Merge tag 'sound-6.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
[platform/kernel/linux-starfive.git] / crypto / crypto_null.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Cryptographic API.
4  *
5  * Null algorithms, aka Much Ado About Nothing.
6  *
7  * These are needed for IPsec, and may be useful in general for
8  * testing & debugging.
9  *
10  * The null cipher is compliant with RFC2410.
11  *
12  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
13  */
14
15 #include <crypto/null.h>
16 #include <crypto/internal/hash.h>
17 #include <crypto/internal/skcipher.h>
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/mm.h>
21 #include <linux/string.h>
22
23 static DEFINE_MUTEX(crypto_default_null_skcipher_lock);
24 static struct crypto_sync_skcipher *crypto_default_null_skcipher;
25 static int crypto_default_null_skcipher_refcnt;
26
27 static int null_compress(struct crypto_tfm *tfm, const u8 *src,
28                          unsigned int slen, u8 *dst, unsigned int *dlen)
29 {
30         if (slen > *dlen)
31                 return -EINVAL;
32         memcpy(dst, src, slen);
33         *dlen = slen;
34         return 0;
35 }
36
37 static int null_init(struct shash_desc *desc)
38 {
39         return 0;
40 }
41
42 static int null_update(struct shash_desc *desc, const u8 *data,
43                        unsigned int len)
44 {
45         return 0;
46 }
47
48 static int null_final(struct shash_desc *desc, u8 *out)
49 {
50         return 0;
51 }
52
53 static int null_digest(struct shash_desc *desc, const u8 *data,
54                        unsigned int len, u8 *out)
55 {
56         return 0;
57 }
58
59 static int null_hash_setkey(struct crypto_shash *tfm, const u8 *key,
60                             unsigned int keylen)
61 { return 0; }
62
63 static int null_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
64                                 unsigned int keylen)
65 { return 0; }
66
67 static int null_setkey(struct crypto_tfm *tfm, const u8 *key,
68                        unsigned int keylen)
69 { return 0; }
70
71 static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
72 {
73         memcpy(dst, src, NULL_BLOCK_SIZE);
74 }
75
76 static int null_skcipher_crypt(struct skcipher_request *req)
77 {
78         struct skcipher_walk walk;
79         int err;
80
81         err = skcipher_walk_virt(&walk, req, false);
82
83         while (walk.nbytes) {
84                 if (walk.src.virt.addr != walk.dst.virt.addr)
85                         memcpy(walk.dst.virt.addr, walk.src.virt.addr,
86                                walk.nbytes);
87                 err = skcipher_walk_done(&walk, 0);
88         }
89
90         return err;
91 }
92
93 static struct shash_alg digest_null = {
94         .digestsize             =       NULL_DIGEST_SIZE,
95         .setkey                 =       null_hash_setkey,
96         .init                   =       null_init,
97         .update                 =       null_update,
98         .finup                  =       null_digest,
99         .digest                 =       null_digest,
100         .final                  =       null_final,
101         .base                   =       {
102                 .cra_name               =       "digest_null",
103                 .cra_driver_name        =       "digest_null-generic",
104                 .cra_blocksize          =       NULL_BLOCK_SIZE,
105                 .cra_module             =       THIS_MODULE,
106         }
107 };
108
109 static struct skcipher_alg skcipher_null = {
110         .base.cra_name          =       "ecb(cipher_null)",
111         .base.cra_driver_name   =       "ecb-cipher_null",
112         .base.cra_priority      =       100,
113         .base.cra_blocksize     =       NULL_BLOCK_SIZE,
114         .base.cra_ctxsize       =       0,
115         .base.cra_module        =       THIS_MODULE,
116         .min_keysize            =       NULL_KEY_SIZE,
117         .max_keysize            =       NULL_KEY_SIZE,
