certs/blacklist: fix kernel doc interface issue
[linux-2.6-microblaze.git] / crypto / chacha_generic.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ChaCha and XChaCha stream ciphers, including ChaCha20 (RFC7539)
4  *
5  * Copyright (C) 2015 Martin Willi
6  * Copyright (C) 2018 Google LLC
7  */
8
9 #include <asm/unaligned.h>
10 #include <crypto/algapi.h>
11 #include <crypto/internal/chacha.h>
12 #include <crypto/internal/skcipher.h>
13 #include <linux/module.h>
14
15 static int chacha_stream_xor(struct skcipher_request *req,
16                              const struct chacha_ctx *ctx, const u8 *iv)
17 {
18         struct skcipher_walk walk;
19         u32 state[16];
20         int err;
21
22         err = skcipher_walk_virt(&walk, req, false);
23
24         chacha_init_generic(state, ctx->key, iv);
25
26         while (walk.nbytes > 0) {
27                 unsigned int nbytes = walk.nbytes;
28
29                 if (nbytes < walk.total)
30                         nbytes = round_down(nbytes, CHACHA_BLOCK_SIZE);
31
32                 chacha_crypt_generic(state, walk.dst.virt.addr,
33                                      walk.src.virt.addr, nbytes, ctx->nrounds);
34                 err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
35         }
36
37         return err;
38 }
39
40 static int crypto_chacha_crypt(struct skcipher_request *req)
41 {
42         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
43         struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
44
45         return chacha_stream_xor(req, ctx, req->iv);
46 }
47
48 static int crypto_xchacha_crypt(struct skcipher_request *req)
49 {
50         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
51         struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
52         struct chacha_ctx subctx;
53         u32 state[16];
54         u8 real_iv[16];
55
56         /* Compute the subkey given the original key and first 128 nonce bits */
57         chacha_init_generic(state, ctx->key, req->iv);
58         hchacha_block_generic(state, subctx.key, ctx->nrounds);
59         subctx.nrounds = ctx->nrounds;
60
61         /* Build the real IV */
62         memcpy(&real_iv[0], req->iv + 24, 8); /* stream position */
63         memcpy(&real_iv[8], req->iv + 16, 8); /* remaining 64 nonce bits */
64
65         /* Generate the stream and XOR it with the data */
66         return chacha_stream_xor(req, &subctx, real_iv);
67 }
68
69 static struct skcipher_alg algs[] = {
70         {
71                 .base.cra_name          = "chacha20",
72                 .base.cra_driver_name   = "chacha20-generic",
73                 .base.cra_priority      = 100,
74                 .base.cra_blocksize     = 1,
75                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
76                 .base.cra_module        = THIS_MODULE,
77
78                 .min_keysize            = CHACHA_KEY_SIZE,
79                 .max_keysize            = CHACHA_KEY_SIZE,
80                 .ivsize                 = CHACHA_IV_SIZE,
81                 .chunksize              = CHACHA_BLOCK_SIZE,
82                 .setkey                 = chacha20_setkey,
83                 .encrypt                = crypto_chacha_crypt,
84                 .decrypt                = crypto_chacha_crypt,
85         }, {
86                 .base.cra_name          = "xchacha20",
87                 .base.cra_driver_name   = "xchacha20-generic",
88                 .base.cra_priority      = 100,
89                 .base.cra_blocksize     = 1,
90                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
91                 .base.cra_module        = THIS_MODULE,
92
93                 .min_keysize            = CHACHA_KEY_SIZE,
94                 .max_keysize            = CHACHA_KEY_SIZE,
95                 .ivsize                 = XCHACHA_IV_SIZE,
96                 .chunksize              = CHACHA_BLOCK_SIZE,
97                 .setkey                 = chacha20_setkey,
98                 .encrypt                = crypto_xchacha_crypt,
99                 .decrypt                = crypto_xchacha_crypt,
100         }, {
101                 .base.cra_name          = "xchacha12",
102                 .base.cra_driver_name   = "xchacha12-generic",
103                 .base.cra_priority      = 100,
104                 .base.cra_blocksize     = 1,
105                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
106                 .base.cra_module        = THIS_MODULE,
107
108                 .min_keysize            = CHACHA_KEY_SIZE,
109                 .max_keysize            = CHACHA_KEY_SIZE,
110                 .ivsize                 = XCHACHA_IV_SIZE,
111                 .chunksize              = CHACHA_BLOCK_SIZE,
112                 .setkey                 = chacha12_setkey,
113                 .encrypt                = crypto_xchacha_crypt,
114                 .decrypt                = crypto_xchacha_crypt,
115         }
116 };
117
118 static int __init chacha_generic_mod_init(void)
119 {
120         return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
121 }
122
123 static void __exit chacha_generic_mod_fini(void)
124 {
125         crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
126 }
127
128 subsys_initcall(chacha_generic_mod_init);
129 module_exit(chacha_generic_mod_fini);
130
131 MODULE_LICENSE("GPL");
132 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
133 MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (generic)");
134 MODULE_ALIAS_CRYPTO("chacha20");
135 MODULE_ALIAS_CRYPTO("chacha20-generic");
136 MODULE_ALIAS_CRYPTO("xchacha20");
137 MODULE_ALIAS_CRYPTO("xchacha20-generic");
138 MODULE_ALIAS_CRYPTO("xchacha12");
139 MODULE_ALIAS_CRYPTO("xchacha12-generic");