xref: /openbmc/linux/crypto/ecb.c (revision d0034a7a4ac7fae708146ac0059b9c47a1543f0d)
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