Merge tag 'for-linus' of https://github.com/openrisc/linux
[platform/kernel/linux-starfive.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/fips.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/scatterlist.h>
23 #include <linux/string.h>
24
25 struct hmac_ctx {
26         struct crypto_shash *hash;
27 };
28
29 static inline void *align_ptr(void *p, unsigned int align)
30 {
31         return (void *)ALIGN((unsigned long)p, align);
32 }
33
34 static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
35 {
36         return align_ptr(crypto_shash_ctx_aligned(tfm) +
37                          crypto_shash_statesize(tfm) * 2,
38                          crypto_tfm_ctx_alignment());
39 }
40
41 static int hmac_setkey(struct crypto_shash *parent,
42                        const u8 *inkey, unsigned int keylen)
43 {
44         int bs = crypto_shash_blocksize(parent);
45         int ds = crypto_shash_digestsize(parent);
46         int ss = crypto_shash_statesize(parent);
47         char *ipad = crypto_shash_ctx_aligned(parent);
48         char *opad = ipad + ss;
49         struct hmac_ctx *ctx = align_ptr(opad + ss,
50                                          crypto_tfm_ctx_alignment());
51         struct crypto_shash *hash = ctx->hash;
52         SHASH_DESC_ON_STACK(shash, hash);
53         unsigned int i;
54
55         if (fips_enabled && (keylen < 112 / 8))
56                 return -EINVAL;
57
58         shash->tfm = hash;
59
60         if (keylen > bs) {
61                 int err;
62
63                 err = crypto_shash_digest(shash, inkey, keylen, ipad);
64                 if (err)
65                         return err;
66
67                 keylen = ds;
68         } else
69                 memcpy(ipad, inkey, keylen);
70
71         memset(ipad + keylen, 0, bs - keylen);
72         memcpy(opad, ipad, bs);
73
74         for (i = 0; i < bs; i++) {
75                 ipad[i] ^= HMAC_IPAD_VALUE;
76                 opad[i] ^= HMAC_OPAD_VALUE;
77         }
78
79         return crypto_shash_init(shash) ?:
80                crypto_shash_update(shash, ipad, bs) ?:
81                crypto_shash_export(shash, ipad) ?:
82                crypto_shash_init(shash) ?:
83                crypto_shash_update(shash, opad, bs) ?:
84                crypto_shash_export(shash, opad);
85 }
86
87 static int hmac_export(struct shash_desc *pdesc, void *out)
88 {
89         struct shash_desc *desc = shash_desc_ctx(pdesc);
90
91         return crypto_shash_export(desc, out);
92 }
93
94 static int hmac_import(struct shash_desc *pdesc, const void *in)
95 {
96         struct shash_desc *desc = shash_desc_ctx(pdesc);
97         struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
98
99         desc->tfm = ctx->hash;
100
101         return crypto_shash_import(desc, in);
102 }
103
104 static int hmac_init(struct shash_desc *pdesc)
105 {
106         return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
107 }
108
109 static int hmac_update(struct shash_desc *pdesc,
110                        const u8 *data, unsigned int nbytes)
111 {
112         struct shash_desc *desc = shash_desc_ctx(pdesc);
113
114         return crypto_shash_update(desc, data, nbytes);
115 }
116
117 static int hmac_final(struct shash_desc *pdesc, u8 *out)
118 {
119         struct crypto_shash *parent = pdesc->tfm;
120         int ds = crypto_shash_digestsize(parent);
121         int ss = crypto_shash_statesize(parent);
122         char *opad = crypto_shash_ctx_aligned(parent) + ss;
123         struct shash_desc *desc = shash_desc_ctx(pdesc);
124
125         return crypto_shash_final(desc, out) ?:
126                crypto_shash_import(desc, opad) ?:
127                crypto_shash_finup(desc, out, ds, out);
128 }
129
130 static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
131                       unsigned int nbytes, u8 *out)
132 {
133
134         struct crypto_shash *parent = pdesc->tfm;
135         int ds = crypto_shash_digestsize(parent);
136         int ss = crypto_shash_statesize(parent);
137         char *opad = crypto_shash_ctx_aligned(parent) + ss;
138         struct shash_desc *desc = shash_desc_ctx(pdesc);