118         .ivsize                 =       NULL_IV_SIZE,
119         .setkey                 =       null_skcipher_setkey,
120         .encrypt                =       null_skcipher_crypt,
121         .decrypt                =       null_skcipher_crypt,
122 };
123
124 static struct crypto_alg null_algs[] = { {
125         .cra_name               =       "cipher_null",
126         .cra_driver_name        =       "cipher_null-generic",
127         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
128         .cra_blocksize          =       NULL_BLOCK_SIZE,
129         .cra_ctxsize            =       0,
130         .cra_module             =       THIS_MODULE,
131         .cra_u                  =       { .cipher = {
132         .cia_min_keysize        =       NULL_KEY_SIZE,
133         .cia_max_keysize        =       NULL_KEY_SIZE,
134         .cia_setkey             =       null_setkey,
135         .cia_encrypt            =       null_crypt,
136         .cia_decrypt            =       null_crypt } }
137 }, {
138         .cra_name               =       "compress_null",
139         .cra_driver_name        =       "compress_null-generic",
140         .cra_flags              =       CRYPTO_ALG_TYPE_COMPRESS,
141         .cra_blocksize          =       NULL_BLOCK_SIZE,
142         .cra_ctxsize            =       0,
143         .cra_module             =       THIS_MODULE,
144         .cra_u                  =       { .compress = {
145         .coa_compress           =       null_compress,
146         .coa_decompress         =       null_compress } }
147 } };
148
149 MODULE_ALIAS_CRYPTO("compress_null");
150 MODULE_ALIAS_CRYPTO("digest_null");
151 MODULE_ALIAS_CRYPTO("cipher_null");
152
153 struct crypto_sync_skcipher *crypto_get_default_null_skcipher(void)
154 {
155         struct crypto_sync_skcipher *tfm;
156
157         mutex_lock(&crypto_default_null_skcipher_lock);
158         tfm = crypto_default_null_skcipher;
159
160         if (!tfm) {
161                 tfm = crypto_alloc_sync_skcipher("ecb(cipher_null)", 0, 0);
162                 if (IS_ERR(tfm))
163                         goto unlock;
164
165                 crypto_default_null_skcipher = tfm;
166         }
167
168         crypto_default_null_skcipher_refcnt++;
169
170 unlock:
171         mutex_unlock(&crypto_default_null_skcipher_lock);
172
173         return tfm;
174 }
175 EXPORT_SYMBOL_GPL(crypto_get_default_null_skcipher);
176
177 void crypto_put_default_null_skcipher(void)
178 {
179         mutex_lock(&crypto_default_null_skcipher_lock);
180         if (!--crypto_default_null_skcipher_refcnt) {
181                 crypto_free_sync_skcipher(crypto_default_null_skcipher);
182                 crypto_default_null_skcipher = NULL;
183         }
184         mutex_unlock(&crypto_default_null_skcipher_lock);
185 }
186 EXPORT_SYMBOL_GPL(crypto_put_default_null_skcipher);
187
188 static int __init crypto_null_mod_init(void)
189 {
190         int ret = 0;
191
192         ret = crypto_register_algs(null_algs, ARRAY_SIZE(null_algs));
193         if (ret < 0)
194                 goto out;
195
196         ret = crypto_register_shash(&digest_null);
197         if (ret < 0)
198                 goto out_unregister_algs;
199
200         ret = crypto_register_skcipher(&skcipher_null);
201         if (ret < 0)
202                 goto out_unregister_shash;
203
204         return 0;
205
206 out_unregister_shash:
207         crypto_unregister_shash(&digest_null);
208 out_unregister_algs:
209         crypto_unregister_algs(null_algs, ARRAY_SIZE(null_algs));
210 out:
211         return ret;
212 }
213
214 static void __exit crypto_null_mod_fini(void)
215 {
216         crypto_unregister_algs(null_algs, ARRAY_SIZE(null_algs));
217         crypto_unregister_shash(&digest_null);
218         crypto_unregister_skcipher(&skcipher_null);
219 }
220
221 subsys_initcall(crypto_null_mod_init);
222 module_exit(crypto_null_mod_fini);
223
224 MODULE_LICENSE("GPL");
225 MODULE_DESCRIPTION("Null Cryptographic Algorithms");