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/algapi.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
crypto_ecb_crypt(struct skcipher_request * req,struct crypto_cipher * cipher,void (* fn)(struct crypto_tfm *,u8 *,const u8 *))15 static int crypto_ecb_crypt(struct skcipher_request *req,
16 struct crypto_cipher *cipher,
17 void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
18 {
19 const unsigned int bsize = crypto_cipher_blocksize(cipher);
20 struct skcipher_walk walk;
21 unsigned int nbytes;
22 int err;
23
24 err = skcipher_walk_virt(&walk, req, false);
25
26 while ((nbytes = walk.nbytes) != 0) {
27 const u8 *src = walk.src.virt.addr;
28 u8 *dst = walk.dst.virt.addr;
29
30 do {
31 fn(crypto_cipher_tfm(cipher), dst, src);
32
33 src += bsize;
34 dst += bsize;
35 } while ((nbytes -= bsize) >= bsize);
36
37 err = skcipher_walk_done(&walk, nbytes);
38 }
39
40 return err;
41 }
42
crypto_ecb_encrypt(struct skcipher_request * req)43 static int crypto_ecb_encrypt(struct skcipher_request *req)
44 {
45 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
46 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
47
48 return crypto_ecb_crypt(req, cipher,
49 crypto_cipher_alg(cipher)->cia_encrypt);
50 }
51
crypto_ecb_decrypt(struct skcipher_request * req)52 static int crypto_ecb_decrypt(struct skcipher_request *req)
53 {
54 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
55 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
56
57 return crypto_ecb_crypt(req, cipher,
58 crypto_cipher_alg(cipher)->cia_decrypt);
59 }
60
crypto_ecb_create(struct crypto_template * tmpl,struct rtattr ** tb)61 static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
62 {
63 struct skcipher_instance *inst;
64 int err;
65
66 inst = skcipher_alloc_instance_simple(tmpl, tb);
67 if (IS_ERR(inst))
68 return PTR_ERR(inst);
69
70 inst->alg.ivsize = 0; /* ECB mode doesn't take an IV */
71
72 inst->alg.encrypt = crypto_ecb_encrypt;
73 inst->alg.decrypt = crypto_ecb_decrypt;
74
75 err = skcipher_register_instance(tmpl, inst);
76 if (err)
77 inst->free(inst);
78
79 return err;
80 }
81
82 static struct crypto_template crypto_ecb_tmpl = {
83 .name = "ecb",
84 .create = crypto_ecb_create,
85 .module = THIS_MODULE,
86 };
87
crypto_ecb_module_init(void)88 static int __init crypto_ecb_module_init(void)
89 {
90 return crypto_register_template(&crypto_ecb_tmpl);
91 }
92
crypto_ecb_module_exit(void)93 static void __exit crypto_ecb_module_exit(void)
94 {
95 crypto_unregister_template(&crypto_ecb_tmpl);
96 }
97
98 subsys_initcall(crypto_ecb_module_init);
99 module_exit(crypto_ecb_module_exit);
100
101 MODULE_LICENSE("GPL");
102 MODULE_DESCRIPTION("ECB block cipher mode of operation");
103 MODULE_ALIAS_CRYPTO("ecb");
104