139
140         return crypto_shash_finup(desc, data, nbytes, out) ?:
141                crypto_shash_import(desc, opad) ?:
142                crypto_shash_finup(desc, out, ds, out);
143 }
144
145 static int hmac_init_tfm(struct crypto_shash *parent)
146 {
147         struct crypto_shash *hash;
148         struct shash_instance *inst = shash_alg_instance(parent);
149         struct crypto_shash_spawn *spawn = shash_instance_ctx(inst);
150         struct hmac_ctx *ctx = hmac_ctx(parent);
151
152         hash = crypto_spawn_shash(spawn);
153         if (IS_ERR(hash))
154                 return PTR_ERR(hash);
155
156         parent->descsize = sizeof(struct shash_desc) +
157                            crypto_shash_descsize(hash);
158
159         ctx->hash = hash;
160         return 0;
161 }
162
163 static void hmac_exit_tfm(struct crypto_shash *parent)
164 {
165         struct hmac_ctx *ctx = hmac_ctx(parent);
166         crypto_free_shash(ctx->hash);
167 }
168
169 static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
170 {
171         struct shash_instance *inst;
172         struct crypto_shash_spawn *spawn;
173         struct crypto_alg *alg;
174         struct shash_alg *salg;
175         u32 mask;
176         int err;
177         int ds;
178         int ss;
179
180         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
181         if (err)
182                 return err;
183
184         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
185         if (!inst)
186                 return -ENOMEM;
187         spawn = shash_instance_ctx(inst);
188
189         err = crypto_grab_shash(spawn, shash_crypto_instance(inst),
190                                 crypto_attr_alg_name(tb[1]), 0, mask);
191         if (err)
192                 goto err_free_inst;
193         salg = crypto_spawn_shash_alg(spawn);
194         alg = &salg->base;
195
196         /* The underlying hash algorithm must not require a key */
197         err = -EINVAL;
198         if (crypto_shash_alg_needs_key(salg))
199                 goto err_free_inst;
200
201         ds = salg->digestsize;
202         ss = salg->statesize;
203         if (ds > alg->cra_blocksize ||
204             ss < alg->cra_blocksize)
205                 goto err_free_inst;
206
207         err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
208         if (err)
209                 goto err_free_inst;
210
211         inst->alg.base.cra_priority = alg->cra_priority;
212         inst->alg.base.cra_blocksize = alg->cra_blocksize;
213         inst->alg.base.cra_alignmask = alg->cra_alignmask;
214
215         ss = ALIGN(ss, alg->cra_alignmask + 1);
216         inst->alg.digestsize = ds;
217         inst->alg.statesize = ss;
218
219         inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
220                                      ALIGN(ss * 2, crypto_tfm_ctx_alignment());
221
222         inst->alg.init = hmac_init;
223         inst->alg.update = hmac_update;
224         inst->alg.final = hmac_final;
225         inst->alg.finup = hmac_finup;
226         inst->alg.export = hmac_export;
227         inst->alg.import = hmac_import;
228         inst->alg.setkey = hmac_setkey;
229         inst->alg.init_tfm = hmac_init_tfm;
230         inst->alg.exit_tfm = hmac_exit_tfm;
231
232         inst->free = shash_free_singlespawn_instance;
233
234         err = shash_register_instance(tmpl, inst);
235         if (err) {
236 err_free_inst:
237                 shash_free_singlespawn_instance(inst);
238         }
239         return err;
240 }
241
242 static struct crypto_template hmac_tmpl = {
243         .name = "hmac",
244         .create = hmac_create,
245         .module = THIS_MODULE,
246 };
247
248 static int __init hmac_module_init(void)
249 {
250         return crypto_register_template(&hmac_tmpl);
251 }
252
253 static void __exit hmac_module_exit(void)
254 {
255         crypto_unregister_template(&hmac_tmpl);
256 }
257
258 subsys_initcall(hmac_module_init);
259 module_exit(hmac_module_exit);
260
261 MODULE_LICENSE("GPL");
262 MODULE_DESCRIPTION("HMAC hash algorithm");
263 MODULE_ALIAS_CRYPTO("hmac");