfm);
87 
88 	crypto_free_cipher(*ctx);
89 }
90 
91 static void lskcipher_free_instance_simple2(struct lskcipher_instance *inst)
92 {
93 	crypto_drop_cipher(lskcipher_instance_ctx(inst));
94 	kfree(inst);
95 }
96 
97 static struct lskcipher_instance *lskcipher_alloc_instance_simple2(
98 	struct crypto_template *tmpl, struct rtattr **tb)
99 {
100 	struct crypto_cipher_spawn *spawn;
101 	struct lskcipher_instance *inst;
102 	struct crypto_alg *cipher_alg;
103 	u32 mask;
104 	int err;
105 
106 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_LSKCIPHER, &mask);
107 	if (err)
108 		return ERR_PTR(err);
109 
110 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
111 	if (!inst)
112 		return ERR_PTR(-ENOMEM);
113 	spawn = lskcipher_instance_ctx(inst);
114 
115 	err = crypto_grab_cipher(spawn, lskcipher_crypto_instance(inst),
116 				 crypto_attr_alg_name(tb[1]), 0, mask);
117 	if (err)
118 		goto err_free_inst;
119 	cipher_alg = crypto_spawn_cipher_alg(spawn);
120 
121 	err = crypto_inst_setname(lskcipher_crypto_instance(inst), tmpl->name,
122 				  cipher_alg);
123 	if (err)
124 		goto err_free_inst;
125 
126 	inst->free = lskcipher_free_instance_simple2;
127 
128 	/* Default algorithm properties, can be overridden */
129 	inst->alg.co.base.cra_blocksize = cipher_alg->cra_blocksize;
130 	inst->alg.co.base.cra_alignmask = cipher_alg->cra_alignmask;
131 	inst->alg.co.base.cra_priority = cipher_alg->cra_priority;
132 	inst->alg.co.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
133 	inst->alg.co.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
134 	inst->alg.co.ivsize = cipher_alg->cra_blocksize;
135 
136 	/* Use struct crypto_cipher * by default, can be overridden */
137 	inst->alg.co.base.cra_ctxsize = sizeof(struct crypto_cipher *);
138 	inst->alg.setkey = lskcipher_setkey_simple2;
139 	inst->alg.init = lskcipher_init_tfm_simple2;
140 	inst->alg.exit = lskcipher_exit_tfm_simple2;
141 
142 	return inst;
143 
144 err_free_inst:
145 	lskcipher_free_instance_simple2(inst);
146 	return ERR_PTR(err);
147 }
148 
149 static int crypto_ecb_create2(struct crypto_template *tmpl, struct rtattr **tb)
150 {
151 	struct lskcipher_instance *inst;
152 	int err;
153 
154 	inst = lskcipher_alloc_instance_simple2(tmpl, tb);
155 	if (IS_ERR(inst))
156 		return PTR_ERR(inst);
157 
158 	/* ECB mode doesn't take an IV */
159 	inst->alg.co.ivsize = 0;
160 
161 	inst->alg.encrypt = crypto_ecb_encrypt2;
162 	inst->alg.decrypt = crypto_ecb_decrypt2;
163 
164 	err = lskcipher_register_instance(tmpl, inst);
165 	if (err)
166 		inst->free(inst);
167 
168 	return err;
169 }
170 
171 static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
172 {
173 	struct crypto_lskcipher_spawn *spawn;
174 	struct lskcipher_alg *cipher_alg;
175 	struct lskcipher_instance *inst;
176 	int err;
177 
178 	inst = lskcipher_alloc_instance_simple(tmpl, tb);
179 	if (IS_ERR(inst)) {
180 		err = crypto_ecb_create2(tmpl, tb);
181 		return err;
182 	}
183 
184 	spawn = lskcipher_instance_ctx(inst);
185 	cipher_alg = crypto_lskcipher_spawn_alg(spawn);
186 
187 	/* ECB mode doesn't take an IV */
188 	inst->alg.co.ivsize = 0;
189 	if (cipher_alg->co.ivsize)
190 		return -EINVAL;
191 
192 	inst->alg.co.base.cra_ctxsize = cipher_alg->co.base.cra_ctxsize;
193 	inst->alg.setkey = cipher_alg->setkey;
194 	inst->alg.encrypt = cipher_alg->encrypt;
195 	inst->alg.decrypt = cipher_alg->decrypt;
196 	inst->alg.init = cipher_alg->init;
197 	inst->alg.exit = cipher_alg->exit;
198 
199 	err = lskcipher_register_instance(tmpl, inst);
200 	if (err)
201 		inst->free(inst);
202 
203 	return err;
204 }
205 
206 static struct crypto_template crypto_ecb_tmpl = {
207 	.name = "ecb",
208 	.create = crypto_ecb_create,
209 	.module = THIS_MODULE,
210 };
211 
212 static int __init crypto_ecb_module_init(void)
213 {
214 	return crypto_register_template(&crypto_ecb_tmpl);
215 }
216 
217 static void __exit crypto_ecb_module_exit(void)
218 {
219 	crypto_unregister_template(&crypto_ecb_tmpl);
220 }
221 
222 subsys_initcall(crypto_ecb_module_init);
223 module_exit(crypto_ecb_module_exit);
224 
225 MODULE_LICENSE("GPL");
226 MODULE_DESCRIPTION("ECB block cipher mode of operation");
227 MODULE_ALIAS_CRYPTO("ecb");
228 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
229