blk-iocost: add three debug stat - cost.wait, indebt and indelay
[linux-2.6-microblaze.git] / crypto / hmac.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Cryptographic API.
4  *
5  * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
6  *
7  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
8  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
9  *
10  * The HMAC implementation is derived from USAGI.
11  * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
12  */
13
14 #include <crypto/hmac.h>
15 #include <crypto/internal/hash.h>
16 #include <crypto/scatterwalk.h>
17 #include <linux/err.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/scatterlist.h>
22 #include <linux/string.h>
23
24 struct hmac_ctx {
25         struct crypto_shash *hash;
26 };
27
28 static inline void *align_ptr(void *p, unsigned int align)
29 {
30         return (void *)ALIGN((unsigned long)p, align);
31 }
32
33 static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
34 {
35         return align_ptr(crypto_shash_ctx_aligned(tfm) +
36                          crypto_shash_statesize(tfm) * 2,
37                          crypto_tfm_ctx_alignment());
38 }
39
40 static int hmac_setkey(struct crypto_shash *parent,
41                        const u8 *inkey, unsigned int keylen)
42 {
43         int bs = crypto_shash_blocksize(parent);
44         int ds = crypto_shash_digestsize(parent);
45         int ss = crypto_shash_statesize(parent);
46         char *ipad = crypto_shash_ctx_aligned(parent);
47         char *opad = ipad + ss;
48         struct hmac_ctx *ctx = align_ptr(opad + ss,
49                                          crypto_tfm_ctx_alignment());
50         struct crypto_shash *hash = ctx->hash;
51         SHASH_DESC_ON_STACK(shash, hash);
52         unsigned int i;
53
54         shash->tfm = hash;
55
56         if (keylen > bs) {
57                 int err;
58
59                 err = crypto_shash_digest(shash, inkey, keylen, ipad);
60                 if (err)
61                         return err;
62
63                 keylen = ds;
64         } else
65                 memcpy(ipad, inkey, keylen);
66
67         memset(ipad + keylen, 0, bs - keylen);
68         memcpy(opad, ipad, bs);
69
70         for (i = 0; i < bs; i++) {
71                 ipad[i] ^= HMAC_IPAD_VALUE;
72                 opad[i] ^= HMAC_OPAD_VALUE;
73         }
74
75         return crypto_shash_init(shash) ?:
76                crypto_shash_update(shash, ipad, bs) ?:
77                crypto_shash_export(shash, ipad) ?:
78                crypto_shash_init(shash) ?:
79                crypto_shash_update(shash, opad, bs) ?:
80                crypto_shash_export(shash, opad);
81 }
82
83 static int hmac_export(struct shash_desc *pdesc, void *out)
84 {
85         struct shash_desc *desc = shash_desc_ctx(pdesc);
86
87         return crypto_shash_export(desc, out);
88 }
89
90 static int hmac_import(struct shash_desc *pdesc, const void *in)
91 {
92         struct shash_desc *desc = shash_desc_ctx(pdesc);
93         struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
94
95         desc->tfm = ctx->hash;
96
97         return crypto_shash_import(desc, in);
98 }
99
100 static int hmac_init(struct shash_desc *pdesc)
101 {
102         return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
103 }
104
105 static int hmac_update(struct shash_desc *pdesc,
106                        const u8 *data, unsigned int nbytes)
107 {
108         struct shash_desc *desc = shash_desc_ctx(pdesc);
109
110         return crypto_shash_update(desc, data, nbytes);
111 }
112
113 static int hmac_final(struct shash_desc *pdesc, u8 *out)
114 {
115         struct crypto_shash *parent = pdesc->tfm;
116         int ds = crypto_shash_digestsize(parent);
117         int ss = crypto_shash_statesize(parent);
118         char *opad = crypto_shash_ctx_aligned(parent) + ss;
119         struct shash_desc *desc = shash_desc_ctx(pdesc);
120
121         return crypto_shash_final(desc, out) ?:
122                crypto_shash_import(desc, opad) ?:
123                crypto_shash_finup(desc, out, ds, out);
124 }
125
126 static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
127                       unsigned int nbytes, u8 *out)
128 {
129
130         struct crypto_shash *parent = pdesc->tfm;
131         int ds = crypto_shash_digestsize(parent);
