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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
25struct hmac_ctx {
26 struct crypto_shash *hash;
27};
28
29static inline void *align_ptr(void *p, unsigned int align)
30{
31 return (void *)ALIGN((unsigned long)p, align);
32}
33
34static 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
41static 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
87static 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
94static 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
104static int hmac_init(struct shash_desc *pdesc)
105{
106 return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
107}
108
109static 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
117static 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
130static 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
145static 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
163static 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
169static 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) {
236err_free_inst:
237 shash_free_singlespawn_instance(inst);
238 }
239 return err;
240}
241
242static struct crypto_template hmac_tmpl = {
243 .name = "hmac",
244 .create = hmac_create,
245 .module = THIS_MODULE,
246};
247
248static int __init hmac_module_init(void)
249{
250 return crypto_register_template(&hmac_tmpl);
251}
252
253static void __exit hmac_module_exit(void)
254{
255 crypto_unregister_template(&hmac_tmpl);
256}
257
258subsys_initcall(hmac_module_init);
259module_exit(hmac_module_exit);
260
261MODULE_LICENSE("GPL");
262MODULE_DESCRIPTION("HMAC hash algorithm");
263MODULE_ALIAS_CRYPTO("hmac");
1/*
2 * Cryptographic API.
3 *
4 * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
5 *
6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
7 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
8 *
9 * The HMAC implementation is derived from USAGI.
10 * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 2 of the License, or (at your option)
15 * any later version.
16 *
17 */
18
19#include <crypto/internal/hash.h>
20#include <crypto/scatterwalk.h>
21#include <linux/err.h>
22#include <linux/init.h>
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/scatterlist.h>
26#include <linux/string.h>
27
28struct hmac_ctx {
29 struct crypto_shash *hash;
30};
31
32static inline void *align_ptr(void *p, unsigned int align)
33{
34 return (void *)ALIGN((unsigned long)p, align);
35}
36
37static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
38{
39 return align_ptr(crypto_shash_ctx_aligned(tfm) +
40 crypto_shash_statesize(tfm) * 2,
41 crypto_tfm_ctx_alignment());
42}
43
44static int hmac_setkey(struct crypto_shash *parent,
45 const u8 *inkey, unsigned int keylen)
46{
47 int bs = crypto_shash_blocksize(parent);
48 int ds = crypto_shash_digestsize(parent);
49 int ss = crypto_shash_statesize(parent);
50 char *ipad = crypto_shash_ctx_aligned(parent);
51 char *opad = ipad + ss;
52 struct hmac_ctx *ctx = align_ptr(opad + ss,
53 crypto_tfm_ctx_alignment());
54 struct crypto_shash *hash = ctx->hash;
55 SHASH_DESC_ON_STACK(shash, hash);
56 unsigned int i;
57
58 shash->tfm = hash;
59 shash->flags = crypto_shash_get_flags(parent)
60 & CRYPTO_TFM_REQ_MAY_SLEEP;
61
62 if (keylen > bs) {
63 int err;
64
65 err = crypto_shash_digest(shash, inkey, keylen, ipad);
66 if (err)
67 return err;
68
69 keylen = ds;
70 } else
71 memcpy(ipad, inkey, keylen);
72
73 memset(ipad + keylen, 0, bs - keylen);
74 memcpy(opad, ipad, bs);
75
76 for (i = 0; i < bs; i++) {
77 ipad[i] ^= 0x36;
78 opad[i] ^= 0x5c;
79 }
80
81 return crypto_shash_init(shash) ?:
82 crypto_shash_update(shash, ipad, bs) ?:
83 crypto_shash_export(shash, ipad) ?:
84 crypto_shash_init(shash) ?:
85 crypto_shash_update(shash, opad, bs) ?:
86 crypto_shash_export(shash, opad);
87}
88
89static int hmac_export(struct shash_desc *pdesc, void *out)
90{
91 struct shash_desc *desc = shash_desc_ctx(pdesc);
92
93 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
94
95 return crypto_shash_export(desc, out);
96}
97
98static int hmac_import(struct shash_desc *pdesc, const void *in)
99{
100 struct shash_desc *desc = shash_desc_ctx(pdesc);
101 struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
102
103 desc->tfm = ctx->hash;
104 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
105
106 return crypto_shash_import(desc, in);
107}
108
109static int hmac_init(struct shash_desc *pdesc)
110{
