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/cipher.h>
10 #include <crypto/internal/skcipher.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15
crypto_ecb_crypt(struct skcipher_request * req,struct crypto_cipher * cipher,void (* fn)(struct crypto_tfm *,u8 *,const u8 *))16 static int crypto_ecb_crypt(struct skcipher_request *req,
17 struct crypto_cipher *cipher,
18 void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
19 {
20 const unsigned int bsize = crypto_cipher_blocksize(cipher);
21 struct skcipher_walk walk;
22 unsigned int nbytes;
23 int err;
24
25 err = skcipher_walk_virt(&walk, req, false);
26
27 while ((nbytes = walk.nbytes) != 0) {
28 const u8 *src = walk.src.virt.addr;
29 u8 *dst = walk.dst.virt.addr;
30
31 do {
32 fn(crypto_cipher_tfm(cipher), dst, src);
33
34 src += bsize;
35 dst += bsize;
36 } while ((nbytes -= bsize) >= bsize);
37
38 err = skcipher_walk_done(&walk, nbytes);
39 }
40
41 return err;
42 }
43
crypto_ecb_encrypt(struct skcipher_request * req)44 static int crypto_ecb_encrypt(struct skcipher_request *req)
45 {
46 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
47 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
48
49 return crypto_ecb_crypt(req, cipher,
50 crypto_cipher_alg(cipher)->cia_encrypt);
51 }
52
crypto_ecb_decrypt(struct skcipher_request * req)53 static int crypto_ecb_decrypt(struct skcipher_request *req)
54 {
55 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
56 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
57
58 return crypto_ecb_crypt(req, cipher,
59 crypto_cipher_alg(cipher)->cia_decrypt);
60 }
61
crypto_ecb_create(struct crypto_template * tmpl,struct rtattr ** tb)62 static int crypto_ecb_create(struct crypto_template *tmpl, struct rtattr **tb)
63 {
64 struct skcipher_instance *inst;
65 int err;
66
67 inst = skcipher_alloc_instance_simple(tmpl, tb);
68 if (IS_ERR(inst))
69 return PTR_ERR(inst);
70
71 inst->alg.ivsize = 0; /* ECB mode doesn't take an IV */
72
73 inst->alg.encrypt = crypto_ecb_encrypt;
74 inst->alg.decrypt = crypto_ecb_decrypt;
75
76 err = skcipher_register_instance(tmpl, inst);
77 if (err)
78 inst->free(inst);
79
80 return err;
81 }
82
83 static struct crypto_template crypto_ecb_tmpl = {
84 .name = "ecb",
85 .create = crypto_ecb_create,
86 .module = THIS_MODULE,
87 };
88
crypto_ecb_module_init(void)89 static int __init crypto_ecb_module_init(void)
90 {
91 return crypto_register_template(&crypto_ecb_tmpl);
92 }
93
crypto_ecb_module_exit(void)94 static void __exit crypto_ecb_module_exit(void)
95 {
96 crypto_unregister_template(&crypto_ecb_tmpl);
97 }
98
99 subsys_initcall(crypto_ecb_module_init);
100 module_exit(crypto_ecb_module_exit);
101
102 MODULE_LICENSE("GPL");
103 MODULE_DESCRIPTION("ECB block cipher mode of operation");
104 MODULE_ALIAS_CRYPTO("ecb");
105