132         int ss = crypto_shash_statesize(parent);
133         char *opad = crypto_shash_ctx_aligned(parent) + ss;
134         struct shash_desc *desc = shash_desc_ctx(pdesc);
135
136         return crypto_shash_finup(desc, data, nbytes, out) ?:
137                crypto_shash_import(desc, opad) ?:
138                crypto_shash_finup(desc, out, ds, out);
139 }
140
141 static int hmac_init_tfm(struct crypto_shash *parent)
142 {
143         struct crypto_shash *hash;
144         struct shash_instance *inst = shash_alg_instance(parent);
145         struct crypto_shash_spawn *spawn = shash_instance_ctx(inst);
146         struct hmac_ctx *ctx = hmac_ctx(parent);
147
148         hash = crypto_spawn_shash(spawn);
149         if (IS_ERR(hash))
150                 return PTR_ERR(hash);
151
152         parent->descsize = sizeof(struct shash_desc) +
153                            crypto_shash_descsize(hash);
154
155         ctx->hash = hash;
156         return 0;
157 }
158
159 static void hmac_exit_tfm(struct crypto_shash *parent)
160 {
161         struct hmac_ctx *ctx = hmac_ctx(parent);
162         crypto_free_shash(ctx->hash);
163 }
164
165 static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
166 {
167         struct shash_instance *inst;
168         struct crypto_shash_spawn *spawn;
169         struct crypto_alg *alg;
170         struct shash_alg *salg;
171         u32 mask;
172         int err;
173         int ds;
174         int ss;
175
176         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
177         if (err)
178                 return err;
179
180         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
181         if (!inst)
182                 return -ENOMEM;
183         spawn = shash_instance_ctx(inst);
184
185         err = crypto_grab_shash(spawn, shash_crypto_instance(inst),
186                                 crypto_attr_alg_name(tb[1]), 0, mask);
187         if (err)
188                 goto err_free_inst;
189         salg = crypto_spawn_shash_alg(spawn);
190         alg = &salg->base;
191
192         /* The underlying hash algorithm must not require a key */
193         err = -EINVAL;
194         if (crypto_shash_alg_needs_key(salg))
195                 goto err_free_inst;
196
197         ds = salg->digestsize;
198         ss = salg->statesize;
199         if (ds > alg->cra_blocksize ||
200             ss < alg->cra_blocksize)
201                 goto err_free_inst;
202
203         err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
204         if (err)
205                 goto err_free_inst;
206
207         inst->alg.base.cra_priority = alg->cra_priority;
208         inst->alg.base.cra_blocksize = alg->cra_blocksize;
209         inst->alg.base.cra_alignmask = alg->cra_alignmask;
210
211         ss = ALIGN(ss, alg->cra_alignmask + 1);
212         inst->alg.digestsize = ds;
213         inst->alg.statesize = ss;
214
215         inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
216                                      ALIGN(ss * 2, crypto_tfm_ctx_alignment());
217
218         inst->alg.init = hmac_init;
219         inst->alg.update = hmac_update;
220         inst->alg.final = hmac_final;
221         inst->alg.finup = hmac_finup;
222         inst->alg.export = hmac_export;
223         inst->alg.import = hmac_import;
224         inst->alg.setkey = hmac_setkey;
225         inst->alg.init_tfm = hmac_init_tfm;
226         inst->alg.exit_tfm = hmac_exit_tfm;
227
228         inst->free = shash_free_singlespawn_instance;
229
230         err = shash_register_instance(tmpl, inst);
231         if (err) {
232 err_free_inst:
233                 shash_free_singlespawn_instance(inst);
234         }
235         return err;
236 }
237
238 static struct crypto_template hmac_tmpl = {
239         .name = "hmac",
240         .create = hmac_create,
241         .module = THIS_MODULE,
242 };
243
244 static int __init hmac_module_init(void)
245 {
246         return crypto_register_template(&hmac_tmpl);
247 }
248
249 static void __exit hmac_module_exit(void)
250 {
251         crypto_unregister_template(&hmac_tmpl);
252 }
253
254 subsys_initcall(hmac_module_init);
255 module_exit(hmac_module_exit);
256
257 MODULE_LICENSE("GPL");
258 MODULE_DESCRIPTION("HMAC hash algorithm");
259 MODULE_ALIAS_CRYPTO("hmac");