111 return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
112}
113
114static int hmac_update(struct shash_desc *pdesc,
115 const u8 *data, unsigned int nbytes)
116{
117 struct shash_desc *desc = shash_desc_ctx(pdesc);
118
119 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
120
121 return crypto_shash_update(desc, data, nbytes);
122}
123
124static int hmac_final(struct shash_desc *pdesc, u8 *out)
125{
126 struct crypto_shash *parent = pdesc->tfm;
127 int ds = crypto_shash_digestsize(parent);
128 int ss = crypto_shash_statesize(parent);
129 char *opad = crypto_shash_ctx_aligned(parent) + ss;
130 struct shash_desc *desc = shash_desc_ctx(pdesc);
131
132 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
133
134 return crypto_shash_final(desc, out) ?:
135 crypto_shash_import(desc, opad) ?:
136 crypto_shash_finup(desc, out, ds, out);
137}
138
139static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
140 unsigned int nbytes, u8 *out)
141{
142
143 struct crypto_shash *parent = pdesc->tfm;
144 int ds = crypto_shash_digestsize(parent);
145 int ss = crypto_shash_statesize(parent);
146 char *opad = crypto_shash_ctx_aligned(parent) + ss;
147 struct shash_desc *desc = shash_desc_ctx(pdesc);
148
149 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
150
151 return crypto_shash_finup(desc, data, nbytes, out) ?:
152 crypto_shash_import(desc, opad) ?:
153 crypto_shash_finup(desc, out, ds, out);
154}
155
156static int hmac_init_tfm(struct crypto_tfm *tfm)
157{
158 struct crypto_shash *parent = __crypto_shash_cast(tfm);
159 struct crypto_shash *hash;
160 struct crypto_instance *inst = (void *)tfm->__crt_alg;
161 struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
162 struct hmac_ctx *ctx = hmac_ctx(parent);
163
164 hash = crypto_spawn_shash(spawn);
165 if (IS_ERR(hash))
166 return PTR_ERR(hash);
167
168 parent->descsize = sizeof(struct shash_desc) +
169 crypto_shash_descsize(hash);
170
171 ctx->hash = hash;
172 return 0;
173}
174
175static void hmac_exit_tfm(struct crypto_tfm *tfm)
176{
177 struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
178 crypto_free_shash(ctx->hash);
179}
180
181static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
182{
183 struct shash_instance *inst;
184 struct crypto_alg *alg;
185 struct shash_alg *salg;
186 int err;
187 int ds;
188 int ss;
189
190 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
191 if (err)
192 return err;
193
194 salg = shash_attr_alg(tb[1], 0, 0);
195 if (IS_ERR(salg))
196 return PTR_ERR(salg);
197
198 err = -EINVAL;
199 ds = salg->digestsize;
200 ss = salg->statesize;
201 alg = &salg->base;
202 if (ds > alg->cra_blocksize ||
203 ss < alg->cra_blocksize)
204 goto out_put_alg;
205
206 inst = shash_alloc_instance("hmac", alg);
207 err = PTR_ERR(inst);
208 if (IS_ERR(inst))
209 goto out_put_alg;
210
211 err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,
212 shash_crypto_instance(inst));
213 if (err)
214 goto out_free_inst;
215
216 inst->alg.base.cra_priority = alg->cra_priority;
217 inst->alg.base.cra_blocksize = alg->cra_blocksize;
218 inst->alg.base.cra_alignmask = alg->cra_alignmask;
219
220 ss = ALIGN(ss, alg->cra_alignmask + 1);
221 inst->alg.digestsize = ds;
222 inst->alg.statesize = ss;
223
224 inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
225 ALIGN(ss * 2, crypto_tfm_ctx_alignment());
226
227 inst->alg.base.cra_init = hmac_init_tfm;
228 inst->alg.base.cra_exit = hmac_exit_tfm;
229
230 inst->alg.init = hmac_init;
231 inst->alg.update = hmac_update;
232 inst->alg.final = hmac_final;
233 inst->alg.finup = hmac_finup;
234 inst->alg.export = hmac_export;
235 inst->alg.import = hmac_import;
236 inst->alg.setkey = hmac_setkey;
237
238 err = shash_register_instance(tmpl, inst);
239 if (err) {
240out_free_inst:
241 shash_free_instance(shash_crypto_instance(inst));
242 }
243
244out_put_alg:
245 crypto_mod_put(alg);
246 return err;
247}
248
249static struct crypto_template hmac_tmpl = {
250 .name = "hmac",
251 .create = hmac_create,
252 .free = shash_free_instance,
253 .module = THIS_MODULE,
254};
255
256static int __init hmac_module_init(void)
257{
258 return crypto_register_template(&hmac_tmpl);
259}
260
261static void __exit hmac_module_exit(void)
262{
263 crypto_unregister_template(&hmac_tmpl);
264}
265
266module_init(hmac_module_init);
267module_exit(hmac_module_exit);
268
269MODULE_LICENSE("GPL");
270MODULE_DESCRIPTION("HMAC hash algorithm");
271MODULE_ALIAS_CRYPTO("hmac");